Actinic light sensitive or radiation sensitive resin composition, resist film, pattern formation method, and method for manufacturing electronic device

Abstract

A first problem addressed by the present invention is to provide an actinic light-sensitive or radiation-sensitive resin composition that can form patterns having excellent LWR and defect suppression. A second problem addressed by the present invention is to provide a resist film, a pattern formation method, and a method for manufacturing a device.　This actinic light-sensitive or radiation-sensitive resin composition contains a resin and a salt that contains an anion moiety represented by formula (1) and a cation moiety represented by formula (X-1) or formula (X-2).

Description

Sensitive actinic ray or radiation-sensitive resin composition, resist film, pattern forming method, and method for manufacturing an electronic device

[0001] The present invention relates to a sensitive actinic ray or radiation-sensitive resin composition, a resist film, a pattern forming method, and a method for manufacturing an electronic device.

[0002] Conventionally, in the manufacturing process of semiconductor devices such as ICs (Integrated Circuits) and LSIs (Large Scale Integration), microfabrication by lithography using a sensitive actinic ray or radiation-sensitive resin composition (hereinafter, also simply referred to as "resist composition") has been performed. In recent years, with the high integration of integrated circuits, the formation of ultra-fine patterns in the sub-micron region or quarter-micron region has been required. Along with this, the exposure wavelength has also tended to become shorter, from g-line to i-line, and further to KrF excimer laser light. Currently, an exposure machine using an ArF excimer laser having a wavelength of 193 nm as a light source has been developed. Further, as a technique for further improving the resolution, the development of the so-called immersion method, in which a liquid with a high refractive index (hereinafter, also referred to as "immersion liquid") is filled between a projection lens and a sample, has been progressing.

[0003] Currently, in addition to excimer laser light, lithography using an electron beam (EB: Electron Beam), X-rays, extreme ultraviolet rays (EUV: Extreme Ultraviolet), etc. is also being developed. Along with this, resist compositions that are effectively sensitive to various actinic rays or radiations have been developed.

[0004] For example, in Patent Document 1, a resist composition containing the following salt compound is disclosed.

[0005]

[0006] Japanese Patent Application Laid-Open No. 2019-211751

[0007] Incidentally, in recent years, there has been progress in further miniaturization of resist patterns, and attempts have been made to form, for example, line and space (LS) patterns with a line width of 16 nm or less, contact hole patterns with a hole diameter of 16 nm or less, and dot patterns with a dot diameter of 16 nm or less. When forming such fine resist patterns, it is required that they have excellent roughness performance (specifically, excellent LWR (Line Width Roughness)) and a small number of defects (hereinafter also referred to as "excellent defect suppression"). The present inventors investigated the resist composition described in Patent Document 1 and found that there is room to further improve the LWR and defect suppression of the resist pattern (hereinafter also simply referred to as "pattern") formed by the resist composition.

[0008] Therefore, the object of the present invention is to provide a photosensitive or radiation-sensitive resin composition that can form a pattern with excellent LWR and defect suppression properties. The object of the present invention is also to provide a resist film, a pattern formation method, and a device manufacturing method.

[0009] The inventors have found that the above problems can be solved by the following configuration.

[0010] [1] A photosensitive or radiation-sensitive resin composition comprising a resin and a salt containing an anionic portion represented by formula (1) described later and a cation portion represented by formula (X-1) or formula (X-2) described later. [2] The photosensitive or radiation-sensitive resin composition according to [1], wherein the anionic portion of the salt is an anionic portion represented by formula (3-1) or formula (3-2) described later. [3] In formula (3-2) above, X ２ The above equation (Y-1) is represented, and *1 is L ２ When bonded to the side, L ２ [2] The photosensitive or radiation-sensitive resin composition described in [2], wherein X represents a divalent linking group having 6 or fewer carbon atoms. [4] In the above formula (3-2), X ２ The above equation (Y-1) is represented, and *1 is R ２[2] A photosensitive or radiation-sensitive resin composition according to [2], bonded to the side. [5] A photosensitive or radiation-sensitive resin composition according to any one of [1] to [4], wherein Wa represents a benzene ring group. [6] A photosensitive or radiation-sensitive resin composition according to any one of [1] to [5], wherein the salt includes a cation portion represented by the above formula (X-1). [7] A photosensitive or radiation-sensitive resin composition according to any one of [1] to [6], wherein the resin includes a repeating unit represented by the formula (18) described later. [8] A photosensitive or radiation-sensitive resin composition according to [7], wherein in the above formula (18), n2 represents an integer from 2 to 5. [9] A photosensitive or radiation-sensitive resin composition according to any one of [1] to [8], wherein the resin includes a repeating unit having an acid-degradable group having a structure in which a polar group is protected by a group that is removed by the action of an acid.

[10] A photosensitive or radiation-sensitive resin composition according to any one of [1] to [9], further comprising a photoacid generator.

[11] A photosensitive or radiation-sensitive film formed with a photosensitive or radiation-sensitive resin composition according to any one of [1] to

[10] .

[12] A pattern-forming method comprising the steps of: forming a photosensitive or radiation-sensitive film on a substrate using a photosensitive or radiation-sensitive resin composition according to any one of [1] to

[10] ; exposing the photosensitive or radiation-sensitive film; and developing the exposed photosensitive or radiation-sensitive film using a developer to form a pattern.

[13] A method for manufacturing an electronic device, comprising the pattern-forming method according to

[12] .

[0011] According to the present invention, a photosensitive or radiation-sensitive resin composition can be provided that can form patterns with excellent LWR and defect suppression properties. Furthermore, according to the present invention, a resist film, a pattern formation method, and a device manufacturing method can also be provided.

[0012] The present invention will now be described in detail. The following descriptions of constituent elements may be based on representative embodiments of the present invention, but the present invention is not limited to such embodiments. In this specification, regarding the notation of groups (atomic groups), unless contrary to the spirit of the present invention, notations that do not specify substituted or unsubstituted include both unsubstituted and substituted groups. For example, "alkyl group" includes not only unsubstituted alkyl groups but also substituted alkyl groups. In this specification, "organic group" means a group containing at least one carbon atom. Unless otherwise specified, monovalent substituents are preferred. In this specification, "active light" or "radiation" means, for example, the emission spectrum of a mercury lamp, far ultraviolet light represented by an excimer laser, extreme ultraviolet light (EUV), X-rays, and electron beams (EB). In this specification, "light" means active light or radiation. In this specification, "exposure" includes not only exposure with emission line spectra from mercury lamps, far ultraviolet light represented by excimer lasers, extreme ultraviolet light, X-rays, and EUV light, but also drawing with particle beams such as electron beams and ion beams, unless otherwise specified. In this specification, "~" is used to mean that the values ​​written before and after it are included as the lower and upper limits. In this specification, the bonding direction of divalent groups is not limited unless otherwise specified. For example, in a compound represented by the formula "X-Y-Z", if Y is -COO-, Y may also be -CO-O- or -O-CO-. Furthermore, the above compound may also be "X-CO-O-Z" or "X-O-CO-Z".

[0013] In this specification, the weight-average molecular weight (Mw), number-average molecular weight (Mn), and degree of dispersion (also called molecular weight distribution) (Mw / Mn) of a resin are defined as polystyrene-converted values ​​obtained by GPC (Gel Permeation Chromatography) measurement using a GPC (Gel Permeation Chromatography) instrument (Tosoh HLC-8120GPC) (solvent: tetrahydrofuran, flow rate (sample injection volume): 10 μL, column: Tosoh TSK gel Multipore HXL-M, column temperature: 40°C, flow rate: 1.0 mL / min, detector: differential refractive index detector).

[0014] In this specification, the acid dissociation constant (pKa) refers to the pKa in aqueous solution, and specifically, it is a value calculated using the software package 1 described below, based on a database of Hammett substituent constants and known literature values. All pKa values ​​described in this specification are values ​​calculated using this software package. Software package 1: Advanced Chemistry Development (ACD / Labs) Software V8.14 for Solaris (1994-2007 ACD / Labs).

[0015] Furthermore, pKa can also be determined by molecular orbital calculations. Specifically, this method involves calculating the H₂ in aqueous solution based on the thermodynamic cycle. ＋ One method is to calculate the dissociation free energy. ＋ The dissociation free energy can be calculated using, for example, the Density Functional Theory (DFT), but various other methods have been reported in the literature and are not limited to this. Several software programs exist that can perform DFT, such as Gaussian 16.

[0016] In this specification, pKa refers to a value calculated using software package 1 based on a database of Hammett substituent constants and known literature values, as described above. However, if pKa cannot be calculated using this method, the value obtained by Gaussian 16 based on DFT (density functional theory) shall be adopted. Furthermore, in this specification, pKa refers to "pKa in aqueous solution" as described above. However, if pKa in aqueous solution cannot be calculated, "pKa in dimethyl sulfoxide (DMSO) solution" shall be adopted.

[0017] In this specification, examples of halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms.

[0018] In this specification, "solids" refers to the components that form the resist film and does not include solvents. Furthermore, any component that forms the resist film is considered a solid, even if its properties are liquid.

[0019] In this specification, one inch can be converted to 0.0254 m.

[0020] [Photosensitive or Radiation-Sensitive Resin Composition] The photosensitive or radiation-sensitive resin composition of the present invention (hereinafter also referred to as the "resist composition") comprises a resin and a salt (hereinafter also referred to as the "specific salt compound") containing an anion portion represented by formula (1) and a cation portion represented by formula (X-1) or formula (X-2). The pattern formed by the resist composition of the present invention having the above configuration exhibits excellent LWR and defect suppression. The reason why the resist composition having the above configuration can solve the problems of the present invention is not necessarily clear, but the inventors speculate as follows. However, the following speculation does not limit the mechanism by which the effect is obtained. In other words, even if the effect is obtained by a mechanism other than the one described below, it is included in the scope of the present invention.

[0021] The inventor speculates that the main reasons why the pattern formed by the resist composition of the present invention is excellent in LWR and defect suppression are as follows: (1) the high light absorption of the resist film with respect to the exposure light, (2) the difficulty of the elimination of halogen atoms due to the decomposition of carbon-halogen bonds from the compound during exposure, (3) the difficulty of the swelling of the resist film after pattern exposure during development, and (4) the small variation in the distribution of components in the resist film. As the mechanism of action by which the resist composition of the present invention exhibits the above characteristics, the following speculation is made. Due to the specific salt compound containing a halogen atom (having an iodine atom in the anion part １ １ and a halogen atom １ also in the cation part), the resist film formed by the resist composition of the present invention has high light absorption during exposure (especially EUV exposure). Also, in the specific salt compound, one aromatic ring included in the anion part (an aromatic ring constituting １ １ an aromatic ring group represented by Wa) has an iodine atom and an ester substituent represented by —CO—O—A as substituents bonded to the ring member atoms constituting said aromatic ring

[0022] Furthermore, typically, when forming a positive pattern using an alkaline developer, salt compounds containing the structures represented by formulas (Y-1) and (Y-2) described later, and / or cation structures containing halogen atoms, tend to attract the alkaline developer into the resist film, causing the film to swell and generating pattern defects. In contrast, within the resist film, the iodine atom in the anionic portion of a specific salt compound and the aromatic ring having an ester substituent interact with the structures represented by formulas (Y-1) and (Y-2) described later, and the cation structures containing halogen atoms. As a result, it is hypothesized that (1) the affinity between the alkaline developer and the resist film is reduced, suppressing the penetration of the alkaline developer, or (2) the density of the resist film is increased, physically suppressing the penetration of the alkaline developer, thereby making film swelling less likely (and thus suppressing pattern defects caused by film swelling). On the other hand, when forming a negative pattern using an organic solvent developer, components generated by exposure from salt compounds containing structures represented by formulas (Y-1) and (Y-2) and / or cation structures containing halogen atoms (specifically, generated acids formed by the addition of protons to the structures represented by formulas (Y-1) and (Y-2) generated from the salt compounds by exposure, and / or residual components derived from cation structures containing halogen atoms formed when the generated acids are produced from the salt compounds by exposure) tend to draw the organic solvent developer into the resist film during development, causing the film to swell and easily generating pattern defects. In contrast, within the resist film, the iodine atom in the generated acid derived from the anionic portion of the specific salt compound and the aromatic ring having an ester substituent interact with the structural portion in the generated acid to which a proton has been added to the structure represented by formulas (Y-1) and (Y-2), and the residue component derived from the cation structure containing a halogen atom. As a result, it is hypothesized that (1) the affinity between the organic solvent developer and the resist film is reduced, suppressing the penetration of the organic solvent developer, or (2) the density of the resist film is increased, physically suppressing the penetration of the organic solvent developer, thereby making film swelling less likely (and thus suppressing pattern defects caused by film swelling).

