Resist composition and method for forming a resist pattern

Abstract

To provide a resist composition that achieves improved etching resistance and can form a resist pattern having excellent lithography properties.SOLUTION: A resist composition is adopted that contains a silicon-containing resin, an acid generator component that generates an acid by exposure, and a photo-disintegrable base that controls the diffusion of the acid generated from the acid generator component by exposure. In the silicon-containing resin, the silicon content is 20-25% relative to the total amount of all the constituent atoms of the silicon-containing resin.SELECTED DRAWING: None

Description

[Technical Field]

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

[0002] In the manufacture of electronic components, a laminate in which a resist film is formed on a substrate such as a silicon wafer using a resist material is subjected to a process including etching. For example, a process is performed in which a resist pattern is formed on the resist film by selectively exposing the resist film, and then dry etching is performed using the resist film as a mask to form a pattern on the substrate.

[0003] In recent years, advances in lithography technology have led to rapid advances in the miniaturization of patterns in the manufacturing of semiconductor devices and liquid crystal display devices. A common method for miniaturizing patterns is to shorten the wavelength (increase the energy) of the exposure light source.

[0004] Resist materials are required to have lithography properties such as sensitivity to these exposure light sources and resolution capable of reproducing patterns with minute dimensions. To satisfy these requirements, a chemically amplified resist composition has been used, which contains a base component whose solubility in a developer changes due to the action of acid, and an acid generator component that generates acid upon exposure. Chemically amplified resist compositions generally use resins having multiple structural units in order to improve lithography properties and the like.

[0005] Furthermore, resist materials are required to have etching resistance in order to function as a mask for substrate processing, and silicon-containing polymers are typically used as base components. For example, Patent Document 1 discloses a negative resist composition that contains a silsesquioxane resin having two specific structural units, an acid generator component, and a crosslinker component in order to accommodate the trend toward finer patterns. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] International Publication No. 2005 / 091073 Summary of the Invention [Problem to be solved by the invention]

[0007] In the future, as patterns become finer, resist films will become thinner, and resist materials will need to have improved etching resistance when etching is performed using the resist pattern as a mask. One possible way to improve such etching resistance is to increase the silicon content in the silicon-containing polymer, which is a base component. On the other hand, as patterns become finer, resist materials are required to have improved lithography properties such as high resolution, reduced LWR (line width roughness: non-uniformity of line width) in the case of line patterns, or improved circularity in the case of hole patterns. However, according to the investigations of the present inventors, when forming a resist pattern using a resist material containing a silicon-containing polymer, it has been confirmed that simply increasing the silicon content in the silicon-containing polymer results in poor pattern resolution and shape, making it difficult to achieve both etching resistance and lithography properties.

[0008] The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a resist composition that can further improve etching resistance and form a resist pattern that has favorable lithography properties, and a method of forming a resist pattern using the same. [Means for solving the problem]

[0009] In order to solve the above problems, the present invention employs the following configuration. That is, a first aspect of the present invention is a resist composition comprising a silicon-containing resin, an acid generator component that generates an acid upon exposure, and a photodegradable base that controls the diffusion of the acid generated from the acid generator component upon exposure, wherein the silicon content in the silicon-containing resin is 20 to 25% of the total amount of all atoms constituting the silicon-containing resin.

[0010] A second aspect of the present invention is a method for forming a resist pattern, comprising: step (i) of forming a resist film on a support using the resist composition according to the first aspect; step (ii) of exposing the resist film to light; and step (iii) of developing the exposed resist film to form a resist pattern. [Effects of the Invention]

[0011] According to the resist composition and method of forming a resist pattern of the present invention, it is possible to form a resist pattern that has improved etching resistance and excellent lithography properties. DETAILED DESCRIPTION OF THE INVENTION

[0012] In this specification and claims, the term "aliphatic" is defined as a relative concept to aromatic, and refers to groups, compounds, etc. that do not have aromaticity. Unless otherwise specified, the term "alkyl group" includes linear, branched, and cyclic monovalent saturated hydrocarbon groups. The same applies to alkyl groups in alkoxy groups. Unless otherwise specified, the term "alkylene group" includes linear, branched and cyclic divalent saturated hydrocarbon groups. The "halogen atom" includes a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. The term "structural unit" refers to a monomer unit that constitutes a polymeric compound (resin, polymer, copolymer). The phrase "may have a substituent" includes both the case where a hydrogen atom (-H) is replaced with a monovalent group and the case where a methylene group (-CH2-) is replaced with a divalent group. The term "exposure" is a general concept that includes irradiation with active energy rays such as ultraviolet rays, radiation, and electron beams.

[0013] The term "acid-decomposable group" refers to a group having acid decomposability in which at least some of the bonds in the structure of the acid-decomposable group can be cleaved by the action of an acid. Examples of acid-decomposable groups whose polarity increases under the action of an acid include groups that decompose under the action of an acid to generate a polar group. Examples of polar groups include a carboxy group, a hydroxyl group, an amino group, and a sulfo group (-SO3H). More specific examples of the acid-decomposable group include groups in which the polar group is protected with an acid-dissociable group (for example, a group in which the hydrogen atom of an OH-containing polar group is protected with an acid-dissociable group).

[0014] The term "acid-dissociable group" refers to either (i) a group having acid dissociability such that the bond between the acid-dissociable group and an atom adjacent to the acid-dissociable group can be cleaved by the action of an acid, or (ii) a group in which a portion of the bond is cleaved by the action of an acid, and then a decarboxylation reaction occurs, thereby cleaving the bond between the acid-dissociable group and an atom adjacent to the acid-dissociable group. The acid-dissociable group constituting the acid-decomposable group must be a group with lower polarity than the polar group generated by dissociation of the acid-dissociable group, and thus, when the acid-dissociable group is dissociated by the action of acid, a polar group with higher polarity than the acid-dissociable group is generated, thereby increasing polarity.As a result, the polarity of the entire component having this acid-dissociable group increases.With the increase in polarity, the solubility in the developer changes relatively, and when the developer is an alkaline developer, the solubility increases, and when the developer is an organic developer, the solubility decreases.

[0015] A "base component" is an organic compound that has film-forming ability. Organic compounds used as base components are broadly divided into non-polymers and polymers. Non-polymers typically have a molecular weight of 500 or more and less than 4000. Hereinafter, the term "low molecular weight compound" refers to a non-polymer with a molecular weight of 500 or more and less than 4000. Polymers typically have a molecular weight of 1000 or more. Hereinafter, the terms "resin," "high molecular weight compound," or "polymer" refer to a polymer with a molecular weight of 1000 or more. The molecular weight of a polymer is determined by the weight average molecular weight converted into polystyrene by GPC (gel permeation chromatography).

[0016] The term "derived structural unit" refers to a structural unit formed by cleavage of a multiple bond between carbon atoms, such as an ethylenic double bond.

[0017] The term "derivative" encompasses compounds in which the hydrogen atom at the α-position of the target compound is substituted with another substituent, such as an alkyl group or a halogenated alkyl group, as well as derivatives thereof. Examples of such derivatives include compounds in which the hydrogen atom of a hydroxyl group of a target compound, which may have the hydrogen atom at the α-position substituted with a substituent, is substituted with an organic group; and compounds in which a substituent other than a hydroxyl group is bonded to a target compound, which may have the hydrogen atom at the α-position substituted with a substituent. Unless otherwise specified, the α-position refers to the first carbon atom adjacent to the functional group. The substituents that replace the hydrogen atom at the α-position of hydroxystyrene include R αx The same can be mentioned.

[0018] In this specification and claims, some structures represented by chemical formulas may have asymmetric carbon atoms, and may exist as enantiomers or diastereomers. In such cases, a single chemical formula represents all isomers. These isomers may be used alone or as a mixture.

[0019] (Resist composition) The resist composition of this embodiment contains a silicon-containing resin, an acid generator component that generates an acid upon exposure, and a photodegradable base that controls the diffusion of the acid generated from the acid generator component upon exposure. When such a resist composition is exposed to light, an acid is generated from the acid generator component, and this acid acts on the silicon-containing resin, changing the solubility of the silicon-containing resin in a developer. Therefore, when a resist film obtained by applying the resist composition to a support is selectively exposed in the formation of a resist pattern, the solubility of the exposed portion of the resist film in a developer changes, while the solubility of the unexposed portion of the resist film in a developer does not change, resulting in a difference in solubility in a developer between the exposed and unexposed portions of the resist film. This allows the formation of a desired resist pattern with high precision by selectively exposing the resist film through a desired mask pattern. The resist composition of this embodiment may be used for an alkaline development process in which an alkaline developer is used in the development treatment during resist pattern formation, or may be used for a solvent development process in which a developer containing an organic solvent (organic developer) is used in the development treatment. The resist composition of this embodiment is particularly useful for an alkaline development process.

[0020] <Silicon-containing resin> The silicon-containing resin (hereafter also referred to as "component (A)") used in the resist composition of this embodiment includes a resin that is soluble in an alkaline developer and has a crosslinkable group. In the resist composition of this embodiment, the silicon content in the component (A) is 20 to 25% relative to the total amount of all atoms constituting the component (A), preferably more than 20% but not more than 25%, more preferably 20.5% or more but not more than 25%, and even more preferably 20.5% or more but not more than 24%. When the silicon content within component (A) is at least as high as the lower limit of the aforementioned range, etching resistance can be further improved, while when it is at most the upper limit of the aforementioned range, a resist pattern with excellent lithography properties can be formed.

[0021] The silicon content in component (A) can be calculated using the following formula. Silicon content (%) = (number of silicon atoms present in the silicon-containing resin × atomic weight of silicon) / (total atomic weight calculated by adding the values ​​obtained by multiplying the number of each atom constituting the silicon-containing resin by each atomic weight) × 100

[0022] For example, in the case of polysiloxane having a repeating structure of the structural unit -[Si(H)O3 / 2]-, the silicon content is {(28 × 1) × 100} / [{(28 × 1) + (16 × 1.5) + (1 × 1)} × 100] ≈ 52.8%. In the case of a polysiloxane composed of 30 mol% of structural units represented by -[Si(H)O3 / 2]- and 70 mol% of structural units represented by -[Si(CH3)O3 / 2]-, {(28×1)×100} / <[{(28×1)+(16×1.5)+(1×1)}×30]+[{(28×1)+(16×1.5)+(12×1)+(1×3)}×70]>≒44.2%. The silicon content can be adjusted, for example, by changing the structure or composition ratio of each constituent unit that constitutes the silicon-containing resin.

[0023] Component (A) may be any silicon-containing resin having a silicon content of 20 to 25% relative to the total amount of all atoms constituting component (A), and is preferably a polysiloxane, and more preferably contains a silsesquioxane resin.

[0024] <Silsesquioxane resin> The silsesquioxane resin in this embodiment is a copolymer whose polymer main chain is composed of a repeating structure of Si—O bonds, and preferably has a structural unit (a1) containing a phenolic hydroxyl group and a structural unit (a2) containing an alkyl group.

[0025] ·Constituent unit (a1) The structural unit (a1) is a structural unit that contains a phenolic hydroxyl group. The structural unit (a1) may be one in which the main chain portion is an Si—O bond and the side chain portion bonded to the Si atom is a “group containing a phenolic hydroxyl group”. In the structural unit (a1), the phenolic hydroxyl group forms a crosslinked structure when exposed to the acid generated from the component (B), which will be described later. This increases the molecular weight of the component (A). Furthermore, because the structural unit (a1) contains the phenolic hydroxyl group, the component (A) is soluble in an alkaline developer, imparting alkaline developability to the resist composition.

[0026] Specific examples of the "group containing a phenolic hydroxyl group" are shown below. In the chemical formula, * indicates a bond.

[0027] [ka]

[0028] A preferred structural unit (a1) is a structural unit represented by the following general formula (a1-1). In addition, in the general formula (a1-1), “-O 1 / 2 "-" indicates that this oxygen atom is shared with another building block.

[0029] [ka] [In the formula, Ra 1 is an alkylene group having 1 to 5 carbon atoms or a single bond. na1 is an integer of 1 to 3.]

[0030] In the general formula (a1-1), Ra 1 is preferably an alkylene group having 1 to 5 carbon atoms. Ra 1 The alkylene group in may be linear, branched or cyclic, and is preferably linear or branched. Ra 1 The alkylene group in Ra has 1 to 5 carbon atoms, preferably 1 to 3 carbon atoms. 1Examples of the alkylene group in include a methylene group, an ethylene group, a propylene group, a butylene group, a pentylene group, and an isopropylene group. Among these, a methylene group, an ethylene group, a propylene group, and an isopropylene group are preferred, a methylene group and an ethylene group are more preferred, and a methylene group is even more preferred.

[0031] In the general formula (a1-1), na1 represents an integer of 1 to 3, preferably 1 or 2, and more preferably 1. The bonding position of the hydroxyl group on the benzene ring may be any of the o-position, m-position, and p-position, and for example, the p-position is industrially preferred.

[0032] The structural unit (a1) contained in the silsesquioxane resin in this embodiment may be one type, or two or more types. The proportion of the structural unit (a1) in the silsesquioxane resin is preferably 40 to 70 mol %, more preferably 45 to 70 mol %, and even more preferably 50 to 65 mol %, based on the total (100 mol %) of all structural units constituting the silsesquioxane resin. When the proportion of the structural unit (a1) is at least as large as the lower limit of the aforementioned preferred range, a resist pattern with excellent lithography properties is more easily formed. On the other hand, when the proportion is at most the upper limit of the aforementioned preferred range, etching resistance is more easily improved.

[0033] ·Constituent unit (a2) The structural unit (a2) is a structural unit that contains an alkyl group. Examples of the structural unit (a2) include those in which the main chain portion is an Si—O bond and the side chain portion bonded to the Si atom is an alkyl group. By including the structural unit (a2), the properties of the resist film formed using the composition can be easily controlled.

