Resist composition and method for forming a resist pattern

Abstract

To provide a resist composition which achieves higher sensitivity, further improves lithographic characteristics such as roughness reduction, and hardly causes film thickness reduction of a pattern, and to provide a resist pattern forming method using the resist composition.SOLUTION: In the resist composition which generates an acid upon exposure and whose solubility in a developer changes by the action of an acid, the total content of a basic component containing a compound represented by general formula (d0) and an acid generator component is regulated to 25 pts.mass or more and 60 pts.mass or less based on 100 pts.mass of a base component. In the formula (d0), Rd0 is a monovalent organic group; Xd0 is -O-, -C(=O)-, -O-C(=O)-, -C(=O)-O-, -S- or -SO2-; Yd0 is an optionally substituted divalent hydrocarbon group or a single bond; Mm+ represents an m-valent organic cation; and m is an integer of 1 or more.SELECTED DRAWING: None

Description

[Technical Field]

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

[0002] In recent years, advances in lithography technology have led to rapid miniaturization of patterns in the manufacturing of semiconductor devices and liquid crystal display elements. Generally, miniaturization is achieved by using shorter wavelengths (higher energy) exposure light sources.

[0003] Resist materials are required to possess lithography characteristics such as sensitivity to these exposure light sources and resolution that can reproduce patterns of fine dimensions. Conventionally, chemically amplified resist compositions have been used as resist materials that satisfy these requirements. These compositions contain a base component whose solubility in a developer changes due to the action of an acid, and an acid generator component that generates acid upon exposure.

[0004] In the formation of resist patterns, the behavior of acids generated from acid-generating agent components upon exposure is considered a significant factor influencing lithography characteristics. In response to this, a chemically amplified resist composition has been proposed that includes both an acid generating agent component and an acid diffusion control agent that controls the diffusion of the acid generated from the acid generating agent component upon exposure.

[0005] For example, Patent Document 1 discloses a radiation-sensitive resin composition containing a resin component whose solubility in a developer changes due to the action of an acid, an acid generating agent component, and an acid diffusion control agent having an anion portion of a specific structure. This acid diffusion control agent is a component that exhibits a quenching effect by undergoing an ion exchange reaction with the acid generated from the acid generating agent component. By incorporating this acid diffusion control agent, the diffusion of the acid generated from the acid generating agent component from the exposed area of ​​the resist film to the unexposed area is controlled, thereby improving the lithography characteristics. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] International Publication No. 2014 / 188762 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] Recently, advancements in lithography technology and the expansion of its application fields have led to rapid miniaturization of patterns. Consequently, when manufacturing semiconductor devices and other components, there is a growing demand for technologies that can form fine patterns with widths of less than 100 nm while maintaining a good shape. However, with conventional resist compositions such as those described in Patent Document 1 above, when attempting to increase sensitivity to exposure light sources such as EUV, it becomes difficult to obtain resist pattern shapes with desired lithography characteristics such as reduced roughness, making it difficult to satisfy all of these lithography characteristics. In contrast, while increasing the amount of acid generator component can improve lithography characteristics, it also has the drawback of making the pattern film thinner.

[0008] The present invention has been made in view of the above circumstances, and aims to provide a resist composition that can be made more sensitive, improves lithography characteristics such as roughness reduction, and is less prone to pattern film thinning, as well as a method for forming a resist pattern using the resist composition. [Means for solving the problem]

[0009] To solve the above problems, the present invention employs the following configuration. In other words, a first aspect of the present invention is a resist composition that generates acid upon exposure and whose solubility in a developer changes due to the action of the acid, comprising: a base component (A) whose solubility in a developer changes due to the action of the acid; an acid generating agent component (B) that generates acid upon exposure; and a base component (D) that controls the diffusion of the acid generated from the acid generating agent component (B) upon exposure, wherein the base component (D) comprises a compound (D0) represented by the following general formula (d0), and the total content of the acid generating agent component (B) and the base component (D) is 25 parts by mass or more and 60 parts by mass or less per 100 parts by mass of the base component (A).

[0010] [ka] [In the formula, Rd 0 Xd is a monovalent organic group. 0 These are -O-, -C(=O)-, -OC(=O)-, -C(=O)-O-, -S-, or -SO2-. Yd 0 This is a divalent hydrocarbon group or single bond, which may have substituents. m+ This represents an m-valent organic cation, where m is an integer greater than or equal to 1.

[0011] A second aspect of the present invention is a method for forming a resist pattern, characterized by comprising the steps of forming a resist film on a support using a resist composition according to the first aspect, exposing the resist film, and developing the exposed resist film to form a resist pattern. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide a resist composition that can be made more sensitive, improves lithography characteristics such as roughness reduction, and is less prone to pattern film thinning, as well as a method for forming a resist pattern using the resist composition. [Brief explanation of the drawing]

[0013] [Figure 1]This graph shows the change in the residual film percentage of the resist film relative to the total content of components (B) and (D) in the resist composition. [Modes for carrying out the invention]

[0014] In this specification and in the claims, "aliphatic" is defined as a concept relative to aromatic, meaning a group, compound, etc., that does not possess aromaticity. Unless otherwise specified, "alkyl group" includes linear, branched, and cyclic monovalent saturated hydrocarbon groups. The same applies to alkyl groups within alkoxy groups. Unless otherwise specified, the term "alkylene group" includes linear, branched, and cyclic divalent saturated hydrocarbon groups. Examples of "halogen atoms" include fluorine, chlorine, bromine, and iodine atoms. "Constituent unit" refers to the monomer unit (monomer unit) that makes up a polymer compound (resin, polymer, copolymer). When it is stated that a group "may have substituents," this includes both cases where a hydrogen atom (-H) is substituted with a monovalent group and cases where a methylene group (-CH2-) is substituted with a divalent group. "Exposure" is a concept that includes all forms of radiation exposure.

[0015] An "acid-degradable group" is a group that has acid-degradability, meaning that at least some of the bonds in its structure can be cleaved by the action of an acid. Examples of acid-degradable groups whose polarity increases upon the action of an acid include groups that decompose upon the action of an acid to produce polar groups. Examples of polar groups include carboxyl groups, hydroxyl groups, amino groups, and sulfo groups (-SO3H). More specifically, examples of acid-degradable groups include groups in which the aforementioned polar group is protected by an acid-dissociable group (for example, a group in which the hydrogen atom of an OH-containing polar group is protected by an acid-dissociable group).

[0016] The term "acid-dissociable group" refers to both (i) a group that has acid-dissociability, in which the bond between the acid-dissociable group and an adjacent atom can be cleaved by the action of an acid, and (ii) a group in which, after some of the bonds are cleaved by the action of an acid, a decarboxylation reaction occurs, which can further cleave the bond between the acid-dissociable group and an adjacent atom. The acid-dissociable group constituting the acid-degradable group must be less polar than the polar group generated by its dissociation. This means that when the acid-dissociable group dissociates due to the action of acid, a polar group with higher polarity is generated, increasing the polarity. As a result, the overall polarity of component (A1) increases. This increase in polarity relatively changes the solubility in the developer; solubility increases when the developer is an alkaline developer, and decreases when the developer is an organic developer.

[0017] A "base component" is an organic compound that has film-forming ability. Organic compounds used as base components are broadly classified into nonpolymers and polymers. Nonpolymers typically have a molecular weight of 500 or more and less than 4000. Hereinafter, "low molecular weight compound" refers to a nonpolymer with a molecular weight of 500 or more and less than 4000. Polymers typically have a molecular weight of 1000 or more. Hereinafter, "resin," "high molecular weight compound," or "polymer" refers to a polymer with a molecular weight of 1000 or more. The molecular weight of polymers shall be the weight-average molecular weight on a polystyrene basis calculated by GPC (gel permeation chromatography).

[0018] "Induced structural units" refer to structural units formed by the cleavage of multiple bonds between carbon atoms, such as ethylenic double bonds. "Acrylic acid ester" may have a substituent that replaces the hydrogen atom bonded to the α-carbon atom. αx ) is an atom or group other than a hydrogen atom. Also, substituents (R αx Itaconic acid diesters in which ) are substituted with substituents containing an ester bond, or substituents (R αxThis also includes α-hydroxyacrylic esters in which the α group is substituted with a hydroxyalkyl group or a group that modifies the hydroxyl group thereof. Unless otherwise specified, the α-carbon atom of the acrylic acid ester refers to the carbon atom to which the carbonyl group of acrylic acid is bonded. Hereafter, acrylic acid esters in which the hydrogen atom bonded to the α-carbon atom is replaced by a substituent are sometimes referred to as α-substituted acrylic acid esters.

[0019] The term "derivative" refers to a compound in which the α-position hydrogen atom of the target compound is substituted with another substituent such as an alkyl group or alkyl halide, as well as derivatives thereof. Examples of such derivatives include those in which the hydrogen atom of the hydroxyl group of the target compound (which may have the α-position hydrogen atom substituted with a substituent) is substituted with an organic group; and those in which a substituent other than a hydroxyl group is bonded to the target compound (which may have the α-position hydrogen atom substituted with a substituent). Unless otherwise specified, the α-position refers to the first carbon atom adjacent to the functional group. As substituents that substitute the hydrogen atom at the α-position of hydroxystyrene, R αx Similar examples include the above.

[0020] In this specification and in the claims, depending on the structure represented by the chemical formula, an asymmetric carbon may be present, and enantioisomers or diastereomers may exist. In such cases, a single chemical formula will represent all of these isomers. These isomers may be used individually or as a mixture.

[0021] (Resist composition) The resist composition of this embodiment generates acid upon exposure, and its solubility in the developer changes due to the action of the acid. The resist composition contains a base component (A) (hereinafter also referred to as "component (A)") whose solubility in a developer solution changes due to the action of an acid, an acid generating agent component (B) (hereinafter also referred to as "component (B)") that generates acid upon exposure, and a base component (D) (hereinafter also referred to as "component (D)") that controls the diffusion of the acid generated from component (B) upon exposure.

[0022] When a resist film is formed using the resist composition of this embodiment and selective exposure is performed on the resist film, acid is generated from component (B) in the exposed areas of the resist film. The solubility of component (A) in the developer changes due to the action of this acid, while the solubility of component (A) in the developer does not change in the unexposed areas of the resist film. As a result, a difference in solubility in the developer occurs between the exposed and unexposed areas. Therefore, when the resist film is developed, if the resist composition is positive type, the exposed areas of the resist film are dissolved and removed to form a positive type resist pattern, and if the resist composition is negative type, the unexposed areas of the resist film are dissolved and removed to form a negative type resist pattern.

[0023] In this specification, a resist composition in which the exposed portion of the resist film is dissolved and removed to form a positive-type resist pattern is referred to as a positive-type resist composition, and a resist composition in which the unexposed portion of the resist film is dissolved and removed to form a negative-type resist pattern is referred to as a negative-type resist composition. The resist composition of this embodiment may be a positive-type resist composition or a negative-type resist composition. Furthermore, the resist composition of this embodiment may be for an alkaline development process using an alkaline developer in the development process during resist pattern formation, or for a solvent development process using a developer containing an organic solvent (organic developer) in the development process.

[0024] <(A) component> In the resist composition of this embodiment, component (A) is a base component whose solubility in the developer solution changes due to the action of an acid. Component (A) preferably contains a resin component (A1) (hereinafter also referred to as "component (A1)") whose solubility in the developer changes due to the action of an acid. By using component (A1), the polarity of the substrate component changes before and after exposure, so that good development contrast can be obtained not only in the alkaline development process but also in the solvent development process. (A) The component used is at least component (A1), and other high-molecular-weight compounds and / or low-molecular-weight compounds may be used in combination with component (A1).

[0025] When an alkaline development process is applied, the substrate component containing component (A1) is poorly soluble in the alkaline developer before exposure. When acid is generated from component (B) upon exposure, the polarity increases due to the action of the acid, and the solubility in the alkaline developer increases. Therefore, when a resist film obtained by coating the resist composition onto a support is selectively exposed during the formation of a resist pattern, the exposed parts of the resist film change from poorly soluble to soluble in the alkaline developer, while the unexposed parts of the resist film remain poorly soluble in the alkali. Thus, a positive-type resist pattern is formed by alkaline development.

[0026] On the other hand, when a solvent development process is applied, the substrate component containing component (A1) is highly soluble in organic developer before exposure. When acid is generated from component (B) upon exposure, the polarity increases due to the action of the acid, and the solubility in organic developer decreases. Therefore, when selectively exposing the resist film obtained by coating the resist composition onto a support during the formation of a resist pattern, the exposed parts of the resist film change from soluble to poorly soluble in organic developer, while the unexposed parts of the resist film remain soluble. Thus, by developing with an organic developer, a contrast can be created between the exposed and unexposed parts, and a negative-type resist pattern is formed.

[0027] In the resist composition of this embodiment, component (A) may be used alone or in combination of two or more types.

[0028] ·Regarding the component (A1) The component (A1) is a resin component whose solubility in a developing solution changes by the action of an acid. As the component (A1), those having a constitutional unit (a1) containing an acid-decomposable group whose polarity increases by the action of an acid are preferable. The component (A1) may have other constitutional units in addition to the constitutional unit (a1), if necessary.

[0029] ≪Constitutional unit (a1)≫ The constitutional unit (a1) is a constitutional unit containing an acid-decomposable group whose polarity increases by the action of an acid.

[0030] Examples of the acid-dissociable group include those proposed as the acid-dissociable group of the base resin for chemically amplified resist compositions. Specific examples of those proposed as the acid-dissociable group of the base resin for chemically amplified resist compositions include the "acetal-type acid-dissociable group", "tertiary alkyl ester-type acid-dissociable group", and "tertiary alkyloxycarbonyl acid-dissociable group" described below.

[0031] Acetal-type acid-dissociable group: Examples of the acid-dissociable group that protects a carboxy group or a hydroxy group among the polar groups include, for example, an acid-dissociable group represented by the following general formula (a1-r-1) (hereinafter sometimes referred to as "acetal-type acid-dissociable group").

[0032]

Chemical formula

[0033] In formula (a1-r-1), Ra’ 1 and Ra’2 Preferably, at least one of them is a hydrogen atom, and more preferably, both are hydrogen atoms. Ra' 1 Or Ra' 2 If the alkyl group is an alkyl group having 1 to 5 carbon atoms, then an alkyl group having 1 to 5 carbon atoms is preferred. Specifically, linear or branched alkyl groups are preferred. More specifically, examples include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, etc., with methyl or ethyl groups being more preferred, and methyl groups being particularly preferred.

[0034] In formula (a1-r-1), Ra' 3 Examples of hydrocarbon groups include linear or branched alkyl groups, or cyclic hydrocarbon groups. The linear alkyl group preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and even more preferably 1 or 2 carbon atoms. Specifically, examples include methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, etc. Among these, methyl group, ethyl group, or n-butyl group is preferred, and methyl group or ethyl group is more preferred.

[0035] The branched alkyl group preferably has 3 to 10 carbon atoms, and more preferably 3 to 5 carbon atoms. Specifically, examples include isopropyl group, isobutyl group, tert-butyl group, isopentyl group, neopentyl group, 1,1-diethylpropyl group, 2,2-dimethylbutyl group, etc., with isopropyl group being preferred.

[0036] Ra' 3 When the hydrocarbon group is a cyclic hydrocarbon group, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic group or a monocyclic group. As a monocyclic aliphatic hydrocarbon group, a group obtained by removing one hydrogen atom from a monocycloalkane is preferred. The monocycloalkane is preferably one having 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane. The polycyclic aliphatic hydrocarbon group is preferably a polycycloalkane from which one hydrogen atom has been removed, and the polycycloalkane is preferably one having 7 to 12 carbon atoms, specifically including adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, and the like.

[0037] Ra' 3 When the cyclic hydrocarbon group becomes an aromatic hydrocarbon group, the aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring. This aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20, even more preferably 6 to 15, and particularly preferably 6 to 12. Examples of aromatic rings include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are replaced by heteroatoms. Examples of heteroatoms in aromatic heterocycles include oxygen atoms, sulfur atoms, and nitrogen atoms. Examples of aromatic heterocycles include pyridine rings and thiophene rings. Ra' 3 Specific examples of aromatic hydrocarbon groups in this context include: a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocycle (aryl group or heteroaryl group); a group obtained by removing one hydrogen atom from an aromatic compound containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); and a group in which one of the hydrogen atoms of the aromatic hydrocarbon ring or aromatic heterocycle is substituted with an alkylene group (e.g., 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 bonded to the aromatic hydrocarbon ring or aromatic heterocycle is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0038] Ra' 3The cyclic hydrocarbon group in may have substituents. Examples of substituents include -R P1 ,-R P2 -OR P1 ,-R P2 -CO-R P1 ,-R P2 -CO-OR P1 ,-R P2 -O-CO-R P1 ,-R P2 -OH, -R P2 -CN or -R P2 -COOH (These substituents are collectively referred to as "Ra" below) x5 It is also called "[...]." Examples include [...]. Here, R P1 This is a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, a monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms. Also, R P2 R is a single bond, a divalent chain saturated hydrocarbon group having 1 to 10 carbon atoms, a divalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms. However, R P1 and R P2 Some or all of the hydrogen atoms in the chain-like saturated hydrocarbon group, aliphatic cyclic saturated hydrocarbon group, and aromatic hydrocarbon group may be substituted with fluorine atoms. The aliphatic cyclic hydrocarbon group may have one or more of the substituents individually, or it may have one or more of each of the substituents. Examples of monovalent, chain-like saturated hydrocarbon groups having 1 to 10 carbon atoms include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, and decyl groups. Examples of monovalent aliphatic cyclic saturated hydrocarbon groups having 3 to 20 carbon atoms include monocyclic aliphatic saturated hydrocarbon groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclodecyl, and cyclododecyl groups; and polycyclic aliphatic saturated hydrocarbon groups such as bicyclo[2.2.2]octanyl, tricyclo[5.2.1.02,6]decanyl, tricyclo[3.3.1.13,7]decanyl, tetracyclo[6.2.1.13,6.02,7]dodecanyl, and adamantyl groups. Examples of monovalent aromatic hydrocarbon groups having 6 to 30 carbon atoms include groups obtained by removing one hydrogen atom from an aromatic hydrocarbon ring, such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene.

[0039] Ra' 3 However, Ra' 1 , Ra' 2 When the cyclic group is bonded to any of the above to form a ring, the cyclic group is preferably a 4- to 7-membered ring, and more preferably a 4- to 6-membered ring. Specific examples of the cyclic group include a tetrahydropyranyl group and a tetrahydrofuranyl group.

[0040] Tertiary alkyl ester type acid-dissociating group: Among the polar groups mentioned above, an example of an acid-dissociating group that protects a carboxyl group is the acid-dissociating group represented by the following general formula (a1-r-2). Furthermore, among the acid-dissociable groups represented by the following formula (a1-r-2), those composed of alkyl groups may, for convenience, be referred to below as "tertiary alkyl ester type acid-dissociable groups."

[0041] [ka] [In the formula, Ra' 4 ~Ra' 6 Each of these is a hydrocarbon group, Ra' 5 , Ra' 6 They may be joined to each other to form a ring.

[0042] Ra'4 Examples of hydrocarbon groups include linear or branched alkyl groups, linear or cyclic alkenyl groups, or cyclic hydrocarbon groups. Ra' 4 In the above, linear or branched alkyl groups, cyclic hydrocarbon groups (monocyclic aliphatic hydrocarbon groups, polycyclic aliphatic hydrocarbon groups, aromatic hydrocarbon groups) are defined as Ra' 3 Similar examples include the above. Ra' 4 The linear or cyclic alkenyl group in this is preferably an alkenyl group having 2 to 10 carbon atoms. Ra' 5 , Ra' 6 The hydrocarbon group is the aforementioned Ra' 3 Similar examples include the above.

[0043] Ra' 5 and Ra' 6 When these groups bond to each other to form a ring, the following groups are preferred: the group represented by the general formula (a1-r2-1), the group represented by the general formula (a1-r2-2), and the group represented by the general formula (a1-r2-3). Meanwhile, Ra' 4 ~Ra' 6 When these are independent hydrocarbon groups that are not bonded to each other, the groups represented by the following general formula (a1-r2-4) are preferred.

[0044] [ka] [In formula (a1-r2-1), Ra' 10 This represents a linear or branched alkyl group having 1 to 12 carbon atoms, which may be partially substituted with halogen atoms or heteroatom-containing groups. 11 Ra' 10 This indicates a group that forms an aliphatic cyclic group with a bonded carbon atom. In formula (a1-r2-2), Ya is a carbon atom. Xa is a group that forms a cyclic hydrocarbon group with Ya. Some or all of the hydrogen atoms in this cyclic hydrocarbon group may be substituted. 101 ~Ra 103Each of these is independently a hydrogen atom, a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, or a monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms. Some or all of the hydrogen atoms in these linear saturated hydrocarbon groups and aliphatic cyclic saturated hydrocarbon groups may be substituted. 101 ~Ra 103 Two or more of these may be bonded to each other to form a cyclic structure. In formula (a1-r2-3), Yaa is a carbon atom. Xaa is a group that forms an aliphatic cyclic group together with Yaa. Ra 104 is an aromatic hydrocarbon group which may have substituents. In formula (a1-r2-4), Ra' 12 and Ra' 13 Each of these is independently a monovalent, chain-like saturated hydrocarbon group having 1 to 10 carbon atoms, or a hydrogen atom. Some or all of the hydrogen atoms in this chain-like saturated hydrocarbon group may be substituted. 14 This is a hydrocarbon group that may have substituents. * indicates a bond.

[0045] In the above equation (a1-r2-1), Ra' 10 This is a linear or branched alkyl group having 1 to 12 carbon atoms, which may be partially substituted with halogen atoms or heteroatom-containing groups.

[0046] Ra' 10 In this context, the linear alkyl group has 1 to 12 carbon atoms, preferably 1 to 10 carbon atoms, and particularly preferably 1 to 5 carbon atoms. Ra' 10 In this, the branched alkyl group is the Ra' 3 Similar examples include the above.

[0047] Ra' 10 In this case, the alkyl group may be partially substituted with a halogen atom or a heteroatom-containing group. For example, some of the hydrogen atoms constituting the alkyl group may be substituted with a halogen atom or a heteroatom-containing group. Also, some of the carbon atoms constituting the alkyl group (such as a methylene group) may be substituted with a heteroatom-containing group. Examples of heteroatoms used here include oxygen atoms, sulfur atoms, and nitrogen atoms. Examples of heteroatom-containing groups include (-O-), -C(=O)-O-, -OC(=O)-, -C(=O)-, -OC(=O)-O-, -C(=O)-NH-, -NH-, -S-, -S(=O)2-, -S(=O)2-O-, etc.