[0023] Furthermore, since resist films typically contain many organic compounds such as resins, salt compounds tend to aggregate within the resist film, leading to variations in the component distribution within the resist film. As described in Patent Document 1, introducing halogen atoms into the cation portion of salt compounds is effective in suppressing aggregation of salt compounds. However, when forming fine patterns such as LS patterns with a line width of 16 nm or less, contact hole patterns with a hole diameter of 16 nm or less, and dot patterns with a dot diameter of 16 nm or less, this is not sufficient to achieve the desired performance. In contrast, the specific salt compound is composed of a cation portion having a halogen atom and an anion portion containing an aromatic ring with an iodine atom and an ester substituent, and having a structure represented by formulas (Y-1) and (Y-2) described later. This is thought to specifically increase its compatibility with organic compounds such as resins, and as a result, it is presumed to become more compatible with resins within the resist film, allowing for more uniform distribution within the film. As a result, the resulting pattern tends to have excellent LWR.

[0024] Hereinafter, the superior LWR of the pattern formed by the resist composition of the present invention, and / or the superior defect suppression of the pattern formed by the resist composition of the present invention, will also be referred to as "superior effects of the present invention."

[0025] [Specific Salt Compound] The resist composition contains a salt (specific salt compound) comprising an anionic portion represented by formula (1) described later (hereinafter also referred to as the "specific anionic portion") and a cation portion represented by formula (X-1) or formula (X-2) described later (hereinafter also referred to as the "specific cation portion"). The specific anionic portion may have multiple anionic structural sites. For example, it may have two or more structural sites selected from the group consisting of formula (Y-1) and formula (Y-2), or it may have an anionic structural site (other anionic structural site) that is different from the structural site selected from the group consisting of formula (Y-1) and formula (Y-2). Furthermore, the specific salt compound has a specific cation portion as a cation that acts as a counter to the specific anionic portion. When there are two or more specific cation portions, the multiple specific cation portions may be the same or different from each other. Furthermore, if the specific salt compound has other anionic structural sites, the type of cation that acts as a counter to the other anionic structural sites is not particularly limited, but it is preferable that it be a cation represented by formula (X-1) or formula (X-2) described above. The specific anionic part and the specific cation part will be described in detail below.

[0026] <Specific Anion Part> The specific salt compound contains an anion part represented by formula (1) (specific anion part).

[0027]

[0028] In formula (1), Wa represents an aromatic ring group. １ This represents a monovalent organic group. A ２ represents a monovalent substituent. n represents an integer greater than or equal to 1. m represents an integer greater than or equal to 0. However, if m is 0, A １ A monovalent organic group represented by contains at least one structural site selected from the group consisting of formulas (Y-1) and (Y-2). When m is 1 or greater, A １ A monovalent organic group represented by m A ２ At least one of the monovalent substituents represented by includes at least one structural site selected from the group consisting of formulas (Y-1) and (Y-2). In the formula, A ２If there are multiple A ２ They may be the same or different from one another.

[0029]

[0030] In equations (Y-1) and (Y-2), *1 and *2 represent the bonding positions.

[0031] The following provides a detailed description of the specific anion section.

[0032] In formula (1), Wa represents an aromatic ring group. The aromatic ring group represented by Wa in formula (1) is a group formed by removing m + n + 1 hydrogen atoms from an aromatic ring. The aromatic ring constituting the aromatic ring group represented by Wa may be monocyclic or polycyclic. The aromatic ring may be either an aromatic hydrocarbon ring or an aromatic heterocyclic ring, but an aromatic hydrocarbon ring is preferred. The number of ring member atoms of the aromatic ring is preferably 5 to 20, more preferably 5 to 15, and even more preferably 6 to 10. When the aromatic ring is an aromatic heterocyclic ring, it is preferable that it has heteroatoms selected from nitrogen atoms, oxygen atoms, and sulfur atoms as ring member atoms. Among the aromatic rings, a benzene ring or a naphthalene ring is preferred, and a benzene ring is more preferred in that it provides superior effects of the present invention. In other words, a benzene ring group is preferred for Wa.

[0033] In formula (1), A １ This represents a monovalent organic group. A １ The monovalent organic group represented by is not particularly limited, but examples include optionally substituted alkyl groups, optionally substituted monovalent aromatic ring groups, optionally substituted aralkyl groups, optionally substituted monovalent lactone groups, optionally substituted oxacycloalkyl groups, and monovalent organic groups containing a structural moiety (divalent group) selected from the group consisting of formulas (Y-1) and (Y-2).

[0034] Furthermore, it is preferable that the optionally substituted alkyl groups, optionally substituted monovalent aromatic ring groups, optionally substituted aralkyl groups, optionally substituted monovalent lactone groups, and optionally substituted oxacycloalkyl groups mentioned above do not contain structural sites selected from the group consisting of formulas (Y-1) and (Y-2).

[0035] The number of carbon atoms in the alkyl group (alkyl group portion without substituents) is preferably 1 to 20, more preferably 1 to 6, even more preferably 1 to 3, and particularly preferably 1 or 2. The alkyl group may be linear, branched, or cyclic. Examples include linear or branched alkyl groups such as methyl, ethyl, n-propyl, i-propyl, n-butyl, t-butyl, and n-hexyl groups, monocyclic cycloalkyl groups such as cyclopentyl and cyclohexyl groups, and polycyclic cycloalkyl groups such as norbornyl, tetracyclodecanyl, tetracyclododecanyl, and adamantyl groups.

[0036] Examples of substituents that the alkyl group may have include the group exemplified by substituent T described later.

[0037] The monovalent aromatic ring group described above is not particularly limited and may be monocyclic or polycyclic, and may be either an aryl group or a heteroaryl group. The number of ring member atoms of the monovalent aromatic ring group is preferably 6 to 15, and more preferably 6 to 10. The monovalent aromatic ring group is preferably an aryl group, more preferably a phenyl group, a naphthyl group, or an anthracenyl group, and even more preferably a phenyl group. Examples of substituents that the monovalent aromatic ring group may have are the groups exemplified by substituent T described later.

[0038] The aralkyl group described above is preferably a structure in which one of the hydrogen atoms in the alkyl group described above is substituted with the aryl group described above. The number of carbon atoms in the aralkyl group is preferably 7 to 20, and more preferably 7 to 15. Examples of substituents that the aralkyl group may have are the substituent T described later.

[0039] The monovalent lactone group is preferably a monovalent lactone group of 5 to 7 members, and more preferably a monovalent lactone group in which another ring structure is fused to the 5 to 7 member lactone ring in a manner that forms a bicyclo or spiro structure. Examples of substituents that the monovalent lactone group may have are the groups exemplified by substituent T described later.

[0040] The oxacycloalkyl group may be monocyclic or polycyclic. The number of ring member atoms of the oxacycloalkyl group is preferably 5 to 15, and more preferably 5 to 10. Specific examples of oxacycloalkyl groups include oxapentamethylene and oxacyclohexyl groups. Substituents that the oxacycloalkyl group may have include the groups exemplified by substituent T described later.

[0041] (Substituents T) Halogen atoms such as fluorine, chlorine, bromine, and iodine; alkoxy groups such as methoxy, ethoxy, and tert-butoxy; aryloxy groups such as phenoxy and p-tolyloxy; alkoxycarbonyl groups such as methoxycarbonyl, ethoxycarbonyl, butoxycarbonyl, and phenoxycarbonyl; acyloxy groups such as acetoxy, propionyloxy, and benzoyloxy; acyl groups such as acetyl, benzoyl, and isobutyryl; alkyl groups; monovalent aromatic ring groups (aryl and heteroaryl groups); monovalent cyclic carbonate groups (preferably with 3 to 7 carbon atoms); monovalent lactone groups (preferably lactone groups with 5 to 7 member rings); vinyl groups; hydroxyl groups; carboxylic acid groups; sulfonic acid groups, and combinations thereof. Note that alkyl groups may be linear, branched, or cyclic. Furthermore, the aryl group and heteroaryl group may be monocyclic or polycyclic. Also, the carboxylic acid group and sulfonic acid group may be in a salt structure. The countercation may also preferably be a cation represented by formula (X-1) or formula (X-2), which will be described later.

[0042] The organic group containing a structural site selected from the group consisting of formulas (Y-1) and (Y-2) described above is not particularly limited, but for example, the group represented by formula (A1) can be cited. Formula (A1) *-L ２ -X ２ -R ２ In formula (A1), L ２ L represents a single bond or a divalent linking group. ２ The divalent linking group represented by is not particularly limited, but examples include alkylene groups in which the methylene group may be substituted with at least one -CO- and -O-, divalent aromatic ring groups (arylene groups having 6 to 10 carbon atoms are preferred, and phenylene groups are more preferred), and linking groups formed by linking multiple of these. ２ X ２ The atom at the opposite bond position (*) is preferably a carbon atom. The alkylene group and the divalent aromatic ring group may further have substituents. Examples of substituents include the groups exemplified by substituent T above, of which fluorine atoms and iodine atoms are preferred, and fluorine atoms are more preferred. L ２ Examples of divalent linking groups represented by include phenylene groups which may have substituents, and alkylene groups which may have substituents and in which the methylene group may be substituted with at least one -CO- and -O- (preferably having 1 to 12 carbon atoms).

[0043] In formula (A1), X ２ This represents a divalent group selected from the group consisting of formulas (Y-1) and (Y-2) described above.

[0044] In formula (A1), R ２ R represents a monovalent organic group. ２ The monovalent organic group represented by is not particularly limited, but examples include optionally substituted alkyl groups, optionally substituted monovalent aromatic ring groups, and optionally substituted aralkyl groups.

[0045] The number of carbon atoms in the alkyl group (alkyl group portion without substituents) is preferably 1 to 20, more preferably 1 to 6, even more preferably 1 to 3, and particularly preferably 1 or 2. The alkyl group may be linear, branched, or cyclic, but linear or branched alkyl groups such as methyl, ethyl, n-propyl, i-propyl, n-butyl, t-butyl, and n-hexyl groups are preferred. Substituents that the alkyl group may have include the groups exemplified by substituent T above, with fluorine atoms being preferred. Furthermore, the alkyl group may also have a sulfonic acid base having a cation represented by formula (X-1) or formula (X-2), described later, as a substituent.

[0046] A suitable example of an alkyl group which may have the above substituents is a perfluoroalkyl group, or a fluoroalkyl group which has a sulfonic acid base having a cation represented by formula (X-1) or formula (X-2), described later, as a countercation as a substituent.

[0047] The monovalent aromatic ring group described above is not particularly limited and may be monocyclic or polycyclic, and may be either an aryl group or a heteroaryl group. The number of ring member atoms of the monovalent aromatic ring group is preferably 6 to 15, and more preferably 6 to 10. The monovalent aromatic ring group is preferably an aryl group, more preferably a phenyl group, a naphthyl group, or an anthracenyl group, and even more preferably a phenyl group. Examples of substituents that the monovalent aromatic ring group may have are the groups exemplified by substituent T described above.

[0048] The aralkyl group described above is preferably a structure in which one of the hydrogen atoms in the alkyl group described above is substituted with the aryl group described above. The number of carbon atoms in the aralkyl group is preferably 7 to 20, and more preferably 7 to 15. Examples of substituents that the aralkyl group may have are the groups exemplified by substituent T described above.

[0049] X ２ This represents a divalent group represented by formula (Y-1), and *1 is L ２When bonded to the side, L ２ It is also preferable that this represents a divalent linking group with 6 or fewer carbon atoms. ２ When represents a divalent group represented by formula (Y-1), then *1 is R ２ It is also preferable that the bond is on the side.

[0050] *-L, represented by formula (A1) ２ -X ２ -R ２ Specific examples of a base include the base represented by formula (A1X) or formula (A1Y).

[0051]

[0052] In formula (A1X), R ２１ and R ２２ Each of these independently represents a hydrogen atom, or a monovalent substituent other than a fluorine atom and a perfluoroalkyl group. ２１ and R ２２ Specific examples of monovalent substituents represented by include the groups exemplified by the substituent T mentioned above, other than fluorine atoms and perfluoroalkyl groups, and among these, alkyl groups other than perfluoroalkyl groups, which may have substituents, are preferred.