[0034] A preferred structural unit (a2) is a structural unit represented by the following general formula (a2-1). In addition, in general formula (a2-1), “-O 1 / 2"-" indicates that this oxygen atom is shared with another building block.

[0035] [ka] [In the formula, Ra 2 is an alkyl group having 1 to 10 carbon atoms.]

[0036] In the general formula (a2-1), Ra 2 The alkyl group in may be linear, branched or cyclic, and is preferably linear or branched. Ra 2 The alkyl group in Ra has 1 to 10 carbon atoms, preferably 1 to 5 carbon atoms, and more preferably 1 to 3 carbon atoms. 2 Examples of the alkyl group in include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, an octyl group, a decyl group, an isopropyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a 2-ethylhexyl group, etc. Among these, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, an isopropyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group are preferred, a methyl group, an ethyl group, a propyl group, and an isopropyl group are more preferred, a methyl group and an ethyl group are even more preferred, and a methyl group is particularly preferred.

[0037] The structural unit (a2) contained in the silsesquioxane resin in this embodiment may be of one type, or may be of two or more types. The proportion of the structural unit (a2) in the silsesquioxane resin is preferably 30 to 60 mol %, more preferably 30 to 55 mol %, and even more preferably 35 to 50 mol %, based on the total (100 mol %) of all structural units constituting the silsesquioxane resin. When the proportion of the structural unit (a2) is at least as large as the lower limit of the aforementioned preferred range, etching resistance is more likely to be improved, while when it is no more than the upper limit of the aforementioned preferred range, a resist pattern with excellent lithography properties is more likely to be formed.

[0038] Other constituent units The silsesquioxane resin in this embodiment may further include other structural units in addition to the structural units (a1) and (a2) described above. There are no particular limitations on such other structural units, and many of those conventionally known to be used in resist resins for KrF excimer lasers, ArF excimer lasers, and the like can be used. Other structural units include, for example, the structural unit (a3) ​​represented by the following chemical formula (a3-1-1). This structural unit (a3) ​​is useful for improving lithography properties. The introduction of the structural unit (a3) ​​makes it easy to control the dissolution rate.

[0039] [ka]

[0040] The silsesquioxane resin of the present embodiment may have one or more types of other structural units. When the silsesquioxane resin further contains other structural units in addition to the structural unit (a1) and the structural unit (a2), the proportion of such other structural units in the silsesquioxane resin is preferably 20 mol % or less, more preferably 10 mol % or less, and particularly preferably 5 mol % or less, relative to the total (100 mol %) of all structural units constituting the silsesquioxane resin.

[0041] Furthermore, the silsesquioxane resin in this embodiment is a copolymer whose polymer main chain is composed of a repeating structure of Si-O bonds, and preferably has a structural unit (a3) ​​represented by the above chemical formula (a3-1-1) and a structural unit (a4) containing at least one of an alkoxy group and a hydroxy group. Examples of the structural unit (a4) include those in which the main chain portion is an Si-O bond and the side chain portion bonded to the Si atom is an alkoxy group; and those in which the main chain portion is an Si-O bond and the side chain portion bonded to the Si atom is a hydroxy group. Preferred examples of the structural unit (a4) include those represented by the same general formula (a2-1) above, and the structural unit (a4) represented by Ra 2 is an alkoxy group or a hydroxy group. The number of carbon atoms in the alkyl group constituting the alkoxy group here is preferably 1 to 5, and more preferably 1 to 3. The alkoxy group here is preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group, and particularly preferably a methoxy group or an ethoxy group.

[0042] When the silsesquioxane resin is a copolymer having the structural unit (a3) ​​and the structural unit (a4), the proportion of the structural unit (a3) ​​in the silsesquioxane resin is preferably 50 to 95 mol%, more preferably 60 to 95 mol%, even more preferably 70 to 95 mol%, and particularly preferably 80 to 90 mol%, relative to the total (100 mol%) of all structural units constituting the silsesquioxane resin. When the proportion of the structural unit (a3) ​​is within this preferred range, a resist pattern with excellent lithography properties is more easily formed.

[0043] Among copolymers having the structural unit (a3) ​​and the structural unit (a4), a silsesquioxane resin composed of the structural unit (a3), a structural unit whose main chain portion is an Si-O bond and whose side chain portion bonded to the Si atom is an alkoxy group, and a structural unit whose main chain portion is an Si-O bond and whose side chain portion bonded to the Si atom is a hydroxy group is preferred.

[0044] In the resist composition of this embodiment, the component (A) preferably contains a silsesquioxane resin having the structural unit (a1) and the structural unit (a2) described above. Among these, a silsesquioxane resin having a structural unit represented by general formula (a1-1) and a structural unit represented by general formula (a2-1) is preferred, and a silsesquioxane resin consisting of a structural unit represented by general formula (a1-1) and a structural unit represented by general formula (a2-1) is more preferred.

[0045] The total content of the structural units (a1) and (a2) possessed by the silsesquioxane resin contained in the component (A) is preferably 50 mol% or more, more preferably 70 mol% or more, even more preferably 80 mol% or more, and particularly preferably 90 mol% or more, relative to the total (100 mol%) of all structural units constituting the component (A). It may be 100 mol%, and 100 mol% (i.e., a copolymer of the structural units (a1) and (a2)) is most preferred.

[0046] Within the component (A), the molar ratio of the structural units (a1) to the structural units (a2) is preferably structural units (a1) / structural units (a2)=40 / 60 to 70 / 30, more preferably 45 / 55 to 70 / 30, and particularly preferably 50 / 50 to 65 / 35. By ensuring that the molar ratio of structural unit (a1) / structural unit (a2) is at least as large as the lower limit of the above-mentioned preferred range, a resist pattern with excellent lithography properties can be easily formed. On the other hand, by ensuring that the molar ratio of structural unit (a1) / structural unit (a2) is at most the upper limit of the above-mentioned preferred range, etching resistance can be further improved.

[0047] The mass average molecular weight (Mw) of the component (A) (based on polystyrene standards measured by gel permeation chromatography (GPC)) is not particularly limited and is, for example, 800 or more, preferably 1,000 to 20,000, more preferably 2,000 to 10,000, and even more preferably 3,000 to 7,000. By ensuring that the Mw of component (A) is at most the upper limit of the above-mentioned preferred range, the solubility in organic solvents is further improved, while by ensuring that it is at least the lower limit of the above-mentioned preferred range, the patterning properties of the resist film are improved, and the lithography properties of the formed resist pattern are further enhanced.

[0048] The resist composition of this embodiment may contain one type of component (A), or two or more types of components. The amount of the component (A) in the resist composition of this embodiment may be adjusted depending on factors such as the film thickness to be formed.

[0049] <Acid generator component> The resist composition of this embodiment contains, in addition to the above-mentioned component (A), an acid generator component (hereafter also referred to as “component (B)”) that generates acid upon exposure. There are no particular restrictions on the component (B), and any of the acid generators that have been proposed as acid generators for chemically amplified resist compositions can be used. Examples of such acid generators include onium salt-based acid generators such as iodonium salts and sulfonium salts, oxime sulfonate-based acid generators, diazomethane-based acid generators such as bisalkyl or bisaryl sulfonyl diazomethanes and poly(bissulfonyl) diazomethanes, nitrobenzyl sulfonate-based acid generators, imino sulfonate-based acid generators, and disulfone-based acid generators.

[0050] Examples of the onium salt acid generator include a compound represented by the following general formula (b-1) (hereinafter also referred to as "component (b-1)"), a compound represented by general formula (b-2) (hereinafter also referred to as "component (b-2)"), or a compound represented by general formula (b-3) (hereinafter also referred to as "component (b-3)").

[0051] [ka] [In the formula, R 101 and R 104 ~R 108 R are each independently a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent. 104 and R 105 R may be bonded to each other to form a ring structure. 102 is a fluorinated alkyl group having 1 to 5 carbon atoms or a fluorine atom. 101 is a divalent linking group containing an oxygen atom or a single bond. 101 ~V 103 are each independently a single bond, an alkylene group, or a fluorinated alkylene group. 101 ~L 102 are each independently a single bond or an oxygen atom.103 ~L 105 are each independently a single bond, —CO— or —SO2—; m is an integer of 1 or more; and M' m+ is an m-valent onium cation.

[0052] {anion part} Anion in component (b-1) In the general formula (b-1), R 101 represents a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent.

[0053] Optionally substituted cyclic groups: The cyclic group is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. An aliphatic hydrocarbon group means a hydrocarbon group that does not have aromaticity. Furthermore, the aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated.

[0054] R 101 The aromatic hydrocarbon group in the formula (I) is a hydrocarbon group having an aromatic ring. The number of carbon atoms in the aromatic hydrocarbon group is preferably 3 to 30, more preferably 5 to 30, even more preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 10. However, the number of carbon atoms does not include the number of carbon atoms in the substituent. R 101 Specific examples of the aromatic ring contained in the aromatic hydrocarbon group in the above formula include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, and aromatic heterocycles in which some of the carbon atoms constituting these aromatic rings are substituted with heteroatoms. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. R 101Specific examples of the aromatic hydrocarbon group in the formula (I) include a group in which one hydrogen atom has been removed from the aromatic ring (aryl group: for example, phenyl group, naphthyl group, etc.), and a group in which one hydrogen atom of the aromatic ring has been substituted with an alkylene group (for example, arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.). The number of carbon atoms in the alkylene group (alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0055] R 101 The cyclic aliphatic hydrocarbon group in the formula (I) is an aliphatic hydrocarbon group containing a ring in the structure. Examples of aliphatic hydrocarbon groups that contain a ring in their structure include alicyclic hydrocarbon groups (groups in which one hydrogen atom has been removed from an aliphatic hydrocarbon ring), groups in which an alicyclic hydrocarbon group is bonded to the end of a straight-chain or branched-chain aliphatic hydrocarbon group, and groups in which an alicyclic hydrocarbon group is interposed in the middle of a straight-chain or branched-chain aliphatic hydrocarbon group. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms. The alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. The monocyclic alicyclic hydrocarbon group is preferably a group in which one or more hydrogen atoms have been removed from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group in which one or more hydrogen atoms have been removed from a polycycloalkane, and the polycycloalkane preferably has 7 to 30 carbon atoms. Among these, the polycycloalkane is more preferably a polycycloalkane having a bridged ring polycyclic skeleton, such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane; or a polycycloalkane having a fused ring polycyclic skeleton, such as a cyclic group having a steroid skeleton.

[0056] Among them, R 101The cyclic aliphatic hydrocarbon group in is preferably a group in which one or more hydrogen atoms have been removed from a monocycloalkane or a polycycloalkane, more preferably a group in which one hydrogen atom has been removed from a polycycloalkane, particularly preferably an adamantyl group or a norbornyl group, and most preferably an adamantyl group.

[0057] The linear aliphatic hydrocarbon group which may be bonded to the alicyclic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6, even more preferably 1 to 4, and most preferably 1 to 3. The linear aliphatic hydrocarbon group is preferably a linear alkylene group, and specific examples thereof include a methylene group [-CH2-], an ethylene group [-(CH2)2-], a trimethylene group [-(CH2)3-], a tetramethylene group [-(CH2)4-], and a pentamethylene group [-(CH2)5-]. The branched aliphatic hydrocarbon group which may be bonded to the alicyclic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, even more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms. The branched aliphatic hydrocarbon group is preferably a branched alkylene group, and specific examples thereof include alkyl alkylene groups such as alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, and -C(CH2CH3)2-; alkylethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, and -C(CH2CH3)2-CH2-; alkyl trimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; and alkyl tetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-. The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0058] Also, R 101The cyclic hydrocarbon group in may contain a heteroatom, such as a heterocycle. Specific examples include lactone-containing cyclic groups represented by the following general formulae (a2-r-1) to (a2-r-7), -SO2- containing cyclic groups represented by the following general formulae (a5-r-1) to (a5-r-4), and other heterocyclic groups represented by the following chemical formulae (r-hr-1) to (r-hr-16). In the formula, * represents Y in the general formula (b-1). 101 represents a bond bonded to

[0059] [ka] [In the formula, Ra' 21 are each independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR", -OC(=O)R", a hydroxyalkyl group, or a cyano group; R" is a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or an -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.

[0060] In the general formulas (a2-r-1) to (a2-r-7), Ra' 21 The alkyl group in the formula (I) is preferably an alkyl group having 1 to 6 carbon atoms. The alkyl group is preferably linear or branched. Specific examples include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, and a hexyl group. Among these, a methyl group or an ethyl group is preferred, and a methyl group is particularly preferred. Ra' 21 The alkoxy group in the formula (1) is preferably an alkoxy group having 1 to 6 carbon atoms. The alkoxy group is preferably linear or branched. Specifically, the alkoxy group in the formula (1) is preferably linear or branched. 21 Examples of the alkyl group include a group in which the alkyl groups mentioned above are linked to an oxygen atom (—O—). Ra' 21 The halogen atom in is preferably a fluorine atom. Ra' 21 The halogenated alkyl group in the formula Ra' is 21 Examples of the halogenated alkyl group include groups in which some or all of the hydrogen atoms of the alkyl group have been substituted with the halogen atoms. As the halogenated alkyl group, a fluorinated alkyl group is preferred, and a perfluoroalkyl group is particularly preferred.