[0048] In formula (a1-r2-1), Ra' 11 (Ra' 10 The aliphatic cyclic group formed with the bonded carbon atom is Ra' in formula (a1-r-1). 3 The aliphatic hydrocarbon groups (alicyclic hydrocarbon groups) listed above, which are monocyclic or polycyclic groups, are preferred. Among these, monocyclic alicyclic hydrocarbon groups are preferred, and specifically, cyclopentyl groups and cyclohexyl groups are more preferred, with cyclopentyl groups being even more preferred.

[0049] In formula (a1-r2-2), the cyclic hydrocarbon group formed by Xa together with Ya is Ra' in formula (a1-r-1). 3 Examples include groups obtained by further removing one or more hydrogen atoms from a cyclic monovalent hydrocarbon group (aliphatic hydrocarbon group). The cyclic hydrocarbon group formed by Xa and Ya may have substituents. Examples of such substituents include the above-mentioned Ra' 3 Examples include substituents similar to those that may be present on the cyclic hydrocarbon group in the above. In formula (a1-r2-2), Ra 101 ~Ra 103 Examples of monovalent chain-like saturated hydrocarbon groups having 1 to 10 carbon atoms include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, and decyl groups. Ra 101 ~Ra 103Examples of the monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms include monocyclic aliphatic saturated hydrocarbon groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclodecyl group, cyclododecyl group; polycyclic aliphatic saturated hydrocarbon groups such as bicyclo[2.2.2]octanyl group, tricyclo[5.2.1.02,6]decanyl group, tricyclo[3.3.1.13,7]decanyl group, tetracyclo[6.2.1.13,6.02,7]dodecanyl group, adamantyl group, and the like. Ra 101 ~Ra 103 Among them, from the viewpoint of ease of synthesis, a hydrogen atom or a monovalent chain-like saturated hydrocarbon group having 1 to 10 carbon atoms is preferable, and among them, a hydrogen atom, a methyl group, and an ethyl group are more preferable, and a hydrogen atom is particularly preferable.

[0050] The above Ra 101 ~Ra 103 Examples of the substituent of the chain-like saturated hydrocarbon group or the aliphatic cyclic saturated hydrocarbon group represented by are the same groups as those of the above Ra x5 and the like.

[0051] Ra 101 ~Ra 103 Examples of the group containing a carbon-carbon double bond formed by two or more of Ra~Ra bonding to each other to form a cyclic structure include cyclopentenyl group, cyclohexenyl group, methylcyclopentenyl group, methylcyclohexenyl group, cyclopentylideneethenyl group, cyclohexylideneethenyl group, and the like. Among them, from the viewpoint of ease of synthesis, cyclopentenyl group, cyclohexenyl group, and cyclopentylideneethenyl group are preferable.

[0052] In formula (a1-r2-3), the aliphatic cyclic group formed by Xaa together with Yaa is preferably a group cited as the aliphatic hydrocarbon group which is a monocyclic group or a polycyclic group of Ra' in formula (a1-r-1). 3 and the like. In formula (a1-r2-3), Ra 104Examples of the aromatic hydrocarbon group in [the compound] include a group obtained by removing one or more hydrogen atoms from an aromatic hydrocarbon ring having 5 to 30 carbon atoms. Among them, Ra 104 is preferably a group obtained by removing one or more hydrogen atoms from an aromatic hydrocarbon ring having 6 to 15 carbon atoms, more preferably a group obtained by removing one or more hydrogen atoms from benzene, naphthalene, anthracene or phenanthrene, even more preferably a group obtained by removing one or more hydrogen atoms from benzene, naphthalene or anthracene, particularly preferably a group obtained by removing one or more hydrogen atoms from benzene, and most preferably a group obtained by removing one or more hydrogen atoms from benzene.

[0053] Examples of the substituent that Ra 104 in formula (a1-r2-3) may have include, for example, a methyl group, an ethyl group, a propyl group, a hydroxyl group, a carboxyl group, a halogen atom, an alkoxy group (such as a methoxy group, an ethoxy group, a propoxy group, a butoxy group, etc.), an alkyloxycarbonyl group, and the like.

[0054] In formula (a1-r2-4), Ra’ 12 and Ra’ 13 are each independently a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms or a hydrogen atom. Examples of the monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms in Ra’ 12 and Ra’ 13 are the same as those of the monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms in Ra 101 ~Ra 103 above. Some or all of the hydrogen atoms of this linear saturated hydrocarbon group may be substituted. Ra’ 12 and Ra’ 13 are preferably a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, more preferably an alkyl group having 1 to 5 carbon atoms, even more preferably a methyl group or an ethyl group, and particularly preferably a methyl group. When the linear saturated hydrocarbon group represented by the above Ra’ 12 and Ra’ 13 is substituted, examples of the substituent include the same groups as those of Ra x5 described above.

[0055] In formula (a1-r2-4), Ra' 14 Ra' is a hydrocarbon group that may have substituents. 14 Examples of hydrocarbon groups in this context include linear or branched alkyl groups, or cyclic hydrocarbon groups.

[0056] Ra' 14 The linear alkyl group in this compound preferably has 1 to 5 carbon atoms, more preferably 1 to 4, and even more preferably 1 or 2 carbon atoms. Specifically, examples include methyl, ethyl, n-propyl, n-butyl, and n-pentyl groups. Among these, methyl, ethyl, or n-butyl groups are preferred, and methyl or ethyl groups are more preferred.

[0057] Ra' 14 The branched alkyl group in the compound preferably has 3 to 10 carbon atoms, and more preferably 3 to 5 carbon atoms. Specifically, examples include isopropyl group, isobutyl group, tert-butyl group, isopentyl group, neopentyl group, 1,1-diethylpropyl group, 2,2-dimethylbutyl group, etc., with isopropyl group being preferred.

[0058] Ra' 14 When the hydrocarbon group is a cyclic hydrocarbon group, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic group or a monocyclic group. As a monocyclic aliphatic hydrocarbon group, a group obtained by removing one hydrogen atom from a monocycloalkane is preferred. The monocycloalkane is preferably one having 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane. The polycyclic aliphatic hydrocarbon group is preferably a polycycloalkane from which one hydrogen atom has been removed, and the polycycloalkane is preferably one having 7 to 12 carbon atoms, specifically including adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, and the like.

[0059] Ra' 14As for aromatic hydrocarbon groups in this context, Ra 104 Examples include those similar to aromatic hydrocarbon groups in [the text]. Among them, Ra' 14 The group is preferably an aromatic hydrocarbon ring having 6 to 15 carbon atoms from which one or more hydrogen atoms have been removed; more preferably a group from which one or more hydrogen atoms have been removed from benzene, naphthalene, anthracene, or phenanthrene; even more preferably a group from which one or more hydrogen atoms have been removed from benzene, naphthalene, or anthracene; particularly preferably a group from which one or more hydrogen atoms have been removed from naphthalene or anthracene; and most preferably a group from which one or more hydrogen atoms have been removed from naphthalene. Ra' 14 A substituent that may be present is Ra 104 Examples of substituents that may be present include those similar to those that the molecule may have.

[0060] Ra' in equation (a1-r2-4) 14 If is a naphthyl group, the position where it bonds with the tertiary carbon atom in formula (a1-r2-4) may be either position 1 or position 2 of the naphthyl group. Ra' in equation (a1-r2-4) 14 If is an anthyl group, the position where it bonds with the tertiary carbon atom in formula (a1-r2-4) may be position 1, 2, or 9 of the anthyl group.

[0061] Specific examples of the group represented by the above formula (a1-r2-1) are given below.

[0062] [ka]

[0063] [ka]

[0064] [ka]

[0065] Specific examples of the group represented by the formula (a1-r2-2) are listed below.

[0066] [Chemical formula]

[0067] [Chemical formula]

[0068] [Chemical formula]

[0069] Specific examples of the group represented by the formula (a1-r2-3) are listed below.

[0070] [Chemical formula]

[0071] Specific examples of the group represented by the formula (a1-r2-4) are listed below.

[0072] [Chemical formula]

[0073] Tertiary alkyloxycarbonyl acid dissociable group: Among the above polar groups, examples of the acid dissociable group for protecting a hydroxyl group include an acid dissociable group represented by the following general formula (a1-r-3) (hereinafter sometimes referred to as "tertiary alkyloxycarbonyl acid dissociable group" for convenience).

[0074] [Chemical formula] [In the formula, Ra’ 7 ~Ra’ 9 are each an alkyl group. ]

[0075] In formula (a1-r-3), Ra' 7 ~Ra' 9 Each of these is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably an alkyl group having 1 to 3 carbon atoms. Furthermore, the total number of carbon atoms in each alkyl group is preferably 3 to 7, more preferably 3 to 5, and most preferably 3 to 4.

[0076] Examples of constituent units (a1) include constituent units derived from acrylic acid esters in which the hydrogen atom bonded to the α-carbon atom may be substituted with a substituent, constituent units derived from acrylamide, constituent units derived from hydroxystyrene or hydroxystyrene derivatives in which at least a portion of the hydrogen atoms in the hydroxyl group of a constituent unit are protected by a substituent containing the acid-degradable group, and constituent units derived from vinyl benzoic acid or vinyl benzoic acid derivatives in which at least a portion of the hydrogen atoms in the -C(=O)-OH group are protected by a substituent containing the acid-degradable group.

[0077] As for the constituent unit (a1), among the above, a constituent unit derived from an acrylic acid ester in which the hydrogen atom bonded to the α-carbon atom may be substituted with a substituent is preferred. A preferred specific example of such a constituent unit (a1) is a constituent unit represented by the following general formula (a1-1) or (a1-2).

[0078] [ka] [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. Va 1 n is a divalent hydrocarbon group which may have an ether bond. a1 is an integer between 0 and 2. 1 This is an acid-dissociable group represented by the general formula (a1-r-1) or (a1-r-2) above. 1 is n a2 It is a +1 valent hydrocarbon group, n a2 is an integer between 1 and 3, and Ra2 is an acid dissociable group represented by the above general formula (a1-r-1) or (a1-r-3).

[0079] In the formula (a1-1), the alkyl group having 1 to 5 carbon atoms for R is preferably a linear or branched alkyl group having 1 to 5 carbon atoms. Specifically, 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 the like. The halogenated alkyl group having 1 to 5 carbon atoms is a group in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are substituted with halogen atoms. As the halogen atom, a fluorine atom is particularly preferable. R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms. From the viewpoint of easy availability in industry, a hydrogen atom or a methyl group is most preferable.

[0080] In the formula (a1-1), Va 1 The divalent hydrocarbon group in is may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0081] Va 1 The aliphatic hydrocarbon group as the divalent hydrocarbon group in is may be saturated or unsaturated, and is usually preferably saturated. More specifically, examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, or an aliphatic hydrocarbon group containing a ring in its structure.

[0082] The linear aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable. Specifically, examples include a methylene group [-CH2-], an ethylene group [-(CH2)2-], a trimethylene group [-(CH2)3-], a tetramethylene group [-(CH2)4-], a pentamethylene group [-(CH2)5-], and the like. The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, even more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms. Preferred branched aliphatic hydrocarbon groups include branched alkylene groups, specifically 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-; alkyltrimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; and alkylalkylene groups such as alkyltetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-. In the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferred.

[0083] Examples of aliphatic hydrocarbon groups containing a ring in the aforementioned structure include alicyclic hydrocarbon groups (groups obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring), groups in which an alicyclic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and groups in which an alicyclic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group include those similar to the linear or branched aliphatic hydrocarbon group described above. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably has 3 to 12 carbon atoms. The alicyclic hydrocarbon group may be polycyclic or monocyclic. A preferred monocyclic alicyclic hydrocarbon group is a monocycloalkane from which two hydrogen atoms have been removed. The monocycloalkane is preferably one having 3 to 6 carbon atoms, specifically cyclopentane, cyclohexane, etc. A preferred polycyclic alicyclic hydrocarbon group is a polycycloalkane from which two hydrogen atoms have been removed, and the polycycloalkane is preferably one having 7 to 12 carbon atoms, specifically adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc.

[0084] Va 1 In this context, an aromatic hydrocarbon group as a divalent hydrocarbon group is a hydrocarbon group having an aromatic ring. The aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30, even more preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 12. However, this number of carbon atoms does not include the number of carbon atoms in substituents. Specific examples of aromatic rings in aromatic hydrocarbon groups include aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are replaced by heteroatoms. Examples of heteroatoms in aromatic heterocycles include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of the aromatic hydrocarbon group include a group obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring (arylene group); and a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring (aryl group) in which one hydrogen atom is replaced by an alkylene group (for example, a group obtained by removing one more hydrogen atom from the aryl group in an arylalkyl group such as a 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.

[0085] In the above formula (a1-1), Ra 1 This is an acid-dissociable group represented by the above formula (a1-r-1) or (a1-r-2).

[0086] In the above formula (a1-2), Wa 1 n in a2 The +1 valent hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group means a hydrocarbon group that does not have aromaticity, and may be saturated or unsaturated, but is usually preferred to be saturated. Examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group containing a ring in its structure, or a group that is a combination of a linear or branched aliphatic hydrocarbon group and an aliphatic hydrocarbon group containing a ring in its structure. The aforementioned n a2 The +1 valent is preferably 2 to 4 valent, and more preferably 2 or 3 valent.

[0087] In the above formula (a1-2), Ra 2 This is an acid-dissociable group represented by the general formula (a1-r-1) or (a1-r-3) above.

[0088] The following are specific examples of the constituent units represented by the above formula (a1-1). In each of the following formulas, R α This represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0089] [ka]

[0090] [ka]

[0091] [ka]

[0092] [ka]

[0093] [ka]

[0094] [ka]

[0095] [ka]

[0096] [ka]

[0097] The constituent units (a1) of component (A1) may be one type or two or more types. As for the constituent unit (a1), the constituent unit represented by formula (a1-1) is more preferable because it is easier to improve the characteristics (sensitivity, shape, etc.) in electron beam or EUV lithography. Among these, the constituent unit (a1) is particularly preferred if it includes a constituent unit represented by the following general formula (a1-1-1).

[0098] [ka] [In the formula, Ra 1 " is an acid-dissociable group represented by the general formula (a1-r2-1), (a1-r2-2), or (a1-r2-3).

[0099] In the above formula (a1-1-1), R, Va 1 and n a1 R, Va in the above formula (a1-1) 1 and n a1 It is similar to that. The explanation of the acid-dissociable groups represented by the general formulas (a1-r2-1), (a1-r2-2), or (a1-r2-3) is as described above. Ra 1 Among these, acid-dissociable groups represented by general formula (a1-r2-2) or general formula (a1-r2-3) are preferred because they can enhance reactivity for EB or EUV applications.

[0100] The proportion of constituent units (a1) in component (A1) is preferably 5 to 80 mol%, more preferably 10 to 75 mol%, even more preferably 30 to 70 mol%, and particularly preferably 40 to 60 mol%, relative to the total amount (100 mol%) of all constituent units that make up component (A1). By keeping the proportion of the constituent unit (a1) within the aforementioned preferred range, the efficiency of the deprotection reaction and the solubility of the developer can be appropriately ensured, making it easier to obtain the effects of the present invention.

[0101] <<Other constituent units>> Component (A1) may have other constituent units in addition to the constituent unit (a1) described above, as needed. Other constituent units include, for example, the constituent unit (a10) represented by the general formula (a10-1) described below; the constituent unit (a2) containing a lactone-containing cyclic group, a -SO2--containing cyclic group, or a carbonate-containing cyclic group; the constituent unit (a3) ​​containing a polar group-containing aliphatic hydrocarbon group; the constituent unit (a4) containing an acid-nondissociable aliphatic cyclic group; and the constituent unit (st) derived from styrene or styrene derivatives.

[0102] Regarding the constituent unit (a10): The constituent unit (a10) is a constituent unit represented by the following general formula (a10-1).

[0103] [ka] [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halogen having 1 to 5 carbon atoms. x1 Wa is a single bond or a divalent linking group. x1n is an aromatic hydrocarbon group which may have substituents. ax1 [ is an integer greater than or equal to 1.]

[0104] In the above formula (a10-1), R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halogen having 1 to 5 carbon atoms. The C1-C5 alkyl group in R is preferably a linear or branched alkyl group having C1-C5, specifically including methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, and neopentyl groups. The C1-C5 alkyl halide in R is a group in which some or all of the hydrogen atoms of the C1-C5 alkyl group are substituted with halogen atoms. Fluorine atoms are particularly preferred as the halogen atoms. For R, a hydrogen atom, a C1-C5 alkyl group, or a C1-C5 fluorinated alkyl group is preferred, and for ease of industrial availability, a hydrogen atom, a methyl group, or a trifluoromethyl group is more preferred, a hydrogen atom or a methyl group is even more preferred, and a methyl group is particularly preferred.

[0105] In the above formula (a10-1), Ya x1 It is a single bond or a divalent linking group. In the above chemical formula, Ya x1 The divalent linking group in this is not particularly limited, but suitable examples include divalent hydrocarbon groups which may have substituents, and divalent linking groups which contain heteroatoms.

[0106] • Divalent hydrocarbon groups which may have substituents: Ya x1 If is a divalent hydrocarbon group which may have substituents, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0107] ··Ya x1 Aliphatic hydrocarbon groups in An aliphatic hydrocarbon group refers to a hydrocarbon group that does not possess aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated, but is usually preferable to be saturated. Examples of the aliphatic hydrocarbon group include linear or branched aliphatic hydrocarbon groups, or aliphatic hydrocarbon groups containing a ring in their structure.

[0108] ...linear or branched aliphatic hydrocarbon groups The linear aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, even more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. As for the linear aliphatic hydrocarbon group, linear alkylene groups are preferred, specifically the methylene group [-CH2-], ethylene group [-(CH2)2-], trimethylene group [-(CH2)3-], tetramethylene group [-(CH2)4-], pentamethylene group [-(CH2)5-], etc. The branched aliphatic 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. Preferred branched aliphatic hydrocarbon groups include branched alkylene groups, specifically 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-; alkyltrimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; and alkylalkylene groups such as alkyltetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-. In the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferred.

[0109] The linear or branched aliphatic hydrocarbon group may or may not have substituents. Examples of substituents include fluorine atoms, fluorinated alkyl groups having 1 to 5 carbon atoms substituted with fluorine atoms, and carbonyl groups.

[0110] ...Aliphatic hydrocarbon groups containing a ring in their structure Examples of aliphatic hydrocarbon groups containing a ring in the structure include cyclic aliphatic hydrocarbon groups that may contain substituents containing heteroatoms in the ring structure (groups obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring), groups in which the cyclic aliphatic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and groups in which the cyclic aliphatic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group are the same as those described above. The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably has 3 to 12 carbon atoms. The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. A preferred monocyclic alicyclic hydrocarbon group is a group obtained by removing two hydrogen atoms from a monocycloalkane. The monocycloalkane is preferably one having 3 to 6 carbon atoms, specifically cyclopentane, cyclohexane, etc. A preferred polycyclic alicyclic hydrocarbon group is a group obtained by removing two hydrogen atoms from a polycycloalkane, and the polycycloalkane is preferably one having 7 to 12 carbon atoms, specifically adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc.

[0111] The cyclic aliphatic hydrocarbon group may or may not have substituents. Examples of substituents include alkyl groups, alkoxy groups, halogen atoms, alkyl halides, hydroxyl groups, and carbonyl groups. The alkyl group used as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. As the alkoxy group used as the substituent, an alkoxy group having 1 to 5 carbon atoms is preferred, a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, and a tert-butoxy group are more preferred, and a methoxy group and an ethoxy group are even more preferred. A fluorine atom is preferred as the halogen atom used as the substituent. Examples of halogenated alkyl groups as substituents include groups in which some or all of the hydrogen atoms of the alkyl group are substituted with halogen atoms. A cyclic aliphatic hydrocarbon group may have some of the carbon atoms constituting its ring structure replaced by substituents containing heteroatoms. Preferred substituents containing heteroatoms are -O-, -C(=O)-O-, -S-, -S(=O)2-, and -S(=O)2-O-.

[0112] ··Ya x1 Aromatic hydrocarbon groups in The aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring. The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20, even more preferably 6 to 15, and particularly preferably 6 to 12. However, this carbon number does not include the carbon atoms in substituents. Examples of aromatic rings include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are replaced by heteroatoms. Examples of heteroatoms in aromatic heterocycles include oxygen atoms, sulfur atoms, and nitrogen atoms. Examples of aromatic heterocycles include pyridine rings and thiophene rings. Specific examples of aromatic hydrocarbon groups include groups obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring or aromatic heterocycle (arylene group or heteroarylene group); groups obtained by removing two hydrogen atoms from aromatic compounds containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); and groups in which one hydrogen atom of an aryl group or heteroaryl group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocycle (aryl group or heteroaryl group) is substituted with an alkylene group (e.g., groups obtained by removing one more hydrogen atom from an aryl group in an arylalkyl group such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.). The number of carbon atoms in the alkylene group bonded to the aryl group or heteroaryl group is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0113] The aromatic hydrocarbon group may have its hydrogen atoms substituted with substituents. For example, the hydrogen atoms bonded to the aromatic ring in the aromatic hydrocarbon group may be substituted with substituents. Examples of such substituents include alkyl groups, alkoxy groups, halogen atoms, alkyl halides, hydroxyl groups, and the like. The alkyl group used as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. Examples of the substituents include alkoxy groups, halogen atoms, and alkyl halides that substitute for hydrogen atoms on the cyclic aliphatic hydrocarbon group.