[0053] The alkyl group may be linear, branched, or cyclic. The alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 6, and even more preferably 1 to 3 carbon atoms. The alkyl group may also have further substituents. The substituents are not particularly limited, but examples include the groups exemplified by substituent T above. ２１ and R ２２ Of these, hydrogen atoms are preferred.

[0054] In formula (A1X), R ｆ２１ ~R ｆ２４ Each of these independently represents a hydrogen atom, a fluorine atom, or a perfluoroalkyl group. However, R ｆ２１ and R ｆ２２ At least one of the following, and R ｆ２３ and R ｆ２４At least one of these represents a fluorine atom or a perfluoroalkyl group. The perfluoroalkyl group may be linear, branched, or cyclic. The number of carbon atoms in the perfluoroalkyl group is preferably 1 to 10, more preferably 1 to 6, even more preferably 1 to 3, and a perfluoromethyl group is particularly preferred.

[0055] In formula (A1X), R ｆ２５ Each of these independently represents a fluorine atom, an optionally substituted aryl group, or a sulfonic acid base or carboxylic acid base having a cation represented by formula (X-1) or formula (X-2) described later as a countercation. The aryl group may be monocyclic or polycyclic. The aryl group is preferably a benzene ring group. The substituents that the aryl group may have are not particularly limited, but include the groups exemplified by substituent T above, with iodine atoms being particularly preferred.

[0056] In formula (A1X), m2a, m2b, and m2c each independently represent an integer from 0 to 4. m2a is preferably an integer from 0 to 2. m2b is preferably an integer from 0 to 2, and more preferably 0 or 1. m2c is preferably an integer from 0 to 3. At least one of m2b and m2c is preferably an integer of 1 or more. In formula (A1X), X ２ X represents a divalent group selected from the group consisting of formulas (Y-1) and (Y-2) described above. ２ This represents a divalent group represented by formula (Y-1), and *1 is -(C(R ２１ ) (Caution ２２ )) ｍ２ａ - (C(R ｆ２１ ) (Caution ｆ２２ )) ｍ２ｂ - If it is bonded to the - side, -(C(R ２１ ) (Caution ２２ )) ｍ２ａ - (C(R ｆ２１ ) (Caution ｆ２２ )) ｍ２ｂ It is also preferable that the total number of carbon atoms is 6 or less. ２ When *1 represents a divalent group represented by formula (Y-1), then *1 is -(C(R ｆ２３)(R ｆ２４ )) ｍ２ｃ -R ｆ２５ It is also preferable that it is bonded to the -R side. In the formula (A1X), * represents a bonding position.

[0057] In the formula (A1Y), R ｆ２６ and R ｆ２７ are synonymous with R ｆ２１ to R ｆ２４ in the formula (A1X), and the preferred embodiments are also the same. However, at least one of R ｆ２６ and R ｆ２７ represents a fluorine atom or a perfluoroalkyl group. In the formula (A1Y), R ｆ２８ , X ２ , and * are synonymous with R ｆ２５ , X ２ , and * in the formula (A1X), and the preferred embodiments are also the same. In the formula (A1Y), m2d represents an integer from 0 to 4, and among them, an integer from 1 to 3 is preferable. In the formula (A1Y), AL ２１ represents an arylene group which may have a substituent. The arylene group may be either a monocyclic or polycyclic group. As the arylene group, a phenylene group is preferable. The substituent that the above arylene group may have is not particularly limited, but examples include the groups exemplified by the above substituent T.X ２ represents a divalent group represented by the formula (Y-1), and when *1 is bonded to the -AL ２１ - side, it is also preferable that the total carbon number of -AL ２１ - is 6 or less. When X ２ represents a divalent group represented by the formula (Y-1), it is also preferable that *1 is bonded to the - (C(R ｆ２６ )(R ｆ２７ )) ｍ２ｄ -R ｆ２８ side.

[0058] In the formula (1), A ２ represents a monovalent substituent. The monovalent substituent represented by A ２ is not particularly limited, but examples include the groups exemplified by the above substituent T, and monovalent organic groups containing a structural moiety (divalent group) selected from the group consisting of the formula (Y-1) and the formula (Y-2). Note that A ２The monovalent substituent represented by is a group other than an iodine atom and a group represented by -COO-A １ and is preferably a group other than the group represented by １ .

[0059] The monovalent organic group containing the structural moiety selected from the group consisting of the above formulas (Y-1) and (Y-2) is not particularly limited, and examples thereof include a group represented by formula (A2). Formula (A2) *-L １ -X １ -R １ In formula (A2), L １ represents a single bond or a divalent linking group. The divalent linking group represented by L １ is not particularly limited, and examples thereof include -CO-, -O-, -S-, -SO-, -SO ２ -, an alkylene group, a divalent aromatic ring group (preferably an arylene group having 6 to 10 carbon atoms, more preferably a phenylene group), and a linking group formed by linking a plurality of these. The above alkylene group and the above divalent aromatic ring group may further have a substituent. Examples of the substituent include the groups exemplified by the above substituent T, and among them, a fluorine atom is preferable.[[ID=1...]]

[0060] The divalent linking group represented by L １ is preferably a group represented by formula (L1A). Formula (L1A) *-L １１ -L １２ -* In formula (L1A), L １１ represents a single bond, -COO-, or -O-. In formula (L1A), L １２ represents a single bond, an alkylene group in which a methylene group may be substituted with at least one of -CO- and -O-, a divalent aromatic ring group (preferably an arylene group having from a carbon number of 6 to 10, more preferably a phenylene group), or a linking group formed by linking a plurality of these. Note that the atom at the bonding position of L １２ with L １１ is preferably a carbon atom. The above alkylene group and the above divalent aromatic ring group may further have a substituent. Examples of the substituent include the groups exemplified by the above substituent T, and among them, a fluorine atom is preferable. L １２Examples of the divalent linking group represented by include a phenylene group which may have substituents, and an alkylene group which may have substituents and in which the methylene group may be substituted with at least one -CO- and -O- (preferably having 1 to 12 carbon atoms, more preferably 1 to 6 carbon atoms, and even more preferably 1 to 4 carbon atoms). In formula (L1A), * represents the bond position.

[0061] In formula (A2), X １ This represents a divalent group selected from the group consisting of formulas (Y-1) and (Y-2) described above.

[0062] In formula (A2), R １ R represents a monovalent organic group. １ As a monovalent organic group represented by the above formula (A1), R ２ This is synonymous with a monovalent organic group represented by , and the preferred embodiment is the same.

[0063] *-L, represented by formula (A2) １ -X １ -R １ Specific examples of a base include the base represented by formula (A2X) or formula (A2Y).

[0064]

[0065] In formula (A2X), R １１ and R １２ Each of these independently represents a hydrogen atom, or a monovalent substituent other than a fluorine atom and a perfluoroalkyl group. １１ and R １２ Specific examples of monovalent substituents represented by include the groups exemplified by the substituent T mentioned above, other than fluorine atoms and perfluoroalkyl groups, and among these, alkyl groups other than perfluoroalkyl groups, which may have substituents, are preferred.

[0066] The alkyl group may be linear, branched, or cyclic. The alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 6, and even more preferably 1 to 3 carbon atoms. The alkyl group may also have further substituents. The substituents are not particularly limited, but examples include the groups exemplified by substituent T above.１１ and R １２ Of these, hydrogen atoms are preferred.

[0067] In formula (A2X), R ｆ１１ ~R ｆ１４ Each of these independently represents a hydrogen atom, a fluorine atom, or a perfluoroalkyl group. However, R ｆ１１ and R ｆ１２ At least one of the following, and R ｆ１３ and R ｆ１４ At least one of these represents a fluorine atom or a perfluoroalkyl group. The perfluoroalkyl group may be linear, branched, or cyclic. The number of carbon atoms in the perfluoroalkyl group is preferably 1 to 10, more preferably 1 to 6, even more preferably 1 to 3, and a perfluoromethyl group is particularly preferred.

[0068] In formula (A2X), R ｆ１５ Each of these independently represents a fluorine atom, an optionally substituted aryl group, or a sulfonic acid base or carboxylic acid base having a cation represented by formula (X-1) or formula (X-2) described later as a countercation. The aryl group may be monocyclic or polycyclic. The aryl group is preferably a benzene ring group. The substituents that the aryl group may have are not particularly limited, but include the groups exemplified by substituent T above, with iodine atoms being particularly preferred.

[0069] In formula (A2X), m1a, m1b, and m1c each independently represent an integer from 0 to 4. m1a is preferably an integer from 0 to 2. m1b is preferably an integer from 0 to 2, and more preferably 0 or 1. m1c is preferably an integer from 0 to 3. At least one of m1b and m1c is preferably an integer of 1 or more. In formula (A2X), X １ L represents a divalent group selected from the group consisting of formulas (Y-1) and (Y-2) described above. In formula (A2X), L １１ represents a single bond, -COO-, or -O-. In formula (A2X), * represents the bond position.

[0070] In formula (A2Y), Rｆ１６ and R ｆ１７ R in equation (A2X) ｆ１１ ~R ｆ１４ This is synonymous with the same, and the preferred embodiment is also the same. However, R ｆ１６ and R ｆ１７ At least one of these represents a fluorine atom or a perfluoroalkyl group. In formula (A2Y), R ｆ１８ , X １ , L １２ , and * are R in formula (A2X). ｆ１５ , X １ , L １１ , and * are synonymous, and the preferred embodiment is the same. In formula (A2Y), m1d represents an integer from 0 to 4, and is preferably an integer from 1 to 3. In formula (A2Y), AL １１ represents an arylene group which may have substituents. The arylene group may be monocyclic or polycyclic. A phenylene group is preferred as the arylene group. The substituents which the above arylene group may have are not particularly limited, but examples include the groups exemplified by substituent T above.

[0071] In formula (1), n ​​represents an integer of 1 or more. In other words, the aromatic ring group represented by Wa has n iodine atoms as substituents. There is no particular upper limit to n, but it is preferably 6 or less. n is preferably an integer from 1 to 4, and more preferably an integer from 1 to 3.

[0072] In formula (1), m represents an integer greater than or equal to 0. There is no particular upper limit to m, but it is preferably 6 or less, preferably 4 or less, and more preferably 2 or less. For example, m is preferably an integer between 0 and 3, more preferably an integer between 0 and 2, and even more preferably 0 or 1.

[0073] However, if m is 0 in equation (1), A １ A monovalent organic group represented by contains at least one structural site selected from the group consisting of formulas (Y-1) and (Y-2). When m is 1 or greater, A １ A monovalent organic group represented by m A ２At least one of the monovalent substituents represented by includes at least one structural site selected from the group consisting of formulas (Y-1) and (Y-2). The number of structural sites selected from the group consisting of formulas (Y-1) and (Y-2) in formula (1) is preferably 1 to 3, more preferably 1 or 2, and even more preferably 1. In formula (1), the atoms adjacent to (bonding to *1 and *2) the structural sites *1 and *2 selected from the group consisting of formulas (Y-1) and (Y-2) are also preferably carbon atoms.

[0074] The specific anion portion is preferably a structure represented by formula (3-1) or formula (3-2).

[0075]

[0076] In equation (3-1), Wa, A １ , and n are Wa and A in equation (1), respectively. １ , and are synonymous with n, and the preferred embodiment is the same. Note that A １ The monovalent organic group represented by may or may not include a structural site selected from the group consisting of formulas (Y-1) and (Y-2), but it is preferable that it does not include a structural site selected from the group consisting of formulas (Y-1) and (Y-2). Furthermore, the aromatic ring group represented by Wa in formula (3-1) is an m1+n+y+1 valent aromatic ring group, which is a group formed by removing m1+n+y+1 hydrogen atoms from an aromatic ring. In formula (3-1), L １ , X １ , and R １ These are L in formula (A2), respectively. １ , X １ , and R １ This is synonymous with the same as the preferred embodiment. Note that -L in formula (3-1) １ -X １ -R １ A concrete example of the base represented by formula (A2) is -L １ -X １ -R １ This is the same as the specific example.

[0077] In equation (3-1), m1 represents an integer greater than or equal to 1. m1 preferably represents an integer between 1 and 2, and more preferably represents 1.

[0078] In formula (3-1), R １ａ R represents a monovalent substituent. １ａ The monovalent substituent represented by is not particularly limited, but examples include the group exemplified by substituent T above. １ａ The group represented by this is an iodine atom, -L １ -X １ -R １ The group represented by -COO-A １ It is preferable that the base is not represented by . In formula (3-1), y represents an integer of 0 or more. It is preferable that y represents an integer from 0 to 3. In formula (3-1), L １ If there are multiple L １ They may be the same or different from each other. １ If there are multiple X １ They may be the same or different from each other. １ If multiple R １ They may be the same or different from each other. １ａ If multiple R １ａ They may be the same or different from one another.