[0061] Ra' 21 In -COOR" and -OC(=O)R", R" is a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or an -SO2- containing cyclic group. The alkyl group in R'' may be linear, branched, or cyclic, and preferably has 1 to 15 carbon atoms. When R″ is a linear or branched alkyl group, it preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and is particularly preferably a methyl group or an ethyl group. When R" is a cyclic alkyl group, it preferably has 3 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specific examples include groups in which one or more hydrogen atoms have been removed from a monocycloalkane which may or may not be substituted with a fluorine atom or a fluorinated alkyl group; and groups in which one or more hydrogen atoms have been removed from a polycycloalkane such as a bicycloalkane, tricycloalkane, or tetracycloalkane. More specific examples include groups in which one or more hydrogen atoms have been removed from a monocycloalkane such as cyclopentane or cyclohexane; and groups in which one or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. Examples of the lactone-containing cyclic group in R″ include the same groups as those represented by the general formulae (a2-r-1) to (a2-r-7) above. The carbonate-containing cyclic group in R″ is the same as the carbonate-containing cyclic group described below, and specific examples include groups represented by the general formulae (ax3-r-1) to (ax3-r-3). The -SO2-containing cyclic group in R'' is the same as the -SO2-containing cyclic group described below, and specific examples include groups represented by general formulae (a5-r-1) to (a5-r-4). Ra' 21 The hydroxyalkyl group in the formula (I) preferably has 1 to 6 carbon atoms, and specifically, the hydroxyalkyl group in the formula (I) is preferably a hydroxyalkyl group having 1 to 6 carbon atoms. 21 and a group in which at least one hydrogen atom of the alkyl group is substituted with a hydroxyl group.

[0062] In the general formulae (a2-r-2), (a2-r-3), and (a2-r-5), the alkylene group having 1 to 5 carbon atoms for A" is preferably a straight-chain or branched-chain alkylene group, and examples thereof include a methylene group, an ethylene group, an n-propylene group, and an isopropylene group. When the alkylene group contains an oxygen atom or a sulfur atom, specific examples thereof include groups in which -O- or -S- is present at the terminal or between carbon atoms of the alkylene group, such as -O-CH2-, -CH2-O-CH2-, -S-CH2-, and -CH2-S-CH2-. A" is preferably an alkylene group having 1 to 5 carbon atoms or -O-, more preferably an alkylene group having 1 to 5 carbon atoms, and most preferably a methylene group.

[0063] [ka] [In the formula, Ra' 51 are each independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR", -OC(=O)R", a hydroxyalkyl group, or a cyano group; R" is a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or an -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.

[0064] In the general formulae (a5-r-1) and (a5-r-2), A" is the same as A" in the general formulae (a2-r-2), (a2-r-3), and (a2-r-5). Ra' 51 The alkyl group, alkoxy group, halogen atom, halogenated alkyl group, -COOR", -OC(=O)R", and hydroxyalkyl group in the general formulae (a2-r-1) to (a2-r-7) are each represented by Ra' 21 Examples of the above include those mentioned in the explanation of the above.

[0065] [ka] [In the formula, Ra' x31 are each independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR", -OC(=O)R", a hydroxyalkyl group, or a cyano group; R" is a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or an -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.

[0066] In the general formulae (ax3-r-2) to (ax3-r-3), A" is the same as A" in the general formulae (a2-r-2), (a2-r-3) and (a2-r-5). Ra' 31 The alkyl group, alkoxy group, halogen atom, halogenated alkyl group, -COOR", -OC(=O)R", and hydroxyalkyl group in the general formulae (a2-r-1) to (a2-r-7) are each represented by Ra' 21 Examples of the above include those mentioned in the explanation of the above.

[0067] [ka]

[0068] R 101 Examples of the substituent in the cyclic group include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, and a nitro group. The alkyl group as a substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. The alkoxy group as a substituent is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group, and most preferably a methoxy group or an ethoxy group. Examples of the halogen atom as a substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, with a fluorine atom being preferred. Examples of halogenated alkyl groups as substituents include alkyl groups having 1 to 5 carbon atoms, such as methyl, ethyl, propyl, n-butyl, and tert-butyl groups, in which some or all of the hydrogen atoms have been substituted with the above-mentioned halogen atoms. The carbonyl group as a substituent is a group that substitutes a methylene group (-CH2-) that constitutes a cyclic hydrocarbon group.

[0069] R 101 The cyclic hydrocarbon group in may be a fused ring group containing a fused ring in which an aliphatic hydrocarbon ring and an aromatic ring are fused. Examples of the fused ring include a polycycloalkane having a polycyclic skeleton of a bridged ring system to which one or more aromatic rings are fused. Specific examples of the bridged ring system polycycloalkane include bicycloalkanes such as bicyclo[2.2.1]heptane (norbornane) and bicyclo[2.2.2]octane. The fused ring group is preferably a group containing a fused ring in which two or three aromatic rings are fused to a bicycloalkane, and more preferably a group containing a fused ring in which two or three aromatic rings are fused to a bicyclo[2.2.2]octane. 101 Specific examples of the fused cyclic group in the formula (b-1) include those represented by the following chemical formulas (r-br-1) to (r-br-2). In the formula, * represents Y in the general formula (b-1).101 represents a bond bonded to

[0070] [ka]

[0071] R 101 Examples of the substituent that the fused cyclic group in the formula (I) may have include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, an aromatic hydrocarbon group, and an alicyclic hydrocarbon group. The alkyl group, alkoxy group, halogen atom, and halogenated alkyl group as the substituent of the fused cyclic group are the same as those described above in R 101 Examples of the substituents for the cyclic group in the formula (I) include the same as those listed above. Examples of the aromatic hydrocarbon group as the substituent of the fused ring group include a group in which one hydrogen atom has been removed from an aromatic ring (aryl group: for example, a phenyl group, a naphthyl group, etc.), a group in which one hydrogen atom of the aromatic ring has been substituted with an alkylene group (for example, an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, a 2-naphthylethyl group, etc.), and heterocyclic groups represented by the above chemical formulas (r-hr-1) to (r-hr-6). Examples of the alicyclic hydrocarbon group as a substituent of the fused cyclic group include groups in which one hydrogen atom has been removed from a monocycloalkane such as cyclopentane or cyclohexane; groups in which one hydrogen atom has been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane or tetracyclododecane; lactone-containing cyclic groups represented by the general formulae (a2-r-1) to (a2-r-7) above; —SO—-containing cyclic groups represented by the general formulae (a5-r-1) to (a5-r-4) above; and heterocyclic groups represented by the chemical formulae (r-hr-7) to (r-hr-16) above.

[0072] A chain alkyl group which may have a substituent: R 101The chain alkyl group may be either a straight chain or a branched chain. The linear alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 carbon atoms. The branched alkyl group preferably has 3 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and most preferably 3 to 10 carbon atoms. Specific examples include a 1-methylethyl group, a 1-methylpropyl group, a 2-methylpropyl group, a 1-methylbutyl group, a 2-methylbutyl group, a 3-methylbutyl group, a 1-ethylbutyl group, a 2-ethylbutyl group, a 1-methylpentyl group, a 2-methylpentyl group, a 3-methylpentyl group, and a 4-methylpentyl group.

[0073] An optionally substituted chain alkenyl group: R 101 The chain alkenyl group may be either linear or branched, and preferably has 2 to 10 carbon atoms, more preferably 2 to 5, even more preferably 2 to 4, and particularly preferably 3. Examples of the linear alkenyl group include a vinyl group, a propenyl group (allyl group), and a butynyl group. Examples of the branched alkenyl group include a 1-methylvinyl group, a 2-methylvinyl group, a 1-methylpropenyl group, and a 2-methylpropenyl group. Of the chain alkenyl groups mentioned above, linear alkenyl groups are preferred, vinyl groups and propenyl groups are more preferred, and vinyl groups are particularly preferred.

[0074] R 101 Examples of the substituent in the chain alkyl or alkenyl group include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, an amino group, and the above-mentioned R 101 Examples of the cyclic groups include the cyclic groups shown in the formula:

[0075] Among the above, R 101is preferably a cyclic group which may have a substituent, and more preferably a cyclic hydrocarbon group which may have a substituent. More specifically, preferred are a phenyl group, a naphthyl group, a group in which one or more hydrogen atoms have been removed from a polycycloalkane, a lactone-containing cyclic group represented by each of the general formulae (a2-r-1) to (a2-r-7), and an —SO2- containing cyclic group represented by each of the general formulae (a5-r-1) to (a5-r-4).

[0076] In the general formula (b-1), Y 101 is a single bond or a divalent linking group containing an oxygen atom. Y 101 is a divalent linking group containing an oxygen atom, 101 may contain atoms other than oxygen atoms. Examples of atoms other than oxygen atoms include carbon atoms, hydrogen atoms, sulfur atoms, and nitrogen atoms. Examples of divalent linking groups containing an oxygen atom include non-hydrocarbon oxygen-containing linking groups such as an oxygen atom (ether bond: -O-), an ester bond (-C(=O)-O-), an oxycarbonyl group (-O-C(=O)-), an amide bond (-C(=O)-NH-), a carbonyl group (-C(=O)-), and a carbonate bond (-O-C(=O)-O-); and combinations of such non-hydrocarbon oxygen-containing linking groups with alkylene groups. A sulfonyl group (-SO2-) may be further linked to these combinations. Examples of such divalent linking groups containing an oxygen atom include linking groups represented by the following general formulae (y-al-1) to (y-al-7).

[0077] [ka] [In the formula, V' 101 is a single bond or an alkylene group having 1 to 5 carbon atoms, and V' 102 is a divalent saturated hydrocarbon group having 1 to 30 carbon atoms.

[0078] V' 102The divalent saturated hydrocarbon group in is preferably an alkylene group having 1 to 30 carbon atoms, more preferably an alkylene group having 1 to 10 carbon atoms, and even more preferably an alkylene group having 1 to 5 carbon atoms.

[0079] V' 101 and V' 102 The alkylene group in may be a straight-chain alkylene group or a branched-chain alkylene group, and is preferably a straight-chain alkylene group. V' 101 and V' 102 Specific examples of the alkylene group in the formula (I) include a methylene group [-CH2-]; alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, and -C(CH2CH3)2-; an ethylene group [-CH2CH2-]; -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, and -CH(CH2CH3)CH2 -, etc.; a trimethylene group (n-propylene group) [-CH2CH2CH2-]; alkyl trimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; a tetramethylene group [-CH2CH2CH2CH2-]; alkyl tetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-; and a pentamethylene group [-CH2CH2CH2CH2CH2-]. Also, V' 101 or V' 102 Some methylene groups in the alkylene group in the formula (I) may be substituted with a divalent aliphatic cyclic group having 5 to 10 carbon atoms. The aliphatic cyclic group is preferably a divalent group in which one hydrogen atom has been removed from a cyclic aliphatic hydrocarbon group (a monocyclic aliphatic hydrocarbon group or a polycyclic aliphatic hydrocarbon group), and more preferably a cyclohexylene group, a 1,5-adamantylene group, or a 2,6-adamantylene group.

[0080] Y 101As the linking group, a divalent linking group containing an ester bond or a divalent linking group containing an ether bond is preferred, and the linking groups represented by the above general formulae (y-al-1) to (y-al-5) are more preferred.

[0081] In the general formula (b-1), V 101 is a single bond, an alkylene group, or a fluorinated alkylene group. 101 The alkylene group and fluorinated alkylene group in the formula (V) preferably have 1 to 4 carbon atoms. 101 The fluorinated alkylene group in 101 In particular, groups in which some or all of the hydrogen atoms of the alkylene group in the formula (I) are substituted with fluorine atoms are preferred. 101 is preferably a single bond or a fluorinated alkylene group having 1 to 4 carbon atoms.

[0082] In the general formula (b-1), R 102 is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. 102 is preferably a fluorine atom or a perfluoroalkyl group having 1 to 5 carbon atoms, and more preferably a fluorine atom.

[0083] Specific examples of the anion moiety represented by the general formula (b-1) include, for example, Y 101 When Y is a single bond, examples of the anion include a fluorinated alkylsulfonate anion such as a trifluoromethanesulfonate anion or a perfluorobutanesulfonate anion; 101 When is a divalent linking group containing an oxygen atom, examples of the anions include those represented by any of the following general formulae (an-1) to (an-3).

[0084] [ka] [In the formula, R” 101R" is an aliphatic cyclic group which may have a substituent, a monovalent heterocyclic group represented by each of the above chemical formulas (r-hr-1) to (r-hr-6), a fused cyclic group represented by the above chemical formula (r-br-1) or (r-br-2), or a chain alkyl group which may have a substituent. 102 R" is an aliphatic cyclic group which may have a substituent, a fused cyclic group represented by the chemical formula (r-br-1) or (r-br-2) above, a lactone-containing cyclic group represented by each of the general formulae (a2-r-1), (a2-r-3) to (a2-r-7) above, or an -SO2- containing cyclic group represented by each of the general formulae (a5-r-1) to (a5-r-4) above. 103 V" is an aromatic cyclic group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a chain alkenyl group which may have a substituent. 101 is a single bond, an alkylene group having 1 to 4 carbon atoms, or a fluorinated alkylene group having 1 to 4 carbon atoms. 102 is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms; each v" is independently an integer of 0 to 3, each q" is independently an integer of 0 to 20, and n" is 0 or 1.

[0085] R” 101 , R” 102 and R” 103 The aliphatic cyclic group which may have a substituent is represented by R 101 The substituent is preferably a group exemplified as the cyclic aliphatic hydrocarbon group in the general formula (b-1). 101 Examples of the substituents that may be substituted on the cyclic aliphatic hydrocarbon group in the above formula (1) include the same as those that may be substituted on the cyclic aliphatic hydrocarbon group in the above formula (1).

[0086] R” 103 The aromatic cyclic group which may have a substituent in the general formula (b-1) is R 101 The substituent is preferably a group exemplified as the aromatic hydrocarbon group in the cyclic hydrocarbon group in the general formula (b-1). 101 Examples of the substituents that may substitute the aromatic hydrocarbon group in the above formula (1) include the same as those in the above formula (1).

[0087] R” 101 The chain alkyl group which may have a substituent is R 101 The alkyl group is preferably one of the groups exemplified as the chain alkyl group in the above formula. R” 103 The chain alkenyl group which may have a substituent is R 101 Preferably, it is a group exemplified as the chain alkenyl group in the above formula.