[0114] • Divalent linking groups containing heteroatoms: Ya x1When is a divalent linking group containing a heteroatom, preferred linking groups include -O-, -C(=O)-O-, -OC(=O)-, -C(=O)-, -OC(=O)-O-, -C(=O)-NH-, -NH-, -NH-C(=NH)- (H may be substituted with substituents such as alkyl groups or acyl groups), -S-, -S(=O)2-, -S(=O)2-O-, and the general formula -Y 21 -OY 22 -, -Y 21 -O-, -Y 21 -C(=O)-O-, -C(=O)-OY 21 -,-[Y 21 -C(=O)-O] m” -Y 22 -, -Y 21 -OC(=O)-Y 22 - or -Y 21 -S(=O)2-OY 22 - is represented by the base [wherein Y 21 and Y 22 Each of these is a divalent hydrocarbon group which may have substituents independently, O is an oxygen atom, and m'' is an integer from 0 to 3. When the divalent linking group containing the heteroatom is -C(=O)-NH-, -C(=O)-NH-C(=O)-, -NH-, or -NH-C(=NH)-, the H may be substituted with substituents such as alkyl groups or acyl groups. The substituent (alkyl group, acyl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8, and particularly preferably 1 to 5 carbon atoms. General formula-Y 21 -OY 22 -, -Y 21 -O-, -Y 21 -C(=O)-O-, -C(=O)-OY 21 -,-[Y 21 -C(=O)-O] m” -Y 22 -, -Y 21 -OC(=O)-Y 22 - or -Y 21 -S(=O)2-OY 22 - Middle, Y 21 and Y 22Each of these is independently a divalent hydrocarbon group which may have substituents. The divalent hydrocarbon group is the aforementioned Ya x1 Examples include those similar to the divalent linking groups (divalent hydrocarbon groups that may have substituents) mentioned in the description of divalent linking groups in [the relevant section]. Y 21 Preferably, the group is a linear aliphatic hydrocarbon group, more preferably a linear alkylene group, even more preferably a linear alkylene group having 1 to 5 carbon atoms, and particularly preferably a methylene group or an ethylene group. Y 22 The group is preferably a linear or branched aliphatic hydrocarbon group, more preferably a methylene group, an ethylene group, or an alkylmethylene group. The alkyl group in the alkylmethylene group is preferably a linear alkyl group having 1 to 5 carbon atoms, more preferably a linear alkyl group having 1 to 3 carbon atoms, and most preferably a methyl group. Formula - [Y 21 -C(=O)-O] m” -Y 22 In the base represented by -, m'' is an integer between 0 and 3, preferably between 0 and 2, more preferably 0 or 1, and particularly preferably 1. That is, in the formula -[Y 21 -C(=O)-O] m” -Y 22 As a base represented by -, formula -Y 21 -C(=O)-OY 22 Groups represented by - are particularly preferred. Among them, the group represented by formula -(CH2) a’ -C(=O)-O-(CH2) b’ A base represented by - is preferred. In the formula, a' is an integer from 1 to 10, preferably an integer from 1 to 8, more preferably an integer from 1 to 5, even more preferably 1 or 2, and most preferably 1. b' is an integer from 1 to 10, preferably an integer from 1 to 8, more preferably an integer from 1 to 5, even more preferably 1 or 2, and most preferably 1.

[0115] Among the above, Ya x1Preferably, the group is a single bond, an ester bond [-C(=O)-O-, -OC(=O)-], an ether bond (-O-), a linear or branched alkylene group, or a combination thereof, with single bonds and ester bonds [-C(=O)-O-, -OC(=O)-] being more preferred.

[0116] In the above formula (a10-1), Wa x1 This is an aromatic hydrocarbon group which may have substituents. Wa x1 The aromatic hydrocarbon group in this context may be an aromatic ring that may have substituents (n ax1 Examples include groups with 1+1 hydrogen atoms removed. The aromatic ring here is not particularly limited as long as it is a cyclic conjugated system with 4n+2 π electrons, and may be monocyclic or polycyclic. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20, even more preferably 6 to 15, and particularly preferably 6 to 12. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are replaced by heteroatoms. Examples of heteroatoms in aromatic heterocycles include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of aromatic heterocycles include pyridine rings and thiophene rings. Also, Wa x1 The aromatic hydrocarbon group in this context is an aromatic compound containing an aromatic ring which may have two or more substituents (e.g., biphenyl, fluorene, etc.) (n ax1 Another example is a group with (+1) hydrogen atoms removed. Among the above, Wa x1 Examples include benzene, naphthalene, anthracene, or biphenyl (n ax1 A group with (+1) hydrogen atoms removed is preferred, and (n ax1 A group with (+1) hydrogen atoms removed is more preferable, and from benzene (n ax1 A group with (+1) hydrogen atoms removed is even more preferable.

[0117] Wa x1The aromatic hydrocarbon group in may or may not have substituents. Examples of substituents include alkyl groups, alkoxy groups, halogen atoms, and alkyl halides. Examples of alkyl groups, alkoxy groups, halogen atoms, and alkyl halides as substituents include Ya x1 Examples of substituents for cyclic aliphatic hydrocarbon groups in are similar to those listed above. The substituents are preferably linear or branched alkyl groups having 1 to 5 carbon atoms, more preferably linear or branched alkyl groups having 1 to 3 carbon atoms, even more preferably ethyl or methyl groups, and particularly preferably methyl groups. x1 In this context, it is preferable that the aromatic hydrocarbon group does not have substituents.

[0118] In the above formula (a10-1), n ax1 is an integer greater than or equal to 1, preferably an integer between 1 and 10, more preferably an integer between 1 and 5, even more preferably 1, 2, or 3, and particularly preferably 1 or 2.

[0119] The following are specific examples of the constituent unit (a10) represented by the above formula (a10-1). In each of the following equations, R α This represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0120] [ka]

[0121] [ka]

[0122] [ka]

[0123] [ka]

[0124] The constituent units (a10) of component (A1) may be one type or two or more types. If component (A1) has constituent units (a10), the proportion of constituent units (a10) in component (A1) is preferably 5 to 80 mol%, more preferably 10 to 75 mol%, even more preferably 30 to 70 mol%, and particularly preferably 40 to 60 mol%, relative to the total amount (100 mol%) of all constituent units that make up component (A1). By setting the proportion of the constituent unit (a10) within the aforementioned preferred range, the efficiency of supplying protons in the resist film is increased, and the solubility in the developer solution can be appropriately ensured, making it easier to obtain the effects of the present invention.

[0125] Regarding the constituent unit (a2): Component (A1) may also have a constituent unit (a2) containing a lactone-containing cyclic group, an -SO2-- containing cyclic group, or a carbonate-containing cyclic group, in addition to the constituent unit (a1) (excluding those corresponding to constituent unit (a1)). The lactone-containing cyclic group, -SO2--containing cyclic group, or carbonate-containing cyclic group of the constituent unit (a2) is effective in improving the adhesion of the resist film to the substrate when component (A1) is used to form a resist film. Furthermore, the presence of constituent unit (a2) improves lithography characteristics, for example, by appropriately adjusting the acid diffusion length, improving the adhesion of the resist film to the substrate, and appropriately adjusting the solubility during development.

[0126] A "lactone-containing cyclic group" refers to a cyclic group that contains a ring (lactone ring) containing -OC(=O)- within its cyclic skeleton. The lactone ring is counted as the first ring. If it consists only of a lactone ring, it is called a monocyclic group. If it also has other ring structures, it is called a polycyclic group regardless of those structures. A lactone-containing cyclic group may be a monocyclic group or a polycyclic group. Any lactone-containing cyclic group can be used in the constituent unit (a2) without any particular limitations. Specifically, examples include the groups represented by the following general formulas (a2-r-1) to (a2-r-7).

[0127] [ka] [In the formula, Ra' 21 Each of these is independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR'', -OC(=O)R'', a hydroxyalkyl group, or a cyano group; R'' is a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or a -SO2--containing cyclic group; A'' is a C1-C5 alkylene group which may contain an oxygen atom (-O-) or a sulfur atom (-S-), an oxygen atom, or a sulfur atom, where n' is an integer from 0 to 2 and m' is 0 or 1.

[0128] In the general formulas (a2-r-1) to (a2-r-7), Ra' 21 The alkyl group in is preferably an alkyl group having 1 to 6 carbon atoms. The alkyl group is preferably linear or branched. Specifically, examples include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, hexyl group, etc. Among these, the methyl group or ethyl group is preferred, and the methyl group is particularly preferred. Ra' 21 The alkoxy group in is preferably an alkoxy group having 1 to 6 carbon atoms. The alkoxy group is preferably linear or branched. Specifically, the Ra' 21 Examples of alkyl groups in this context include groups formed by linking an alkyl group with an oxygen atom (-O-). Ra' 21 In this mixture, a fluorine atom is preferred as the halogen atom. Ra' 21 The halogenated alkyl group in is the Ra' 21 Examples include groups in which some or all of the hydrogen atoms of the alkyl group are substituted with the halogen atoms. Fluorinated alkyl groups are preferred as the halogenated alkyl group, and perfluoroalkyl groups are particularly preferred.

[0129] Ra' 21 In -COOR'' and -OC(=O)R'', R'' is either a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or a -SO2--containing cyclic group. The alkyl group in R'' can be linear, branched, or cyclic, and preferably has 1 to 15 carbon atoms. When R'' is a linear or branched alkyl group, it is preferably 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and particularly preferably a methyl group or an ethyl group. When R'' is a cyclic alkyl group, it is preferably 3 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specifically, examples include groups obtained by removing one or more hydrogen atoms from monocycloalkanes which may or may not be substituted with a fluorine atom or a fluorinated alkyl group; and groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as bicycloalkanes, tricycloalkanes, and tetracycloalkanes. More specifically, examples include groups obtained by removing one or more hydrogen atoms from monocycloalkanes such as cyclopentane and cyclohexane; and groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Examples of lactone-containing cyclic groups in R'' include those similar to those represented by the general formulas (a2-r-1) to (a2-r-7) mentioned above. The carbonate-containing cyclic groups in R'' are the same as those described later, and specifically include the groups represented by the general formulas (ax3-r-1) to (ax3-r-3), respectively. The -SO2-containing cyclic groups in R'' are the same as those described later, and specifically include the groups represented by the general formulas (a5-r-1) to (a5-r-4), respectively. Ra' 21 The hydroxyalkyl group in is preferably one having 1 to 6 carbon atoms, specifically the Ra' 21Examples include groups in which at least one hydrogen atom of the alkyl group is substituted with a hydroxyl group.

[0130] In the general formulas (a2-r-2), (a2-r-3), and (a2-r-5) above, the alkylene group having 1 to 5 carbon atoms in A'' is preferably a linear or branched alkylene group, such as a methylene group, ethylene group, n-propylene group, or isopropylene group. When the alkylene group contains an oxygen atom or a sulfur atom, specific examples include a group in which -O- or -S- is interposed at the end or between carbon atoms of the alkylene group, such as O-CH2-, -CH2-O-CH2-, -S-CH2-, or -CH2-S-CH2-. As A'', an alkylene group having 1 to 5 carbon atoms or -O- is preferred, an alkylene group having 1 to 5 carbon atoms is more preferred, and a methylene group is most preferred.

[0131] The following are specific examples of the groups represented by the general formulas (a²-r-1) to (a²-r-7).

[0132] [ka]

[0133] [ka]

[0134] A "-SO2-containing cyclic group" refers to a cyclic group that contains a ring with -SO2- in its cyclic skeleton. Specifically, it is a cyclic group in which the sulfur atom (S) in -SO2- forms part of the cyclic skeleton. The ring containing -SO2- in its cyclic skeleton is counted as the first ring. If it consists only of this ring, it is called a monocyclic group. If it has other ring structures, it is called a polycyclic group regardless of those structures. A -SO2-containing cyclic group may be a monocyclic group or a polycyclic group. The -SO2--containing cyclic group is preferably a cyclic group that contains -O-SO2- in its cyclic skeleton, that is, a cyclic group that contains a sultone ring in which the -OS- in -O-SO2- forms part of the cyclic skeleton. More specifically, examples of -SO2- containing cyclic groups include the groups represented by the following general formulas (a5-r-1) to (a5-r-4).

[0135] [ka] [In the formula, Ra' 51 Each of these is independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR'', -OC(=O)R'', a hydroxyalkyl group, or a cyano group; R'' is a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or a -SO2--containing cyclic group; A'' is a C1-C5 alkylene group which may contain an oxygen atom or a sulfur atom, an oxygen atom, or a sulfur atom, and n' is an integer from 0 to 2.

[0136] In the general formulas (a5-r-1) to (a5-r-2) above, A'' is the same as A'' in the general formulas (a2-r-2), (a2-r-3), and (a2-r-5) above. Ra' 51 In this context, the alkyl group, alkoxy group, halogen atom, halogenated alkyl group, -COOR'', -OC(=O)R'', and hydroxyalkyl group are, respectively, Ra' in the general formulas (a2-r-1) to (a2-r-7). 21 The same things mentioned in the explanation about this topic can be cited. Specific examples of the groups represented by the general formulas (a5-r-1) to (a5-r-4) are given below. In the formulas, "Ac" indicates an acetyl group.

[0137] [ka]

[0138] [ka]

[0139] [ka]

[0140] A "carbonate-containing cyclic group" refers to a cyclic group that contains a ring (carbonate ring) containing -OC(=O)-O- within its cyclic framework. The carbonate ring is counted as the first ring. If it consists only of a carbonate ring, it is called a monocyclic group. If it also has other ring structures, it is called a polycyclic group regardless of those structures. A carbonate-containing cyclic group may be a monocyclic group or a polycyclic group. Any carbonate ring-containing cyclic group can be used without any particular limitations. Specifically, examples include the groups represented by the following general formulas (ax3-r-1) to (ax3-r-3).

[0141] [ka] [In the formula, Ra' x31 Each of the following is independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR'', -OC(=O)R'', a hydroxyalkyl group, or a cyano group; R'' is a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or a -SO2--containing cyclic group; A'' is a C1-C5 alkylene group which may contain an oxygen atom or a sulfur atom, an oxygen atom or a sulfur atom, p' is an integer from 0 to 3, and q' is 0 or 1.

[0142] In the above general formulas (ax3-r-2) to (ax3-r-3), A'' is the same as A'' in the above general formulas (a2-r-2), (a2-r-3), and (a2-r-5). Ra' 31 In this context, the alkyl group, alkoxy group, halogen atom, halogenated alkyl group, -COOR'', -OC(=O)R'', and hydroxyalkyl group are, respectively, Ra' in the general formulas (a2-r-1) to (a2-r-7).21 The same things mentioned in the explanation about this topic can be cited. The following are specific examples of groups represented by the general formulas (ax3-r-1) to (ax3-r-3).

[0143] [ka]

[0144] Among the constituent units (a2), those derived from acrylic acid esters in which the hydrogen atom bonded to the α-carbon atom may be substituted with a substituent are preferred. The constituent unit (a2) is preferably a constituent unit represented by the following general formula (a2-1).

[0145] [ka] [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halogen having 1 to 5 carbon atoms. 21 It is a single bond or a divalent linking group. 21 The R' is -O-, -COO-, -CON(R')-, -OCO-, -CONHCO-, or -CONHCS-, where R' represents a hydrogen atom or a methyl group. However, La 21 If -O-, Ya 21 It does not become -CO-. 21 This is a lactone-containing cyclic group, a carbonate-containing cyclic group, or a -SO2--containing cyclic group.

[0146] In formula (a2-1) above, R is the same as described above. R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, and a hydrogen atom or a methyl group is particularly preferred due to their industrial availability.

[0147] In the above formula (a2-1), Ya 21 The divalent linking group in this is not particularly limited, but preferred examples include divalent hydrocarbon groups which may have substituents, and divalent linking groups which contain heteroatoms.

[0148] • Divalent hydrocarbon groups which may have substituents: Ya 21 If is a divalent hydrocarbon group which may have substituents, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0149] ··Ya 21 Aliphatic hydrocarbon groups in An aliphatic hydrocarbon group refers to a hydrocarbon group that does not possess aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated, but is usually preferable to be saturated. Examples of the aliphatic hydrocarbon group include linear or branched aliphatic hydrocarbon groups, or aliphatic hydrocarbon groups containing a ring in their structure.

[0150] ...linear or branched aliphatic hydrocarbon groups The linear aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, even more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. As for the linear aliphatic hydrocarbon group, linear alkylene groups are preferred, specifically the methylene group [-CH2-], ethylene group [-(CH2)2-], trimethylene group [-(CH2)3-], tetramethylene group [-(CH2)4-], pentamethylene group [-(CH2)5-], etc. The branched aliphatic 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. Preferred branched aliphatic hydrocarbon groups include branched alkylene groups, specifically 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-; alkyltrimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; and alkylalkylene groups such as alkyltetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-. In the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferred.

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

[0152] ...Aliphatic hydrocarbon groups containing a ring in their structure Examples of aliphatic hydrocarbon groups containing a ring in the structure include cyclic aliphatic hydrocarbon groups that may contain substituents containing heteroatoms in the ring structure (groups obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring), groups in which the cyclic aliphatic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and groups in which the cyclic aliphatic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group are the same as those described above. The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably has 3 to 12 carbon atoms. The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. A preferred monocyclic alicyclic hydrocarbon group is a group obtained by removing two hydrogen atoms from a monocycloalkane. The monocycloalkane is preferably one having 3 to 6 carbon atoms, specifically cyclopentane, cyclohexane, etc. A preferred polycyclic alicyclic hydrocarbon group is a group obtained by removing two hydrogen atoms from a polycycloalkane, and the polycycloalkane is preferably one having 7 to 12 carbon atoms, specifically adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc.

[0153] The cyclic aliphatic hydrocarbon group may or may not have substituents. Examples of substituents include alkyl groups, alkoxy groups, halogen atoms, alkyl halides, hydroxyl groups, and carbonyl groups. The alkyl group used as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. As the alkoxy group used as the substituent, an alkoxy group having 1 to 5 carbon atoms is preferred, a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, and a tert-butoxy group are more preferred, and a methoxy group and an ethoxy group are even more preferred. A fluorine atom is preferred as the halogen atom used as the substituent. Examples of halogenated alkyl groups as substituents include groups in which some or all of the hydrogen atoms of the alkyl group are substituted with halogen atoms. A cyclic aliphatic hydrocarbon group may have some of the carbon atoms constituting its ring structure replaced by substituents containing heteroatoms. Preferred substituents containing heteroatoms are -O-, -C(=O)-O-, -S-, -S(=O)2-, and -S(=O)2-O-.

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

[0155] The aromatic hydrocarbon group may have its hydrogen atoms substituted with substituents. For example, the hydrogen atoms bonded to the aromatic ring in the aromatic hydrocarbon group may be substituted with substituents. Examples of such substituents include alkyl groups, alkoxy groups, halogen atoms, alkyl halides, hydroxyl groups, and the like. The alkyl group used as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. Examples of the substituents include alkoxy groups, halogen atoms, and alkyl halides that substitute for hydrogen atoms on the cyclic aliphatic hydrocarbon group.

[0156] • Divalent linking groups containing heteroatoms: Ya 21 When is a divalent linking group containing a heteroatom, preferred linking groups include -O-, -C(=O)-O-, -OC(=O)-, -C(=O)-, -OC(=O)-O-, -C(=O)-NH-, -NH-, -NH-C(=NH)- (H may be substituted with substituents such as alkyl groups or acyl groups), -S-, -S(=O)2-, -S(=O)2-O-, and the general formula -Y 21 -OY 22 -, -Y 21 -O-, -Y 21 -C(=O)-O-, -C(=O)-OY 21 -,-[Y 21 -C(=O)-O] m” -Y 22 -, -Y 21 -OC(=O)-Y 22 - or -Y 21 -S(=O)2-OY 22 - is represented by the base [wherein Y 21 and Y 22 Each of these is a divalent hydrocarbon group which may have substituents independently, O is an oxygen atom, and m'' is an integer from 0 to 3. When the divalent linking group containing the heteroatom is -C(=O)-NH-, -C(=O)-NH-C(=O)-, -NH-, or -NH-C(=NH)-, the H may be substituted with substituents such as alkyl groups or acyl groups. The substituent (alkyl group, acyl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8, and particularly preferably 1 to 5 carbon atoms. General formula-Y 21 -OY22 -, -Y 21 -O-, -Y 21 -C(=O)-O-, -C(=O)-OY 21 -,-[Y 21 -C(=O)-O] m” -Y 22 -, -Y 21 -OC(=O)-Y 22 - or -Y 21 -S(=O)2-OY 22 - Middle, Y 21 and Y 22 Each of these is independently a divalent hydrocarbon group which may have substituents. The divalent hydrocarbon group is the aforementioned Ya 21 Examples include those similar to the divalent linking groups (divalent hydrocarbon groups that may have substituents) mentioned in the description of divalent linking groups in [the relevant section]. Y 21 Preferably, the group is a linear aliphatic hydrocarbon group, more preferably a linear alkylene group, even more preferably a linear alkylene group having 1 to 5 carbon atoms, and particularly preferably a methylene group or an ethylene group. Y 22 The group is preferably a linear or branched aliphatic hydrocarbon group, more preferably a methylene group, an ethylene group, or an alkylmethylene group. The alkyl group in the alkylmethylene group is preferably a linear alkyl group having 1 to 5 carbon atoms, more preferably a linear alkyl group having 1 to 3 carbon atoms, and most preferably a methyl group. Formula - [Y 21 -C(=O)-O] m” -Y 22 In the base represented by -, m'' is an integer between 0 and 3, preferably between 0 and 2, more preferably 0 or 1, and particularly preferably 1. That is, in the formula -[Y 21 -C(=O)-O] m” -Y 22 As a base represented by -, formula -Y 21 -C(=O)-OY 22 Groups represented by - are particularly preferred. Among them, the group represented by formula -(CH2) a’ -C(=O)-O-(CH2) b’A base represented by - is preferred. In the formula, a' is an integer from 1 to 10, preferably an integer from 1 to 8, more preferably an integer from 1 to 5, even more preferably 1 or 2, and most preferably 1. b' is an integer from 1 to 10, preferably an integer from 1 to 8, more preferably an integer from 1 to 5, even more preferably 1 or 2, and most preferably 1.

[0157] Among the above, Ya 21 Preferably, the group is a single bond, an ester bond [-C(=O)-O-], an ether bond (-O-), a linear or branched alkylene group, or a combination thereof.

[0158] In the above formula (a2-1), Ra 21 This is a lactone-containing cyclic group, an -SO2-- containing cyclic group, or a carbonate-containing cyclic group. Ra 21 In this context, suitable examples of lactone-containing cyclic groups, -SO2--containing cyclic groups, and carbonate-containing cyclic groups include the groups represented by the general formulas (a2-r-1) to (a2-r-7), the groups represented by the general formulas (a5-r-1) to (a5-r-4), and the groups represented by the general formulas (ax3-r-1) to (ax3-r-3), respectively. Among these, lactone-containing cyclic groups or -SO2--containing cyclic groups are preferred, and the groups represented by the general formulas (a2-r-1), (a2-r-2), (a2-r-6), or (a5-r-1) are more preferred. Specifically, any of the groups represented by the chemical formulas (r-lc-1-1) to (r-lc-1-7), (r-lc-2-1) to (r-lc-2-18), (r-lc-6-1), (r-sl-1-1), or (r-sl-1-18) are more preferred.

[0159] The constituent units (a2) of component (A1) may be one type or two or more types. If component (A1) has constituent units (a2), the proportion of constituent units (a2) is preferably 5 to 60 mol%, more preferably 10 to 60 mol%, even more preferably 20 to 55 mol%, and particularly preferably 30 to 50 mol%, relative to the total amount (100 mol%) of all constituent units that make up component (A1). If the proportion of constituent unit (a2) is set above a preferred lower limit, the effects of including constituent unit (a2) are sufficiently obtained due to the effects described above, and if it is below the upper limit, a balance can be achieved with other constituent units, resulting in good lithography characteristics.