[0079] In equation (3-2), Wa, A ２ , m, and n are Wa, A in equation (1), respectively. ２ , m, and n are synonymous, and the preferred embodiment is the same. Note that A ２ The monovalent substituent represented by may or may not include a structural site selected from the group consisting of formulas (Y-1) and (Y-2), but it is preferable that it does not include a structural site selected from the group consisting of formulas (Y-1) and (Y-2). Furthermore, the aromatic ring group represented by Wa in formula (3-2) is an m+n+1 valent aromatic ring group, which is a group formed by removing m+n+1 hydrogen atoms from an aromatic ring. In formula (3-2), L ２ , X ２ , and R ２ These are L in formula (A1), respectively. ２ , X ２ , and R ２ This is synonymous with the same as the preferred embodiment. Note that -L in formula (3-2)２ -X ２ -R ２ A concrete example of the base represented by formula (A1) is -L ２ -X ２ -R ２ This is the same as the specific example. In equation (3-2), A ２ If there are multiple A ２ They may be the same or different from one another.

[0080] In equation (3-2), X ２ It is preferable that this represents equation (Y-1). In equation (3-2), X ２ This represents equation (Y-1), and *1 is L ２ When bonded to the side, L ２ It is preferable that X represents a divalent linking group having 6 or fewer carbon atoms. In formula (3-2), X ２ If represents equation (Y-1), then *1 is R ２ It is also preferable that the bond is on the side.

[0081] Specific examples of the anionic portion (specific anionic portion) represented by formula (1) are shown below, but the present invention is not limited thereto. In the following, "Me" represents a methyl group.

[0082]

[0083] <Specific Cationic Part> The specific salt compound includes a cationic part (specific cationic part) represented by formula (X-1) or formula (X-2). It is preferable that the specific salt compound includes a cationic part represented by formula (X-1) in terms of superior effects of the present invention.

[0084]

[0085] R ｘ１ Each of these independently represents a monovalent organic group. However, R ｘ１ At least one of them is a monovalent organic group having a halogen atom. Three R ｘ１ Two of these atoms may bond to form a ring structure. Among the halogen atoms, fluorine atoms or iodine atoms are preferred.

[0086] In the above equation (X-1), R ｘ１The number of carbon atoms in the monovalent organic group represented is preferably 1 to 30, and more preferably 1 to 20. ｘ１ Two of these may bond to form a ring structure, and the ring may contain an oxygen atom, a sulfur atom, an ester group, an amide group, or a carbonyl group. ｘ１ Examples of groups formed by the bonding of two of these include alkylene groups (e.g., butylene and pentylene groups) and -CH ２ -CH ２ -O-CH ２ -CH ２ - is one example.

[0087] Preferred embodiments of the cation represented by formula (X-1) include cation (X-1-1), cation (X-1-2), cation (X-1-3b), and cation (X-1-4b), which will be described later.

[0088] First, let's explain the cation (X-1-1). The cation (X-1-1) consists of the three R's in the above formula (X-1). ｘ１ It is an arylsulfonium cation in which at least one of the groups is an aryl group. The arylsulfonium cation has three R groups. ｘ１ All of them may be aryl groups, or three R ｘ１ Some of the groups may be aryl groups, and the rest may be alkyl groups or cycloalkyl groups. ｘ１ One of them is an aryl group, and there are three R ｘ１ The remaining two of these may bond to form a ring structure, which may contain an oxygen atom, a sulfur atom, an ester group, an amide group, or a carbonyl group. ｘ１ Examples of groups formed by the bonding of two of these include alkylene groups in which one or more methylene groups may be substituted with an oxygen atom, a sulfur atom, an ester group, an amide group, and / or a carbonyl group (e.g., butylene group, pentylene group, and -CH ２ -CH ２ -O-CH ２ -CH ２-) are examples. However, the arylsulfonium cation has a halogen atom. In the arylsulfonium cation, the position of introduction of the halogen atom is not particularly limited, but it is preferable that at least one of the aryl groups has a halogen atom. Specifically, in the arylsulfonium cation, it is preferable that at least one of the aryl groups has a halogen atom as a substituent, or has a substituent having a halogen atom.

[0089] Examples of arylsulfonium cations include triarylsulfonium cations having at least one halogen atom, diarylalkylsulfonium cations having at least one halogen atom, diarylcycloalkylsulfonium cations having at least one halogen atom, aryldialkylsulfonium cations having at least one halogen atom, and aryldicycloalkylsulfonium cations having at least one halogen atom.

[0090] The aryl group contained in the arylsulfonium cation is preferably a phenyl group or a naphthyl group, with the phenyl group being more preferred. When the arylsulfonium cation has two or more aryl groups, the two or more aryl groups may be the same or different. The aryl group may be an aryl group having a heterocyclic structure containing an oxygen atom, a nitrogen atom, or a sulfur atom, etc. Examples of heterocyclic structures include pyrrole residues, furan residues, thiophene residues, indole residues, benzofuran residues, and benzothiophene residues. The alkyl or cycloalkyl group that the arylsulfonium cation may have is preferably a linear alkyl group having 1 to 15 carbon atoms, a branched alkyl group having 3 to 15 carbon atoms, or a cycloalkyl group having 3 to 15 carbon atoms, with methyl group, ethyl group, propyl group, n-butyl group, sec-butyl group, t-butyl group, cyclopropyl group, cyclobutyl group, or cyclohexyl group being more preferred.

[0091] As described above, the arylsulfonium cation has at least one halogen atom, and preferably at least one of the aryl groups has a halogen atom. Specifically, it is preferable that at least one of the aryl groups has a halogen atom as a substituent, or has a substituent having a halogen atom. Preferred substituents that the arylsulfonium cation may have are alkyl groups (e.g., C1-C15) which may have a halogen atom (or may be substituted with a halogen atom), cycloalkyl groups (e.g., C3-C15) which may have a halogen atom, aryl groups (e.g., C6-C14) which may have a halogen atom, alkoxy groups (e.g., C1-C15) which may have a halogen atom, cycloalkylalkoxy groups (e.g., C8-C15) which may have a halogen atom, aryloxy groups (e.g., C6-C10) which may have a halogen atom, halogen atoms (e.g., fluorine and iodine), hydroxyl groups, carboxyl groups, ester groups, sulfinyl groups, sulfonyl groups, alkylthio groups which may have a halogen atom, phenylthio groups which may have a halogen atom, or alkyloxycarbonylalkyleneoxy groups which may have a halogen atom. The above substituents may also form an acid-degradable group in any combination. An acid-degradable group is a group that decomposes and increases in polarity upon the action of an acid, and it is preferable that the polar group is protected by a group that is eliminated by the action of an acid.

[0092] Next, we will explain the cation (X-1-2). The cation (X-1-2) consists of the three R's in formula (X-1). ｘ１ However, each independently represents a cation of a monovalent organic group that does not have an aromatic ring. The term "aromatic ring" also includes aromatic rings containing heteroatoms. However, the three R's ｘ１ At least one of them has a halogen atom.

[0093] R ｘ１ The number of carbon atoms in the organic group that does not have an aromatic ring is preferably 1 to 30, and more preferably 1 to 20. ｘ１Each of these is preferably an alkyl group, a cycloalkyl group, an allyl group, or a vinyl group, and more preferably a linear or branched 2-oxoalkyl group, a 2-oxocycloalkyl group, or an alkoxycarbonylmethyl group.

[0094] R ｘ１ Examples of alkyl and cycloalkyl groups represented by include linear alkyl groups having 1 to 10 carbon atoms or branched alkyl groups having 3 to 10 carbon atoms (e.g., methyl group, ethyl group, propyl group, butyl group, and pentyl group), and cycloalkyl groups having 3 to 10 carbon atoms (e.g., cyclopentyl group, cyclohexyl group, and norbornyl group).

[0095] In the cation (X-1-2), as described above, R ｘ１ At least one of the monovalent organic groups that do not have an aromatic ring, represented by R, has a halogen atom. ｘ１ At least one of the monovalent organic groups that do not have an aromatic ring, represented by , has a halogen atom as a substituent, or has a substituent that has a halogen atom. ｘ１ Specific examples of substituents that a monovalent organic group without an aromatic ring may have include the group exemplified as a substituent that an aryl sulfonium cation (X-1-1) may have.

[0096] Next, we will explain the cation (X-1-3b). The cation (X-1-3b) is a cation represented by the following formula (X-1-3b).

[0097]

[0098] In formula (X-1-3b), R １ｃ ~R ５ｃEach of these independently represents a hydrogen atom, an alkyl group (e.g., C1-C15) which may have a halogen atom, a cycloalkyl group (e.g., C3-C15) which may have a halogen atom, an aryl group (e.g., C6-C14) which may have a halogen atom, an alkoxy group (e.g., C1-C15) which may have a halogen atom, an aryloxy group (e.g., C6-C14) which may have a halogen atom, an alkoxycarbonyl group (e.g., C2-C14) which may have a halogen atom, an alkylcarbonyloxy group (e.g., C2-C14) which may have a halogen atom, a cycloalkylcarbonyloxy group (e.g., C4-C15) which may have a halogen atom, a halogen atom, a hydroxyl group, a nitro group, an alkylthio group (e.g., C1-C15) which may have a halogen atom, or an arylthio group (e.g., C6-C14) which may have a halogen atom. ６ｃ and R ７ｃ Each of these independently represents a hydrogen atom, an alkyl group which may have a halogen atom (e.g., a t-butyl group, e.g., with 1 to 15 carbon atoms), a cycloalkyl group which may have a halogen atom (e.g., with 3 to 15 carbon atoms), a halogen atom, a cyano group, or an aryl group which may have a halogen atom (e.g., with 6 to 14 carbon atoms). ｘ and R ｙ Each of these independently represents an alkyl group (e.g., C1-C15) which may have a halogen atom, a cycloalkyl group (e.g., C3-C15) which may have a halogen atom, a 2-oxoalkyl group (e.g., C1-C15) which may have a halogen atom, a 2-oxocycloalkyl group (e.g., C3-C15) which may have a halogen atom, an alkoxycarbonylalkyl group (e.g., C3-C15) which may have a halogen atom, an allyl group which may have a halogen atom, or a vinyl group which may have a halogen atom.

[0099] R １ｃ ~R ５ｃ Two or more of the following, R ５ｃ and R ６ｃ , R ６ｃ and R ７ｃ, R ５ｃ and R ｘ , and R ｘ and R ｙ These rings may be bonded to each other to form a ring which may have substituents, and each of these rings may independently contain an oxygen atom, a sulfur atom, a ketone group, an ester bond, or an amide bond. Examples of the above rings include aromatic or non-aromatic hydrocarbon rings, aromatic or non-aromatic heterorings, and polycyclic fused rings formed by the combination of two or more of these rings. Examples of rings include 3 to 10-membered rings, preferably 4 to 8-membered rings, and more preferably 5 or 6-membered rings.

[0100] R １ｃ ~R ５ｃ Two or more of the following, R ６ｃ and R ７ｃ , and R ｘ and R ｙ Examples of groups formed by the bonding include alkylene groups such as butylene and pentylene groups. The methylene group in the alkylene group may be substituted with a heteroatom such as an oxygen atom. ５ｃ and R ６ｃ , and R ５ｃ and R ｘ The groups formed by the bonding of these elements are preferably single bonds or alkylene groups. Examples of alkylene groups include methylene groups and ethylene groups.

[0101] R １ｃ ~R ５ｃ , R ６ｃ , R ７ｃ , R ｘ , R ｙ , and R １ｃ ~R ５ｃ Two or more of the following, R ５ｃ and R ６ｃ , R ６ｃ and R ７ｃ , R ５ｃ and R ｘ , and R ｘ and R ｙ Specific examples of substituents that may be present on the ring formed by the bonding of these elements include the group exemplified as a substituent that may be present on the arylsulfonium cation, which is a cation (X-1-1).