[0088] Anion in component (b-2) In the general formula (b-2), R 104 , R 105 are each independently a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and each is 101 However, R 104 , R 105 may be bonded to each other to form a ring. R 104 , R 105 is preferably a chain alkyl group which may have a substituent, more preferably a linear or branched alkyl group, or a linear or branched fluorinated alkyl group. The chain alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 7 carbon atoms, and even more preferably 1 to 3 carbon atoms. 104 , R 105 The number of carbon atoms in the chain alkyl group of R is preferably as small as possible within the above range of carbon atoms, for reasons such as good solubility in resist solvents. 104 , R 105In the chain alkyl group, the greater the number of hydrogen atoms substituted with fluorine atoms, the stronger the acid strength and the improved transparency to high-energy light of 250 nm or less and electron beams, which is preferable. The proportion of fluorine atoms in the chain alkyl group, i.e., the fluorination rate, is preferably 70 to 100%, more preferably 90 to 100%, and most preferably a perfluoroalkyl group in which all hydrogen atoms are substituted with fluorine atoms. In the general formula (b-2), V 102 , V 103 are each independently a single bond, an alkylene group, or a fluorinated alkylene group, and each represents V in the general formula (b-1). 101 The same can be mentioned. In the general formula (b-2), L 101 , L 102 are each independently a single bond or an oxygen atom.

[0089] Anion in component (b-3) In the general formula (b-3), R 106 ~R 108 are each independently a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and each is 101 The same can be mentioned. In the general formula (b-3), L 103 ~L 105 are each independently a single bond, —CO— or —SO2—.

[0090] Among the above, the anion moiety of component (B) is preferably the anion in component (b-1). Among these, anions represented by any of the above general formulas (an-1) to (an-3) are more preferred, anions represented by either general formula (an-1) or (an-2) are even more preferred, and anions represented by general formula (an-2) are particularly preferred.

[0091] {cation part} In the general formula (b-1), general formula (b-2), and general formula (b-3), M'm+ represents an m-valent onium cation. Among these, sulfonium cation and iodonium cation are preferred. m is an integer of 1 or greater.

[0092] Preferred cationic moieties ((M' m+ ) 1 / m ) includes organic cations represented by the following general formulas (ca-1) to (ca-5), respectively.

[0093] [ka] [In the formula, R 201 ~R 207 , and R 211 ~R 212 R each independently represents an aryl group, an alkyl group, or an alkenyl group which may have a substituent. 201 ~R 203 , R 206 ~R 207 , R 211 ~R 212 may be bonded to each other to form a ring together with the sulfur atom in the formula. 208 ~R 209 R each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. 210 is an optionally substituted aryl group, an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted -SO2- containing cyclic group. 201 represents -C(=O)- or -C(=O)-O-. Y 201 each independently represents an arylene group, an alkylene group, or an alkenylene group. x is 1 or 2. W 201 represents a (x+1)-valent linking group.

[0094] In the above general formulas (ca-1) to (ca-5), R 201 ~R 207 , and R 211 ~R 212 The aryl group in the formula (I) includes an unsubstituted aryl group having 6 to 20 carbon atoms, and a phenyl group or a naphthyl group is preferred. R 201 ~R 207 , and R 211 ~R 212 The alkyl group in is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms. R 201 ~R 207 , and R 211 ~R 212 The alkenyl group in the formula (I) preferably has 2 to 10 carbon atoms. R 201 ~R 207 , and R 210 ~R 212 Examples of the substituent that may be possessed by the group include an alkyl group, a halogen atom, a halogenated alkyl group, a carbonyl group, a cyano group, an amino group, an aryl group, and groups represented by the following general formulae (ca-r-1) to (ca-r-7).

[0095] [ka] [In the formula, R' 201 are each independently a hydrogen atom, a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent.

[0096] Optionally substituted cyclic groups: The cyclic group is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. An aliphatic hydrocarbon group means a hydrocarbon group that does not have aromaticity. Furthermore, the aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated.

[0097] R' 201The aromatic hydrocarbon group in the formula (I) is a hydrocarbon group having an aromatic ring. The aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30 carbon atoms, even more preferably 5 to 20 carbon atoms, particularly preferably 6 to 15 carbon atoms, and most preferably 6 to 10 carbon atoms. However, the carbon number does not include the number of carbon atoms in the substituent. R' 201 Specific examples of the aromatic ring contained in the aromatic hydrocarbon group in the above formula include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, and aromatic heterocycles in which some of the carbon atoms constituting these aromatic rings are substituted with heteroatoms. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. R' 201 Specific examples of the aromatic hydrocarbon group in include a group in which one hydrogen atom has been removed from the aromatic ring (aryl group: for example, phenyl group, naphthyl group, etc.), and a group in which one hydrogen atom of the aromatic ring has been substituted with an alkylene group (for example, arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.). The alkylene group (the alkyl chain in the arylalkyl group) preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon atom.

[0098] R' 201 The cyclic aliphatic hydrocarbon group in the formula (I) is an aliphatic hydrocarbon group containing a ring in the structure. Examples of aliphatic hydrocarbon groups that contain a ring in their structure include alicyclic hydrocarbon groups (groups in which one hydrogen atom has been removed from an aliphatic hydrocarbon ring), groups in which an alicyclic hydrocarbon group is bonded to the end of a straight-chain or branched-chain aliphatic hydrocarbon group, and groups in which an alicyclic hydrocarbon group is interposed in the middle of a straight-chain or branched-chain aliphatic hydrocarbon group. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms. The alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. The monocyclic alicyclic hydrocarbon group is preferably a group in which one or more hydrogen atoms have been removed from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group in which one or more hydrogen atoms have been removed from a polycycloalkane, and the polycycloalkane preferably has 7 to 30 carbon atoms. Among these, the polycycloalkane is more preferably a polycycloalkane having a bridged ring polycyclic skeleton, such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane; or a polycycloalkane having a fused ring polycyclic skeleton, such as a cyclic group having a steroid skeleton.

[0099] Among them, R' 201 The cyclic aliphatic hydrocarbon group in is preferably a group in which one or more hydrogen atoms have been removed from a monocycloalkane or a polycycloalkane, more preferably a group in which one hydrogen atom has been removed from a polycycloalkane, particularly preferably an adamantyl group or a norbornyl group, and most preferably an adamantyl group.

[0100] The linear or branched aliphatic hydrocarbon group which may be bonded to the alicyclic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and particularly preferably 1 to 3 carbon atoms. As the straight-chain aliphatic hydrocarbon group, a straight-chain alkylene group is preferred, and specific examples include a methylene group [-CH2-], an ethylene group [-(CH2)2-], a trimethylene group [-(CH2)3-], a tetramethylene group [-(CH2)4-], and a pentamethylene group [-(CH2)5-]. The branched aliphatic hydrocarbon group is preferably a branched alkylene group, and specific examples thereof include alkyl alkylene groups such as alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, and -C(CH2CH3)2-; alkylethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, and -C(CH2CH3)2-CH2-; alkyl trimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; and alkyl tetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-. The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0101] Also, R' 201 The cyclic hydrocarbon group in may contain a heteroatom, such as a heterocycle. Specific examples include the lactone-containing cyclic groups represented by the general formulae (a2-r-1) to (a2-r-7) above, the —SO—-containing cyclic groups represented by the general formulae (a5-r-1) to (a5-r-4) above, and other heterocyclic groups represented by the chemical formulae (r-hr-1) to (r-hr-16) above.

[0102] R' 201 Examples of the substituent in the cyclic group include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, and a nitro group. The alkyl group as a substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. The alkoxy group as a substituent is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group, and most preferably a methoxy group or an ethoxy group. As the halogen atom as a substituent, a fluorine atom is preferred. Examples of halogenated alkyl groups as substituents include alkyl groups having 1 to 5 carbon atoms, such as methyl, ethyl, propyl, n-butyl, and tert-butyl groups, in which some or all of the hydrogen atoms have been substituted with the above-mentioned halogen atoms. The carbonyl group as a substituent is a group that substitutes a methylene group (-CH2-) that constitutes a cyclic hydrocarbon group.

[0103] A chain alkyl group which may have a substituent: R' 201 The chain alkyl group may be either a straight chain or a branched chain. The linear alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 carbon atoms. The branched alkyl group preferably has 3 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and most preferably 3 to 10 carbon atoms. Specific examples include a 1-methylethyl group, a 1-methylpropyl group, a 2-methylpropyl group, a 1-methylbutyl group, a 2-methylbutyl group, a 3-methylbutyl group, a 1-ethylbutyl group, a 2-ethylbutyl group, a 1-methylpentyl group, a 2-methylpentyl group, a 3-methylpentyl group, and a 4-methylpentyl group.

[0104] An optionally substituted chain alkenyl group: R' 201 The chain alkenyl group may be either linear or branched, and preferably has 2 to 10 carbon atoms, more preferably 2 to 5 carbon atoms, even more preferably 2 to 4 carbon atoms, and particularly preferably 3 carbon atoms. Examples of the linear alkenyl group include a vinyl group, a propenyl group (allyl group), and a butynyl group. Examples of the branched alkenyl group include a 1-methylvinyl group, a 2-methylvinyl group, a 1-methylpropenyl group, and a 2-methylpropenyl group. Of the chain alkenyl groups mentioned above, linear alkenyl groups are preferred, vinyl groups and propenyl groups are more preferred, and vinyl groups are particularly preferred.

[0105] R' 201 Examples of the substituent in the chain alkyl or alkenyl group include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, an amino group, the above-mentioned R' 201 Examples of the cyclic groups include the cyclic groups shown in the formula:

[0106] R' 201 In addition to the above-mentioned optionally substituted cyclic groups, optionally substituted chain alkyl groups, and optionally substituted chain alkenyl groups, examples of optionally substituted cyclic groups or optionally substituted chain alkyl groups include tertiary alkyl ester-type acid-dissociable groups.

[0107] Among them, R' 201 is preferably a cyclic group which may have a substituent, and more preferably a cyclic hydrocarbon group which may have a substituent. More specifically, for example, a phenyl group, a naphthyl group, a group in which one or more hydrogen atoms have been removed from a polycycloalkane, a lactone-containing cyclic group represented by each of the general formulae (a2-r-1) to (a2-r-7), or an —SO2- containing cyclic group represented by each of the general formulae (a5-r-1) to (a5-r-4) is preferred.

[0108] In the above general formulas (ca-1) to (ca-5), R 201 ~R 203 , R 206 ~R 207 , R 211 ~R 212 When they are bonded to each other to form a ring together with the sulfur atom in the formula, they may not contain a heteroatom such as a sulfur atom, an oxygen atom, or a nitrogen atom, or a carbonyl group, -SO-, -SO2-, -SO3-, -COO-, -CONH-, or -N(R N )-(applicable R Nis an alkyl group having 1 to 5 carbon atoms.) The ring formed is preferably a 3- to 10-membered ring, including the sulfur atom, and particularly preferably a 5- to 7-membered ring, inclusive of the sulfur atom. Specific examples of the ring formed include a thiophene ring, a thiazole ring, a benzothiophene ring, a benzothiophene ring, a dibenzothiophene ring, a 9H-thioxanthene ring, a thioxanthone ring, a thianthrene ring, a phenoxathiin ring, a tetrahydrothiophenium ring, and a tetrahydrothiopyranium ring.

[0109] R 208 ~R 209 each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and when they are alkyl groups, they may be bonded to each other to form a ring.

[0110] R 210 is an optionally substituted aryl group, an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted -SO2- containing cyclic group. R 210 The aryl group in the formula (I) includes an unsubstituted aryl group having 6 to 20 carbon atoms, and a phenyl group or a naphthyl group is preferred. R 210 The alkyl group in 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 As the -SO2- containing cyclic group which may have a substituent in the formula (a5-r-1), an "-SO2- containing polycyclic group" is preferred, and a group represented by the above general formula (a5-r-1) is more preferred.

[0111] Y 201 each independently represents an arylene group, an alkylene group, or an alkenylene group. Y 201 The arylene group in the formula (b-1) is R101 Examples of the aromatic hydrocarbon group in the above formula include groups in which one hydrogen atom has been removed from the aryl groups exemplified above. Y 201 The alkylene group and alkenylene group in the formula (b-1) are 101 Examples of the chain alkyl group and the chain alkenyl group include groups in which one hydrogen atom has been removed from the groups exemplified above as the chain alkyl group and the chain alkenyl group.

[0112] In the general formula (ca-4), x is 1 or 2. W 201 is an (x+1)-valent, i.e., a divalent or trivalent linking group. W 201 The divalent linking group in W is preferably a divalent hydrocarbon group which may have a substituent. 201 The divalent linking group in may be linear, branched, or cyclic, and is preferably cyclic. Among them, a group in which two carbonyl groups are combined at both ends of an arylene group is preferred. Examples of the arylene group include a phenylene group and a naphthylene group, and a phenylene group is particularly preferred. W 201 The trivalent linking group in 201 Examples of the divalent linking group include a group in which one hydrogen atom has been removed from the divalent linking group shown in the formula (1), and a group in which the divalent linking group is further bonded to the divalent linking group shown in the formula (1). 201 The trivalent linking group in the formula (I) is preferably a group in which two carbonyl groups are bonded to an arylene group.

[0113] Specific examples of suitable cations represented by the general formula (ca-1) include cations represented by the following chemical formulas (ca-1-1) to (ca-1-70).

[0114] [ka]

[0115] [ka]

[0116] [ka] [In the formula, g1, g2, and g3 represent the number of repeating units, where g1 is an integer of 1 to 5, g2 is an integer of 0 to 20, and g3 is an integer of 0 to 20.]