[0160] Regarding the constituent unit (a3): Component (A1) may also have a constituent unit (a3) ​​containing a polar group-containing aliphatic hydrocarbon group in addition to the constituent unit (a1) (excluding those corresponding to constituent unit (a1) or constituent unit (a2)). The presence of constituent unit (a3) ​​in component (A1) increases the hydrophilicity of component (A), contributing to improved resolution. Furthermore, the acid diffusion length can be appropriately adjusted.

[0161] Examples of polar groups include hydroxyl groups, cyano groups, carboxyl groups, and hydroxyalkyl groups in which some of the hydrogen atoms of an alkyl group are replaced with fluorine atoms, with hydroxyl groups being particularly preferred. Examples of aliphatic hydrocarbon groups include linear or branched hydrocarbon groups having 1 to 10 carbon atoms (preferably alkylene groups) and cyclic aliphatic hydrocarbon groups (cyclic groups). The cyclic group may be monocyclic or polycyclic, and can be appropriately selected from among the many proposed options for resins used in resist compositions for ArF excimer lasers.

[0162] When the cyclic group is a monocyclic group, it is more preferable that it has 3 to 10 carbon atoms. Among these, structural units derived from acrylic acid esters containing an aliphatic monocyclic group containing a hydroxyl group, a cyano group, a carboxyl group, or a hydroxyalkyl group in which some of the hydrogen atoms of the alkyl group are substituted with fluorine atoms are more preferred. Examples of such monocyclic groups include groups obtained by removing two or more hydrogen atoms from a monocycloalkane. Specifically, these include groups obtained by removing two or more hydrogen atoms from monocycloalkanes such as cyclopentane, cyclohexane, and cyclooctane. Among these monocyclic groups, groups obtained by removing two or more hydrogen atoms from cyclopentane and groups obtained by removing two or more hydrogen atoms from cyclohexane are industrially preferred.

[0163] If the cyclic group is a polycyclic group, it is more preferable that the number of carbon atoms in the polycyclic group be 7 to 30. Among these, structural units derived from acrylic acid esters containing an aliphatic polycyclic group containing a hydroxyl group, a cyano group, a carboxyl group, or a hydroxyalkyl group in which some of the hydrogen atoms of the alkyl group are substituted with fluorine atoms are more preferred. Examples of such polycyclic groups include groups obtained by removing two or more hydrogen atoms from bicycloalkanes, tricycloalkanes, tetracycloalkanes, etc. Specifically, examples include groups obtained by removing two or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Among these polycyclic groups, groups obtained by removing two or more hydrogen atoms from adamantane, norbornane, and tetracyclododecane are industrially preferred.

[0164] As for the constituent unit (a3), any unit containing a polar group-containing aliphatic hydrocarbon group can be used without any particular limitations. The constituent unit (a3) ​​is preferably a constituent unit derived from an acrylic acid ester in which the hydrogen atom bonded to the α-carbon atom may be substituted with a substituent, and which includes a polar group-containing aliphatic hydrocarbon group. As for the constituent unit (a3), when the hydrocarbon group in the polar group-containing aliphatic hydrocarbon group is a linear or branched hydrocarbon group having 1 to 10 carbon atoms, a constituent unit derived from hydroxyethyl ester of acrylic acid is preferred. Furthermore, as for the constituent unit (a3), when the hydrocarbon group in the polar group-containing aliphatic hydrocarbon group is a polycyclic group, the constituent unit represented by formula (a3-1), formula (a3-2), and formula (a3-3) below are preferred; when it is a monocyclic group, the constituent unit represented by formula (a3-4) is preferred.

[0165] [ka] [In the formula, R is the same as above, j is an integer between 1 and 3, k is an integer between 1 and 3, t' is an integer between 1 and 3, l is an integer between 0 and 5, and s is an integer between 1 and 3.]

[0166] In formula (a3-1), j is preferably 1 or 2, and more preferably 1. When j is 2, it is preferable that the hydroxyl group is bonded to the 3rd and 5th positions of the adamantyl group. When j is 1, it is preferable that the hydroxyl group is bonded to the 3rd position of the adamantyl group. It is preferable that j is 1, and it is particularly preferable that the hydroxyl group is bonded to the 3-position of the adamantyl group.

[0167] In formula (a3-2), k is preferably 1. The cyano group is preferably bonded to the 5th or 6th position of the norbornyl group.

[0168] In formula (a3-3), t' is preferably 1. l is preferably 1. s is preferably 1. These are preferably formed by a 2-norbornyl group or a 3-norbornyl group bonded to the terminal end of the carboxyl group of the acrylic acid. The fluorinated alkyl alcohol is preferably bonded to the 5th or 6th position of the norbornyl group.

[0169] In formula (a3-4), t' is preferably 1 or 2. l is preferably 0 or 1. s is preferably 1. The fluorinated alkyl alcohol is preferably bonded to the 3 or 5 position of the cyclohexyl group.

[0170] (A1) The constituent units (a3) ​​of component (A1) may be one type or two or more types. If component (A1) has constituent units (a3), the proportion of constituent units (a3) ​​is preferably 1 to 30 mol%, more preferably 2 to 25 mol%, and even more preferably 5 to 20 mol%, relative to the total (100 mol%) of all constituent units that make up component (A1). By setting the proportion of constituent unit (a3) ​​above a preferred lower limit, the effects of including constituent unit (a3) ​​are fully obtained through the aforementioned effects. If it is below a preferred upper limit, a balance with other constituent units can be maintained, resulting in good lithography characteristics.

[0171] Regarding the constituent unit (a4): Component (A1) may further have a constituent unit (a4) containing an acid-nondissociable aliphatic cyclic group, in addition to the constituent unit (a1). The presence of component (A1) as a constituent unit (a4) improves the dry etching resistance of the formed resist pattern. Additionally, the hydrophobicity of component (A) increases. This improved hydrophobicity contributes to improvements in resolution, resist pattern shape, and other properties, particularly in solvent development processes. In the constituent unit (a4), the "acid-non-dissociating cyclic group" is a cyclic group that remains in the constituent unit without dissociating when acid is generated in the resist composition due to exposure (for example, when acid is generated from a constituent unit or component (B) that generates acid due to exposure).

[0172] As the constituent unit (a4), for example, a constituent unit derived from an acrylic acid ester containing an acid-nondissociable aliphatic cyclic group is preferred. Many of the cyclic groups that have been conventionally known to be used as resin components in resist compositions for ArF excimer lasers, KrF excimer lasers (preferably for ArF excimer lasers), etc., can be used. The cyclic group is preferably at least one selected from a tricyclodecyl group, an adamantyl group, a tetracyclododecyl group, an isobornyl group, and a norbornyl group, due to their industrial availability. These polycyclic groups may have linear or branched alkyl groups having 1 to 5 carbon atoms as substituents. Specifically, the constituent units (a4) can be exemplified by the constituent units represented by the following general formulas (a4-1) to (a4-7).

[0173] [ka] [In the formula, R α This is the same as above.

[0174] (A1) The constituent units (a4) of component (A1) may be one type or two or more types. If component (A1) has constituent units (a4), the proportion of constituent units (a4) is preferably 1 to 40 mol%, and more preferably 5 to 20 mol%, relative to the total amount (100 mol%) of all constituent units that make up component (A1). By setting the proportion of constituent unit (a4) above a preferred lower limit, the effects of including constituent unit (a4) can be fully obtained. On the other hand, by setting it below a preferred upper limit, it becomes easier to balance it with other constituent units.

[0175] Regarding the constituent unit (st): The constituent unit (st) is a constituent unit derived from styrene or a styrene derivative. "Constituent unit derived from styrene" means a constituent unit formed by the cleavage of the ethylenic double bond of styrene. "Constituent unit derived from a styrene derivative" means a constituent unit formed by the cleavage of the ethylenic double bond of a styrene derivative (excluding those corresponding to constituent unit (a10)).

[0176] A "styrene derivative" refers to a compound in which at least some of the hydrogen atoms of styrene are substituted with substituents. Examples of styrene derivatives include those in which the hydrogen atom at the α-position of styrene is substituted with a substituent, those in which one or more hydrogen atoms of the benzene ring of styrene are substituted with substituents, and those in which the hydrogen atom at the α-position of styrene and one or more hydrogen atoms of the benzene ring are substituted with substituents.

[0177] Examples of substituents that substitute for the α-hydrogen atom of styrene include C1-C5 alkyl groups or C1-C5 halogenated alkyl groups. The C1-C5 alkyl group is preferably a linear or branched alkyl group having C1-C5. Specifically, examples include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, and the like. The C1-C5 alkyl halide is a group in which some or all of the hydrogen atoms of the C1-C5 alkyl group are substituted with halogen atoms. Fluorine atoms are particularly preferred as the halogen atoms. Preferably, the substituent that substitutes the α-hydrogen atom of styrene is an alkyl group having 1 to 5 carbon atoms or a fluorinated alkyl group having 1 to 5 carbon atoms, more preferably an alkyl group having 1 to 3 carbon atoms or a fluorinated alkyl group having 1 to 3 carbon atoms, and even more preferably a methyl group due to its industrial availability.

[0178] Examples of substituents that substitute for hydrogen atoms in the benzene ring of styrene include alkyl groups, alkoxy groups, halogen atoms, and alkyl halides. The alkyl group used as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. As the alkoxy group used as the substituent, an alkoxy group having 1 to 5 carbon atoms is preferred, a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, and a tert-butoxy group are more preferred, and a methoxy group and an ethoxy group are even more preferred. A fluorine atom is preferred as the halogen atom used as the substituent. Examples of halogenated alkyl groups as substituents include groups in which some or all of the hydrogen atoms of the alkyl group are substituted with halogen atoms. As substituents to substitute for hydrogen atoms in the benzene ring of styrene, C1-C5 alkyl groups are preferred, methyl groups or ethyl groups are more preferred, and methyl groups are even more preferred.

[0179] The constituent unit (st) is preferably a constituent unit derived from styrene, or a constituent unit derived from a styrene derivative in which the hydrogen atom at the α position of styrene is substituted with an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms; more preferably a constituent unit derived from styrene, or a constituent unit derived from a styrene derivative in which the hydrogen atom at the α position of styrene is substituted with a methyl group; and even more preferably a constituent unit derived from styrene.

[0180] (A1) The constituent units (st) of the component may be one type or two or more types. (A1) If component (A1) has constituent units (st), the proportion of constituent units (st) is preferably 1 to 30 mol%, and more preferably 3 to 20 mol%, relative to the total amount (100 mol%) of all constituent units that make up component (A1).

[0181] The (A1) component contained in the resist composition may be used alone or in combination of two or more types. In the resist composition of this embodiment, component (A1) is a polymer compound having a repeating structure of the constituent unit (a1). A preferred (A1) component is a polymer compound having a repeating structure of constituent units (a1) and (a2), and among these, a polymer compound having a repeating structure of constituent units (a1), (a2), and (a3) ​​is more preferred.

[0182] In the case of a polymer compound having a repeating structure of constituent units (a1), (a2), and (a3), The proportion of constituent units (a1) in the polymer compound is preferably 10 to 75 mol%, more preferably 30 to 70 mol%, and even more preferably 40 to 60 mol%, relative to the total amount (100 mol%) of all constituent units that make up the polymer compound. The proportion of constituent units (a2) in the polymer compound is preferably 10 to 60 mol%, more preferably 20 to 55 mol%, and even more preferably 30 to 50 mol%, relative to the total amount (100 mol%) of all constituent units that make up the polymer compound. The proportion of constituent units (a3) ​​in the polymer compound is preferably 1 to 30 mol%, more preferably 2 to 25 mol%, and even more preferably 5 to 20 mol%, relative to the total amount (100 mol%) of all constituent units that make up the polymer compound.

[0183] Furthermore, preferred components (A1) include polymer compounds having a repeating structure of constituent units (a1) and (a10). In this case, the proportion of constituent units (a1) in the polymer compound is preferably 5 to 80 mol%, more preferably 10 to 75 mol%, even more preferably 30 to 70 mol%, and particularly preferably 40 to 60 mol%, relative to the total amount (100 mol%) of all constituent units constituting the polymer compound. Furthermore, the proportion of constituent units (a10) in the polymer compound is preferably 5 to 80 mol%, more preferably 10 to 75 mol%, even more preferably 30 to 70 mol%, and particularly preferably 40 to 60 mol%, relative to the total amount (100 mol%) of all constituent units constituting the polymer compound.

[0184] Such component (A1) can be produced by dissolving monomers that induce each constituent unit in a polymerization solvent and then adding a radical polymerization initiator such as azobisisobutyronitrile (AIBN) or dimethyl azobisisobutyrate (e.g., V-601) to the mixture and polymerizing it. Alternatively, such component (A1) can be produced by dissolving a monomer that induces the constituent unit (a1) and, if necessary, a monomer that induces a constituent unit other than the constituent unit (a1) in a polymerization solvent, adding the above-mentioned radical polymerization initiator to this solution, polymerizing it, and then carrying out a deprotection reaction. Furthermore, during polymerization, a chain transfer agent such as HS-CH2-CH2-CH2-C(CF3)2-OH may be used in combination to introduce a -C(CF3)2-OH group at the terminal. Copolymers in which a hydroxyalkyl group, in which some of the hydrogen atoms of the alkyl group are replaced with fluorine atoms, are introduced are effective in reducing development defects and LER (line edge roughness: uneven unevenness of the line sidewall).

[0185] The weight-average molecular weight (Mw) of component (A1) (based on polystyrene conversion by gel permeation chromatography (GPC)) is not particularly limited, but is preferably 1,000 to 50,000, more preferably 2,000 to 30,000, and even more preferably 3,000 to 20,000. If the Mw of component (A1) is below the preferred upper limit of this range, it has sufficient solubility in the resist solvent for use as a resist, and if it is above the preferred lower limit of this range, it has good dry etching resistance and a good cross-sectional shape of the resist pattern. (A1) The degree of dispersion of component (Mw / Mn) is not particularly limited, but is preferably 1.0 to 4.0, more preferably 1.0 to 3.0, and particularly preferably 1.0 to 2.0. Mn represents the number-average molecular weight.

[0186] (A2) About the ingredients The resist composition of this embodiment may also include, as component (A), a base component (hereinafter referred to as "component (A2)") that does not correspond to component (A1) and whose solubility in the developer solution changes due to the action of an acid. (A2) The component is not particularly limited and can be arbitrarily selected from a large number of components that have been conventionally known as base components for chemically amplified resist compositions. (A2) Component may be a single high-molecular-weight compound or a low-molecular-weight compound, or two or more may be used in combination.

[0187] The proportion of component (A1) in component (A) is preferably 25% by mass or more, more preferably 50% by mass or more, even more preferably 75% by mass or more, and may also be 100% by mass, based on the total mass of component (A). When the proportion is 25% by mass or more, it becomes easier to form a resist pattern that is excellent in various lithography characteristics such as high sensitivity, resolution, and roughness improvement.

[0188] In the resist composition of this embodiment, the content of component (A) may be adjusted according to the resist film thickness to be formed.

[0189] <(B) component> In the resist composition of this embodiment, component (B) is an acid generator component that generates acid upon exposure. (B) The component is not particularly limited, and any acid generators previously proposed 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; oximesulfonate-based acid generators; diazomethane-based acid generators such as bisalkyl or bisarylsulfonyl diazomethanes and poly(bissulfonyl) diazomethanes; nitrobenzyl sulfonate-based acid generators, iminosulfonate-based acid generators, and disulfone-based acid generators, among many others.

[0190] Examples of onium salt-based acid generators include the compound represented by the following general formula (b-1) (hereinafter also referred to as "component (b-1)"), the compound represented by the general formula (b-2) (hereinafter also referred to as "component (b-2)"), or the compound represented by the general formula (b-3) (hereinafter also referred to as "component (b-3)").

[0191] [ka] [In the formula, R 101 and R 104 ~R 108 Each of these is independently a cyclic group which may have substituents, a linear alkyl group which may have substituents, or a linear alkenyl group which may have substituents. 104 and R 105 These may be bonded to each other to form a ring structure. 102 This is a fluorinated alkyl group having 1 to 5 carbon atoms or a fluorine atom. 101 This is a divalent linking group or single bond containing an oxygen atom. 101 ~V 103 These are, independently, a single bond, an alkylene group, or a fluorinated alkylene group. 101 ~L 102 Each of these is independently either a single bond or an oxygen atom. 103 ~L 105 These are, independently, single bonds, -CO-, or -SO2-. m is an integer greater than or equal to 1, and M' m+ This is an onium cation with a valence of m.

[0192] {Anion Division} • Anion in component (b-1) In formula (b-1), R 101 This is a cyclic group which may have substituents, a linear alkyl group which may have substituents, or a linear alkenyl group which may have substituents.

[0193] Cyclic groups which may have substituents: The cyclic group is preferably a cyclic hydrocarbon group, which 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, but is usually preferred to be saturated.

[0194] R 101 The aromatic hydrocarbon group in this context is a hydrocarbon group having an aromatic ring. The aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30, even more preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 10. However, this carbon number does not include the carbon atoms in substituents. R 101 Specific examples of aromatic rings in aromatic hydrocarbon groups include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, or aromatic heterocycles in which some of the carbon atoms constituting these aromatic rings are substituted with heteroatoms. Examples of heteroatoms in aromatic heterocycles include oxygen atoms, sulfur atoms, nitrogen atoms, etc. R 101 Specific examples of aromatic hydrocarbon groups in this context include groups obtained by removing one hydrogen atom from the aromatic ring (aryl groups: for example, phenyl groups, naphthyl groups, etc.), and groups in which one of the hydrogen atoms of the aromatic ring is replaced by an alkylene group (for example, arylalkyl groups such as benzyl groups, phenethyl groups, 1-naphthylmethyl groups, 2-naphthylmethyl groups, 1-naphthylethyl groups, and 2-naphthylethyl groups). 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.

[0195] R 101 In this context, cyclic aliphatic hydrocarbon groups include aliphatic hydrocarbon groups that contain a ring in their structure. Examples of aliphatic hydrocarbon groups containing a ring in this structure include alicyclic hydrocarbon groups (groups from 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 linear or branched aliphatic hydrocarbon group, and groups in which an alicyclic hydrocarbon group is interposed in the middle of a linear or branched 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. A preferred monocyclic alicyclic hydrocarbon group is a group obtained by removing one or more hydrogen atoms from a monocycloalkane. The monocycloalkane is preferably one having 3 to 6 carbon atoms, specifically cyclopentane, cyclohexane, etc. A preferred polycyclic alicyclic hydrocarbon group is a group obtained by removing one or more hydrogen atoms from a polycycloalkane, and the polycycloalkane is preferably one having 7 to 30 carbon atoms. Among these, polycycloalkanes having a bridging ring polycyclic skeleton such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane; and polycycloalkanes having a fused ring polycyclic skeleton such as a steroid skeleton are more preferred.

[0196] Among them, R 101 The cyclic aliphatic hydrocarbon group in is preferably a monocycloalkane or polycycloalkane from which one or more hydrogen atoms have been removed, more preferably a polycycloalkane from which one hydrogen atom has been removed, with adamantyl and norbornyl groups being particularly preferred, and the adamantyl group being the most preferred.

[0197] 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. Examples of linear aliphatic hydrocarbon groups include linear alkylene groups, specifically methylene groups [-CH2-], ethylene groups [-(CH2)2-], trimethylene groups [-(CH2)3-], tetramethylene groups [-(CH2)4-], pentamethylene groups [-(CH2)5-], and the like. The branched aliphatic hydrocarbon group, which may be bonded to the alicyclic hydrocarbon group, preferably has 2 to 10 carbon atoms, more preferably 3 to 6, even more preferably 3 or 4, and most preferably 3. Preferred branched aliphatic hydrocarbon groups include branched alkylene groups, specifically 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-; alkyltrimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; and alkylalkylene groups such as alkyltetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-. In the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferred.

[0198] Also, R 101 The cyclic hydrocarbon group in the formula may contain heteroatoms, such as heterocycles. Specifically, examples include lactone-containing cyclic groups represented by the general formulas (a2-r-1) to (a2-r-7), the -SO2--containing cyclic groups represented by the general formulas (a5-r-1) to (a5-r-4), and other heterocyclic groups represented by the following chemical formulas (r-hr-1) to (r-hr-16). In the formulas, * represents Y in formula (b-1). 101 This represents a coupling that connects to something.

[0199] [ka]

[0200] R 101 Examples of substituents on the cyclic group include alkyl groups, alkoxy groups, halogen atoms, alkyl halides, hydroxyl groups, carbonyl groups, and nitro groups. As the alkyl group substituent, alkyl groups having 1 to 5 carbon atoms are preferred, with methyl, ethyl, propyl, n-butyl, and tert-butyl groups being the most preferred. As substituents, alkoxy groups having 1 to 5 carbon atoms are preferred, methoxy groups, ethoxy groups, n-propoxy groups, iso-propoxy groups, n-butoxy groups, and tert-butoxy groups are more preferred, and methoxy groups and ethoxy groups are most preferred. As the halogen atom used as a substituent, a fluorine atom is preferred. Examples of alkyl halides used 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 are substituted with the halogen atoms. A carbonyl group as a substituent is a group that substitutes for a methylene group (-CH2-) that constitutes a cyclic hydrocarbon group.

[0201] R 101 The cyclic hydrocarbon group in may be a fused ring group containing a fused ring formed by the fusion of an aliphatic hydrocarbon ring and an aromatic ring. Examples of the fused ring include a polycycloalkane having a bridging ring system with one or more aromatic rings fused to it. Specific examples of the bridging 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 formed by the fusion of two or three aromatic rings to a bicycloalkane, and more preferably a group containing a fused ring formed by the fusion of two or three aromatic rings to bicyclo[2.2.2]octane. 101Specific examples of fused ring groups in this context include the fused ring groups represented by the following formulas (r-br-1) to (r-br-2). In the formulas, * represents Y in formula (b-1). 101 This represents a coupling that connects to something.