[0102] However, in equation (X-1-3b), R １ｃ ~R ５ｃ , R ６ｃ , R ７ｃ , R ｘ , and R ｙ One of the following, or R １ｃ ~R ５ｃ , R ６ｃ , R ７ｃ , R ｘ , R ｙ , and R １ｃ ~R ５ｃ Two or more of the following, R ５ｃ and R ６ｃ , R ６ｃ and R ７ｃ , R ５ｃ and R ｘ , and R ｘ and R ｙ At least one of the rings formed by the bonding of these elements has a halogen atom. In particular, R １ｃ ~R ５ｃ It is preferable that one of them has a halogen atom (preferably an iodine atom or a fluorine atom).

[0103] Next, we will explain the cation (X-1-4b). The cation (X-1-4b) is a cation represented by the following formula (X-1-4b).

[0104]

[0105] In equation (X-1-4b), l represents an integer from 0 to 2, and r represents an integer from 0 to 8. １３ R represents a hydrogen atom, a halogen atom (e.g., a fluorine atom and an iodine atom), a hydroxyl group, an alkyl group which may have a halogen atom (e.g., C1-C15), an alkoxy group which may have a halogen atom (e.g., C1-C15), a carboxyl group, an alkoxycarbonyl group which may have a halogen atom (e.g., C2-C15), or a cycloalkyl group which may have a halogen atom (e.g., C3-C15). Note that these groups may have substituents other than halogen atoms. １４R represents a hydroxyl group, a halogen atom (e.g., a fluorine atom and an iodine atom), an alkyl group which may have a halogen atom (e.g., C1-C15), an alkoxy group which may have a halogen atom (e.g., C1-C15), an alkoxycarbonyl group which may have a halogen atom (e.g., C2-C15), an alkylcarbonyl group which may have a halogen atom (e.g., C2-C15), an alkylsulfonyl group which may have a halogen atom (e.g., C1-C15), a cycloalkylsulfonyl group which may have a halogen atom (e.g., C3-C15), or a cycloalkyl group which may have a halogen atom (e.g., C3-C15). These groups may have substituents. １４ If multiple instances exist, R １４ They may be identical or different from one another. １５ Each independently represents an alkyl group (e.g., having 1 to 15 carbon atoms) which may have a halogen atom, a cycloalkyl group (e.g., having 3 to 15 carbon atoms) which may have a halogen atom, or a naphthyl group which may have a halogen atom. １５ The two R atoms may bond to each other to form a ring which may have substituents. １５ When these atoms bond to each other to form a ring, the ring may contain heteroatoms such as oxygen atoms or nitrogen atoms. In one embodiment, two R １５ It is preferable that the alkyl group is an alkylene group and that they bond to each other to form a ring structure. The alkyl group, cycloalkyl group and naphthyl group and the two R １５ The ring formed by the bonding of these elements may have substituents. Specific examples of substituents include the groups exemplified as substituents that the arylsulfonium cation (X-1-1) may have.

[0106] In formula (X-1-4b), R １３ , R １４ , and R １５ The alkyl group may be linear or branched. The alkyl group preferably has 1 to 10 carbon atoms. The alkyl group is preferably a methyl group, ethyl group, n-butyl group, or t-butyl group.

[0107] However, in equation (X-1-4b), R １３ , R １４ , and R １５ One or two of the R １５ A ring which may have substituents formed by the bonding of atoms to each other has halogen atoms. In particular, a ring in which r represents an integer of 1 or more, and r atoms １４ Preferably, at least one of these atoms is a halogen atom (preferably an iodine atom or a fluorine atom).

[0108]

[0109] In formula (X-2), R ｘ２ Each of these independently represents an organic group. However, R ｘ２ At least one of them is an organic group having a halogen atom. Next, let's explain formula (X-2). ｘ２ The monovalent organic group represented by represents an aryl group which may have a halogen atom, an alkyl group which may have a halogen atom, or a cycloalkyl group which may have a halogen atom. The aryl group is preferably a phenyl group or a naphthyl group, and more preferably a phenyl group. It may also be an aryl group having a heterocycle containing an oxygen atom, a nitrogen atom, or a sulfur atom. Examples of the heterocycle aryl group skeleton include pyrrole, furan, thiophene, indole, benzofuran, and benzothiophene. The alkyl group is preferably a linear alkyl group having 1 to 10 carbon atoms or a branched alkyl group having 3 to 10 carbon atoms (e.g., a methyl group, an ethyl group, a propyl group, a butyl group, or a pentyl group). The cycloalkyl group is preferably a cycloalkyl group having 3 to 10 carbon atoms (e.g., a cyclopentyl group, a cyclohexyl group, or a norbornyl group). Specific examples of substituents that the aryl group, alkyl group, and cycloalkyl group may have include the groups exemplified as substituents that the arylsulfonium cation (X-1-1) may have.

[0110] However, in equation (X-2), R ｘ２At least one of the monovalent organic groups represented by has a halogen atom. That is, R ｘ２ At least one of the monovalent organic groups represented by has a halogen atom as a substituent, or has a substituent that has a halogen atom.

[0111] Specific examples of specific cation moieties are shown below, but the present invention is not limited thereto.

[0112]

[0113]

[0114]

[0115] The specific salt compound is typically a compound that generates acid upon irradiation (exposure) with active light or radiation. The content of the specific salt compound in the resist composition is not particularly limited, but is preferably 0.5% by mass or more, more preferably 1.0% by mass or more, and even more preferably 5.0% by mass or more, based on the total solid content of the resist composition. Furthermore, the content of the specific salt compound is preferably 60.0% by mass or less, more preferably 50.0% by mass or less, even more preferably 40.0% by mass or less, and even more preferably 30.0% by mass or less, based on the total solid content of the resist composition. Only one type of specific salt compound may be used, or two or more types may be used. When two or more types of specific salt compounds are used, it is preferable that their total content is within the range of the above preferred content.

[0116] [Photoacid Generator] The resist composition may contain a photoacid generator. The photoacid generator is not particularly limited as long as it is a compound that generates acid upon irradiation (exposure) with active light or radiation. Note that the above photoacid generator is a compound that does not fall under the category of the specific salt compounds described above. It is preferable that the photoacid generator generates an acid with a pKa of less than 0 upon exposure. The pKa of the acid generated from the photoacid generator upon exposure is preferably -0.1 or less, and more preferably -0.5 or less. Furthermore, the pKa of the acid generated from the photoacid generator upon exposure is preferably -5.0 or more, and more preferably -4.5 or more.

[0117] The photoacid generator may be in the form of a low molecular weight compound, or it may be incorporated into a part of the resin. Alternatively, both the low molecular weight compound form and the form incorporated into a part of the resin may be used in combination. The photoacid generator is preferably in the form of a low molecular weight compound. When the photoacid generator is in the form of a low molecular weight compound, its molecular weight is not particularly limited, but it is preferably 500 to 3000, more preferably 600 to 2500, and even more preferably 700 to 2000. When the photoacid generator is incorporated into a part of the resin, it may be incorporated into a part of an acid-degradable resin, or into a resin different from the acid-degradable resin.

[0118] Examples of photoacid generators include, "M ＋ X － Examples of compounds represented by '' (onium salts) include compounds that generate organic acids upon exposure. Examples of organic acids include sulfonic acids (aliphatic sulfonic acids, aromatic sulfonic acids, and camphor sulfonic acids, etc.), carboxylic acids (aliphatic carboxylic acids, aromatic carboxylic acids, and aralkyl carboxylic acids, etc.), carbonylsulfonylimide acid, bis(alkylsulfonyl)imide acid, and tris(alkylsulfonyl)methidic acid.

[0119] "M ＋ X － In the compound represented by ", M ＋ The symbol represents a cation, preferably an organic cation. The valency of the cation may be monovalent or divalent or higher. The cation is preferably a cation represented by formula (ZaI) (hereinafter also referred to as "cation (ZaI)") or a cation represented by formula (ZaII) (hereinafter also referred to as "cation (ZaII)").

[0120]

[0121] In the above formula (ZaI), R ２０１ , R ２０２ , and R ２０３ Each of these independently represents an organic group. ２０１ , R ２０２ , and R ２０３ The number of carbon atoms in the organic group is preferably 1 to 30, and more preferably 1 to 20.２０１ ~R ２０３ Two of these may bond to form a ring structure, and the ring may contain an oxygen atom, a sulfur atom, an ester group, an amide group, or a carbonyl group. ２０１ ~R ２０３ Examples of groups formed by the bonding of two of these include alkylene groups (e.g., butylene and pentylene groups) and -CH ２ -CH ２ -O-CH ２ -CH ２ - is an example. When the resist composition of the present invention is used as an EUV resist, R ２０１ ~R ２０５ Preferably, the cation contains a fluorine atom or an iodine atom as a substituent. Preferred embodiments of the cation represented by formula (ZaI) include cation (ZaI-1), cation (ZaI-2), cation (ZaI-3b), and cation (ZaI-4b), which will be described later.

[0122] First, let's explain the cation (ZaI-1). The cation (ZaI-1) is R in the above formula (ZaI). ２０１ ~R ２０３ It is an arylsulfonium cation in which at least one of the groups is an aryl group. ２０１ ~R ２０３ All of them may be aryl groups, or R ２０１ ~R ２０３ A portion of it may be an aryl group, and the remainder may be an alkyl group or a cycloalkyl group. ２０１ ~R ２０３ One of them is an aryl group, R ２０１ ~R ２０３ The remaining two of these may bond to form a ring structure, and the ring may contain an oxygen atom, a sulfur atom, an ester group, an amide group, or a carbonyl group. ２０１ ~R ２０３ Examples of groups formed by the bonding of two of these include alkylene groups in which one or more methylene groups may be substituted with an oxygen atom, a sulfur atom, an ester group, an amide group, and / or a carbonyl group (e.g., butylene group, pentylene group, and -CH ２ -CH２ -O-CH ２ -CH ２ Examples of arylsulfonium cations include triarylsulfonium cation, diarylalkylsulfonium cation, diarylcycloalkylsulfonium cation, aryldialkylsulfonium cation, and aryldicycloalkylsulfonium cation.

[0123] The aryl group contained in the arylsulfonium cation is preferably a phenyl group or a naphthyl group, with the phenyl group being more preferred. When the arylsulfonium cation has two or more aryl groups, the two or more aryl groups may be the same or different. The aryl group may be an aryl group having a heterocyclic structure containing an oxygen atom, a nitrogen atom, or a sulfur atom, etc. Examples of heterocyclic structures include pyrrole residues, furan residues, thiophene residues, indole residues, benzofuran residues, and benzothiophene residues. The alkyl or cycloalkyl group that the arylsulfonium cation may have is preferably a linear alkyl group having 1 to 15 carbon atoms, a branched alkyl group having 3 to 15 carbon atoms, or a cycloalkyl group having 3 to 15 carbon atoms, with methyl group, ethyl group, propyl group, n-butyl group, sec-butyl group, t-butyl group, cyclopropyl group, cyclobutyl group, or cyclohexyl group being more preferred.

[0124] The above aryl group may have substituents, and preferred substituents are alkyl groups (e.g., C1-C15), cycloalkyl groups (e.g., C3-C15), aryl groups (e.g., C6-C14), alkoxy groups (e.g., C1-C15), cycloalkylalkoxy groups (e.g., C1-C15), halogen atoms (e.g., fluorine and iodine), hydroxyl groups, carboxyl groups, ester groups, sulfinyl groups, sulfonyl groups, alkylthio groups, phenylthio groups, or alkyloxycarbonylalkyleneoxy groups. The above substituents may have further substituents if possible, and it is also preferable that the alkyl group has a halogen atom as a substituent to form a halogenated alkyl group such as a trifluoromethyl group. It is also preferable that the above substituents form an acid-degradable group in any combination. An acid-degradable group is a group that decomposes and increases in polarity upon the action of an acid, and it is preferable that the polar group is protected by a group that is eliminated upon the action of an acid.

[0125] Next, we will explain the cation (ZaI-2). The cation (ZaI-2) is R in formula (ZaI). ２０１ ~R ２０３ However, each of these independently represents a cation that does not have an aromatic ring. The term "aromatic ring" also includes aromatic rings containing heteroatoms. R ２０１ ~R ２０３ The number of carbon atoms in the organic group that does not have an aromatic ring is preferably 1 to 30, and more preferably 1 to 20. ２０１ ~R ２０３ The members are preferably alkyl groups, cycloalkyl groups, allyl groups, or vinyl groups, more preferably linear or branched 2-oxoalkyl groups, 2-oxocycloalkyl groups, or alkoxycarbonylmethyl groups, and even more preferably linear or branched 2-oxoalkyl groups.