[0117] [ka]

[0118] [ka]

[0119] [ka] [In the formula, R” 201 is a hydrogen atom or a substituent, and the substituent is the same as R 201 ~R 207 , and R 210 ~R 212 The substituents are the same as those exemplified as the substituents that may be possessed by the group

[0120] Specific examples of suitable cations represented by the general formula (ca-2) include diphenyliodonium cation, bis(4-tert-butylphenyl)iodonium cation, and the like.

[0121] Specific examples of suitable cations represented by the general formula (ca-3) include cations represented by the following chemical formulas (ca-3-1) to (ca-3-6).

[0122] [ka]

[0123] Specific examples of suitable cations represented by the general formula (ca-4) include cations represented by the following chemical formulas (ca-4-1) to (ca-4-2).

[0124] [ka]

[0125] Specific examples of suitable cations represented by the general formula (ca-5) include cations represented by the following general formulas (ca-5-1) to (ca-5-3).

[0126] [ka]

[0127] Among the above, the cation part ((M' m+ ) 1 / m ) is preferably a cation represented by general formula (ca-1).

[0128] In the resist composition of this embodiment, the component (B) may be used either as a single type, or in combination of two or more types. When the resist composition contains the component (B), the amount of the component (B) in the resist composition is preferably 0.5 to 40 parts by mass, even more preferably 1 to 30 parts by mass, and particularly preferably 1 to 25 parts by mass, per 100 parts by mass of the component (A). By ensuring that the amount of component (B) falls within the above-mentioned preferred range, sufficient pattern formation is achieved. Furthermore, when the components of the resist composition are dissolved in an organic solvent, a homogeneous solution is easily obtained, and the storage stability of the resist composition is also favorable.

[0129] <Photodegradable base> The resist composition of this embodiment contains, in addition to the above-described components (A) and (B), a photodegradable base (hereinafter also referred to as "component (D1)") that controls the diffusion of the acid generated from the component (B) (acid generator component) upon exposure. The component (D1) functions as a quencher (acid diffusion controller) that traps the acid generated in the resist composition upon exposure.

[0130] By including the component (D1) in the resist composition of this embodiment, the contrast between exposed and unexposed areas of the resist film can be further improved when forming a resist pattern. The component (D1) is not particularly limited as long as it decomposes upon exposure to light and loses its acid diffusion controllability, and is preferably at least one selected from the group consisting of a compound represented by the following general formula (d1-1) (hereinafter referred to as "component (d1-1)"), a compound represented by the following general formula (d1-2) (hereinafter referred to as "component (d1-2)"), and a compound represented by the following general formula (d1-3) (hereinafter referred to as "component (d1-3)"): The components (d1-1) to (d1-3) do not act as quenchers in the exposed areas of the resist film because they decompose and lose their acid diffusion control properties (basicity), but act as quenchers in the unexposed areas of the resist film.

[0131] [ka] [In the formula, Rd 1 ~Rd 4 are each independently a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent. 2 In this case, no fluorine atom is bonded to the carbon atom adjacent to the S atom. 1 is a single bond or a divalent linking group; m is an integer of 1 or more; M m+ are each independently an m-valent organic cation.

[0132] {(d1-1) component} Anion part In the general formula (d1-1), Rd 1 is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and each of the R' 201 The same can be mentioned. Among these, Rd1 is preferably an aromatic hydrocarbon group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a chain-like alkyl group which may have a substituent. Substituents which these groups may have include a hydroxyl group, an oxo group, an alkyl group, an aryl group, a fluorine atom, a fluorinated alkyl group, a lactone-containing cyclic group represented by each of the above general formulas (a2-r-1) to (a2-r-7), an ether bond, an ester bond, or a combination thereof. When an ether bond or an ester bond is contained as a substituent, it may be connected via an alkylene group, and in this case, the substituent is preferably a linking group represented by each of the above general formulas (y-al-1) to (y-al-5). Suitable examples of the aromatic hydrocarbon group include a phenyl group, a naphthyl group, and a polycyclic structure containing a bicyclooctane skeleton (a polycyclic structure consisting of a bicyclooctane skeleton and another ring structure). The aliphatic cyclic group is more preferably a group in which one or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. The chain alkyl group preferably has 1 to 10 carbon atoms, and specific examples thereof include straight-chain alkyl groups such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, and a decyl group; and branched-chain alkyl groups such as a 1-methylethyl group, a 1-methylpropyl group, a 2-methylpropyl group, a 1-methylbutyl group, a 2-methylbutyl group, a 3-methylbutyl group, a 1-ethylbutyl group, a 2-ethylbutyl group, a 1-methylpentyl group, a 2-methylpentyl group, a 3-methylpentyl group, and a 4-methylpentyl group.

[0133] When the chain-like alkyl group is a fluorinated alkyl group having a fluorine atom or a fluorinated alkyl group as a substituent, the number of carbon atoms in the fluorinated alkyl group is preferably 1 to 11, more preferably 1 to 8, and even more preferably 1 to 4. The fluorinated alkyl group may contain atoms other than fluorine atoms. Examples of atoms other than fluorine atoms include oxygen atoms, sulfur atoms, and nitrogen atoms. Road1 The alkyl group is preferably a fluorinated alkyl group in which some or all of the hydrogen atoms constituting a linear alkyl group have been substituted with fluorine atoms, and particularly preferably a fluorinated alkyl group in which all of the hydrogen atoms constituting a linear alkyl group have been substituted with fluorine atoms (linear perfluoroalkyl group).

[0134] Preferred examples of the anion moiety of the component (d1-1) are shown below.

[0135] [ka]

[0136] Cation part In the general formula (d1-1), M m+ is an m-valent organic cation. M m+ Suitable organic cations include those similar to those represented by the general formulae (ca-1) to (ca-5), with the cation represented by the general formula (ca-1) being more preferred, and the cations represented by the chemical formulae (ca-1-1) to (ca-1-70) being even more preferred. The component (d1-1) may be used alone or in combination of two or more.

[0137] {(d1-2) component} Anion part In the general formula (d1-2), Rd 2 is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and R' 201 The same can be mentioned. However, Rd 2 In the above, the carbon atom adjacent to the S atom is not bonded to a fluorine atom (is not substituted with fluorine), which makes the anion of the (d1-2) component an appropriate weak acid anion, thereby improving the quenching ability. Road 2is preferably a chain alkyl group which may have a substituent, or an aliphatic cyclic group which may have a substituent. The chain alkyl group preferably has 1 to 10 carbon atoms, and more preferably 3 to 10. The aliphatic cyclic group is more preferably a group (which may have a substituent) in which one or more hydrogen atoms have been removed from adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, or the like; or a group in which one or more hydrogen atoms have been removed from camphor, or the like. Road 2 The hydrocarbon group may have a substituent, and the substituent may be Rd 1 Examples of the substituents include the same as those that may be contained in the hydrocarbon group (aromatic hydrocarbon group, aliphatic cyclic group, chain alkyl group) in the above.

[0138] Preferred examples of the anion moiety of the component (d1-2) are shown below.

[0139] [ka]

[0140] Cation part In the general formula (d1-2), M m+ is an m-valent organic cation, and M in the general formula (d1-1) m+ is the same as: The component (d1-2) may be used alone or in combination of two or more.

[0141] {(d1-3) component} Anion part In the general formula (d1-3), Rd 3 is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and 201 The Rd is preferably a fluorine atom-containing cyclic group, a chain alkyl group, or a chain alkenyl group. Among these, a fluorinated alkyl group is preferred, and the Rd 1The same fluorinated alkyl groups as those mentioned above are more preferred.

[0142] In the general formula (d1-3), Rd 4 is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and R' 201 The same can be mentioned. Among these, alkyl groups, alkoxy groups, alkenyl groups and cyclic groups which may have a substituent are preferred. Road 4 The alkyl group in Rd is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. 4 A portion of the hydrogen atoms of the alkyl group may be substituted with a hydroxyl group, a cyano group, or the like. Road 4 The alkoxy group in is preferably an alkoxy group having 1 to 5 carbon atoms, and specific examples of the alkoxy group having 1 to 5 carbon atoms include a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, and a tert-butoxy group. Of these, a methoxy group and an ethoxy group are preferred.

[0143] Road 4 The alkenyl group in R' 201 Examples include the same alkenyl groups as those in the above, and a vinyl group, a propenyl group (allyl group), a 1-methylpropenyl group, or a 2-methylpropenyl group is preferred. These groups may further have an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms as a substituent.

[0144] Road 4 The cyclic group in the formula (I) is the same as the R' 201Examples of the cyclic group include the same as the cyclic group in the above, and preferred are alicyclic groups obtained by removing one or more hydrogen atoms from a cycloalkane such as cyclopentane, cyclohexane, adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane, or aromatic groups such as a phenyl group or a naphthyl group. 4 When Rd is an alicyclic group, the resist composition dissolves well in an organic solvent, resulting in excellent lithography properties. 4 When is an aromatic group, in lithography using EUV or the like as an exposure light source, the resist composition exhibits excellent light absorption efficiency, and exhibits favorable sensitivity and lithography properties.

[0145] In the general formula (d1-3), Yd 1 is a single bond or a divalent linking group. Yd 1 The divalent linking group in is not particularly limited, but examples thereof include divalent hydrocarbon groups (aliphatic hydrocarbon groups, aromatic hydrocarbon groups) which may have a substituent, and divalent linking groups containing a hetero atom. Yd 1 is preferably a carbonyl group, an ester bond, an amide bond, an alkylene group, or a combination thereof. The alkylene group is more preferably a linear or branched alkylene group, and further preferably a methylene group or an ethylene group.

[0146] Preferred examples of the anion moiety of the component (d1-3) are shown below.

[0147] [ka]

[0148] [ka]

[0149] Cation part In the general formula (d1-3), M m+is an m-valent organic cation, and M in the general formula (d1-1) m+ is the same as: The component (d1-3) may be used alone or in combination of two or more.

[0150] The component (D1) may be any one of the components (d1-1) to (d1-3) above, or a combination of two or more of them. In the resist composition of this embodiment, the amount of the component (D1) relative to 100 parts by mass of the component (A) is preferably 0.1 to 30 parts by mass, and more preferably 0.2 to 30 parts by mass. When the amount of the component (D1) is at least as large as the preferred lower limit, particularly good lithography properties and resist pattern shape are likely to be obtained, while when it is at most the upper limit, good sensitivity can be maintained and excellent throughput can be achieved.

[0151] Manufacturing method of component (D1): The method for producing the components (d1-1) and (d1-2) is not particularly limited, and they can be produced by known methods. The method for producing component (d1-3) is not particularly limited, and it can be produced, for example, in a manner similar to that described in US2012-0149916.

[0152] <Other ingredients> The resist composition of this embodiment may further contain other components in addition to the above-described components (A), (B), and (D1). Examples of other components include the following components (C), (D2), (E), (F), and (S).

[0153] <Crosslinking agent component (C)> The resist composition of this embodiment preferably further contains a crosslinker component (hereinafter also referred to as “component (C)”) in addition to the above-mentioned components (A), (B), and (D1). Component (C) is subjected to the action of acid generated from component (B) upon exposure to light, and forms a crosslinked structure with component (A), thereby improving etching resistance. As the component (C), a crosslinking agent that is blended in known chemically amplified negative resist compositions can be used.

[0154] Examples of component (C) include compounds obtained by reacting an amino group-containing compound (such as melamine, acetoguanamine, benzoguanamine, urea, ethyleneurea, or glycoluril) with formaldehyde, or with formaldehyde and an alcohol having 1 to 5 carbon atoms, and then substituting the hydrogen atom of the amino group with a hydroxymethyl group or an alkoxymethyl group having 1 to 5 carbon atoms. Specific examples of such component (C) include hexamethoxymethylmelamine, bismethoxymethylurea, bismethoxymethylbismethoxyethyleneurea, tetrakismethoxymethylglycoluril, tetrakisbutoxymethylglycoluril, etc. Among these, preferred are compounds in which urea is reacted with formaldehyde, or formaldehyde and an alcohol having 1 to 5 carbon atoms, and the hydrogen atom of the amino group is substituted with a hydroxymethyl group or an alkoxymethyl group having 1 to 5 carbon atoms, and among these, for example, bismethoxymethylurea is particularly preferred because it is possible to form a good resist pattern without being greatly affected by the amount added.

[0155] The component (C) may be used alone or in combination of two or more. In the resist composition of this embodiment, the amount of the component (C) relative to 100 parts by mass of the component (A) is preferably 1 to 50 parts by mass, more preferably 3 to 40 parts by mass, even more preferably 3 to 30 parts by mass, and most preferably 5 to 25 parts by mass. When the content of component (C) is at least the lower limit of the above-mentioned preferred range, crosslinking proceeds sufficiently, resulting in improved resolution and lithography properties. Furthermore, a good resist pattern with minimal swelling can be obtained. On the other hand, when the content of component (C) is at most the upper limit of the above-mentioned preferred range, the storage stability of the resist composition is good, and deterioration of sensitivity over time is more easily suppressed.

[0156] <Base components> The resist composition of this embodiment may further contain a base component other than the component (D1), in addition to the components (A), (B), and (D1) described above. Examples of the base component other than the component (D1) include a nitrogen-containing organic compound (D2) (hereinafter referred to as "component (D2)") that does not fall under the category of the component (D1).

[0157] The component (D2) is not particularly limited as long as it acts as an acid diffusion controller and does not fall under the category of component (D1), and any known component may be used. Among these, aliphatic amines are preferred, and among these, secondary aliphatic amines and tertiary aliphatic amines are particularly preferred. The aliphatic amine is an amine having one or more aliphatic groups, and the aliphatic groups preferably have 1 to 12 carbon atoms. Examples of aliphatic amines include amines in which at least one hydrogen atom of ammonia NH3 has been substituted with an alkyl group or hydroxyalkyl group having 12 or less carbon atoms (alkylamines or alkyl alcohol amines), and cyclic amines. Specific examples of alkylamines and alkyl alcoholamines include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, and n-decylamine; dialkylamines such as diethylamine, di-n-propylamine, di-n-heptylamine, di-n-octylamine, and dicyclohexylamine; trialkylamines such as trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine, and tri-n-dodecylamine; and alkyl alcoholamines such as diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, di-n-octanolamine, and tri-n-octanolamine. Among these, trialkylamines having 5 to 10 carbon atoms are more preferred, and tri-n-pentylamine or tri-n-octylamine is particularly preferred.