[0202] [ka]

[0203] R 101 Examples of substituents that the fused ring group in the compound may have include alkyl groups, alkoxy groups, halogen atoms, alkyl halides, hydroxyl groups, carbonyl groups, nitro groups, aromatic hydrocarbon groups, and alicyclic hydrocarbon groups. The alkyl group, alkoxy group, halogen atom, and halogenated alkyl group as substituents of the fused cyclic group are as described above in R 101 Examples of substituents on cyclic groups in the above are similar to those listed. Examples of aromatic hydrocarbon groups as substituents on the fused ring group include groups obtained by removing one hydrogen atom from an aromatic ring (aryl groups: for example, phenyl groups, naphthyl groups, etc.), groups in which one of the hydrogen atoms of the aromatic ring is replaced by an alkylene group (for example, arylalkyl groups such as benzyl groups, phenethyl groups, 1-naphthylmethyl groups, 2-naphthylmethyl groups, 1-naphthylethyl groups, 2-naphthylethyl groups, etc.), and heterocyclic groups represented by the above formulas (r-hr-1) to (r-hr-6). Examples of alicyclic hydrocarbon groups as substituents on the fused cyclic group include: groups obtained by removing one hydrogen atom from monocycloalkanes such as cyclopentane and cyclohexane; groups obtained by removing one hydrogen atom from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane; lactone-containing cyclic groups represented by the general formulas (a2-r-1) to (a2-r-7); -SO2--containing cyclic groups represented by the general formulas (a5-r-1) to (a5-r-4); and heterocyclic groups represented by the formulas (r-hr-7) to (r-hr-16).

[0204] Chain-like alkyl groups which may have substituents: R 101 The chain-like alkyl group may be either linear or branched. The linear alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 carbon atoms. Specifically, examples include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decanyl group, undecyl group, dodecyl group, tridecyl group, isotridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, isohexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, eicosyl group, henicosyl group, docosyl group, and the like. 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. Specifically, examples include 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylbutyl group, 2-ethylbutyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, and 4-methylpentyl group.

[0205] A chain-like alkenyl group which may have substituents: R 101 The linear alkenyl group may be 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 carbon atoms. Examples of linear alkenyl groups include vinyl groups, propenyl groups (allyl groups), and butynyl groups. Examples of branched alkenyl groups include 1-methylvinyl groups, 2-methylvinyl groups, 1-methylpropenyl groups, and 2-methylpropenyl groups. Among the above, linear alkenyl groups are preferred, vinyl groups and propenyl groups are more preferred, and vinyl groups are particularly preferred.

[0206] R 101Examples of substituents in the chain-like alkyl or alkenyl group include alkoxy groups, halogen atoms, alkyl halides, hydroxyl groups, carbonyl groups, nitro groups, amino groups, and the above R 101 Examples include cyclic groups in this context.

[0207] Among the above, R 101 The cyclic group is preferably a substituted group, and more preferably a substituted cyclic hydrocarbon group. More specifically, preferred are a phenyl group, a naphthyl group, a polycycloalkane from which one or more hydrogen atoms have been removed; a lactone-containing cyclic group represented by the general formulas (a2-r-1) to (a2-r-7); and a -SO2-containing cyclic group represented by the general formulas (a5-r-1) to (a5-r-4).

[0208] In formula (b-1), Y 101 It is a single bond or a divalent linking group containing an oxygen atom. Y 101 If Y is a divalent linking group containing an oxygen atom, 101 It may contain atoms other than oxygen atoms. Examples of atoms other than oxygen atoms include carbon atoms, hydrogen atoms, sulfur atoms, nitrogen atoms, etc. Examples of divalent linking groups containing an oxygen atom include non-hydrocarbon oxygen-containing linking groups such as oxygen atoms (ether bond: -O-), ester bonds (-C(=O)-O-), oxycarbonyl groups (-OC(=O)-), amide bonds (-C(=O)-NH-), carbonyl groups (-C(=O)-), and carbonate bonds (-OC(=O)-O-); and combinations of such non-hydrocarbon oxygen-containing linking groups with alkylene groups. A sulfonyl group (-SO2-) may be further linked to this combination. Examples of such divalent linking groups containing an oxygen atom include the linking groups represented by the following general formulas (y-al-1) to (y-al-7).

[0209] [ka] [In the formula, V' 101V' is a single bond or an alkylene group having 1 to 5 carbon atoms. 102 It is a divalent saturated hydrocarbon group having 1 to 30 carbon atoms.

[0210] V' 102 The divalent saturated hydrocarbon group in is preferably an alkylene group having 1 to 30 carbon atoms, more preferably an alkylene group having 1 to 10 carbon atoms, and even more preferably an alkylene group having 1 to 5 carbon atoms.

[0211] V' 101 and V' 102 The alkylene group in this product may be a linear alkylene group or a branched alkylene group, but a linear alkylene group is preferred. V' 101 and V' 102 Specifically, the alkylene groups in these include: methylene group [-CH2-]; alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, -C(CH2CH3)2-; ethylene group [-CH2CH2-]; -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2 Examples include alkylethylene groups such as -CH2CH2CH2-; trimethylene groups (n-propylene groups) [-CH2CH2CH2-]; alkyltrimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; tetramethylene groups [-CH2CH2CH2CH2-]; alkyltetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-; and pentamethylene groups [-CH2CH2CH2CH2CH2-]. Also, oshiV' 101 or V' 102 Some of the methylene groups in the alkylene group may be substituted with a divalent aliphatic cyclic group having 5 to 10 carbon atoms. The aliphatic cyclic group is Ra' in formula (a1-r-1). 3A divalent group is preferred, which is obtained by removing one more hydrogen atom from a cyclic aliphatic hydrocarbon group (monocyclic aliphatic hydrocarbon group, polycyclic aliphatic hydrocarbon group), and a cyclohexylene group, a 1,5-adamantilene group, or a 2,6-adamantilene group is more preferred.

[0212] Y 101 Preferably, the linking group is a divalent linking group containing an ester bond or a divalent linking group containing an ether bond, and more preferably the linking groups represented by the above formulas (y-al-1) to (y-al-5).

[0213] In formula (b-1), V 101 This is a single bond, an alkylene group, or a fluorinated alkylene group. 101 The alkylene group and fluorinated alkylene group in this case preferably have 1 to 4 carbon atoms. 101 As for the fluorinated alkylene group in V 101 Examples include groups in which some or all of the hydrogen atoms of the alkylene group are replaced with fluorine atoms. Among these, V 101 It is preferable that it is a single bond or a fluorinated alkylene group having 1 to 4 carbon atoms.

[0214] In formula (b-1), R 102 R is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. 102 It is preferably a fluorine atom or a perfluoroalkyl group having 1 to 5 carbon atoms, and more preferably a fluorine atom.

[0215] A specific example of the anion part represented by the above formula (b-1) is, for example, Y 101 When it is a single bond, examples include fluorinated alkyl sulfonate anions such as trifluoromethanesulfonate anions and perfluorobutanesulfonate anions; Y 101 When is a divalent linking group containing an oxygen atom, the anions can be represented by any of the following formulas (an-1) to (an-3).

[0216] [ka] [In the formula, R” 101 R” is an optionally substituted aliphatic cyclic group, a monovalent heterocyclic group represented by the above chemical formulas (r-hr-1) to (r-hr-6), a fused cyclic group represented by the above formula (r-br-1) or (r-br-2), or an optionally substituted linear alkyl group. 102 R” is an aliphatic cyclic group which may have substituents, a fused cyclic group represented by formula (r-br-1) or (r-br-2), a lactone-containing cyclic group represented by the general formulas (a2-r-1), (a2-r-3) to (a2-r-7), respectively, or a -SO2-containing cyclic group represented by the general formulas (a5-r-1) to (a5-r-4), respectively. 103 V” is an optionally substituted aromatic cyclic group, an optionally substituted aliphatic cyclic group, or an optionally substituted linear alkenyl group. 101 This 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 [wherein 'v' is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms; where 'v' is an independent integer from 0 to 3, where 'q' is an independent integer from 0 to 20, and where 'n' is 0 or 1.]

[0217] R" 101 , R” 102 and R” 103 The aliphatic cyclic group which may have substituents is R in formula (b-1) above. 101 It is preferable that the substituent is the group exemplified as a cyclic aliphatic hydrocarbon group in formula (b-1). 101 Examples include substituents similar to those that may be substituted for the cyclic aliphatic hydrocarbon group in the above.

[0218] R" 103 The aromatic cyclic group which may have substituents in formula (b-1) is R 101 It is preferable that the substituent is the aromatic hydrocarbon group exemplified in the cyclic hydrocarbon group in formula (b-1). 101Examples include substituents similar to those that may be substituted for the aromatic hydrocarbon group in the above.

[0219] R" 101 The chain-like alkyl group which may have substituents in formula (b-1) is R 101 It is preferable that the group is one of the examples given as a chain-like alkyl group in the compound. R" 103 The chain-like alkenyl group which may have substituents in formula (b-1) is R 101 It is preferable that the group is one of the examples given as a chain-like alkenyl group in the formula.

[0220] • Anion in component (b-2) In formula (b-2), R 104 , R 105 Each of these is independently a cyclic group which may have a substituent, a linear alkyl group which may have a substituent, or a linear alkenyl group which may have a substituent, and each of them is R in formula (b-1) 101 Similar examples can be given. However, R 104 , R 105 These may be bonded to each other to form a ring. R 104 , R 105 The alkyl group is preferably a linear alkyl group which may have substituents, and more preferably a linear or branched alkyl group, or a linear or branched fluorinated alkyl group. The number of carbon atoms in the chain-like alkyl group is preferably 1 to 10, more preferably 1 to 7, and even more preferably 1 to 3. 104 , R 105 The number of carbon atoms in the chain-like alkyl group is preferably small within the above range of carbon atoms, for reasons such as good solubility in the resist solvent. 104 , R 105In the chain-like alkyl group, a larger number of hydrogen atoms substituted with fluorine atoms is preferable because it increases the acid strength and improves transparency to high-energy light and electron beams below 250 nm. The proportion of fluorine atoms in the chain-like alkyl group, i.e., the fluorination rate, is preferably 70-100%, more preferably 90-100%, and most preferably a perfluoroalkyl group in which all hydrogen atoms are substituted with fluorine atoms. In formula (b-2), V 102 , V 103 These are, independently, a single bond, an alkylene group, or a fluorinated alkylene group, and each is V in formula (b-1). 101 Similar examples include the above. In formula (b-2), L 101 , L 102 Each of these is either a single bond or an oxygen atom, independently of the others.

[0221] • Anion in component (b-3) In formula (b-3), R 106 ~R 108 Each of these is independently a cyclic group which may have a substituent, a linear alkyl group which may have a substituent, or a linear alkenyl group which may have a substituent, and each of them is R in formula (b-1). 101 Similar examples include the above. In formula (b-3), L 103 ~L 105 These are, independently, single bonds, -CO-, or -SO2-.

[0222] Among the above, the anion in component (b-1) is preferred as the anion portion of component (B). Among these, an anion represented by any of the above general formulas (an-1) to (an-3) is more preferred, an anion represented by either general formula (an-1) or (an-2) is even more preferred, and an anion represented by general formula (an-2) is particularly preferred.

[0223] {cation part} In the above equations (b-1), (b-2), and (b-3), M' m+This represents an onium cation with an m-valence. Among these, sulfonium cations and iodonium cations are preferred. m is an integer greater than or equal to 1.

[0224] Preferred cation portion ((M' m+ ) 1 / m Examples of organic cations include those represented by the following general formulas (ca-1) to (ca-5).

[0225] [ka] [In the formula, R 201 ~R 207 , and R 211 ~R 212 Each of these independently represents an aryl group, alkyl group, or alkenyl group, which may have substituents. 201 ~R 203 , R 206 ~R 207 , R 211 ~R 212 These atoms may bond to each other to form a ring with the sulfur atom in the formula. 208 ~R 209 Each of these independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. 210 This 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 This represents -C(=O)- or -C(=O)-O-. 201 Each of these independently represents an arylene group, an alkylene group, or an alkenylene group. x is either 1 or 2. W 201 This represents a (x+1) valence linking group.

[0226] In the above general formulas (ca-1) to (ca-5), R 201 ~R 207 , and R 211 ~R 212 Examples of aryl groups in this compound include unsubstituted aryl groups having 6 to 20 carbon atoms, with phenyl and naphthyl groups being preferred. R201 ~R 207 , and R 211 ~R 212 The alkyl group in is preferably a linear or cyclic alkyl group having 1 to 30 carbon atoms. R 201 ~R 207 , and R 211 ~R 212 The alkenyl group in this compound preferably has 2 to 10 carbon atoms. R 201 ~R 207 , and R 210 ~R 212 Examples of substituents that may be present include alkyl groups, halogen atoms, alkyl halides, carbonyl groups, cyano groups, amino groups, aryl groups, and groups represented by the following general formulas (ca-r-1) to (ca-r-7).

[0227] [ka] [In the formula, R' 201 Each of these is independently a hydrogen atom, an optionally substituted cyclic group, an optionally substituted linear alkyl group, or an optionally substituted linear alkenyl group.

[0228] Cyclic groups that may have substituents: The cyclic group is preferably a cyclic hydrocarbon group, which 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, but is usually preferred to be saturated.

[0229] R' 201The aromatic hydrocarbon group in this formula is a hydrocarbon group having an aromatic ring. The aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30, even more preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 10. However, this carbon number does not include the carbon atoms in substituents. R' 201 Specific examples of aromatic rings in aromatic hydrocarbon groups include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, or aromatic heterocycles in which some of the carbon atoms constituting these aromatic rings are substituted with heteroatoms. Examples of heteroatoms in aromatic heterocycles include oxygen atoms, sulfur atoms, nitrogen atoms, etc. R' 201 Specific examples of aromatic hydrocarbon groups in this context include groups obtained by removing one hydrogen atom from the aromatic ring (aryl groups: e.g., phenyl group, naphthyl group, etc.), and groups in which one of the hydrogen atoms of the aromatic ring is replaced by an alkylene group (e.g., 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.

[0230] R' 201 In this context, cyclic aliphatic hydrocarbon groups include aliphatic hydrocarbon groups that contain a ring in their structure. Examples of aliphatic hydrocarbon groups containing a ring in this structure include alicyclic hydrocarbon groups (groups from 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 linear or branched aliphatic hydrocarbon group, and groups in which an alicyclic hydrocarbon group is interposed in the middle of a linear or branched 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. A preferred monocyclic alicyclic hydrocarbon group is a group obtained by removing one or more hydrogen atoms from a monocycloalkane. The monocycloalkane is preferably one having 3 to 6 carbon atoms, specifically cyclopentane, cyclohexane, etc. A preferred polycyclic alicyclic hydrocarbon group is a group obtained by removing one or more hydrogen atoms from a polycycloalkane, and the polycycloalkane is preferably one having 7 to 30 carbon atoms. Among these, polycycloalkanes having a bridging ring polycyclic skeleton such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane; and polycycloalkanes having a fused ring polycyclic skeleton such as a steroid skeleton are more preferred.

[0231] Among them, R' 201 The cyclic aliphatic hydrocarbon group in is preferably a monocycloalkane or polycycloalkane from which one or more hydrogen atoms have been removed, more preferably a polycycloalkane from which one hydrogen atom has been removed, with adamantyl and norbornyl groups being particularly preferred, and the adamantyl group being the most preferred.

[0232] 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, even more preferably 1 to 4 carbon atoms, and particularly preferably 1 to 3 carbon atoms. As for the linear aliphatic hydrocarbon group, linear alkylene groups are preferred, specifically the methylene group [-CH2-], ethylene group [-(CH2)2-], trimethylene group [-(CH2)3-], tetramethylene group [-(CH2)4-], pentamethylene group [-(CH2)5-], etc. Preferred branched aliphatic hydrocarbon groups include branched alkylene groups, specifically 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-; alkyltrimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; and alkylalkylene groups such as alkyltetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-. In the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferred.

[0233] Also, R' 201 The cyclic hydrocarbon group in the above formula may contain heteroatoms, such as heterocycles. Specifically, examples include lactone-containing cyclic groups represented by the general formulas (a2-r-1) to (a2-r-7), -SO2--containing cyclic groups represented by the general formulas (a5-r-1) to (a5-r-4), and other heterocyclic groups represented by the above chemical formulas (r-hr-1) to (r-hr-16).

[0234] R' 201 Examples of substituents in the cyclic group include alkyl groups, alkoxy groups, halogen atoms, alkyl halides, hydroxyl groups, carbonyl groups, and nitro groups. As the alkyl group substituent, alkyl groups having 1 to 5 carbon atoms are preferred, with methyl, ethyl, propyl, n-butyl, and tert-butyl groups being the most preferred. As substituents, alkoxy groups having 1 to 5 carbon atoms are preferred, methoxy groups, ethoxy groups, n-propoxy groups, iso-propoxy groups, n-butoxy groups, and tert-butoxy groups are more preferred, and methoxy groups and ethoxy groups are most preferred. As the halogen atom used as a substituent, a fluorine atom is preferred. Examples of alkyl halides used 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 are substituted with the halogen atoms. A carbonyl group as a substituent is a group that substitutes for a methylene group (-CH2-) that constitutes a cyclic hydrocarbon group.

[0235] Chain-like alkyl groups that may have substituents: R' 201 The chain-like alkyl group may be either linear or branched. The linear alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 carbon atoms. 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. Specifically, examples include 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylbutyl group, 2-ethylbutyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, and 4-methylpentyl group.

[0236] A chain-like alkenyl group which may have substituents: R' 201 The linear alkenyl group may be linear or branched, preferably having 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 linear alkenyl groups include vinyl group, 1-propenyl group, 2-propenyl group (allyl group), and butynyl group. Examples of branched alkenyl groups include 1-methylvinyl group, 1-methylpropenyl group, and 2-methylpropenyl group. Among the above, linear alkenyl groups are preferred, vinyl groups and propenyl groups are more preferred, and vinyl groups are particularly preferred.

[0237] R' 201 Substituents in the chain-like alkyl or alkenyl group include, for example, alkoxy groups, halogen atoms, alkyl halides, hydroxyl groups, carbonyl groups, nitro groups, amino groups, and the above R' 201 Examples include cyclic groups in this context.

[0238] R' 201 In addition to those mentioned above, the optionally substituted cyclic groups, optionally substituted linear alkyl groups, or optionally substituted linear alkenyl groups may also include those similar to the acid-dissociable group represented by formula (a1-r-2) above, as optionally substituted cyclic groups or optionally substituted linear alkyl groups.

[0239] Among them, R' 201 The cyclic group is preferably a cyclic group which may have substituents, and more preferably a cyclic hydrocarbon group which may have substituents. More specifically, preferred groups include, for example, a phenyl group, a naphthyl group, a polycycloalkane from which one or more hydrogen atoms have been removed; lactone-containing cyclic groups represented by the general formulas (a2-r-1) to (a2-r-7); and -SO2--containing cyclic groups represented by the general formulas (a5-r-1) to (a5-r-4).

[0240] In the above general formulas (ca-1) to (ca-5), R 201 ~R 207 , and R 210 ~R 212 Among the substituents that may be present, electron-withdrawing groups are preferred. There may be one electron-withdrawing group or two or more electron-withdrawing groups. Examples of electron-withdrawing groups include acyl groups, methanesulfonyl groups (mesyl groups), halogen atoms, alkyl halides, alkoxy halides, aryl oxy halides, alkylamino halides, alkylthio halides, cyano groups, nitro groups, dialkylphosphono groups, diarylphosphono groups, alkylsulfonyl groups, arylsulfonyl groups, sulfonyl oxy groups, acylthio groups, sulfamoyl groups, thiocyanate groups, and thiocarbonyl groups. Among the above, fluorine atoms or fluorinated alkyl groups are preferred from the viewpoint of increasing sensitivity. The fluorinated alkyl group is preferably a fluorinated alkyl group having 1 to 5 carbon atoms.

[0241] When the electron-withdrawing group is a fluorine atom or a fluorinated alkyl group, the number of fluorine atoms in the cation portion of component (B) is preferably 1 to 9, more preferably 2 to 6, and even more preferably 3 or 4. While a higher fluorine atom count generally leads to better sensitivity, if the count remains below the upper limit of a desirable range, the solubility of each component of the resist composition in the developer is maintained, and the degradation of roughness is more easily suppressed.

[0242] In the above general formulas (ca-1) to (ca-5), R 201 ~R 203 , R 206 ~R 207 , R 211 ~R 212 When these atoms bond to each other and form a ring with the sulfur atom in the formula, they may be heteroatoms such as sulfur, oxygen, or nitrogen atoms, or carbonyl groups, -SO-, -SO2-, -SO3-, -COO-, -CONH-, or -N(R N )-(applicable R Nis an alkyl group having 1 to 5 carbon atoms. It may also be bonded via functional groups such as ). The formed ring is preferably a 3 to 10-membered ring, and particularly preferably a 5 to 7-membered ring, including the sulfur atom in its ring skeleton. Specific examples of the formed ring include, for example, a thiophene ring, a thiazole ring, a benzothiophene ring, a dibenzothiophene ring, a 9H-thioxanthene ring, a thioxanthone ring, a thianthlene ring, a phenoxatiyine ring, a tetrahydrothiophenium ring, and a tetrahydrothiopyranium ring.

[0243] R 208 ~R 209 Each of these 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. If an alkyl group is formed, it may bond to each other to form a ring.

[0244] R 210 This 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 Examples of aryl groups in this compound include unsubstituted aryl groups having 6 to 20 carbon atoms, with phenyl and naphthyl groups being preferred. R 210 The alkyl group in is preferably a linear or cyclic alkyl group having 1 to 30 carbon atoms. R 210 The alkenyl group in this compound preferably has 2 to 10 carbon atoms. R 210 In this context, the SO2-containing cyclic group which may have substituents is preferably a "-SO2-containing polycyclic group," and more preferably a group represented by the general formula (a5-r-1).

[0245] Y 201 Each of these independently represents an arylene group, an alkylene group, or an alkenylene group. Y 201 The arylene group in the above formula (b-1) is R 101An example of an aromatic hydrocarbon group in this context is the aryl group exemplified above, with one hydrogen atom removed. Y 201 The alkylene group and alkenylene group in the above formula (b-1) are R 101 Examples of the chain-like alkyl groups and chain-like alkenyl groups mentioned above include groups obtained by removing one hydrogen atom from the examples provided.

[0246] In the above equation (ca-4), x is either 1 or 2. W 201 This is a (x+1) valence, i.e., a divalent or trivalent linking group. W 201 In this, the divalent linking group is preferably a divalent hydrocarbon group which may have substituents, and Ya in the general formula (a2-1) described above. 21 Examples of divalent hydrocarbon groups that may have substituents, similar to the above, can be given. 201 The divalent linking group in this compound may be linear, branched, or cyclic, with cyclic being preferred. Among these, a group in which two carbonyl groups are combined at both ends of an arylene group is preferred. Examples of arylene groups include phenylene groups and naphthylene groups, with phenylene groups being particularly preferred. W 201 The trivalent linking group in is the aforementioned W 201 Examples include a group obtained by removing one hydrogen atom from a divalent linking group, and a group in which another divalent linking group is bonded to the aforementioned divalent linking group. 201 In this compound, a trivalent linking group is preferably a group in which two carbonyl groups are bonded to an arylene group.