[0126] R ２０１ ~R ２０３Examples of alkyl and cycloalkyl groups represented by include linear alkyl groups having 1 to 10 carbon atoms or branched alkyl groups having 3 to 10 carbon atoms (e.g., methyl group, ethyl group, propyl group, butyl group, and pentyl group), and cycloalkyl groups having 3 to 10 carbon atoms (e.g., cyclopentyl group, cyclohexyl group, and norbornyl group). ２０１ ~R ２０３ This may be further substituted with a halogen atom, an alkoxy group (e.g., having 1 to 5 carbon atoms), a hydroxyl group, a cyano group, or a nitro group.

[0127] Next, we will explain the cation (ZaI-3b). The cation (ZaI-3b) is a cation represented by the following formula (ZaI-3b).

[0128]

[0129] In formula (ZaI-3b), R １ｃ ~R ５ｃ Each of these independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an alkoxy group, an aryloxy group, an alkoxycarbonyl group, an alkylcarbonyloxy group, a cycloalkylcarbonyloxy group, a halogen atom, a hydroxyl group, a nitro group, an alkylthio group, or an arylthio group. ６ｃ and R ７ｃ Each of these independently represents a hydrogen atom, an alkyl group (e.g., a t-butyl group), a cycloalkyl group, a halogen atom, a cyano group, or an aryl group. ｘ and R ｙ Each of these independently represents an alkyl group, a cycloalkyl group, a 2-oxoalkyl group, a 2-oxocycloalkyl group, an alkoxycarbonylalkyl group, an allyl group, or a vinyl group.

[0130] R １ｃ ~R ５ｃ Two or more of the following, R ５ｃ and R ６ｃ , R ６ｃ and R ７ｃ , R ５ｃ and R ｘ , and R ｘ and R ｙThese elements may be bonded to each other to form a ring, and each of these rings may independently contain an oxygen atom, a sulfur atom, a ketone group, an ester bond, or an amide bond. Examples of the above rings include aromatic or non-aromatic hydrocarbon rings, aromatic or non-aromatic heterorings, and polycyclic fused rings formed by the combination of two or more of these rings. Examples of rings include 3 to 10-membered rings, preferably 4 to 8-membered rings, and more preferably 5 or 6-membered rings.

[0131] R １ｃ ~R ５ｃ Two or more of the following, R ６ｃ and R ７ｃ , and R ｘ and R ｙ Examples of groups formed by the bonding include alkylene groups such as butylene and pentylene groups. The methylene group in the alkylene group may be substituted with a heteroatom such as an oxygen atom. ５ｃ and R ６ｃ , and R ５ｃ and R ｘ The groups formed by the bonding of these elements are preferably single bonds or alkylene groups. Examples of alkylene groups include methylene groups and ethylene groups.

[0132] R １ｃ ~R ５ｃ , R ６ｃ , R ７ｃ , R ｘ , R ｙ , and R １ｃ ~R ５ｃ Two or more of the following, R ５ｃ and R ６ｃ , R ６ｃ and R ７ｃ , R ５ｃ and R ｘ , and R ｘ and R ｙ The rings formed by the bonding of these elements to each other may have substituents.

[0133] Next, we will explain the cation (ZaI-4b). The cation (ZaI-4b) is a cation represented by the following formula (ZaI-4b).

[0134]

[0135] In equation (ZaI-4b), l represents an integer from 0 to 2, and r represents an integer from 0 to 8. １３ R represents a group containing a hydrogen atom, a halogen atom (e.g., a fluorine atom and an iodine atom), a hydroxyl group, an alkyl group, an alkyl halide, an alkoxy group, a carboxyl group, an alkoxycarbonyl group, or a cycloalkyl group (which may be a cycloalkyl group itself or a group containing a cycloalkyl group as part). These groups may have substituents. １４ R represents a hydroxyl group, a halogen atom (e.g., a fluorine atom and an iodine atom), an alkyl group, an alkyl halide, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylsulfonyl group, a cycloalkylsulfonyl group, or a group containing a cycloalkyl group (which may be a cycloalkyl group itself or a group containing a cycloalkyl group in part). These groups may have substituents. １４ The fields in which multiple instances exist may be independent or distinct from each other. １５ Each of these independently represents an alkyl group, a cycloalkyl group, or a naphthyl group. １５ They may bond to each other to form a ring. Two R １５ When these atoms bond to each other to form a ring, the ring may contain heteroatoms such as oxygen atoms or nitrogen atoms. In one embodiment, two R １５ It is preferable that the alkyl group is an alkylene group and that they bond to each other to form a ring structure. The alkyl group, cycloalkyl group and naphthyl group and the two R １５ The ring formed by the bonding of these elements may have substituents.

[0136] In formula (ZaI-4b), R １３ , R １４ and R １５ The alkyl group may be linear or branched. The alkyl group preferably has 1 to 10 carbon atoms. The alkyl group is preferably a methyl group, ethyl group, n-butyl group, or t-butyl group.

[0137] Next, we will explain equation (ZaII). In equation (ZaII), R ２０４ and R２０５ Each of these independently represents an aryl group, an alkyl group, or a cycloalkyl group. ２０４ and R ２０５ The aryl group is preferably a phenyl group or a naphthyl group, with the phenyl group being more preferred. Alternatively, it may be an aryl group having a heterocycle containing an oxygen atom, a nitrogen atom, or a sulfur atom. Examples of heterocycle aryl group skeletons include pyrrole, furan, thiophene, indole, benzofuran, and benzothiophene. ２０４ and R ２０５ The alkyl and cycloalkyl groups are preferably linear alkyl groups having 1 to 10 carbon atoms, branched alkyl groups having 3 to 10 carbon atoms (e.g., methyl group, ethyl group, propyl group, butyl group, or pentyl group), or cycloalkyl groups having 3 to 10 carbon atoms (e.g., cyclopentyl group, cyclohexyl group, or norbornyl group).

[0138] R ２０４ and R ２０５ The aryl group, alkyl group, and cycloalkyl group may each independently have substituents. ２０４ and R ２０５ Examples of substituents that the aryl group, alkyl group, and cycloalkyl group may have include alkyl groups (e.g., having 1 to 15 carbon atoms), cycloalkyl groups (e.g., having 3 to 15 carbon atoms), aryl groups (e.g., having 6 to 15 carbon atoms), alkoxy groups (e.g., having 1 to 15 carbon atoms), halogen atoms, hydroxyl groups, and phenylthio groups.

[0139] Specific examples of organic cations are shown below, but the present invention is not limited thereto.

[0140]

[0141]

[0142] "M ＋ X － In the compound represented by ", X －The symbol represents an anion, preferably an organic anion. The valency of the anion may be monovalent or divalent or greater. The anion is preferably one with a remarkably low ability to undergo nucleophilic reactions, and more preferably a non-nucleophilic anion. The organic anion may be used alone or in combination of two or more.

[0143] Examples of non-nucleophilic anions include sulfonate anions (aliphatic sulfonate anions, aromatic sulfonate anions, and camphor sulfonate anions, etc.), carboxylic acid anions (aliphatic carboxylic acid anions, aromatic carboxylic acid anions, and aralkyl carboxylic acid anions, etc.), sulfonylimide anions, bis(alkylsulfonyl)imide anions, and tris(alkylsulfonyl)methide anions.

[0144] The aliphatic moiety in aliphatic sulfonic acid anions and aliphatic carboxylic acid anions may be a linear or branched alkyl group or a cycloalkyl group, with linear or branched alkyl groups having 1 to 30 carbon atoms or cycloalkyl groups having 3 to 30 carbon atoms being preferred. The alkyl group may be, for example, a fluoroalkyl group (which may have substituents other than fluorine atoms; it may also be a perfluoroalkyl group).

[0145] In aromatic sulfonic acid anions and aromatic carboxylic acid anions, aryl groups having 6 to 14 carbon atoms are preferred, such as phenyl groups, tolyl groups, and naphthyl groups.

[0146] The alkyl groups, cycloalkyl groups, and aryl groups listed above may have substituents. Examples of substituents include nitro groups, halogen atoms such as fluorine and chlorine atoms, carboxyl groups, hydroxyl groups, amino groups, cyano groups, alkoxy groups (preferably having 1 to 15 carbon atoms), alkyl groups (preferably having 1 to 10 carbon atoms), cycloalkyl groups (preferably having 3 to 15 carbon atoms), aryl groups (preferably having 6 to 14 carbon atoms), alkoxycarbonyl groups (preferably having 2 to 7 carbon atoms), acyl groups (preferably having 2 to 12 carbon atoms), alkoxycarbonyloxy groups (preferably having 2 to 7 carbon atoms), alkylthio groups (preferably having 1 to 15 carbon atoms), alkylsulfonyl groups (preferably having 1 to 15 carbon atoms), alkyliminosulfonyl groups (preferably having 1 to 15 carbon atoms), and aryloxysulfonyl groups (preferably having 6 to 20 carbon atoms). When the resist composition of the present invention is used as an EUV resist, it is also preferable, and more preferable, to include a fluorine atom or an iodine atom as a substituent. There is no limit to the number of fluorine or iodine atoms, but from the viewpoint of EUV light absorption efficiency, the more the better.

[0147] In aralkyl carboxylate anions, aralkyl groups having 7 to 14 carbon atoms are preferred. Examples of aralkyl groups having 7 to 14 carbon atoms include benzyl, phenethyl, naphthylmethyl, naphthylethyl, and naphthylbutyl groups.

[0148] An example of a sulfonylimid anion is the saccharin anion.

[0149] In bis(alkylsulfonyl)imido anions and tris(alkylsulfonyl)methide anions, alkyl groups having 1 to 5 carbon atoms are preferred. Substituents for these alkyl groups include halogen atoms, halogen-substituted alkyl groups, alkoxy groups, alkylthio groups, alkyloxysulfonyl groups, aryloxysulfonyl groups, and cycloalkylaryloxysulfonyl groups, with fluorine atoms or fluorine-substituted alkyl groups being preferred. Furthermore, the alkyl groups in bis(alkylsulfonyl)imido anions may be bonded to each other to form a ring structure.

[0150] Other non-nucleophilic anions include, for example, fluorinated phosphorus (e.g., PF). ６ － ), fluorinated boron (for example, BF ４ － ), and fluorinated antimony (e.g., SbF ６ － ) are some examples.

[0151] Preferred non-nucleophilic anions include aliphatic sulfonic acid anions in which at least the α-position of the sulfonic acid is substituted with a fluorine atom, aromatic sulfonic acid anions substituted with a fluorine atom or a group containing a fluorine atom, bis(alkylsulfonyl)imide anions in which the alkyl group is substituted with a fluorine atom, or tris(alkylsulfonyl)methide anions in which the alkyl group is substituted with a fluorine atom. Among these, perfluoroaliphatic sulfonic acid anions (preferably having 4 to 8 carbon atoms) or benzenesulfonic acid anions containing a fluorine atom are more preferred, and nonafluorobutanesulfonic acid anions, perfluorooctanesulfonic acid anions, pentafluorobenzenesulfonic acid anions, or 3,5-bis(trifluoromethyl)benzenesulfonic acid anions are even more preferred.

[0152] As a non-nucleophilic anion, the anion represented by the following formula (AN1) is also preferred.

[0153]

[0154] In formula (AN1), R １ and R２ Each of these independently represents a hydrogen atom or a substituent. Examples of substituents include hydrocarbon groups, hydroxyl groups, oxy hydrocarbon groups, oxycarbonyl hydrocarbon groups, amino groups, hydrocarbon-substituted amino groups, and hydrocarbon-substituted amide groups, such as -R', -OH, -OR', -OCOR', and -NH. ２ ,-NR' ２ , -NHR', or -NHCOR' are preferred. R' is a monovalent hydrocarbon group. Among them, R １ and R ２ Each of these is independently preferably a hydrocarbon group (cycloalkyl group is preferred) or a hydrogen atom.

[0155] Examples of monovalent hydrocarbon groups represented by R' above include alkyl groups such as methyl, ethyl, propyl, and butyl groups; alkenyl groups such as ethenyl, propenyl, and butenyl groups; monovalent linear or branched hydrocarbon groups such as alkynyl groups such as ethynyl, propynyl, and butynyl groups; cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, norbornyl, and adamantyl groups; monovalent alicyclic hydrocarbon groups such as cyclopropenyl, cyclobutenyl, cyclopentenyl, and norbornenyl groups; aryl groups such as phenyl, tolyl, xylyl, mesityl, naphthyl, methylnaphthyl, anthryl, and methylanthryl groups; and monovalent aromatic hydrocarbon groups such as benzyl, phenethyl, phenylpropyl, naphthylmethyl, and anthrylmethyl groups.