[0158] Examples of cyclic amines include heterocyclic compounds containing a nitrogen atom as a heteroatom. The heterocyclic compounds may be monocyclic (aliphatic monocyclic amines) or polycyclic (aliphatic polycyclic amines). Specific examples of the aliphatic monocyclic amine include piperidine and piperazine. The aliphatic polycyclic amine preferably has 6 to 10 carbon atoms, and specific examples thereof include 1,5-diazabicyclo[4.3.0]-5-nonene, 1,8-diazabicyclo[5.4.0]-7-undecene, hexamethylenetetramine, and 1,4-diazabicyclo[2.2.2]octane.

[0159] Other aliphatic amines include tris(2-methoxymethoxyethyl)amine, tris{2-(2-methoxyethoxy)ethyl}amine, tris{2-(2-methoxyethoxymethoxy)ethyl}amine, tris{2-(1-methoxyethoxy)ethyl}amine, tris{2-(1-ethoxyethoxy)ethyl}amine, tris{2-(1-ethoxypropoxy)ethyl}amine, tris[2-{2-(2-hydroxyethoxy)ethoxy}ethyl]amine, and triethanolamine triacetate, with triethanolamine triacetate being preferred.

[0160] Furthermore, an aromatic amine may be used as the component (D2). Examples of aromatic amines include 4-dimethylaminopyridine, pyrrole, indole, pyrazole, imidazole or derivatives thereof, tribenzylamine, 2,6-diisopropylaniline, and N-tert-butoxycarbonylpyrrolidine.

[0161] The component (D2) may be used alone or in combination of two or more. When the resist composition contains the component (D2), the amount of the component (D2) within the resist composition is typically within a range from 0.01 to 5 parts by mass per 100 parts by mass of the component (A). By ensuring this range, the resist pattern shape and stability over time during storage are improved.

[0162] <<At least one compound (E) selected from the group consisting of organic carboxylic acids, phosphorus oxoacids, and derivatives thereof>> The resist composition of this embodiment may contain, as an optional component, at least one compound (E) (hereafter referred to as "component (E)") selected from the group consisting of organic carboxylic acids, and phosphorus oxo acids and derivatives thereof, for the purposes of preventing sensitivity degradation and improving the resist pattern shape and stability over time. Suitable organic carboxylic acids include, for example, acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, and salicylic acid. Examples of phosphorus oxoacids include phosphoric acid, phosphonic acid, and phosphinic acid, with phosphonic acid being particularly preferred. Examples of derivatives of phosphorus oxoacids include esters in which the hydrogen atoms of the above oxoacids are substituted with hydrocarbon groups, and examples of the hydrocarbon groups include alkyl groups having 1 to 5 carbon atoms and aryl groups having 6 to 15 carbon atoms. Examples of the derivatives of phosphoric acid include phosphoric acid esters such as di-n-butyl phosphoric acid ester and diphenyl phosphoric acid ester. Examples of the derivatives of phosphonic acid include phosphonic acid esters such as dimethyl phosphonate, di-n-butyl phosphonate, phenylphosphonic acid, diphenyl phosphonate, and dibenzyl phosphonate. Derivatives of phosphinic acid include phosphinic acid esters and phenylphosphinic acid. In the resist composition of this embodiment, the component (E) may be used either as a single type, or in combination of two or more types. When the resist composition contains the component (E), the amount of the component (E) is typically within a range from 0.01 to 10 parts by mass per 100 parts by mass of the component (A).

[0163] <Fluorine additive component (F)> The resist composition of this embodiment may contain a fluorine additive component (hereafter referred to as “component (F)”) in order to impart water repellency to the resist film or to improve lithography properties. As the component (F), for example, the fluorine-containing polymer compounds described in JP-A Nos. 2010-002870, 2010-032994, 2010-277043, 2011-13569, and 2011-128226 can be used. More specifically, component (F) may be a polymer having a structural unit (f1) represented by the following general formula (f1-1): This polymer is preferably a polymer (homopolymer) consisting solely of the structural unit (f1) represented by the following general formula (f1-1); a copolymer of the structural unit (f1) with a structural unit containing an acid-decomposable group whose polarity increases upon the action of acid; or a copolymer of a structural unit containing an acid-decomposable group whose polarity increases upon the action of acid, the structural unit (f1), and a structural unit derived from acrylic acid or methacrylic acid. Here, the structural unit containing an acid-decomposable group whose polarity increases upon the action of acid that is copolymerized with the structural unit (f1) is preferably a structural unit derived from 1-ethyl-1-cyclooctyl(meth)acrylate or a structural unit derived from 1-methyl-1-adamantyl(meth)acrylate.

[0164] [ka] [wherein R is the same as defined above, and Rf 102 and Rf 103 each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms; Rf 102 and Rf 103 may be the same or different. 1is an integer from 0 to 5, and Rf 101 is an organic group containing a fluorine atom.

[0165] In the general formula (f1-1), R bonded to the carbon atom at the α-position is the same as defined above. R is preferably a hydrogen atom or a methyl group. In the general formula (f1-1), Rf 102 and Rf 103 The halogen atom in Rf is preferably a fluorine atom. 102 and Rf 103 Examples of the alkyl group having 1 to 5 carbon atoms for R include the same alkyl groups having 1 to 5 carbon atoms as those for R, and a methyl group or an ethyl group is preferred. 102 and Rf 103 Specific examples of the halogenated alkyl group having 1 to 5 carbon atoms include groups in which some or all of the hydrogen atoms of an alkyl group having 1 to 5 carbon atoms have been substituted with halogen atoms. As the halogen atom, a fluorine atom is preferred. Among these, Rf 102 and Rf 103 is preferably a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 5 carbon atoms, and more preferably a hydrogen atom, a fluorine atom, a methyl group, or an ethyl group. In the general formula (f1-1), nf 1 is an integer of 0 to 5, preferably an integer of 0 to 3, and more preferably 1 or 2.

[0166] In the general formula (f1-1), Rf 101 is an organic group containing a fluorine atom, and is preferably a hydrocarbon group containing a fluorine atom. The fluorine atom-containing hydrocarbon group may be linear, branched, or cyclic, and preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and particularly preferably 1 to 10 carbon atoms. Furthermore, 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, and particularly preferably 60% or more, because this increases the hydrophobicity of the resist film during immersion exposure. Among them, Rf 101 is more preferably a fluorinated hydrocarbon group having 1 to 6 carbon atoms, and particularly preferably a trifluoromethyl group, -CH2-CF3, -CH2-CF2-CF3, -CH(CF3)2, -CH2-CH2-CF3, or -CH2-CH2-CF2-CF2-CF2-CF3.

[0167] The weight-average molecular weight (Mw) of component (F) (based on polystyrene standards measured by gel permeation chromatography) is preferably 1,000 to 50,000, more preferably 5,000 to 40,000, and most preferably 10,000 to 30,000. When the Mw is below the upper limit of this range, the component has sufficient solubility in a resist solvent for use as a resist, and when the Mw is above the lower limit of this range, the resulting resist film has good water repellency. The dispersity (Mw / Mn) of the component (F) is preferably from 1.0 to 5.0, more preferably from 1.0 to 3.0, and most preferably from 1.0 to 2.5.

[0168] In the resist composition of this embodiment, the component (F) may be used alone, or in combination of two or more different compounds. When the resist composition contains the component (F), the component (F) is typically used in an amount of 0.5 to 10 parts by mass per 100 parts by mass of the component (A).

[0169] <Organic solvent component (S)> The resist composition of this embodiment can be produced by dissolving the resist materials in an organic solvent component (hereafter referred to as “component (S)”). The component (S) can be any solvent that is capable of dissolving the individual components used and forming a homogeneous solution, and any solvent that is appropriately selected from among those known to be conventionally used as solvents for chemically amplified resist compositions can be used. Examples of the component (S) include lactones such as γ-butyrolactone; ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl-n-pentyl ketone, methyl isopentyl ketone, and 2-heptanone; polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, and dipropylene glycol; compounds having an ester bond such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, and dipropylene glycol monoacetate; and compounds having an ether bond such as monoalkyl ethers or monophenyl ethers of the above polyhydric alcohols or compounds having an ester bond, such as monomethyl ether, monoethyl ether, monopropyl ether, and monobutyl ether. Examples of suitable solvents include derivatives of polyhydric alcohols (among which, propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PGME) are preferred); cyclic ethers such as dioxane, and esters such as methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, and ethyl ethoxypropionate; aromatic organic solvents such as anisole, ethyl benzyl ether, cresyl methyl ether, diphenyl ether, dibenzyl ether, phenetole, butyl phenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene, and mesitylene, and dimethyl sulfoxide (DMSO). In the resist composition of this embodiment, the component (S) may be used either alone or as a mixed solvent of two or more different solvents. Of these, PGMEA, PGME, γ-butyrolactone, EL, and cyclohexanone are preferred.

[0170] A mixed solvent of PGMEA and a polar solvent is also preferred as component (S). The blending ratio (mass ratio) may be determined appropriately taking into consideration the compatibility of PGMEA with the polar solvent, but is preferably within the range of 1:9 to 9:1, and more preferably 2:8 to 8:2. More specifically, when EL or cyclohexanone is blended as the polar solvent, the mass ratio of PGMEA:EL or cyclohexanone is preferably 1:9 to 9:1, more preferably 2:8 to 8:2. When PGME is blended as the polar solvent, the mass ratio of PGMEA:PGME is preferably 1:9 to 9:1, more preferably 2:8 to 8:2. Furthermore, a mixed solvent of PGMEA, PGME, and cyclohexanone is also preferred. Another preferred component (S) is a mixed solvent of at least one selected from PGMEA and EL with γ-butyrolactone, in which the mass ratio of the former to the latter is preferably 70:30 to 95:5.

[0171] There are no particular restrictions on the amount of component (S) used, and it is set appropriately depending on the coating film thickness so as to provide a concentration that allows application to a substrate, etc. Generally, the component (S) is used so that the solids concentration of the resist composition falls within the range of 0.1 to 20 mass %, and preferably 0.2 to 16 mass %.

[0172] The resist composition of this embodiment may further contain, if desired, compatible additives such as an additional resin for improving the performance of the resist film, a dissolution inhibitor, a plasticizer, a stabilizer, a colorant, an antihalation agent, or a dye.

[0173] The resist composition of this embodiment may be prepared by dissolving the resist material in component (S) and then removing impurities using a polyimide porous film, a polyamideimide porous film, or the like. For example, the resist composition may be filtered using a filter made of a polyimide porous film, a filter made of a polyamideimide porous film, or a filter made of a polyimide porous film and a polyamideimide porous film. Examples of such polyimide porous films and polyamideimide porous films include those described in JP 2016-155121 A.

[0174] The resist composition of this embodiment can be produced, for example, by mixing the above-mentioned silicon-containing resin (A) having a silicon content of 20 to 25%, an acid generator component, a photodegradable base, and, if necessary, other components, with an organic solvent component. One embodiment of the method for producing such a resist composition includes a step (P1) of preparing a silicon-containing resin (A) having a silicon content of 20 to 25%, and a step (P2) of mixing the silicon-containing resin (A), an acid generator component, and a photodegradable base.

[0175] The silicon-containing resin (A) prepared in the step (P1) may be a silicon-containing resin manufactured to have a silicon content of 20 to 25% as calculated using the following formula, or may be a commercially available silicon-containing resin having a silicon content of 20 to 25% as calculated using the following formula:

[0176] The silicon content in component (A) can be calculated using the following formula. Silicon content (%) = (number of silicon atoms present in the silicon-containing resin × atomic weight of silicon) / (total atomic weight calculated by adding the values ​​obtained by multiplying the number of each atom constituting the silicon-containing resin by each atomic weight) × 100

[0177] In the step (P2), other components may be further mixed as needed. Furthermore, the method for producing a resist composition may also include other steps in addition to the steps (P1) and (P2).

[0178] The resist composition of the present embodiment described above contains a silicon-containing resin, an acid generator component that generates acid upon exposure, and a photodegradable base that controls the diffusion of the acid generated from the acid generator component upon exposure, and the silicon-containing resin used has a silicon content of 20 to 25%. As described above, when the silicon content of the silicon-containing polymer, which is a base material component of a resist material, is increased in order to improve etching resistance, the resolution and shape of the pattern are deteriorated. To address this issue, the resist composition of this embodiment contains a silicon-containing resin, and employs a configuration in which this silicon-containing resin has a silicon content of 20 to 25% and a photodecomposable base is combined as an acid diffusion controller. As a result, the resist composition of this embodiment can further enhance etching resistance and form a resist pattern with excellent lithography properties.

[0179] (Method for forming a resist pattern) A method for forming a resist pattern according to a second aspect of the present invention is a method comprising: step (i) of forming a resist film on a support using the resist composition according to the first aspect of the present invention; step (ii) of exposing the resist film to light; and step (iii) of developing the exposed resist film to form a resist pattern. One embodiment of the resist pattern forming method is, for example, a resist pattern forming method carried out as follows.

[0180] Process (i): First, the resist composition of the above-described embodiment is applied onto a support using a spinner or the like, and then baked (post-apply bake (PAB)) at a temperature of, for example, 80 to 150°C for 40 to 120 seconds, preferably 60 to 90 seconds, to form a resist film.