[0247] The following are suitable cations represented by the above formula (ca-1).

[0248] [ka]

[0249] [ka]

[0250] [ka] [In the formula, g1, g2, and g3 represent the number of repetitions, where g1 is an integer from 1 to 5, g2 is an integer from 0 to 20, and g3 is an integer from 0 to 20.]

[0251] [ka]

[0252] [ka]

[0253] [ka]

[0254] [ka]

[0255] [ka]

[0256] [ka] [In the formula, R” 201 is a hydrogen atom or a substituent, and the substituent is the aforementioned R 201 ~R 207 , and R 210 ~R 212 These are the same as those listed as substituents that may be present.

[0257] [ka]

[0258] Specific examples of suitable cations represented by the formula (ca-2) include diphenyliodonium cation and bis(4-tert-butylphenyl)iodonium cation.

[0259] Specific examples of suitable cations represented by the above formula (ca-3) include the cations represented by the following formulas (ca-3-1) to (ca-3-6).

[0260] [ka]

[0261] Specific examples of suitable cations represented by the above formula (ca-4) include the cations represented by the following formulas (ca-4-1) to (ca-4-2).

[0262] [ka]

[0263] Specific examples of suitable cations represented by the above formula (ca-5) include the cations represented by the following general formulas (ca-5-1) to (ca-5-3).

[0264] [ka]

[0265] In the resist composition of this embodiment, the cation portion of component (B) is preferably an organic cation having an electron-withdrawing group, and more preferably an organic cation having an electron-withdrawing group in any of the organic cations represented by the general formulas (ca-1) to (ca-5) above.

[0266] In the resist composition of this embodiment, the cation portion of component (B) is preferably a cation represented by the general formula (ca-1) having an electron-withdrawing group. That is, a cation represented by any of the above chemical formulas (ca-1-1) to (ca-1-8), (ca-1-43) to (ca-1-45), (ca-1-70) to (ca-1-84), (ca-1-97) to (ca-1-102) is preferred, and a cation represented by the above chemical formulas (ca-1-1), (ca-1-7), or (ca-1-76) is more preferred.

[0267] In the resist composition of this embodiment, component (B) is preferably a compound represented by the following general formula (b-1-1) (hereinafter also referred to as "component (b-1-1)").

[0268] [ka] [In the formula, R b1 , R b2 and R b3 Each of these is independently an aryl group which may have substituents, or two or more of them are bonded to each other to form a ring with the sulfur atom in the formula. 101 R is a cyclic group which may have substituents, a linear alkyl group which may have substituents, or a linear alkenyl group which may have substituents. 102 This is a fluorinated alkyl group having 1 to 5 carbon atoms or a fluorine atom. 101 This is a divalent linking group or single bond containing an oxygen atom. 101 This is a single bond or an oxygen atom.

[0269] {(b-1-1) component anionic part} The anionic portion in component (b-1-1) is the same as the anion in component (b-1) described above.

[0270] {(b-1-1) component cation} R b1 R is an aryl group having an electron-withdrawing group. b1The aryl group in the above formula (ca-1) is R 201 ~R 203 Examples include those similar to the aryl group in [the given text].

[0271] R b1 The aryl group in this formula preferably has an electron-withdrawing group as a substituent. The electron-withdrawing group is R in the above formula (ca-1). 201 ~R 203 Examples include electron-withdrawing groups that the aryl group in the above may have. In this case, R b1 The number of electron-withdrawing groups in the aryl group may be one or two or more. Also, R b1 If the aryl group in has multiple electron-withdrawing groups, they may be the same or different.

[0272] R b2 and R b3 Each of these is an aryl group which may independently have substituents, or which are bonded to each other to form a ring with the sulfur atom in the formula. The aryl group is as follows: b1 Examples include those similar to the aryl group in R. b2 and R b3 The substituents that the aryl group in the above formula (ca-1) may have are R 201 ~R 203 Examples of substituents that may be present on the aryl group in the above are similar to those mentioned above.

[0273] R b2 and R b3 The ring formed by the interaction of these atoms with the sulfur atom in the formula is R in formula (ca-1) above. 201 ~R 203 However, examples include rings similar to those formed by mutual bonding with the sulfur atoms in the formula, but the dibenzothiophene ring is particularly preferred as the resulting ring.

[0274] (b-1-1) As for the cation portion in component (b-1-1), from the viewpoint of further improving sensitivity, R b2 and R b3It is preferable that these atoms bond to each other and form a ring together with the sulfur atom in the formula. On the other hand, from the viewpoint of improving roughness reduction, it is preferable that the aryl groups may each have substituents independently, and it is more preferable that the aryl groups may have electron-withdrawing groups.

[0275] The following are specific examples of component (B), but are not limited to these.

[0276] [ka]

[0277] Among the components (B) in the resist composition of this embodiment, the acid generator represented by the chemical formula (B-6) is preferred from the viewpoint of further improving sensitivity. On the other hand, from the viewpoint of improving roughness reduction, an acid generator represented by the above chemical formulas (B-1), (B-4), or (B-6) is preferred.

[0278] In the resist composition of this embodiment, component (B) may be used alone or in combination of two or more types. In the resist composition of this embodiment, the content of component (B) is preferably 20 parts by mass or more, more preferably 20 to 60 parts by mass, even more preferably 25 to 55 parts by mass, and particularly preferably 30 to 50 parts by mass, per 100 parts by mass of component (A). (B) When the content of component (B) is above the preferred lower limit, lithography characteristics such as sensitivity, resolution, LWR (linewise roughness), and shape are further improved in resist pattern formation. On the other hand, when it is below the preferred upper limit, solubility in the developer is more easily increased.

[0279] <(D) component> In the resist composition of this embodiment, component (D) is a basic component that controls the diffusion of acid generated from component (B) by exposure. By using a resist composition containing component (D), the contrast between the exposed and unexposed areas of the resist film can be further improved when forming a resist pattern. In addition, component (D) includes compound (D0) represented by the general formula (d0) described later (hereinafter also referred to as "component (D0)"). Furthermore, component (D) may contain, in addition to component (D0), a base component that does not correspond to component (D0).

[0280] • About component (D0) Component (D0) is a compound represented by the following general formula (d0).

[0281] [ka] [In the formula, Rd 0 Xd is a monovalent organic group. 0 These are -O-, -C(=O)-, -OC(=O)-, -C(=O)-O-, -S-, or -SO2-. Yd 0 This is a divalent hydrocarbon group or single bond, which may have substituents. m+ This represents an m-valent organic cation, where m is an integer greater than or equal to 1.

[0282] {(D0) component anion part} In the above formula (d0), Rd 0 This is a monovalent organic group. Examples of such monovalent organic groups include hydrocarbon groups that may have substituents.

[0283] Rd in equation (d0) 0 Examples of hydrocarbon groups that may have substituents include optionally substituted cyclic groups, optionally substituted linear alkyl groups, or optionally substituted linear alkenyl groups.

[0284] Cyclic groups which may have substituents: The cyclic group is preferably a cyclic hydrocarbon group, which 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, but is usually preferred to be saturated.

[0285] Rd 0 The aromatic hydrocarbon group in this context is a hydrocarbon group having an aromatic ring. The aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30, even more preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 10. However, this carbon number does not include the carbon atoms in substituents. Rd 0 Specific examples of aromatic rings in aromatic hydrocarbon groups include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, or aromatic heterocycles in which some of the carbon atoms constituting these aromatic rings are substituted with heteroatoms. Examples of heteroatoms in aromatic heterocycles include oxygen atoms, sulfur atoms, nitrogen atoms, etc. Rd 0 Specific examples of aromatic hydrocarbon groups in this context include groups obtained by removing one hydrogen atom from the aromatic ring (aryl groups: for example, phenyl groups, naphthyl groups, etc.), and groups in which one of the hydrogen atoms of the aromatic ring is replaced by an alkylene group (for example, arylalkyl groups such as benzyl groups, phenethyl groups, 1-naphthylmethyl groups, 2-naphthylmethyl groups, 1-naphthylethyl groups, and 2-naphthylethyl groups). 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.

[0286] Rd 0 In this context, cyclic aliphatic hydrocarbon groups include aliphatic hydrocarbon groups that contain a ring in their structure. Examples of aliphatic hydrocarbon groups containing a ring in this structure include alicyclic hydrocarbon groups (groups from 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 linear or branched aliphatic hydrocarbon group, and groups in which an alicyclic hydrocarbon group is interposed in the middle of a linear or branched 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. A preferred monocyclic alicyclic hydrocarbon group is a group obtained by removing one or more hydrogen atoms from a monocycloalkane. The monocycloalkane is preferably one having 3 to 6 carbon atoms, specifically cyclopentane, cyclohexane, etc. A preferred polycyclic alicyclic hydrocarbon group is a group obtained by removing one or more hydrogen atoms from a polycycloalkane, and the polycycloalkane is preferably one having 7 to 30 carbon atoms. Among these, polycycloalkanes having a bridging ring polycyclic skeleton such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane; and polycycloalkanes having a fused ring polycyclic skeleton such as a steroid skeleton are more preferred.

[0287] Among them, Rd 0 The cyclic aliphatic hydrocarbon group in is preferably a monocycloalkane or polycycloalkane from which one or more hydrogen atoms have been removed, more preferably a polycycloalkane from which one hydrogen atom has been removed, with adamantyl and norbornyl groups being particularly preferred, and the adamantyl group being the most preferred.

[0288] 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. Examples of linear aliphatic hydrocarbon groups include linear alkylene groups, specifically methylene groups [-CH2-], ethylene groups [-(CH2)2-], trimethylene groups [-(CH2)3-], tetramethylene groups [-(CH2)4-], pentamethylene groups [-(CH2)5-], and the like. The branched aliphatic hydrocarbon group, which may be bonded to the alicyclic hydrocarbon group, preferably has 2 to 10 carbon atoms, more preferably 3 to 6, even more preferably 3 or 4, and most preferably 3. Preferred branched aliphatic hydrocarbon groups include branched alkylene groups, specifically 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-; alkyltrimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; and alkylalkylene groups such as alkyltetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-. In the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferred.

[0289] Also, Rd 0 The cyclic hydrocarbon group in the formula may contain heteroatoms, such as heterocycles. Specifically, examples include lactone-containing cyclic groups represented by the general formulas (a2-r-1) to (a2-r-7), -SO2--containing cyclic groups represented by the general formulas (a5-r-1) to (a5-r-4), and other heterocyclic groups represented by the chemical formulas (r-hr-1) to (r-hr-16). In the formula, * represents Xd in formula (d0). 0 This becomes a coupling joint.

[0290] Chain-like alkyl groups which may have substituents: Rd 0 The chain-like alkyl group may be either linear or branched. The linear alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 carbon atoms. Specifically, examples include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decanyl group, undecyl group, dodecyl group, tridecyl group, isotridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, isohexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, eicosyl group, henicosyl group, docosyl group, and the like. 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. Specifically, examples include 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylbutyl group, 2-ethylbutyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, and 4-methylpentyl group.

[0291] A chain-like alkenyl group which may have substituents: Rd 0 The linear alkenyl group may be 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 carbon atoms. Examples of linear alkenyl groups include vinyl groups, propenyl groups (allyl groups), and butynyl groups. Examples of branched alkenyl groups include 1-methylvinyl groups, 2-methylvinyl groups, 1-methylpropenyl groups, and 2-methylpropenyl groups. Among the above, linear alkenyl groups are preferred, vinyl groups and propenyl groups are more preferred, and vinyl groups are particularly preferred.

[0292] In the above formula (d0), Rd 0Among the above, optionally substituted cyclic groups are preferred, optionally substituted cyclic hydrocarbon groups are more preferred, optionally substituted aromatic hydrocarbon groups are even more preferred, optionally substituted phenyl or naphthyl groups are particularly preferred, and phenyl or naphthyl groups are most preferred.

[0293] The substituents in the hydrocarbon group, which may have substituents, may be monovalent or divalent substituents. Examples of the monovalent substituents include carboxyl groups, hydroxyl groups, amino groups, sulfo groups, halogen atoms, alkyl halides, alkoxy groups, alkyloxycarbonyl groups, and nitro groups. Examples of the divalent substituents include -O-, -C(=O)-O-, -C(=O)-, -OC(=O)-O-, -C(=O)-NH-, -NH-, =N-, -NH-C(=NH)-, -S-, -S(=O)2-, and -S(=O)2-O-. The H in the divalent substituent may be substituted with substituents such as alkyl groups and acyl groups.

[0294] In the above equation (d0), Xd 0 The molecule is -O-, -C(=O)-, -OC(=O)-, -C(=O)-O-, -S-, or -SO2-, and among these, -O-, -C(=O)-, -OC(=O)-, or -S- is preferred.

[0295] In the above equation (d0), Yd 0 This is a divalent hydrocarbon group or single bond, which may have substituents.

[0296] • Divalent hydrocarbon groups which may have substituents: Yd 0 The divalent hydrocarbon group in which substituents may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0297] ··Yd 0 Aliphatic hydrocarbon groups in An aliphatic hydrocarbon group refers to a hydrocarbon group that does not possess aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated, but is usually preferable to be saturated. Examples of the aliphatic hydrocarbon group include linear or branched aliphatic hydrocarbon groups, or aliphatic hydrocarbon groups containing a ring in their structure.

[0298] ...linear or branched aliphatic hydrocarbon groups The linear aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, even more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. As for the linear aliphatic hydrocarbon group, linear alkylene groups are preferred, specifically the methylene group [-CH2-], ethylene group [-(CH2)2-], trimethylene group [-(CH2)3-], tetramethylene group [-(CH2)4-], pentamethylene group [-(CH2)5-], etc. The branched aliphatic 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. Preferred branched aliphatic hydrocarbon groups include branched alkylene groups, specifically 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-; alkyltrimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; and alkylalkylene groups such as alkyltetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-. In the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferred.

[0299] The linear or branched aliphatic hydrocarbon group may or may not have substituents. Examples of substituents include fluorine atoms, fluorinated alkyl groups having 1 to 5 carbon atoms substituted with fluorine atoms, and carbonyl groups.

[0300] ...Aliphatic hydrocarbon groups containing a ring in their structure Examples of aliphatic hydrocarbon groups containing a ring in the structure include cyclic aliphatic hydrocarbon groups that may contain substituents containing heteroatoms in the ring structure (groups obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring), groups in which the cyclic aliphatic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and groups in which the cyclic aliphatic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group are the same as those described above. The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably has 3 to 12 carbon atoms. The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. A preferred monocyclic alicyclic hydrocarbon group is a group obtained by removing two hydrogen atoms from a monocycloalkane. The monocycloalkane is preferably one having 3 to 6 carbon atoms, specifically cyclopentane, cyclohexane, etc. A preferred polycyclic alicyclic hydrocarbon group is a group obtained by removing two hydrogen atoms from a polycycloalkane, and the polycycloalkane is preferably one having 7 to 12 carbon atoms, specifically adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc.

[0301] The cyclic aliphatic hydrocarbon group may or may not have substituents. Examples of substituents include alkyl groups, alkoxy groups, halogen atoms, alkyl halides, hydroxyl groups, and carbonyl groups. The alkyl group used as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. As the alkoxy group used as the substituent, an alkoxy group having 1 to 5 carbon atoms is preferred, a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, and a tert-butoxy group are more preferred, and a methoxy group and an ethoxy group are even more preferred. A fluorine atom is preferred as the halogen atom used as the substituent. Examples of halogenated alkyl groups as substituents include groups in which some or all of the hydrogen atoms of the alkyl group are substituted with halogen atoms. A cyclic aliphatic hydrocarbon group may have some of the carbon atoms constituting its ring structure replaced by substituents containing heteroatoms. Preferred substituents containing heteroatoms are -O-, -C(=O)-O-, -S-, -S(=O)2-, and -S(=O)2-O-.

[0302] ··Yd 0 Aromatic hydrocarbon groups in The aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring. The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20, even more preferably 6 to 15, and particularly preferably 6 to 12. However, this carbon number does not include the carbon atoms in substituents. Examples of aromatic rings include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are replaced by heteroatoms. Examples of heteroatoms in aromatic heterocycles include oxygen atoms, sulfur atoms, and nitrogen atoms. Examples of aromatic heterocycles include pyridine rings and thiophene rings. Specific examples of aromatic hydrocarbon groups include groups obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring or aromatic heterocycle (arylene group or heteroarylene group); groups obtained by removing two hydrogen atoms from aromatic compounds containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); and groups in which one hydrogen atom of an aryl group or heteroaryl group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocycle (aryl group or heteroaryl group) is substituted with an alkylene group (e.g., groups obtained by removing one more hydrogen atom from an aryl group in an arylalkyl group such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.). The number of carbon atoms in the alkylene group bonded to the aryl group or heteroaryl group is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0303] The aromatic hydrocarbon group may have its hydrogen atoms substituted with substituents. For example, the hydrogen atoms bonded to the aromatic ring in the aromatic hydrocarbon group may be substituted with substituents. Examples of such substituents include alkyl groups, alkoxy groups, halogen atoms, alkyl halides, hydroxyl groups, and the like. The alkyl group used as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. Examples of the substituents include alkoxy groups, halogen atoms, and alkyl halides that substitute for hydrogen atoms on the cyclic aliphatic hydrocarbon group.

[0304] In formula (d0), Yd 0 Among the above, it is preferable that the aliphatic hydrocarbon group is single-bonded or linear or branched, more preferably single-bonded or linear or branched aliphatic hydrocarbon group having 1 to 10 carbon atoms, and even more preferably single-bonded or linear or branched aliphatic hydrocarbon group having 1 to 5 carbon atoms.

[0305] The following are preferred anions for the anion portion of component (D0).

[0306] [ka]

[0307] [ka]

[0308] {(D0) component cation} In the above formula (d0), M m+ This represents an m-valent organic cation. Among these, sulfonium cations and iodonium cations are preferred. m is an integer of 1 or greater.

[0309] Preferred cation portion ((M m+ ) 1 / m Examples of these include organic cations similar to those represented by general formulas (ca-1) to (ca-5) in component (B) mentioned above, and among them, the cation represented by general formula (ca-1) is preferred.

[0310] In the resist composition of this embodiment, component (D0) is preferably a compound represented by the following general formula (d01) (hereinafter also referred to as "component (D01)").

[0311] [ka] [In the formula, Rd 0 Xd is a monovalent organic group. 0 These are -O-, -C(=O)-, -OC(=O)-, -C(=O)-O-, -S-, or -SO2-. Yd 0 R is a divalent hydrocarbon group or single bond, which may have substituents. d1 ~R d3 These are either aryl groups that may each have substituents independently, or they are bonded to each other to form a ring with the sulfur atom in the formula.

[0312] {(D01) component anionic part} The anion portion in component (D01) is the same as the anion in component (D0) described above.

[0313] {(D01) component cation} In formula (d01), R d1 ~R d3 These are either aryl groups that may independently have substituents, or they are bonded to each other to form a ring with the sulfur atom in the formula. Examples of these aryl groups that may have substituents are the same as the aryl groups that may have substituents in the organic cation represented by the general formula (ca-1) described above. R d1 ~R d3 In this context, the ring formed by mutual bonding with the sulfur atom in the formula is R in the organic cation represented by the general formula (ca-1) mentioned above. 201 ~R 203 However, examples include rings formed by the atoms bonding with each other together with the sulfur atoms in the formula.

[0314] The following are specific examples of the (D0) component, but are not limited to these.

[0315] [ka]

[0316] [ka]

[0317] In the resist composition of this embodiment, component (D0) may be used alone or in combination of two or more types. In the resist composition of this embodiment, the content of component (D0) is preferably 4 parts by mass or more, more preferably 4 to 20 parts by mass, even more preferably 4 to 15 parts by mass, and particularly preferably 4.5 to 15 parts by mass, per 100 parts by mass of component (A). When the content of component (D0) is above the preferred lower limit mentioned above, solubility in the developer can be adequately ensured, making it easier to obtain particularly good lithography characteristics and resist pattern shapes. On the other hand, when it is below the preferred upper limit mentioned above, various lithography characteristics are good.

[0318] The proportion of component (D0) in component (D) is preferably 50% by mass or more, more preferably 75% by mass or more, even more preferably 90% by mass or more, and may be 100% by mass, based on the total mass (100% by mass) of component (D). When the proportion is 50% by mass or more, the effects of the present invention are more easily obtained.

[0319] As component (D), for example, a photodegradable base (D1) that does not fall under component (D0) above and decomposes upon exposure, losing its ability to control acid diffusion (hereinafter referred to as "component (D1)"), or a nitrogen-containing organic compound (D2) that does not fall under component (D0) or component (D1) (hereinafter referred to as "component (D2)") may be used.

[0320] • About the (D1) component Component (D1) is not limited to any compound that does not fall under component (D0) and decomposes upon exposure, losing its acid diffusion controllability. Preferably, it is one or more compounds selected from the group consisting of a compound represented by the following general formula (d1-1) (hereinafter referred to as "component (d1-1)"), a compound represented by the following general formula (d1-2) (hereinafter referred to as "component (d1-2)"), and a compound represented by the following general formula (d1-3) (hereinafter referred to as "component (d1-3)"). Components (d1-1) to (d1-3) decompose in the exposed areas of the resist film and lose their acid diffusion control properties (basicity), so they do not act as quenchers, but they act as quenchers in the unexposed areas of the resist film.

[0321] [ka] [In the formula, Rd 1 ~Rd 4Rd in general formula (d1-2) is a cyclic group which may have substituents, a linear alkyl group which may have substituents, or a linear alkenyl group which may have substituents. 2 In this example, assume that no fluorine atoms are bonded to carbon atoms adjacent to the sulfur atom. 1 is a single bond or a divalent linking group. m is an integer greater than or equal to 1, and M' m+ These are each independently m-valent onium cations.

[0322] {(d1-1) component} · Anion Club In formula (d1-1), Rd 1 R in formula (b-1) is a cyclic group which may have substituents, a linear alkyl group which may have substituents, or a linear alkenyl group which may have substituents, and each of these is R 101 Examples include those similar to the above. Among these, Rd 1 Preferred substituents are optionally substituted aromatic hydrocarbon groups, optionally substituted aliphatic cyclic groups, or optionally substituted linear alkyl groups. Examples of substituents these groups may have include hydroxyl groups, oxo groups, alkyl groups, aryl groups, fluorine atoms, fluorinated alkyl groups, lactone-containing cyclic groups represented by the general formulas (a2-r-1) to (a2-r-7), ether bonds, ester bonds, or combinations thereof. When ether bonds or ester bonds are included as substituents, they may be mediated via alkylene groups, and in this case, preferred substituents are the linking groups represented by the above 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 (for example, a polycyclic structure consisting of a bicyclooctane skeleton ring structure and other ring structures). The aliphatic cyclic group is more preferably a group obtained by removing one or more hydrogen atoms from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. The linear alkyl group preferably has 1 to 10 carbon atoms, and specifically includes linear alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, and decyl groups; and branched alkyl groups such as 1-methylethyl, 1-methylpropyl, 2-methylpropyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 1-ethylbutyl, 2-ethylbutyl, 1-methylpentyl, 2-methylpentyl, 3-methylpentyl, and 4-methylpentyl groups.