[0156] L represents a divalent linking group. Examples of divalent linking groups include -CO-, -NH-, -O-, -S-, -SO-, and -SO ２ Examples of divalent linking groups include alkylene groups (preferably having 1 to 6 carbon atoms), cycloalkylene groups (preferably having 3 to 15 carbon atoms), alkenylene groups (preferably having 2 to 6 carbon atoms), and divalent linking groups formed by combining multiples thereof. Among these, examples of divalent linking groups include -O-CO-O-, -COO-, -CONH-, -CO-, -O-, and -SO ２-, -O-CO-O-alkylene group-, -COO-alkylene group-, or -CONH-alkylene group- are preferred, and -O-CO-O-, -O-CO-O-alkylene group-, -COO-, -CONH-, -SO ２ - or -COO-alkylene group- is more preferred.

[0157] For L, a group represented by the following formula (AN1-1) is preferred. * ａ - (CR ２ａ ２ ) Ｘ -Q- (CR ２ｂ ２ ) Ｙ - * ｂ (AN1-1)

[0158] In formula (AN1-1), * ａ R in equation (AN1) ３ This indicates the connection point with [the other element]. * ｂ -C(R) in equation (AN1) １ ) (Caution ２ ) - Represents the connection position with . X and Y each independently represent integers from 0 to 10, preferably integers from 0 to 3. R ２ａ and R ２ｂ Each of these independently represents a hydrogen atom or a substituent. ２ａ and R ２ｂ If there are multiple instances of each, then there are multiple instances of R ２ａ and R ２ｂ These may be the same or different. However, if Y is 1 or greater, -C(R) in equation (AN1) １ ) (Caution ２ )- and CR that bind directly ２ｂ ２ In R ２ｂ is anything other than a fluorine atom. Q is * Ａ -O-CO-O-* Ｂ , * Ａ -CO-* Ｂ , * Ａ -CO-O-* Ｂ , * Ａ -O-CO-* Ｂ , * Ａ -O-* Ｂ , * Ａ -S-*Ｂ , or, * Ａ -SO ２ - * Ｂ This represents the condition that X+Y in equation (AN1-1) is 1 or greater, and R in equation (AN1-1) is greater than or equal to 1. ２ａ and R ２ｂ If all of them are hydrogen atoms, then Q is * Ａ -O-CO-O-* Ｂ , * Ａ -CO-* Ｂ , * Ａ -O-CO-* Ｂ , * Ａ -O-* Ｂ , * Ａ -S-* Ｂ , or, * Ａ -SO ２ - * Ｂ This represents. * Ａ R in equation (AN1) ３ This indicates the connection position on the side, * Ｂ This is -SO in equation (AN1). ３ － This indicates the connection point on the side.

[0159] In formula (AN1), R ３ R represents an organic group. The above organic group is not particularly limited and may be a linear group (e.g., a linear alkyl group), a branched group (e.g., a branched alkyl group such as a t-butyl group), or a cyclic group. The above organic group may have substituents and may have heteroatoms (oxygen atom, sulfur atom, and / or nitrogen atom, etc.). Among these, R ３ It is preferable that the organic group has a cyclic structure. The cyclic structure may be monocyclic or polycyclic and may have substituents. It is preferable that the ring in the organic group containing the cyclic structure is directly bonded to L in formula (AN1). The organic group having the cyclic structure may have, for example, heteroatoms (oxygen atom, sulfur atom, and / or nitrogen atom). The heteroatoms may be substituted for one or more carbon atoms forming the cyclic structure.

[0160] The organic group having the above-mentioned cyclic structure is preferably a cyclic hydrocarbon group, a lactone ring group, or a sultone ring group, with a cyclic hydrocarbon group being more preferred. The above-mentioned cyclic hydrocarbon group is preferably a monocyclic or polycyclic cycloalkyl group. These groups may have substituents. The above-mentioned cycloalkyl group may be monocyclic (e.g., a cyclohexyl group) or polycyclic (e.g., an adamantyl group), and the number of carbon atoms is preferably 5 to 12.

[0161] R ３ It is preferable that it contains a halogen atom. ３ The halogen atoms included are preferably fluorine atoms or iodine atoms, with iodine atoms being more preferred. If iodine atoms are present, a structure in which they are directly bonded to carbon atoms on the aromatic ring is preferred. When the resist composition of the present invention is used as an EUV resist, a larger number of halogen atoms is preferable from the viewpoint of EUV light absorption efficiency.

[0162] Examples of anions represented by formula (AN1) include those described in

[0040] to

[0044] of Japanese Patent Publication No. 2018-155908,

[0184] to

[0185] and

[0197] to

[0198] of Japanese Patent Publication No. 2021-128331,

[0124] to

[0125] and

[0137] to

[0138] of International Publication No. 2022 / 064863, and

[0056] to

[0061] of Japanese Patent Publication No. 2023-177048, the above descriptions are incorporated herein by reference.

[0163] As a non-nucleophilic anion, the anion represented by the following formula (AN2) is also preferred.

[0164]

[0165] In formula (AN2), o represents an integer from 1 to 3. p represents an integer from 0 to 10. q represents an integer from 0 to 10. L represents a divalent linking group. The definition of L is the same as that of L in formula (AN1).

[0166] Xf represents a hydrogen atom, a fluorine atom, an alkyl group substituted with one or more fluorine atoms, or an organic group without a fluorine atom. The number of carbon atoms in this alkyl group is preferably 1 to 10, more preferably 1 to 4. As the alkyl group substituted with one or more fluorine atoms, a perfluoroalkyl group is preferred. Xf is preferably a fluorine atom or a perfluoroalkyl group having 1 to 4 carbon atoms, and fluorine atom or CF ３ It is more preferable that all Xf are fluorine atoms, and even more preferable that all Xf are fluorine atoms.

[0167] R ４ and R ５ Each of these independently represents a hydrogen atom, a fluorine atom, an alkyl group, or an alkyl group substituted with one or more fluorine atoms. ４ and R ５ If multiple instances exist, R ４ and R ５ These may be the same or different. ４ and R ５ The alkyl group represented by preferably has 1 to 4 carbon atoms. The alkyl group may have substituents. ４ and R ５ A hydrogen atom is preferred as the element.

[0168] W represents an organic group containing a cyclic structure. Among these, a cyclic organic group is preferred. The carbon atoms constituting the cyclic organic group (carbon atoms contributing to ring formation) may be carbonyl carbons. Examples of cyclic organic groups include alicyclic groups, aryl groups, and heterocyclic groups. Alicyclic groups may be monocyclic or polycyclic. Examples of monocyclic alicyclic groups include monocyclic cycloalkyl groups such as cyclopentyl groups, cyclohexyl groups, and cyclooctyl groups. Examples of polycyclic alicyclic groups include polycyclic cycloalkyl groups such as norbornyl groups, tricyclodecanyl groups, tetracyclodecanyl groups, tetracyclododecanyl groups, and adamantyl groups. Among these, alicyclic groups having a bulky structure with 7 or more carbon atoms, such as norbornyl groups, tricyclodecanyl groups, tetracyclodecanyl groups, tetracyclododecanyl groups, and adamantyl groups, are preferred.

[0169] The aryl group may be monocyclic or polycyclic. Examples of the above aryl group include the phenyl group, naphthyl group, phenanthryl group, and anthryl group. The heterocyclic group may be monocyclic or polycyclic. The heterocyclic group may or may not be aromatic. Examples of aromatic heterocyclic rings include the furan ring, thiophene ring, benzofuran ring, benzothiophene ring, dibenzofuran ring, dibenzothiophene ring, and pyridine ring. Examples of heterocyclic rings that are not aromatic include the tetrahydropyran ring, lactone ring, sultone ring, and decahydroisoquinoline ring. The heterocyclic ring in the heterocyclic group is preferably a furan ring, thiophene ring, pyridine ring, or decahydroisoquinoline ring.

[0170] The above-mentioned cyclic organic group may have substituents. Examples of substituents include alkyl groups (which may be linear or branched, preferably having 1 to 12 carbon atoms), cycloalkyl groups (which may be monocyclic, polycyclic, or spirocyclic, preferably having 3 to 20 carbon atoms), aryl groups (preferably having 6 to 14 carbon atoms), hydroxyl groups, alkoxy groups, ester groups, amide groups, urethane groups, ureido groups, thioether groups, sulfonamide groups, and sulfonic acid ester groups.

[0171] It is preferable that W contains halogen atoms. Preferably, the halogen atoms in W are fluorine atoms or iodine atoms, with iodine atoms being more preferable. If iodine atoms are present, a structure in which they are directly bonded to carbon atoms on an aromatic ring is preferred. When the resist composition of the present invention is used as an EUV resist, a larger number of halogen atoms is preferable from the viewpoint of EUV light absorption efficiency.

[0172] Anions represented by formula (AN2) include SO ３ － -CF ２ -CH ２ -OCO-(L) ｑ’ -W, SO ３ － -CF ２ -CHF-CH ２ -OCO-(L)ｑ’ -W, SO ３ － -CF ２ -COO-(L) ｑ’ -W, SO ３ － -CF ２ -CF ２ -CH ２ -CH ２ - (L) ｑ -W, or SO ３ － -CF ２ -CH(CF ３ )-OCO-(L) ｑ’ -W is preferred. q' represents an integer from 0 to 10. L, q, and W are the same as in formula (AN2).

[0173] Anions represented by formula (AN2) include

[0076] in International Publication No. 2023 / 157455,

[0071] to

[0089] in Japanese Patent Publication No. 2021-081708,

[0033] to

[0045] in Japanese Patent Publication No. 2018-005224,

[0031] to

[0039] in Japanese Patent Publication No. 2018-025789, and Japanese Patent Publication No. 2021 Examples include the anions described in

[0176] to

[0183] and

[0186] to

[0196] of Publication No. 128331,

[0116] to

[0123] and

[0126] to

[0136] of International Publication No. 2022 / 064863, and

[0076] of International Publication No. 2023 / 157455, which are incorporated herein by reference.

[0174] As a non-nucleophilic anion, an aromatic sulfonic acid anion represented by the following formula (AN3) is also preferred.

[0175]

[0176] In formula (AN3), Ar represents an aryl group (such as a phenyl group) and may further have substituents other than a sulfonic acid anion and a -(D-B) group. Examples of further substituents include a fluorine atom and a hydroxyl group. n represents an integer of 0 or more. n is preferably 1 to 4, more preferably 2 to 3, and even more preferably 3.

[0177] D represents a single bond or a divalent linking group. Examples of divalent linking groups include ether groups, thioether groups, carbonyl groups, sulfoxide groups, sulfone groups, sulfonic acid ester groups, ester groups, and groups consisting of two or more combinations thereof.

[0178] B represents a hydrocarbon group. B is preferably an aliphatic hydrocarbon group, and more preferably an isopropyl group, a cyclohexyl group, or an aryl group which may have further substituents (such as a tricyclohexylphenyl group).

[0179] It is preferable that B contains halogen atoms. Preferably, the halogen atoms in B are fluorine atoms or iodine atoms, with iodine atoms being more preferable. If iodine atoms are present, a structure in which they are directly bonded to carbon atoms on an aromatic ring is preferred. When the resist composition is used as an EUV resist, a larger number of halogen atoms is preferable from the viewpoint of EUV light absorption efficiency.

[0180] Examples of anions represented by formula (AN3) include those described in

[0029] to

[0034] of Japanese Patent Publication No. 2018-159744,

[0045] of Japanese Patent Publication No. 2018-155908,

[0037] to

[0055] and

[0062] to

[0064] of Japanese Patent Publication No. 2023-177048, the above descriptions are incorporated herein by reference.

[0181] As a non-nucleophilic anion, disulfonamide anions are also preferred. Disulfonamide anions include, for example, N － (SO ２ -R ｑ ) ２ This is an anion represented by R. ｑ R represents an alkyl group which may have substituents, preferably a fluoroalkyl group, and more preferably a perfluoroalkyl group. ｑ They may be joined to each other to form a ring. Two R ｑ The group formed by the bonding of these atoms is preferably an alkylene group, which may have substituents, preferably a fluoroalkylene group, and more preferably a perfluoroalkylene group. The alkylene group preferably has 2 to 4 carbon atoms.

[0182] Furthermore, non-nucleophilic anions include those represented by the following formulas (d1-1) to (d1-4).