[0181] Step (ii): Next, the resist film is subjected to selective exposure using an exposure device such as a KrF exposure device, an ArF exposure device, an electron beam lithography device, or an EUV exposure device, by exposure through a mask (mask pattern) on which a predetermined pattern is formed, or by lithography using direct irradiation with an electron beam without using a mask pattern. After the exposure, baking (post-exposure bake (PEB)) treatment is carried out, for example, at a temperature of 80 to 150° C. for 40 to 120 seconds, preferably 60 to 90 seconds.

[0182] Step (iii): Next, the exposed resist film is developed using an alkaline developer in the case of an alkaline development process, or a developer containing an organic solvent (organic developer) in the case of a solvent development process.

[0183] After the development process, a rinse process is preferably carried out. In the case of an alkaline development process, the rinse process is preferably a water rinse using pure water, and in the case of a solvent development process, it is preferable to use a rinse solution containing an organic solvent. In the case of a solvent development process, the developing or rinsing treatment may be followed by a treatment using a supercritical fluid to remove the developing solution or rinsing solution adhering to the pattern. After the development treatment or rinsing treatment, the film is dried. In some cases, a baking treatment (post-baking) may be performed after the development treatment. In this manner, a resist pattern can be formed.

[0184] The support is not particularly limited, and conventionally known supports can be used, such as substrates for electronic components and those on which a predetermined wiring pattern is formed. More specifically, examples include silicon wafers, substrates made of metals such as copper, chromium, iron, and aluminum, and glass substrates. Materials that can be used for the wiring pattern include copper, aluminum, nickel, and gold. The support may also be a substrate as described above on which an inorganic and / or organic film is provided. Examples of inorganic films include inorganic anti-reflective coatings (inorganic BARCs). Examples of organic films include organic anti-reflective coatings (organic BARCs) and organic films such as lower organic films in multilayer resist methods. Here, the multilayer resist method is a method in which at least one organic film (lower organic film) and at least one resist film (upper resist film) are provided on a substrate, and the lower organic film is patterned using the resist pattern formed on the upper resist film as a mask, and it is said to be able to form patterns with a high aspect ratio. In other words, with the multilayer resist method, the required thickness can be ensured by the lower organic film, so the resist film can be made thinner and fine patterns with a high aspect ratio can be formed. Multilayer resist methods are basically divided into a two-layer structure consisting of an upper resist film and a lower organic film (two-layer resist method), and a three-layer structure consisting of three or more layers with one or more intermediate layers (such as a metal thin film) between the upper resist film and the lower organic film (three-layer resist method).

[0185] The wavelength used for exposure is not particularly limited, and radiation such as ArF excimer laser, KrF excimer laser, F2 excimer laser, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam), X-rays, and soft X-rays can be used. The resist composition is highly useful for use with KrF excimer lasers, ArF excimer lasers, EB or EUV, and is even more useful for use with KrF excimer lasers, EB or EUV.

[0186] The exposure method for the resist film may be a normal exposure (dry exposure) carried out in air or an inert gas such as nitrogen, or may be liquid immersion lithography. Immersion exposure is an exposure method in which the space between the resist film and the lowest lens of the exposure device is filled with a solvent (immersion medium) that has a refractive index greater than that of air, and then exposure (immersion exposure) is performed in that state. The immersion medium is preferably a solvent having a refractive index greater than that of air and less than that of the resist film to be exposed. The refractive index of such a solvent is not particularly limited as long as it is within the above range. Examples of solvents 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, and hydrocarbon-based solvents. Specific examples of the fluorine-based inert liquid include liquids containing as a main component a fluorine-based compound such as C3HCl2F5, C4F9OCH3, C4F9OC2H5, or C5H3F7, and preferably have a boiling point of 70 to 180° C., more preferably 80 to 160° C. If the fluorine-based inert liquid has a boiling point within the above range, it is preferable because the medium used for immersion can be removed simply and easily after exposure is completed. As the fluorine-based inert liquid, particularly preferred are perfluoroalkyl compounds in which all hydrogen atoms of the alkyl group are substituted with fluorine atoms, specifically perfluoroalkyl ether compounds and perfluoroalkylamine compounds. More specifically, the perfluoroalkyl ether compound may include perfluoro(2-butyl-tetrahydrofuran) (boiling point: 102°C), and the perfluoroalkylamine compound may include perfluorotributylamine (boiling point: 174°C). As the liquid immersion medium, water is preferably used from the viewpoints of cost, safety, environmental issues, versatility, and the like.

[0187] The alkaline developer used in the development treatment in the alkaline development process may be, for example, a 0.1 to 10 mass % aqueous solution of tetramethylammonium hydroxide (TMAH).

[0188] The organic solvent contained in the organic developer used in the development treatment in the solvent development process may be any organic solvent capable of dissolving component (A) (component (A) before exposure), and may be appropriately selected from known organic solvents. Specific examples include polar solvents such as ketone solvents, ester solvents, alcohol solvents, nitrile solvents, amide solvents, and ether solvents, as well as hydrocarbon solvents. Ketone-based solvents are organic solvents that contain CC(=O)-C in their structure. Ester-based solvents are organic solvents that contain CC(=O)-OC in their structure. Alcohol-based solvents are organic solvents that contain an alcoholic hydroxyl group in their structure. "Alcoholic hydroxyl group" means a hydroxyl group bonded to a carbon atom of an aliphatic hydrocarbon group. Nitrile-based solvents are organic solvents that contain a nitrile group in their structure. Amide-based solvents are organic solvents that contain an amide group in their structure. Ether-based solvents are organic solvents that contain COC in their structure. Some organic solvents contain multiple types of functional groups that characterize the above-mentioned solvents in their structure, and in such cases, the term "organic solvent" refers to any solvent type containing the functional groups possessed by the organic solvent. For example, diethylene glycol monomethyl ether is considered to be both an alcohol-based solvent and an ether-based solvent in the above classification. The hydrocarbon solvent is a hydrocarbon solvent that is composed of a hydrocarbon that may be halogenated and has no substituents other than halogen atoms, and the halogen atoms are preferably fluorine atoms. Of the above, the organic solvent contained in the organic developer is preferably a polar solvent, and more preferably a ketone solvent, an ester solvent, a nitrile solvent, or the like.

[0189] Examples of ketone solvents include 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, acetone, 4-heptanone, 1-hexanone, 2-hexanone, diisobutyl ketone, cyclohexanone, methylcyclohexanone, phenylacetone, methyl ethyl ketone, methyl isobutyl ketone, acetylacetone, acetonylacetone, ionone, diacetonyl alcohol, acetylcarbinol, acetophenone, methyl naphthyl ketone, isophorone, propylene carbonate, γ-butyrolactone, methyl amyl ketone (2-heptanone), etc. Among these, methyl amyl ketone (2-heptanone) is preferred as the ketone solvent.

[0190] Examples of ester solvents include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, isoamyl acetate, ethyl methoxyacetate, ethyl ethoxyacetate, ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monophenyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monopropyl ether acetate, diethylene glycol monophenyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, 2-methoxybutyl acetate, 3-methoxybutyl acetate, 4-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-ethyl-3-methoxybutyl acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, 2-ethoxybutyl ether ... Dibutyl acetate, 4-ethoxybutyl acetate, 4-propoxybutyl acetate, 2-methoxypentyl acetate, 3-methoxypentyl acetate, 4-methoxypentyl acetate, 2-methyl-3-methoxypentyl acetate, 3-methyl-3-methoxypentyl acetate, 3-methyl-4-methoxypentyl acetate, 4-methyl-4-methoxypentyl acetate, propylene glycol diacetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate Examples of the ester solvent include butyl acetate, ethyl carbonate, propyl carbonate, butyl carbonate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, butyl pyruvate, methyl acetoacetate, ethyl acetoacetate, methyl propionate, ethyl propionate, propyl propionate, isopropyl propionate, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, propyl 3-methoxypropionate, etc. Among these, butyl acetate is preferred as the ester solvent.

[0191] Examples of nitrile solvents include acetonitrile, propionitrile, valeronitrile, and butyronitrile.

[0192] Known additives can be blended into the organic developer as needed. Examples of such additives include surfactants. The surfactant is not particularly limited, but examples include ionic or nonionic fluorine-based and / or silicon-based surfactants. Nonionic surfactants are preferred, and nonionic fluorine-based surfactants or nonionic silicon-based surfactants are more preferred. When a surfactant is added, the amount added is usually 0.001 to 5 mass %, preferably 0.005 to 2 mass %, and more preferably 0.01 to 0.5 mass %, based on the total amount of the organic developer.

[0193] The development process can be carried out by a known development method, such as a method of immersing the support in a developer for a certain period of time (dip method), a method of piling up the developer on the surface of the support by surface tension and leaving it standing for a certain period of time (puddle method), a method of spraying the developer onto the surface of the support (spray method), or a method of continuously applying the developer while scanning a developer application nozzle at a constant speed onto a support rotating at a constant speed (dynamic dispense method).

[0194] The organic solvent contained in the rinse solution used in the rinsing treatment after development in the solvent development process can be appropriately selected from the organic solvents listed above as organic solvents used in the organic developer, and can be one that does not easily dissolve the resist pattern. Usually, at least one solvent selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents, and ether solvents is used. Among these, at least one solvent selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, and amide solvents is preferred, at least one solvent selected from alcohol solvents and ester solvents is more preferred, and alcohol solvents are particularly preferred. The alcohol-based solvent used in the rinse liquid is preferably a monohydric alcohol having 6 to 8 carbon atoms, and the monohydric alcohol may be linear, branched, or cyclic. Specific examples include 1-hexanol, 1-heptanol, 1-octanol, 2-hexanol, 2-heptanol, 2-octanol, 3-hexanol, 3-heptanol, 3-octanol, 4-octanol, and benzyl alcohol. Of these, 1-hexanol, 2-heptanol, and 2-hexanol are preferred, and 1-hexanol and 2-hexanol are more preferred. These organic solvents may be used alone or in combination of two or more. They may also be used in combination with other organic solvents or water. However, taking into consideration the development characteristics, the amount of water in the rinse solution is preferably 30% by mass or less, more preferably 10% by mass or less, even more preferably 5% by mass or less, and particularly preferably 3% by mass or less, based on the total amount of the rinse solution. The rinse solution may contain known additives as needed. Examples of such additives include surfactants. Examples of surfactants include those described above, with nonionic surfactants being preferred, and nonionic fluorine-based surfactants or nonionic silicone-based surfactants being more preferred. When a surfactant is added, the amount added is usually 0.001 to 5 mass %, preferably 0.005 to 2 mass %, and more preferably 0.01 to 0.5 mass %, based on the total amount of the rinse liquid.

[0195] The rinse treatment (cleaning treatment) using a rinse solution can be carried out by a known rinse method, such as a method of continuously applying the rinse solution onto a support rotating at a constant speed (spin coating method), a method of immersing the support in the rinse solution for a certain period of time (dipping method), or a method of spraying the rinse solution onto the surface of the support (spray method).

[0196] According to the method of forming a resist pattern of the present embodiment described above, the resist composition related to the first aspect described above is used, and therefore it is possible to form a resist pattern that has improved etching resistance and excellent lithography properties. In particular, the method of forming a resist pattern of this embodiment is useful for forming a negative resist pattern by alkaline development of the exposed resist film in the step (iii). [Example]

[0197] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0198] <Preparation of Resist Composition (1)> (Example 1, Examples 3 to 5; Comparative Examples 1 to 3) The components shown in Table 1 were mixed and dissolved to prepare resist compositions of each example (solid content: approximately 16% by mass). However, Example 5 is a reference example.

[0199] [Table 1]

[0200] In Table 1, the abbreviations have the following meanings: The values ​​in brackets [ ] are the amounts of each component blended (parts by mass; solid content equivalent). (A)-1: Polymer compound represented by the following chemical formula (A-1). The weight average molecular weight (Mw) calculated in terms of standard polystyrene by GPC measurement is 5,000, and the molecular weight dispersity (Mw / Mn) is 2.20. The copolymer composition ratio (proportion (molar ratio) of each structural unit in the structural formula) is l / m = 60 / 40. The silicon content in the polymer compound is 21.5%.

[0201] The silicon content in the polymer compound represented by the following chemical formula (A-1) was calculated using the following formula. Silicon content (%) = (number of silicon atoms present in the polymer compound represented by chemical formula (A-1) × atomic weight of silicon) / (total atomic weight calculated by adding the values ​​obtained by multiplying the number of each atom constituting the polymer compound represented by chemical formula (A-1) by each atomic weight) × 100

[0202] That is, the silicon content in the polymer compound represented by the chemical formula (A-1) was calculated as follows. {(28×1)×100} / [{(28×1)+(16×3)+(1×7)+(12×7)}×60+{(28×1)+(16×2)+(1×3)+(12×1)}×40]×100=21.5(%)

[0203] (A)-2: Polymer compound represented by the following chemical formula (A-2). The weight average molecular weight (Mw) calculated in terms of standard polystyrene by GPC measurement is 2500, and the molecular weight dispersity (Mw / Mn) is 1.20. The copolymer composition ratio (proportion (molar ratio) of each structural unit in the structural formula) is l / m = 85 / 15. The silicon content in the polymer compound is 0%.

[0204] [ka]

[0205] (A)-5: Polymer compound represented by the following chemical formula (A-5). The weight average molecular weight (Mw) calculated in terms of standard polystyrene by GPC measurement is 5000, and the molecular weight dispersity (Mw / Mn) is 2.23. The copolymer composition ratio (proportion (molar ratio) of each structural unit in the structural formula) is l / m = 55 / 45. The silicon content in the polymer compound is 22.3%.