[0323] When the chain-like alkyl group is a fluorinated alkyl group having a fluorinated 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. Examples of atoms other than fluorine include oxygen atoms, sulfur atoms, nitrogen atoms, and the like. Rd 1 Preferably, the linear alkyl group is a fluorinated alkyl group in which some or all of the hydrogen atoms constituting the linear alkyl group are substituted with fluorine atoms, and particularly preferably, the linear alkyl group is a fluorinated alkyl group (linear perfluoroalkyl group) in which all of the hydrogen atoms constituting the linear alkyl group are substituted with fluorine atoms.

[0324] The following are some preferred specific examples of the anionic portion of component (d1-1).

[0325] [ka]

[0326] • Cation section In formula (d1-1), M' m+ This is an onium cation with an oval value. M' m+Suitable onium cations include those similar to those represented by the general formulas (Ca-1) to (Ca-5) above, and among them, the cation represented by general formula (Ca-1) is preferred. (d1-1) Component may be used alone or in combination of two or more types.

[0327] {(d1-2) component} · Anion Club In formula (d1-2), Rd 2 R in formula (b-1) is a cyclic group which may have substituents, a linear alkyl group which may have substituents, or a linear alkenyl group which may have substituents. 101 Examples include those similar to the above. However, Rd 2 In this example, the carbon atom adjacent to the S atom is assumed to be unbonded to a fluorine atom (not fluorine-substituted). This results in the (d1-2) component anions becoming appropriately weak acid anions, improving the quenching ability of the (D1) component. Rd 2 Preferably, the group is a chain-like alkyl group which may have substituents, or an aliphatic cyclic group which may have substituents. The chain-like alkyl group preferably has 1 to 10 carbon atoms, and more preferably 3 to 10 carbon atoms. The aliphatic cyclic group preferably has one or more hydrogen atoms removed from adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc. (which may have substituents); more preferably has one or more hydrogen atoms removed from camphor, etc. Rd 2 The hydrocarbon group may have substituents, and the substituent may be Rd of formula (d1-1) above. 1 Examples of substituents that may be present on hydrocarbon groups (aromatic hydrocarbon groups, aliphatic cyclic groups, and linear alkyl groups) in the above are similar to those mentioned above.

[0328] The following are preferred specific examples of the anionic portion of component (d1-2).

[0329] [ka]

[0330] • Cation section In formula (d1-2), M' m+ This is an m-valent onium cation, and M' in formula (d1-1) above. m+ It is similar to that. (d1-2) Components may be used individually or in combination of two or more.

[0331] {(d1-3) components} · Anion Club In formula (d1-3), Rd 3 R in formula (b-1) is a cyclic group which may have substituents, a linear alkyl group which may have substituents, or a linear alkenyl group which may have substituents. 101 Examples include those similar to the above, and it is preferable that they are cyclic groups containing a fluorine atom, linear alkyl groups, or linear alkenyl groups. Among these, fluorinated alkyl groups are preferred, and the above Rd 1 A fluorinated alkyl group similar to the one shown is more preferable.

[0332] In formula (d1-3), Rd 4 R in formula (b-1) is a cyclic group which may have substituents, a linear alkyl group which may have substituents, or a linear alkenyl group which may have substituents. 101 Examples include those similar to the above. In particular, alkyl groups, alkoxy groups, alkenyl groups, and cyclic groups, which may have substituents, are preferred. Rd 4 The alkyl group in is preferably a linear or branched alkyl group having 1 to 5 carbon atoms. Specifically, examples include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, etc. 4 Some of the hydrogen atoms in the alkyl group may be substituted with hydroxyl groups, cyano groups, etc. Rd 4The alkoxy group in is preferably an alkoxy group having 1 to 5 carbon atoms. Specifically, examples of alkoxy groups having 1 to 5 carbon atoms include the methoxy group, ethoxy group, n-propoxy group, iso-propoxy group, n-butoxy group, and tert-butoxy group. Among these, the methoxy group and ethoxy group are preferred.

[0333] Rd 4 The alkenyl group in formula (b-1) is R 101 Examples include those similar to the above, with vinyl groups, propenyl groups (allyl groups), 1-methylpropenyl groups, and 2-methylpropenyl groups being preferred. These groups may further have a C1-C5 alkyl group or a C1-C5 halogenated alkyl group as substituents.

[0334] Rd 4 The cyclic group in is R in formula (b-1) above. 101 Examples include those similar to the above, and preferred are alicyclic groups obtained by removing one or more hydrogen atoms from cycloalkanes such as cyclopentane, cyclohexane, adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane, or aromatic groups such as phenyl groups and naphthyl groups. 4 When the group is an alicyclic group, the resist composition dissolves well in organic solvents, resulting in good lithography properties.

[0335] In formula (d1-3), Yd 1 It is a single bond or a divalent linking group. Yd 1 The divalent linking group in formula (a10-1) is not particularly limited, but may include divalent hydrocarbon groups (aliphatic hydrocarbon groups, aromatic hydrocarbon groups) which may have substituents, and divalent linking groups containing heteroatoms. These are, respectively, Ya in formula (a10-1) above. x1 Examples include divalent hydrocarbon groups that may have substituents, and divalent linking groups containing heteroatoms, as mentioned in the explanation of divalent linking groups in [the relevant section]. Yd 1The preferred members are carbonyl groups, ester bonds, amide bonds, alkylene groups, or combinations thereof. The alkylene group is more preferably a linear or branched alkylene group, and even more preferably a methylene group or an ethylene group.

[0336] The following are preferred specific examples of the anionic parts of components (d1-3).

[0337] [ka]

[0338] [ka]

[0339] • Cation section In formula (d1-3), M' m+ This is an m-valent onium cation, and M' in formula (d1-1) above. m+ It is similar to that. (d1-3) Components may be used individually or in combination of two or more.

[0340] Component (D1) may consist of only one of the above components (d1-1) to (d1-3), or it may consist of a combination of two or more components. If the resist composition contains component (D1), the content of component (D1) in the resist composition is preferably 0.5 to 10 parts by mass per 100 parts by mass of component (A). When the content of component (D1) is above the preferred lower limit, particularly good lithography characteristics and resist pattern shapes are easily obtained. On the other hand, when it is below the upper limit, a balance with other components can be achieved, resulting in good lithography characteristics across various categories.

[0341] (D1) Method for producing component: The methods for producing the aforementioned components (d1-1) and (d1-2) are not particularly limited and can be produced by known methods. Furthermore, the method for producing components (d1-3) is not particularly limited and may be, for example, similar to the method described in US2012-0149916.

[0342] • About the (D2) component Component (D2) is a basic component, a nitrogen-containing organic compound that acts as an acid diffusion control agent in the resist composition.

[0343] Component (D2) is not particularly limited as long as it acts as an acid diffusion control agent and does not fall under components (D0) or (D1), for example, aliphatic amines, aromatic amines, etc.

[0344] Among aliphatic amines, secondary and tertiary aliphatic amines are preferred. An aliphatic amine is an amine having one or more aliphatic groups, and it is preferable that the aliphatic groups have 1 to 12 carbon atoms. Examples of aliphatic amines include amines (alkylamines or alkyl alcoholamines) or cyclic amines in which at least one hydrogen atom of ammonia (NH3) is substituted with an alkyl group or hydroxyalkyl group having 12 or fewer carbon atoms. 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 are particularly preferred.

[0345] Examples of cyclic amines include heterocyclic compounds containing a nitrogen atom as a heteroatom. These heterocyclic compounds may be monocyclic (aliphatic monocyclic amines) or polycyclic (aliphatic polycyclic amines). Examples of aliphatic monocyclic amines include piperidine and piperazine. As aliphatic polycyclic amines, those having 6 to 10 carbon atoms are preferred, and specifically 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.

[0346] Other aliphatic amines include tris(2-methoxymethoxyethyl)amine, tris{2-(2-methoxyethoxy)ethyl}amine, tris{2-(2-methoxyethoxymethoxy)ethyl}amine, tris{2-(1-methoxyethoxy)ethyl}amine, tris{2-(1-ethoxyethoxy)ethyl}amine, tris{2-(1-ethoxypropoxy)ethyl}amine, tris[2-{2-(2-hydroxyethoxy)ethoxy}ethyl]amine, triethanolamine triacetate, etc., with triethanolamine triacetate being preferred.

[0347] Examples of aromatic amines include 4-dimethylaminopyridine, pyrrole, indole, pyrazole, imidazole or their derivatives, trimenzylamine, aniline compounds, and N-tert-butoxycarbonylpyrrolidine.

[0348] (D2) Component may be used alone or in combination of two or more types. (D2) Among the above, aromatic amines are preferred for component (D2), and aniline compounds are more preferred. Examples of aniline compounds include 2,6-diisopropylaniline, N,N-dimethylaniline, N,N-dibutylaniline, and N,N-dihexylaniline.

[0349] When the resist composition contains component (D2), component (D2) is typically used in the range of 0.01 to 5 parts by mass per 100 parts by mass of component (A). By using this range, a balance with other components can be achieved, resulting in good lithography characteristics.

[0350] In the resist composition of this embodiment, the total content of component (B) and component (D) is 25 parts by mass or more and 60 parts by mass or less, preferably 25 parts by mass or more and 55 parts by mass or less, and more preferably 30 parts by mass or more and 50 parts by mass or less, per 100 parts by mass of component (A). If the total content of component (B) and component (D) is above the lower limit of the range, lithography characteristics such as sensitivity, roughness reduction, and shape will be further improved during resist pattern formation. On the other hand, if it is below the upper limit of the range, film thinning of the resist pattern will be more easily suppressed.

[0351] Furthermore, the ratio of the content of component (B) to the content of component (D0) in the resist composition [molar ratio (B) / (D0)] is preferably greater than 1, more preferably 1.5 to 10, even more preferably 3.8 to 5.3, and particularly preferably 4.0 to 5.1, as this makes it easier to enhance the effects of the present invention. If the molar ratio (B) / (D0) is above the lower limit of the preferred range described above, lithography characteristics such as sensitivity, roughness reduction, and shape are further improved during resist pattern formation. On the other hand, if it is below the upper limit of the preferred range described above, film thinning of the resist pattern is more easily suppressed.

[0352] <Optional ingredients> The resist composition of this embodiment may further contain components other than those described above (components (A), (B), and (D) (optional components). Examples of such optional components include the (E), (F), and (S) components shown below.

[0353] <<At least one compound (E) selected from the group consisting of organic carboxylic acids, phosphorus oxoacids and their derivatives>> The resist composition of this embodiment may contain, as an optional component, at least one compound (E) selected from the group consisting of organic carboxylic acids and phosphorus oxoacids and their derivatives (hereinafter referred to as "component (E)"). 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 among these. Examples of derivatives of phosphorus oxoacids include esters obtained by substituting the hydrogen atoms of the above oxoacid with hydrocarbon groups, and examples of hydrocarbon groups include alkyl groups having 1 to 5 carbon atoms and aryl groups having 6 to 15 carbon atoms. Examples of phosphoric acid derivatives include phosphate esters such as di-n-butyl phosphate and diphenyl phosphate. Examples of phosphonic acid derivatives include phosphonic acid esters such as dimethyl phosphonate, di-n-butyl phosphonate, phenylphosphonic acid, diphenyl phosphonate, and dibenzyl phosphonate. Examples of phosphinic acid derivatives include phosphinic acid esters and phenylphosphinic acid. In the resist composition of this embodiment, component (E) may be used alone or in combination of two or more types. When the resist composition contains component (E), the content of component (E) is usually in the range of 0.01 to 5 parts by mass per 100 parts by mass of component (A).

[0354] ≪Fluorine additive component (F)≫ The resist composition of this embodiment may contain a fluorine additive component (hereinafter referred to as "component (F)") in order to impart water repellency to the resist film or to improve lithography properties. As component (F), for example, fluorine-containing polymer compounds described in Japanese Patent Publication No. 2010-002870, Japanese Patent Publication No. 2010-032994, Japanese Patent Publication No. 2010-277043, Japanese Patent Publication No. 2011-13569, and Japanese Patent Publication No. 2011-128226 can be used. More specifically, component (F) includes polymers having a constituent unit (f1) represented by the following general formula (f1-1). Preferably, this polymer is a polymer (homopolymer) consisting only of the constituent unit (f1) represented by the following formula (f1-1); a copolymer of the constituent unit (f1) and the constituent unit (a1); or a copolymer of the constituent unit (f1) and a constituent unit derived from acrylic acid or methacrylic acid and the constituent unit (a1). Here, the constituent unit (a1) copolymerized with the constituent unit (f1) is preferably a constituent unit derived from 1-ethyl-1-cyclooctyl (meth)acrylate or a constituent unit derived from 1-methyl-1-adamantyl (meth)acrylate.

[0355] [ka] [In the formula, R is the same as above, and Rf 102 and Rf 103 Each of these 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, and Rf 102 and Rf 103 They may be the same or different. 1 Rf is an integer between 0 and 5. 101 It is an organic group containing a fluorine atom.

[0356] In formula (f1-1), R bonded to the α-carbon atom is the same as described above. R is preferably a hydrogen atom or a methyl group. In formula (f1-1), Rf 102 and Rf 103 As the halogen atom, fluorine is particularly preferred. Rf 102 and Rf 103 Examples of C1-C5 alkyl groups for R include those similar to those for R above, with methyl or ethyl groups being preferred. 102 and Rf 103Specifically, examples of C1-C5 halogenated alkyl groups include groups in which some or all of the hydrogen atoms of the C1-C5 alkyl group are substituted with halogen atoms. Fluorine atoms are particularly preferred as the halogen atom, especially Rf. 102 and Rf 103 Preferably, the element is 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 formula (f1-1), nf 1 is an integer between 0 and 5, preferably between 0 and 3, and more preferably 1 or 2.

[0357] In formula (f1-1), Rf 101 This is an organic group containing a fluorine atom, and preferably a hydrocarbon group containing a fluorine atom. The hydrocarbon group containing a fluorine atom 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 hydrocarbon groups containing fluorine atoms, it is preferable that 25% or more of the hydrogen atoms in the hydrocarbon group are fluorinated, more preferably 50% or more are fluorinated, and particularly preferable that 60% or more are fluorinated, as this increases the hydrophobicity of the resist film during immersion exposure. Among them, Rf 101 More preferably, a fluorinated hydrocarbon group having 1 to 6 carbon atoms is preferred, and trifluoromethyl, -CH2-CF3, -CH2-CF2-CF3, -CH(CF3)2, -CH2-CH2-CF3, and -CH2-CH2-CF2-CF2-CF2-CF3 are particularly preferred.

[0358] The weight-average molecular weight (Mw) of component (F) (based on polystyrene conversion 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. If it is below the upper limit of this range, it has sufficient solubility in resist solvents for use as a resist, and if it is above the lower limit of this range, the water repellency of the resist film is good. The degree of dispersion of component (F) (Mw / Mn) is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and most preferably 1.0 to 2.5.

[0359] In the resist composition of this embodiment, component (F) may be used alone or in combination of two or more types. When the resist composition contains component (F), the amount of component (F) is usually 0.5 to 10 parts by mass per 100 parts by mass of component (A).

[0360] ≪Organic solvent component (S)≫ The resist composition of this embodiment can be manufactured by dissolving the resist material in an organic solvent component (hereinafter referred to as "component (S)"). The (S) component can be any solvent that can dissolve each component used to form a homogeneous solution, and any solvent can be appropriately selected from those conventionally known as solvents for chemically amplified resist compositions. (S) components include, for example, 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 ester bonds such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, or dipropylene glycol monoacetate; monoalkyl ethers such as monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether, or monophenyl ether of the aforementioned polyhydric alcohols or compounds having ester bonds; etc. Examples include derivatives of polyhydric alcohols [of 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, phenethole, butylphenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene, and mesitylene, and dimethyl sulfoxide (DMSO). In the resist composition of this embodiment, component (S) may be used alone or as a mixture of two or more solvents. Among these, PGMEA, PGME, γ-butyrolactone, EL, and cyclohexanone are preferred.

[0361] Furthermore, a mixed solvent obtained by mixing PGMEA and a polar solvent is also preferred as component (S). The mixing ratio (mass ratio) can be appropriately determined considering the compatibility of PGMEA and the polar solvent, but it is preferably in the range of 1:9 to 9:1, and more preferably in the range of 2:8 to 8:2. More specifically, when EL or cyclohexanone is used as the polar solvent, the mass ratio of PGMEA to EL or cyclohexanone is preferably 1:9 to 9:1, more preferably 2:8 to 8:2. When PGME is used as the polar solvent, the mass ratio of PGMEA to PGME is preferably 1:9 to 9:1, more preferably 2:8 to 8:2, and even more preferably 3:7 to 7:3. Furthermore, a mixed solvent of PGMEA, PGME, and cyclohexanone is also preferred. Furthermore, as the (S) component, a mixed solvent of at least one selected from PGMEA and EL and γ-butyrolactone is also preferred. In this case, the mass ratio of the former to the latter is preferably 70:30 to 95:5. The amount of component (S) used is not particularly limited and is set appropriately according to the coating thickness, at a concentration that can be applied to a substrate or the like. Generally, component (S) is used so that the solid content concentration of the resist composition is in the range of 0.1 to 20% by mass, preferably 0.2 to 15% by mass.

[0362] The resist composition of this embodiment may further contain, if desired, miscible additives such as additional resins to improve the performance of the resist film, dissolution inhibitors, plasticizers, stabilizers, colorants, anti-halation agents, dyes, etc.

[0363] The resist composition of this embodiment may be subjected to removal of impurities after dissolving the resist material in component (S), using a polyimide porous membrane, a polyamide-imide porous membrane, or the like. For example, the resist composition may be filtered using a filter made of a polyimide porous membrane, a filter made of a polyamide-imide porous membrane, or a filter made of a polyimide porous membrane and a polyamide-imide porous membrane. Examples of the polyimide porous membrane and the polyamide-imide porous membrane include those described in Japanese Patent Application Publication No. 2016-155121.

[0364] In the resist composition of this embodiment described above, the acid generator component (B) and the base component (D) are contained in a total content of 25 parts by mass or more and 60 parts by mass or less per 100 parts by mass of the base component (A). In addition, component (D) contains a compound (D0) represented by the general formula (d0). This (D0) component is a polar linking group Xd 0 And, at the terminal is the organic group Rd 0 It has such properties that its solubility in the developer is appropriately controlled. As a result, even if components (B) and (D) are added in large quantities to the resist composition, the film thinning that is a problem in conventional resists is less likely to occur. Furthermore, component (D0) has a polar linking group Xd 0 Because it has this property, the acidity of the acid generated from component (D0) is increased. Therefore, it is presumed that the resist composition of the embodiment can achieve high sensitivity, improve lithography characteristics such as roughness reduction, and easily form resist patterns with a high residual film ratio, while also being less prone to pattern film thinning.

[0365] Furthermore, using the resist composition of the embodiment increases the uniformity of compound (D0) within the formed resist film, making it easy to form a high-resolution resist pattern with reduced roughness and a good shape.

[0366] (Method for forming resist patterns) A resist pattern formation method according to a second aspect of the present invention is a method comprising the steps of forming a resist film on a support using the resist composition of the above-described embodiment, exposing the resist film, and developing the exposed resist film to form a resist pattern. One embodiment of such a resist pattern formation method is, for example, a resist pattern formation method carried out as follows.

[0367] First, the resist composition of the above-described embodiment is applied onto a support using a spinner or the like, and a bake (post-application bake (PAB)) treatment is performed for 40 to 120 seconds, preferably 60 to 90 seconds, at a temperature of, for example, 80 to 150°C, to form a resist film. Next, the resist film is subjected to selective exposure using an exposure apparatus such as an electron beam lithography apparatus or an EUV exposure apparatus, either through exposure via a mask (mask pattern) on which a predetermined pattern has been formed, or by direct irradiation with an electron beam without going through a mask pattern. After this, a bake (post-exposure bake (PEB)) treatment is performed for 40 to 120 seconds, preferably 60 to 90 seconds, at a temperature of, for example, 80 to 150°C. Next, the resist film is subjected to a developing process. In the case of an alkaline developing process, an alkaline developer is used, and in the case of a solvent developing process, a developer containing an organic solvent (organic developer) is used.

[0368] After the developing process, a rinsing process is preferably performed. In the case of an alkaline developing process, a water rinse using pure water is preferred, and in the case of a solvent developing process, a rinsing solution containing an organic solvent is preferred. In the case of a solvent development process, after the development or rinsing process, a process may be performed to remove the developer or rinse solution adhering to the pattern using a supercritical fluid. After development or rinsing, the film is dried. In some cases, a bake (post-bake) process may be performed after the development process. In this way, a resist pattern can be formed.

[0369] The support material is not particularly limited and can be any conventionally known material, such as a substrate for electronic components or a substrate on which a predetermined wiring pattern has been formed. More specifically, examples include silicon wafers, metal substrates such as copper, chromium, iron, and aluminum, and glass substrates. As for the wiring pattern material, for example, copper, aluminum, nickel, and gold can be used. Furthermore, the support may be a substrate as described above on which an inorganic and / or organic film is provided. An example of an inorganic film is an inorganic anti-reflective film (inorganic BARC). An example of an organic film is an organic anti-reflective film (organic BARC) or an organic film such as the underlayer organic film in the multilayer resist method. Here, the multilayer resist method is a method in which at least one organic film (lower organic film) and at least one resist film (upper resist film) are placed on a substrate, and the resist pattern formed on the upper resist film is used as a mask to pattern the lower organic film, and it is said that a high aspect ratio pattern can be formed. In other words, with the multilayer resist method, the required thickness can be secured by the lower organic film, so the resist film can be made thinner, and a fine pattern with a high aspect ratio can be formed. Multilayer resist methods can be broadly divided into two types: a two-layer resist method consisting of an upper resist film and a lower organic film, and a three-layer resist method consisting of three or more layers, with one or more intermediate layers (such as a thin metal film) placed between the upper resist film and the lower organic film.