[0206] The silicon content in the polymer compound represented by the chemical formula (A-5) was calculated as follows. {(28×1)×100} / [{(28×1)+(16×3)+(1×7)+(12×7)}×55+{(28×1)+(16×2)+(1×3)+(12×1)}×45]×100=22.3(%)

[0207] (A)-6: Polymer compound represented by the following chemical formula (A-6). The weight average molecular weight (Mw) calculated in terms of standard polystyrene by GPC measurement is 800, and the molecular weight dispersity (Mw / Mn) is 1.22. The copolymer composition ratio (proportion (molar ratio) of each structural unit in the structural formula) is l / m / n = 85 / 5 / 10. The silicon content in the polymer compound is 21.6%.

[0208] The silicon content in the polymer compound represented by the chemical formula (A-6) was calculated as follows. {(28×1)×100} / [{(28×1)+(16×2)+(1×5)+(12×6)}×85+{(28×1)+(16×3)+(1×5)+(12×2)}×5+{(28×1)+(16×3)+(1×1)+(12×0)}×10]×100=21.6(%)

[0209] [ka]

[0210] (B)-1: An acid generator comprising a compound represented by the following chemical formula (B-1). (D)-1: A photodegradable base (component (D1)) consisting of a compound represented by the following chemical formula (D-1). (D)-2: A nitrogen-containing organic compound (component (D2)) represented by the following chemical formula (D-2). (C)-1: A crosslinking agent consisting of a compound represented by the following chemical formula (C-1). (E)-1: Salicylic acid. (Add)-1: A compound represented by the following chemical formula (Add-1). Used as a stabilizer. (S)-1: A mixed solvent of propylene glycol monomethyl ether acetate / γ-butyrolactone=8 / 2 (mass ratio).

[0211] [ka]

[0212] <Resist pattern formation (1)> Process (i): The organic anti-reflective coating composition was applied to a 12-inch silicon wafer using a spinner, and then baked on a hot plate at 225°C for 60 seconds to dry, thereby forming an organic anti-reflective coating with a thickness of 65 nm. Each resist composition of each example (Example 1, Examples 3 to 5, Comparative Examples 1 to 3) was applied onto the above organic anti-reflective coating using a spinner, and then subjected to a post-apply bake (PAB) treatment on a hot plate at a temperature of 85°C for 60 seconds, followed by drying to form a resist film with a thickness of 500 nm.

[0213] Step (ii): Next, the resist film was selectively irradiated with a KrF excimer laser (248 nm) through a mask pattern (binary mask) using a KrF exposure system NSR-S203B (Nikon Corporation; NA (numerical aperture) = 0.60, σ Conv 0.68). Then, post-exposure baking (PEB) was performed at 90° C. for 60 seconds.

[0214] Step (iii): Next, alkaline development was carried out using a 2.38% by mass tetramethylammonium hydroxide (TMAH) aqueous solution "NMD-3" (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.) as a developer at 23° C. for 60 seconds. Thereafter, the substrate was rinsed with pure water for 30 seconds, and then shaken off and dried. As a result, a 1:1 line and space pattern (hereinafter referred to as "LS pattern") with a line width of 6.25 μm and a pitch of 13.00 μm was formed.

[0215] [Evaluation of LWR (Line Width Roughness)] For the LS pattern of the target size (line width 6.25 μm) formed in the above <Formation of Resist Pattern>, 3σ, which is a measure of LWR, was calculated. This is shown in Table 2 as "LWR (nm)". "3σ" indicates three times the standard deviation (σ) (unit: nm) (3σ) obtained from the measurement results of measuring 400 line positions in the longitudinal direction of the line using a length-measuring SEM (scanning electron microscope; accelerating voltage 800V, product name S9380, manufactured by Hitachi High-Technologies Corporation). The smaller the 3σ value, the less rough the line sidewalls are, meaning that an LS pattern with a more uniform width is obtained.

[0216] [Evaluation of LER (Line Edge Roughness)] For the LS pattern of the target size (line width 6.25 μm) formed in the above <Formation of Resist Pattern>, 3σ, which is a measure of LER, was calculated. This is shown in Table 2 as "LER (nm)". "3σ" indicates three times the standard deviation (σ) (unit: nm) (3σ) obtained from the measurement results of measuring 400 line positions in the longitudinal direction of the line using a length-measuring SEM (scanning electron microscope; accelerating voltage 800V, product name S9380, manufactured by Hitachi High-Technologies Corporation). The smaller the 3σ value, the less rough the line sidewalls are, meaning that an LS pattern with a more uniform width is obtained.

[0217] [Table 2]

[0218] The results shown in Table 2 confirm that when the resist compositions of Examples 1 and 3 to 5, to which the present invention is applied, were used, both the LWR and LER values ​​were smaller than when the resist compositions of Comparative Examples 1 to 3, which are outside the scope of the present invention, were used. In other words, it can be confirmed that resist patterns with better lithography properties were formed.

[0219] In this evaluation, in the case of the resist compositions of Comparative Examples 2 and 3, which share the same resin component, no effect was observed from employing a photodegradable base. On the other hand, in the case of the resist compositions of Example 1 and Comparative Example 1, which both contain a silicon-containing resin, the use of a photodegradable base was found to have a significant effect in reducing the roughness of the resist pattern. That is, a synergistic effect was confirmed between the silicon-containing resin with a silicon content of 20 to 25% and the photodegradable base.

[0220] <Preparation of Resist Composition (2)> (Example 2, Comparative Examples 4 and 5) The components shown in Table 3 were mixed and dissolved to prepare resist compositions of each example (solid content: approximately 1.5% by mass).

[0221] [Table 3]

[0222] In Table 3, the abbreviations have the following meanings: The values ​​in brackets [ ] are the amounts of each component blended (parts by mass; solid content equivalent). (A)-1: Polymer compound represented by the following chemical formula (A-1). The weight average molecular weight (Mw) calculated in terms of standard polystyrene by GPC measurement is 5,000, and the molecular weight dispersity (Mw / Mn) is 2.20. The copolymer composition ratio (proportion (molar ratio) of each structural unit in the structural formula) is l / m = 60 / 40. The silicon content in the polymer compound is 21.5%.

[0223] (A)-3: Polymer compound represented by the following chemical formula (A-3). The weight average molecular weight (Mw) calculated in terms of standard polystyrene by GPC measurement is 7000, and the molecular weight dispersity (Mw / Mn) is 1.50. The copolymer composition ratio (proportion (molar ratio) of each structural unit in the structural formula) is l / m = 40 / 60. The silicon content in the polymer compound is 0%.

[0224] (A)-4: Polymer compound represented by the following chemical formula (A-4). The weight average molecular weight (Mw) calculated in terms of standard polystyrene by GPC measurement is 5000, and the molecular weight dispersity (Mw / Mn) is 2.21. The copolymer composition ratio (proportion (molar ratio) of each structural unit in the structural formula) is l / m = 80 / 20. The silicon content in the polymer compound is 18.8%.

[0225] The silicon content in the polymer compound represented by the chemical formula (A-4) was calculated as follows. {(28×1)×100} / [{(28×1)+(16×3)+(1×7)+(12×7)}×80+{(28×1)+(16×2)+(1×3)+(12×1)}×20]×100=18.8(%)

[0226] [ka]

[0227] (B)-2: An acid generator comprising a compound represented by the following chemical formula (B-2). (D)-3: A photodegradable base (component (D1)) consisting of a compound represented by the following chemical formula (D-3). (C)-1: A crosslinking agent consisting of a compound represented by the following chemical formula (C-1). (E)-1: Salicylic acid. (F)-1: Polymer compound represented by the following chemical formula (F-1). The weight average molecular weight (Mw) calculated in terms of standard polystyrene by GPC measurement is 17,000, and the molecular weight dispersity (Mw / Mn) is 1.69. The copolymer composition ratio (the proportion (molar ratio) of each structural unit in the structural formula) is l / m = 80 / 20. (S)-2: A mixed solvent of propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether=2 / 8 (mass ratio).

[0228] [ka]

[0229] <Resist pattern formation (2)> Process (i): Each resist composition (Example 2, Comparative Examples 4 to 5) was applied using a spinner onto an 8-inch silicon substrate that had been treated with hexamethyldisilazane (HMDS), and then post-applied bake (PAB) treatment was performed on a hot plate at 85°C for 60 seconds, followed by drying to form a resist film with a thickness of 35 nm.

[0230] Step (ii): Next, the resist film was subjected to exposure using an electron beam lithography system JEOL-JBX-9300FS (manufactured by JEOL Ltd.; Scan step 4 nm) at an acceleration voltage of 100 kV to produce a 1:1 line and space pattern (hereinafter referred to as "LS pattern") with a target size of 50 nm line width. Thereafter, post-exposure baking (PEB) was performed at 100° C. for 60 seconds.

[0231] Step (iii): Next, alkaline development was carried out at 23° C. for 60 seconds using a 2.38 mass % tetramethylammonium hydroxide (TMAH) aqueous solution "NMD-3" (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.). Thereafter, the substrate was rinsed with pure water for 30 seconds, and then shaken off and dried. As a result, a 1:1 LS pattern with a line width of 50 nm was formed.

[0232] [Evaluation of optimal exposure (Eop)] The optimum exposure dose Eop (μC / cm) for forming an LS pattern of the target size (line width 50 nm) by the above <Formation of resist pattern> 2 ) was sought.

[0233] [Evaluation of LWR (Line Width Roughness)] For the LS pattern of the target size (line width 50 nm) formed in the above <Formation of Resist Pattern>, 3σ, which is a measure of LWR, was calculated. This is shown in Table 4 as "LWR (nm)". "3σ" indicates three times the standard deviation (σ) (unit: nm) (3σ) obtained from the measurement results of measuring 400 line positions in the longitudinal direction of the line using a length-measuring SEM (scanning electron microscope; accelerating voltage 800V, product name S9380, manufactured by Hitachi High-Technologies Corporation). The smaller the 3σ value, the less rough the line sidewalls are, meaning that an LS pattern with a more uniform width is obtained.

[0234] [Evaluation of pattern resolution] When an LS pattern was formed by gradually increasing the exposure dose from the optimum exposure dose Eop, the minimum dimension of the pattern that could be resolved without collapsing was determined using a cross-sectional SEM (scanning electron microscope; product name SU8000, manufactured by Hitachi High-Technologies Corporation). This is shown in Table 4 as "resolution (nm)."

[0235] [Table 4]

[0236] The results shown in Table 4 confirm that when the resist composition of Example 2, to which the present invention is applied, was used, both the LWR and resolution values ​​were smaller than when the resist compositions of Comparative Examples 4 and 5, which are outside the scope of the present invention, were used. In other words, it can be confirmed that a resist pattern with better lithography properties was formed.

[0237] In this evaluation, by comparing Example 2 with Comparative Examples 4 and 5, the effect of combining a photodegradable base with a silicon-containing resin having a silicon content of 20 to 25% can be confirmed.

[0238] [Evaluation of etching resistance] The resist compositions of Example 1 and Comparative Example 2, which differ only in the resin components, were applied to silicon wafers using a spinner, and then subjected to a post-apply bake (PAB) treatment on a hot plate at a temperature of 85°C for 60 seconds, followed by drying to form resist films with a thickness of 500 nm. Next, the following dry etching treatment (a) and dry etching treatment (b) were carried out on each resist film.

[0239] Dry etching process (a): Processing time: 60 seconds using a TCP type dry etching device Gas: CF4

[0240] Dry etching process (b): Processing time: 60 seconds using a TCP type dry etching device Gas: N2 / O2 (71 / 29)

[0241] The etching rate (thickness of the film etched per unit time, nm / sec) was calculated from the film thickness of the resist film before and after each dry etching treatment. Furthermore, based on the etching rate results, the etching selectivity of Comparative Example 2 relative to Example 1 was calculated. These results are shown in Table 5.

[0242] [Table 5]

[0243] The results shown in Table 5 confirm that the resist composition of Example 1, which contains a silicon-containing resin with a silicon content of 20 to 25%, has improved etching resistance compared to the resist composition of Comparative Example 2, which contains a resin component outside the range of the present invention.

Claims

1. a silicon-containing resin; an acid generator component that generates acid upon exposure to light; a photodegradable base that controls diffusion of the acid generated from the acid generator component upon exposure; Contains the silicon content in the silicon-containing resin is 20 to 25% based on the total amount of all atoms constituting the silicon-containing resin; the silicon-containing resin comprises a silsesquioxane resin; The silsesquioxane resin has a structural unit represented by the following general formula (a1-1): A resist composition in which the content of the structural unit represented by general formula (a1-1) is 40 to 70 mol % based on the total of all structural units constituting the silsesquioxane resin. 【Chemistry 1】 [In the formula, Ra 1 is an alkylene group having 1 to 5 carbon atoms or a single bond. na1 is an integer of 1 to 3.

2. The resist composition according to claim 1, wherein the silsesquioxane resin further comprises a structural unit represented by the following general formula (a2-1): 【Chemistry 2】 [In the formula, Ra 2 is an alkyl group having 1 to 10 carbon atoms.]

3. The content ratio (molar ratio) of the structural unit represented by the general formula (a1-1) to the structural unit represented by the general formula (a2-1) is:

3. The resist composition according to claim 2, wherein the ratio of the structural unit represented by general formula (a1-1) to the structural unit represented by general formula (a2-1) is 40 / 60 to 70 / 30.

4. The resist composition according to any one of claims 1 to 3, wherein the photodegradable base comprises at least one selected from the group consisting of a compound represented by the following general formula (d1-1), a compound represented by the following general formula (d1-2), and a compound represented by the following general formula (d1-3): 【Transformation 3】 [In the formula, Rd １ ~Rd ４ are each independently a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent. ２ In the above, no fluorine atom is bonded to the carbon atom adjacent to the S atom. １ is a single bond or a divalent linking group; m is an integer of 1 or more; M ｍ＋ are each independently an m-valent organic cation.

5. The resist composition according to any one of claims 1 to 4, further comprising a crosslinking agent component.

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

7. 7. The method for forming a resist pattern according to claim 6, wherein in the step (iii), the exposed resist film is subjected to alkaline development to form a negative resist pattern.

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