[0370] The wavelength used for exposure is not particularly limited, and the process can be carried out using radiation such as ArF excimer lasers, KrF excimer lasers, F2 excimer lasers, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam), X-rays, and soft X-rays. The resist composition is highly useful for KrF excimer lasers, ArF excimer lasers, EB, or EUV, even more useful for ArF excimer lasers, EB, or EUV, and particularly useful for EB or EUV. In other words, the resist pattern formation method of this embodiment is particularly useful when the step of exposing the resist film includes an operation of exposing the resist film with EUV (extreme ultraviolet) or EB (electron beam).

[0371] The method for exposing the resist film may be conventional exposure (dry exposure) performed in an inert gas such as air or nitrogen, or it may be liquid immersion lithography. Immersion lithography is an exposure method in which the space between the resist film and the lens at the lowest position of the exposure apparatus is first 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. As the immersion medium, a solvent having a refractive index greater than that of air and less than that of the resist film being exposed is preferred. The refractive index of such a solvent is not particularly limited as long as it is within the aforementioned range. Examples of solvents having a refractive index greater than that of air and less than that of the resist film include water, fluorine-based inert liquids, silicon-based solvents, and hydrocarbon-based solvents. Specific examples of fluorinated inert liquids include liquids mainly composed of fluorinated compounds such as C3HCl2F5, C4F9OCH3, C4F9OC2H5, and C5H3F7, with a boiling point of 70 to 180°C being preferred, and more preferably 80 to 160°C. Having a boiling point within the above range of the fluorinated inert liquid is preferable because it allows for the easy removal of the immersion medium after exposure. As fluorinated inert liquids, perfluoroalkyl compounds in which all hydrogen atoms of the alkyl group are replaced with fluorine atoms are particularly preferred. Specific examples of perfluoroalkyl compounds include perfluoroalkyl ether compounds and perfluoroalkylamine compounds. More specifically, perfluoro(2-butyl-tetrahydrofuran) (boiling point 102°C) can be cited as the perfluoroalkyl ether compound, and perfluorotributylamine (boiling point 174°C) can be cited as the perfluoroalkylamine compound. Water is preferred as the immersion medium from the viewpoints of cost, safety, environmental issues, and versatility.

[0372] Examples of alkaline developers used in the alkaline development process include 0.1 to 10% by mass of tetramethylammonium hydroxide (TMAH) aqueous solution. The organic solvent contained in the organic developer solution used in the solvent development process can be any solvent capable of dissolving component (A) (component (A) before exposure), and can be appropriately selected from known organic solvents. Specifically, 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 solvents are organic solvents that contain CC(=O)-C in their structure. Ester solvents are organic solvents that contain CC(=O)-OC in their structure. Alcohol solvents are organic solvents that contain an alcoholic hydroxyl group in their structure. An "alcoholic hydroxyl group" refers to a hydroxyl group bonded to a carbon atom of an aliphatic hydrocarbon group. Nitrile solvents are organic solvents that contain a nitrile group in their structure. Amide solvents are organic solvents that contain an amide group in their structure. Ether solvents are organic solvents that contain COC in their structure. Some organic solvents contain multiple functional groups in their structure that characterize each of the above-mentioned solvents. In such cases, the organic solvent shall be considered to belong to any of the solvent categories that contain the functional groups it possesses. For example, diethylene glycol monomethyl ether shall belong to either the alcohol-based solvent or the ether-based solvent category in the above classification. Hydrocarbon solvents consist of hydrocarbons that may be halogenated and do not have substituents other than halogen atoms. Fluorine atoms are preferred as the halogen atom. Among the above, polar solvents are preferred as organic solvents contained in organic developers, and ketone solvents, ester solvents, nitrile solvents, etc., are preferred.

[0373] 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, and methyl amyl ketone (2-heptanone). Among these, methyl amyl ketone (2-heptanone) is preferred as the ketone solvent.

[0374] Examples of ester solvents include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, isoamyl acetate, ethyl methoxyethyl acetate, ethyl ethoxyethyl acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monophenyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monopropyl ether acetate, diethylene glycol 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 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 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.

[0375] Examples of nitrile solvents include acetonitrile, propionitrile, valeronitrile, and butyronitrile.

[0376] Organic developers may contain known additives as needed. Examples of such additives include surfactants. While not particularly limited, surfactants such as ionic or nonionic fluorine-based and / or silicone-based surfactants can be used. Nonionic surfactants are preferred, with 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% by mass, preferably 0.005 to 2% by mass, and more preferably 0.01 to 0.5% by mass, relative to the total amount of the organic developer.

[0377] The development process can be carried out by known development methods, such as immersing the support in a developer solution for a certain period of time (dip method), piling the developer solution onto the surface of the support using surface tension and leaving it still for a certain period of time (paddle method), spraying the developer solution onto the surface of the support (spray method), or continuously dispensing the developer solution onto a support rotating at a constant speed while scanning the developer dispensing nozzle at a constant speed (dynamic dispensing method).

[0378] As for the organic solvent contained in the rinsing solution used for rinsing after development in the solvent development process, for example, organic solvents that do not easily dissolve the resist pattern can be appropriately selected and used from among the organic solvents listed as organic solvents used in the organic developer solution. Typically, 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 selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, and amide solvents is preferred, at least one selected from alcohol solvents and ester solvents is more preferred, and alcohol solvents are particularly preferred. The alcohol-based solvent used in the rinsing solution is preferably a monohydric alcohol having 6 to 8 carbon atoms, and this monohydric alcohol may be linear, branched, or cyclic. Specifically, examples include 1-hexanol, 1-heptanol, 1-octanol, 2-hexanol, 2-heptanol, 2-octanol, 3-hexanol, 3-heptanol, 3-octanol, 4-octanol, and benzyl alcohol. Among these, 1-hexanol, 2-heptanol, and 2-hexanol are preferred, and 1-hexanol and 2-hexanol are more preferred. These organic solvents may be used individually or in combination of two or more. They may also be mixed with other organic solvents or water. However, considering the developing 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, relative to the total volume of the rinse solution. The rinse solution may contain known additives as needed. Examples of such additives include surfactants. Examples of surfactants are the same as 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% by mass, preferably 0.005 to 2% by mass, and more preferably 0.01 to 0.5% by mass, relative to the total volume of the rinse solution.

[0379] Rinsing (cleaning) using a rinsing solution can be carried out by known rinsing methods. Examples of such rinsing methods include continuously applying the rinsing solution onto a support rotating at a constant speed (rotary coating method), immersing the support in the rinsing solution for a certain period of time (dip method), and spraying the rinsing solution onto the surface of the support (spray method).

[0380] According to the resist pattern formation method of this embodiment described above, since the resist composition of the above-described embodiment is used, sensitivity can be increased when forming the resist pattern, and a resist pattern with better lithography characteristics (such as reduced roughness) can be formed. In addition, in the resist pattern formation method of this embodiment, even if the total content of the acid generator component (B) and the base component (D) in the resist composition is increased, film thinning is less likely to occur, and a resist pattern with a high residual film ratio can be formed. [Examples]

[0381] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0382] <Examples of manufacturing polymer compounds (A-1) to (A-5)> Polymer compounds (A-1) to (A-5) were each obtained by known radical polymerization using monomers that induce the constituent units of each polymer compound in a predetermined molar ratio.

[0383] The obtained polymer compounds (A-1) to (A-5) are shown below.

[0384] [ka]

[0385] Regarding the obtained polymer compound, 13 Table 1 shows the copolymerization composition ratio (proportion (molar ratio) of constituent units derived from each monomer) of the polymer compound determined by 13C-NMR, and the weight-average molecular weight (Mw) and molecular weight dispersion (Mw / Mn) in terms of standard polystyrene, determined by GPC measurement.

[0386] [Table 1]

[0387] <Preparation of the resist composition> (Examples 1-16, Comparative Examples 1-22) The components shown in Tables 2 and 3 were mixed and dissolved to prepare the resist compositions (solid content concentration 1.7% by mass) for each example.

[0388] [Table 2]

[0389] [Table 3]

[0390] In Tables 2 and 3, each abbreviation has the following meaning. The numbers in brackets [ ] represent the amount (parts by mass) of the ingredients. (A)-1 to (A)-5: The above polymer compounds (A-1) to (A-5). (B)-1: An acid generator consisting of a compound represented by the following chemical formula (B-1). (B)-2: An acid generator consisting of a compound represented by the following chemical formula (B-2). (B)-3: An acid generator consisting of a compound represented by the following chemical formula (B-3). (B)-4: An acid generator consisting of a compound represented by the following chemical formula (B-4). (B)-5: An acid generator consisting of a compound represented by the following chemical formula (B-5). (B)-6: An acid generator consisting of a compound represented by the following chemical formula (B-6).

[0391] [ka]

[0392] (D0)-1: A compound represented by the following chemical formula (D0-1). (D0)-2: A compound represented by the following chemical formula (D0-2). (D0)-3: A compound represented by the following chemical formula (D0-3). (D0)-4: A compound represented by the following chemical formula (D0-4). (D0)-5: A compound represented by the following chemical formula (D0-5).

[0393] [ka]

[0394] (D1)-1: An acid diffusion control agent comprising a compound represented by the following chemical formula (D1-1). (D1)-2: An acid diffusion control agent comprising a compound represented by the following chemical formula (D1-2). (D1)-3: An acid diffusion control agent consisting of a compound represented by the following chemical formula (D1-3). (S)-1: A mixed solvent of propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether = 60 / 40 (mass ratio).

[0395] [ka]

[0396] <Formation of resist pattern (1)> Each example of the resist composition was applied to an 8-inch silicon substrate treated with hexamethyldisilazane (HMDS) using a spinner, and a 50 nm thick resist film was formed by pre-baking (PAB) on a hot plate at 110°C for 60 seconds and drying. Next, the resist film was subjected to lithography (exposure) using an electron beam lithography system JEOL-JBX-9300FS (manufactured by JEOL Ltd.) at an acceleration voltage of 100kV, creating a 1:1 line-and-space pattern (hereinafter referred to as "LS pattern") with a target size of 50-20nm line width. Subsequently, a post-exposure heating (PEB) treatment was performed at 100°C for 60 seconds. Next, alkaline development was performed at 23°C for 60 seconds using a 2.38% by mass aqueous solution of tetramethylammonium hydroxide (TMAH) "NMD-3" (product name, manufactured by Tokyo Ohka Kogyo Co., Ltd.). After that, a water rinse was performed with pure water for 15 seconds. As a result, 1:1 LS patterns with line widths of 50 to 20 nm were formed.

[0397] [Evaluation of optimal exposure (Eop)] The optimal exposure dose Eop(μC / cm²) for forming a 50nm LS pattern using the above <Formation of Resist Pattern (1)> is required. 2 We calculated this as "Eop(μC / cm²)". 2 )" is shown in Tables 4 and 5.

[0398] [LWR (Line Wise Roughness) Evaluation] For the LS pattern with a target size of 50 nm formed in the above <Formation of Resist Pattern (1)>, 3σ, a measure of LWR, was determined. This is shown as "LWR(nm)" in Tables 4 and 5. "3σ" represents three times the standard deviation (σ) (unit: nm) obtained from measurements of 400 line positions along the longitudinal direction of the line using a scanning electron microscope (acceleration voltage 800V, product name: S-9380, manufactured by Hitachi High-Technologies Corporation). A smaller value of 3σ indicates less roughness on the line sidewalls, resulting in a more uniformly wide LS pattern.

[0399] [Evaluation of film thinning] Film loss was measured by comparing the film thickness of the resist film after PAB in the large unexposed area described in <Formation of Resist Pattern (1)> above with the film thickness of the resist film after rinsing. For the film thickness of the resist film after rinsing, a change of 3% or less compared to the film thickness of the resist film after PAB (residual film rate of 97% or more) was evaluated as ○, a change of more than 3% but within 5% (residual film rate of 95% or more but less than 97%) was evaluated as △, and a change of more than 5% (residual film rate of less than 95%) was evaluated as ×. This is shown as "film loss (nm)" in Tables 4 and 5.

[0400] [Table 4]

[0401] [Table 5]

[0402] The results shown in Tables 4 and 5 confirm that, according to the resist composition of the embodiment to which the present invention is applied, it is possible to form a resist pattern with good shape, high sensitivity, and reduced roughness during resist pattern formation. In addition, it can be confirmed that in the resist composition of the embodiment to which the present invention is applied, even if the total content of component (B) and component (D) is increased, the reduction of the pattern film is less likely to occur.

[0403] <Formation of resist pattern (2)> Using the resist compositions of Examples 1-3, Comparative Examples 1-3, and Comparative Examples 6-8, 1:1 LS patterns with a line width of 50 nm were formed in the same manner as in <Formation of Resist Pattern (1)> above. Then, in the same manner as in the [evaluation of film thinning] described above, the change in film thickness (residual film percentage) of the resist film after rinsing was determined relative to the resist film thickness after PAB. The results are shown in Figure 1.

[0404] Figure 1 is a graph showing the change in the residual film percentage of the resist film with respect to the total content of components (B) and (D) in the resist composition. In Figure 1, the circle (○) indicates that the change in the resist film thickness after rinsing is within 3% of the change in the resist film thickness after PAB (residual film rate of 97% or more). In Figure 1, "△" indicates the case where the change in film thickness is greater than 3% but within 5% (residual film thickness of 95% or more and less than 97%). In Figure 1, the "×" indicates the case where the change in film thickness is greater than 5% (residual film percentage is less than 95%).

[0405] As shown in Figure 1, in the case of a resist composition using compound (D0-1) as component (D), it can be confirmed that even when the total content of components (B) and (D) is increased to 60 parts by mass, the residual film rate of the resist film remains at 97% or higher. In addition, it can be confirmed that in the resist compositions of Examples 1 to 3, in which the total content of components (B) and (D) is between 25 parts by mass and 60 parts by mass, high sensitivity can be achieved and a resist pattern with a good shape and reduced roughness can be formed. On the other hand, in the case of a resist composition using compound (D1-1) as component (D), when the total content of components (B) and (D) exceeded 25 parts by mass, the residual film rate of the resist film could not be maintained at 97%, and the residual film rate decreased significantly with increasing total content.

Claims

1. A resist composition that generates acid upon exposure and whose solubility in a developer changes due to the action of the acid, The material contains a base component (A) whose solubility in the developer solution changes due to the action of an acid, an acid generating agent component (B) that generates acid upon exposure, and a base component (D) that controls the diffusion of the acid generated from the acid generating agent component (B) upon exposure. The aforementioned base component (D) includes a compound (D0) represented by the following general formula (d0): The total content of the acid generator component (B) and the base component (D) is 25 parts by mass or more and 60 parts by mass or less per 100 parts by mass of the base component (A), in a resist composition (excluding, however, a resist material comprising a base polymer and a sulfonium salt represented by the following general formula (d'-1) and / or an iodonium salt represented by (d'-2), a chemically amplified resist composition comprising an onium salt compound represented by the following formula (d''-1), a chemically amplified resist composition comprising an onium salt compound represented by the following formula (1), and a chemically amplified resist composition comprising an onium salt compound represented by the following formula (2)). 【Chemistry 1】 [In the formula, Rd ０ Xd is an aromatic hydrocarbon group which may have substituents. ０ These are -O-, -C(=O)-, -O-C(=O)-, -C(=O)-O-, -S-, or -SO ２ - is the case. Yd ０ This is a divalent hydrocarbon group or single bond, which may have substituents. ｍ＋ This represents an m-valent organic cation, where m is an integer greater than or equal to 1. 【Chemistry 2】 [wherein, R 1 is a hydroxy group, a carboxy group, a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms, an alkoxy group, an alkoxycarbonyl group, an alkenyloxy group or alkynyloxy group having 2 to 6 carbon atoms, a linear, branched or cyclic acyloxy group having 2 to 6 carbon atoms, a fluorine atom, a chlorine atom, an amino group, -NR 7 -C(=O)-R 8 or -NR 7 -C(=O)-O-R 8 ; R 7 is a hydrogen atom or a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms; R 8 is a linear, branched or cyclic alkyl group having 1 to 8 carbon atoms or a linear, branched or cyclic alkenyl group having 2 to 8 carbon atoms. R 2 , R 3 and R 4 are each independently a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a linear, branched or cyclic alkyl group having 1 to 12 carbon atoms, a linear, branched or cyclic alkenyl group having 2 to 12 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an aralkyl group or aryloxoalkyl group having 7 to 12 carbon atoms, and some or all of the hydrogen atoms of these groups may be substituted with a hydroxy group, a carboxy group, a halogen atom, an oxo group, a cyano group, an amide group, a nitro group, a sultone group, a sulfone group or a sulfonium salt-containing group, and the carbon atoms of these groups may be substituted with an ether group, an ester group, a carbonyl group, a carbonate group or a sulfonic acid ester group. Further, R 2 and R 3 may combine to form a ring together with the sulfur atom to which they are attached. R 5 and R 6 Xd' is a C6-C10 aryl group, a linear, branched, or cyclic C2-C6 alkenyl group, a linear, branched, or cyclic C2-C6 alkynyl group, or a trifluoromethyl group, and some or all of the hydrogen atoms of these groups may be substituted with halogen atoms, trifluoromethyl groups, linear, branched, or cyclic C1-C10 alkyl or alkoxy groups, hydroxyl groups, carboxyl groups, linear, branched, or cyclic C2-C10 alkoxycarbonyl groups, nitro groups, or cyano groups. Xd' is a single bond, or a C1-C20 (pd'+1) valent linking group which may contain an ether group, carbonyl group, ester group, amide group, sultone group, lactam group, carbonate group, halogen atom, hydroxyl group, or carboxyl group. md' is an integer between 1 and 5. nd' is an integer between 0 and 3. pd' is an integer between 1 and 3. 【Transformation 3】 (In the formula, R' １ and R' ２ Each of these is independently a hydrogen atom, a hydroxyl group, or a hydrocarbyl group having 1 to 12 carbon atoms, and the hydrogen atom in the hydrocarbyl group may be substituted with a group containing a heteroatom, and the -CH in the hydrocarbyl group ２ The - may be replaced by -O- or -C(=O)-. Also, R' １ and R' ２ However, they may bond with each other to form a ring with the carbon atoms to which they are bonded. f１ and R ｆ２ Each of these is independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group, but at least one of them is a fluorine atom or a trifluoromethyl group. １ This is a single bond or a hydrocarbylene group having 1 to 15 carbon atoms, and the hydrogen atoms in the hydrocarbylene group may be substituted with a group containing a heteroatom, and the -CH in the hydrocarbylene group ２ The - can be replaced with -O- or -C(=O)-. ２ This is a single bond, an ether bond, or an ester bond. Ar is an aromatic group with 3 to 15 carbon atoms and a (nd''+1) valency, and some or all of the hydrogen atoms of the aromatic group may be substituted with substituents. nd'' is an integer satisfying 1 ≤ nd'' ≤ 5. M'' ＋ (This is a sulfonium cation or an iodonium cation.) 【Chemistry 4】 (In the formula, m, n, and k are each independently 0 or a positive integer, provided that 1 ≤ m + n + k.) R7 is a halogen atom, a trifluoromethyl group, or a trifluoromethoxy group. R8 is a C1-C15 hydrocarbyl group which may contain a hydrogen atom or a heteroatom. L3 is -C(=O)-, -C(=O)-O-, -S(=O)-, -S(=O)²-, or -S(=O)²-O-. L 4 is *-C(=O)-, *-C(=O)-O-, *-S(=O)-, *-S(=O)²-, or -S(=O)²-O-. * represents a bond with ring R 9. L5 is a single bond or a C1-C15 hydrocarbilene group, and the hydrogen atoms in the hydrocarbilene group may be substituted with a heteroatom-containing group, and the -CH2- in the hydrocarbilene group may be substituted with -O-, -C(=O)-, -S-, -S(=O)-, -S(=O)2-, or -N(RN)-. However, when L5 is a hydrocarbilene group, the carbon atom bonded to -OCF2CO2- in the formula does not bond with any heteroatoms other than the oxygen atom in the formula. RN is a hydrogen atom or a C1-C10 hydrocarbyl group, and the hydrogen atoms in the hydrocarbyl group may be substituted with a heteroatom-containing group, and the -CH2- in the hydrocarbyl group may be substituted with -O-, -C(=O)-, or -S(=O)2-. Ring R9 is an (m+n+1) valent cyclic hydrocarbon group when k is 0, and is an (m+n+1) valent cyclic hydrocarbon group containing k L3 when k is a positive integer, and the hydrogen atoms in the cyclic hydrocarbon group may be substituted with heteroatom-containing groups, and the -CH2- in the cyclic hydrocarbon group may be substituted with -O- or -S-. M+ is either a sulfonium cation or an iodonium cation. 【Transformation 5】 (In the formula, R10 and R11 are each independently a C1-C10 hydrocarbyl group which may contain a hydrogen atom or a heteroatom. Also, R10 and R11 may bond to each other to form a ring with the carbon atom to which they are bonded.) R f3 and R f4 are each independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group, but at least one of them is a fluorine atom or a trifluoromethyl group. L4 is either a single bond or a carbonyl group. Ar1 is a (p+1) valent aromatic group having 3 to 15 carbon atoms, which may have substituents. p is an integer that satisfies the conditions 1 ≤ p ≤ 5. M+ is an ammonium cation, a sulfonium cation, or an iodonium cation. R12 is a group represented by the following formulas (R-1), (R-2), (R-3), (R-4), or (R-5). 【Transformation 6】 (In the formula, R r1, R r2, R r3, and R r4 are each independently a hydrocarbyl group having 1 to 10 carbon atoms. Also, R r1 and R r2 may bond to each other to form a ring with the carbon atoms to which they are bonded.) R r5 and R r6 are each independently a hydrogen atom or a hydrocarbyl group having 1 to 5 carbon atoms. Furthermore, any two of R r4, R r5, and R r6 may bond to each other to form a ring with the atom to which they are bonded. The dashed line represents the bond with Ar 1 in equation (2).

2. The resist composition according to claim 1, wherein the content of the compound (D0) is 4 parts by mass or more and 20 parts by mass or less per 100 parts by mass of the base component (A).

3. The resist composition according to claim 1 or 2, wherein the content of the acid generating agent component (B) is 20 parts by mass or more per 100 parts by mass of the base material component (A).

4. The resist composition according to any one of claims 1 to 3, wherein the ratio of the content of the acid generator component (B) to the content of the compound (D0) [molar ratio (B) / (D0)] is 1.5 to 10.

5. A method for forming a resist pattern, comprising the steps of: forming a resist film on a support using a resist composition according to any one of claims 1 to 4; exposing the resist film; and developing the exposed resist film to form a resist pattern.

6. The resist pattern forming method according to claim 5, wherein in the step of exposing the resist film, the resist film is exposed to EUV (extreme ultraviolet) or EB (electron beam).

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