[0183]

[0184] In formula (d1-1), R ５１ represents a hydrocarbon group (e.g., an aryl group such as a phenyl group) which may have substituents (e.g., a hydroxyl group). Examples of anions represented by formula (d1-1) include

[0041] to

[0047] in JP 2017-219836,

[0026] to

[0028] in JP 2018-155902,

[0040] to

[0041] and

[0128] in JP 2020-154212,

[0049] to

[0061] and

[0278] to

[0279] in JP 2021-091666, and International Publication No. 2022 / Examples of anions described in

[0150] to

[0154] of JP 064863,

[0013] to

[0015] of JP 2022-077505,

[0026] to

[0031] and

[0050] to

[0051] of JP 2022-141598,

[0147] of JP 2023-108593, and

[0088] of International Publication No. 2023 / 157455 are included, and the above descriptions are incorporated herein by reference.

[0185] In formula (d1-2), Z ２ｃ represents a hydrocarbon group having 1 to 30 carbon atoms, which may have substituents (however, carbon atoms adjacent to S are not substituted with fluorine atoms). ２ｃ The hydrocarbon group in the above may be linear, branched, or have a cyclic structure. Furthermore, the carbon atoms in the hydrocarbon group (preferably, the ring member carbon atoms when the hydrocarbon group has a cyclic structure) may be carbonyl carbons (-CO-). Examples of the hydrocarbon group include a group having a norbornyl group which may have substituents. The carbon atoms in the norbornyl group may also be carbonyl carbons.

[0186] The anion represented by formula (d1-2) is preferably different from the anions represented by formulas (AN1) to (AN3) described above. For example, Z ２ｃA group other than an aryl group is preferred. Also, Z ２ｃ In, -SO ３ － For Z, the atoms at the α and β positions are preferably atoms other than carbon atoms that have a fluorine atom as a substituent. ２ｃ is, -SO ３ － In relation to this, the atom at the α position and / or the atom at the β position are preferably ring member atoms in the cyclic group.

[0187] In formula (d1-3), R ５２ represents an organic group (preferably a hydrocarbon group having a fluorine atom), Y ３ represents a linear, branched, or cyclic alkylene group, arylene group, or carbonyl group, and Rf represents a hydrocarbon group. Examples of anions represented by formula (d1-3) include those described in

[0040] to

[0046] of Japanese Patent Publication No. 2019-211751,

[0039] to

[0047] of Japanese Patent Publication No. 2021-128331,

[0043] to

[0060] of Japanese Patent Publication No. 2021-165824, and

[0062] and

[0075] of International Publication No. 2023 / 119910, the above descriptions are incorporated herein by reference.

[0188] In formula (d1-4), R ５３ and R ５４ Each of these independently represents an organic group (preferably a hydrocarbon group having a fluorine atom). ５３ and R ５４ They may be joined to each other to form a ring.

[0189] The photoacid generator is preferably at least one selected from the group consisting of compounds (I) to (II).

[0190] (Compound (I)) Compound (I) is a compound having one or more of the following structural sites X and one or more of the following structural sites Y, which generates an acid containing the following first acidic site derived from the following structural site X and the following second acidic site derived from the following structural site Y upon irradiation with active light or radiation. Structural site X: Anionic site A １ － and cation site M １ ＋It consists of and is irradiated with active light or radiation, HA １ Structural site that forms the first acidic site represented by Structural site Y: Anionic site A ２ － and cation site M ２ ＋ It consists of and is irradiated with active light or radiation, HA ２ The structural site (I) that forms the second acidic site represented by satisfies the following condition I.

[0191] Condition I: In the above compound (I), the above cation site M in the above structural site X. １ ＋ and the cation portion M in the structural portion Y. ２ ＋ to H ＋ The compound PI obtained by replacing the above structural site X is the cation site M １ ＋ to H ＋ HA is obtained by replacing it with １ The acid dissociation constant a1 originates from the acidic site represented by the above structure site Y, and the cation site M in the above structural site Y. ２ ＋ to H ＋ HA is obtained by replacing it with ２ It has an acid dissociation constant a2 derived from the acidic site represented by the above, and the acid dissociation constant a2 is greater than the acid dissociation constant a1.

[0192] Condition I will be explained in more detail below. If compound (I) is a compound that generates an acid having, for example, one first acidic site derived from structural site X and one second acidic site derived from structural site Y, then compound PI is "HA １ and HA ２ This falls under the category of "compounds having the above characteristics". More specifically, when the acid dissociation constants a1 and a2 of compound PI are determined, compound PI is "A １ － and HA ２ The pKa at which the compound becomes "a compound having " is the acid dissociation constant a1, and the above "A １ － and HA ２Compounds having "A" １ － and A ２ － The pKa value at which the compound becomes "a compound having the above characteristics" is the acid dissociation constant a2.

[0193] If compound (I) is a compound that generates an acid having, for example, two first acidic sites derived from structural site X and one second acidic site derived from structural site Y, then compound PI is "two HA １ and one HA ２ This falls under the category of "compounds having one A". When the acid dissociation constant of compound PI is determined, compound PI is "a compound having one A １ － and one HA １ and one HA ２ The acid dissociation constant when a compound having " and " is formed, and " １ － and one HA １ and one HA ２ Compounds having "two A １ － and one HA ２ The acid dissociation constant when a compound having the two A's is obtained corresponds to the aforementioned acid dissociation constant a1. １ － and one HA ２ Compounds having "two A １ － and A ２ － The acid dissociation constant when a compound has the above-mentioned structure corresponds to the acid dissociation constant a2. In other words, in the case of compound PI, the above-mentioned cation site M in the above-mentioned structural site X. １ ＋ to H ＋ HA is obtained by replacing it with １ When a compound has multiple acid dissociation constants originating from the acidic site represented by , the value of acid dissociation constant a2 is greater than the largest of the multiple acid dissociation constants a1. １ － and one HA １ and one HA ２ Let aa be the acid dissociation constant when a compound having " １ － and one HA１ and one HA ２ Compounds having "two A １ － and one HA ２ When the acid dissociation constant for a compound having the above is denoted as ab, the relationship between aa and ab satisfies aa < ab.

[0194] The acid dissociation constants a1 and a2 are determined by the acid dissociation constant measurement method described above. The compound PI mentioned above corresponds to the acid generated when compound (I) is irradiated with active light or radiation. If compound (I) has two or more structural sites X, the structural sites X may be the same or different. Also, two or more of the above A １ － , and two or more of the above M １ ＋ These may be the same or different. In compound (I), the above A １ － and A above ２ － , and the above M １ ＋ and the above M ２ ＋ These may be the same or different, but A above １ － and A above ２ － It is preferable that they are all different.

[0195] In the above compound PI, the difference (absolute value) between the acid dissociation constant a1 (the maximum value if there are multiple acid dissociation constants a1) and the acid dissociation constant a2 is preferably 0.1 or more, more preferably 0.5 or more, and even more preferably 1.0 or more. There is no particular upper limit to the difference (absolute value) between the acid dissociation constant a1 (the maximum value if there are multiple acid dissociation constants a1) and the acid dissociation constant a2, but for example, it is 16 or less.

[0196] In the above compound PI, the acid dissociation constant a2 is preferably 20 or less, and more preferably 15 or less. The lower limit of the acid dissociation constant a2 is preferably -4.0 or higher.

[0197] In the above compound PI, the acid dissociation constant a1 is preferably 2.0 or less, and more preferably 0 or less. The lower limit of the acid dissociation constant a1 is preferably -20.0 or higher.

[0198] Anion part A １ － and anion part A ２ － This is a structural site containing a negatively charged atom or group of atoms, and examples include structural sites selected from the group consisting of formulas (AA-1) to (AA-3) and formulas (BB-1) to (BB-6) shown below. Anion site A １ － As such, those that can form an acidic moiety with a small acid dissociation constant are preferred, and among these, those of formula (AA-1) to (AA-3) are more preferred, and those of formula (AA-1) and (AA-3) are even more preferred. Also, anion moiety A ２ － For example, Anion part A １ － It is preferable that the acidic site can form an acidic site with a larger acid dissociation constant than the above, more preferably one of formulas (BB-1) to (BB-6), and even more preferably one of formulas (BB-1) and (BB-4). In formulas (AA-1) to (AA-3) and (BB-1) to (BB-6) below, * represents the bond position. In formula (AA-2), R Ａ R represents a monovalent organic group. Ａ The monovalent organic group represented by is not particularly limited, but examples include a cyano group, a trifluoromethyl group, and a methanesulfonyl group.

[0199]

[0200]

[0201] Cation site M １ ＋ and cation site M ２ ＋ This is a structural site containing a positively charged atom or group of atoms, for example, a monovalent organic cation. Examples of organic cations include M, as described in the above explanation of the photoacid generator.＋ Examples include the same organic cations represented by [the formula shown].

[0202] (Compound (II)) Compound (II) is a compound having two or more of the above-mentioned structural sites X and one or more of the following structural sites Z, which generates an acid containing two or more of the above-mentioned first acidic sites derived from the above-mentioned structural sites X and the above-mentioned structural sites Z upon irradiation with active light or radiation. Structural site Z: A nonionic site capable of neutralizing acid

[0203] Definition of structural site X in compound (II), and A １ － and M １ ＋ The definition of is the definition of structural site X in compound (I) as described above, and A １ － and M １ ＋ This is synonymous with the definition of [the specified term], and the preferred embodiment is also the same.

[0204] In the above compound (II), the above cation moiety M in the above structural moiety X. １ ＋ to H ＋ In compound PII, which is obtained by replacing the above structural site X, the above cation site M １ ＋ to H ＋ HA is obtained by replacing it with １ The preferred range for the acid dissociation constant a1 derived from the acidic site represented by is the same as the acid dissociation constant a1 in compound PI. Note that if compound (II) is, for example, a compound that generates an acid having two of the first acidic sites derived from the structural site X and the structural site Z, then compound PII is "two HA １ This falls under the category of "a compound having one A". When the acid dissociation constant of this compound PII is determined, compound PII is "a compound having one A １ － and one HA １ The acid dissociation constant when a compound having " and " is formed, and " １ － and one HA １ Compounds having "two A １ －The acid dissociation constant when the compound becomes "a compound having " corresponds to the acid dissociation constant a1.

[0205] The acid dissociation constant a1 is determined by the acid dissociation constant measurement method described above. Compound PII refers to the acid generated when compound (II) is irradiated with active light or radiation. The two or more structural sites X may be the same or different. Two or more of the above A １ － , and two or more of the above M １ ＋ These may be the same or different.

[0206] The nonionic site in structural site Z that can neutralize the acid is not particularly limited, and is preferably a site containing a group that can electrostatically interact with a proton, or a functional group having electrons. Examples of groups that can electrostatically interact with a proton, or functional groups having electrons, include functional groups having a macrocyclic structure such as a cyclic polyether, or functional groups having a nitrogen atom with a lone pair of electrons that does not contribute to π-conjugation. A nitrogen atom having a lone pair of electrons that does not contribute to π-conjugation is, for example, a nitrogen atom having the substructure shown in the following formula.

[0207]

[0208] Examples of substructures of functional groups having a group or electron that can electrostatically interact with a proton include crown ether structures, azacrown ether structures, primary to tertiary amine structures, pyridine structures, imidazole structures, and pyrazine structures, among which primary to tertiary amine structures are preferred.

[0209] Examples of non-cationic moieties that compound (I) and compound (II) may have include the anions described in International Publication No. 2022 / 024928, paragraphs

[0277] to

[0280] , which are incorporated herein by reference.

[0210] The content of the photoacid generator in the resist composition is not particularly limited, but is preferably 0.5% by mass or more, more preferably 1.0% by mass or more, and even more preferably 5.0% by mass or more, relative to the total solid content of the resist composition. Furthermore, the content of the photoacid generator is preferably 50.0% by mass or less, more preferably 45.0% by mass or less, and even more preferably 40.0% by mass or less, relative to the total solid content of the resist composition. Only one type of photoacid generator may be used, or two or more types may be used. When two or more types of photoacid generators are used, it is preferable that their total content is within the range of the above preferred content.

[0211] [Acid Diffusion Control Agent] The resist composition of the present invention preferably further contains an acid diffusion control agent. The acid diffusion control agent is a compound different from the above-mentioned specific salt compound and the above-mentioned photoacid generator. The acid diffusion control agent can act as a quencher to trap excess acid generated by irradiation (exposure) with active light or radiation, for example, from components that can generate acid upon exposure (e.g., specific salt compound and photoacid generator), and to suppress the reaction of the acid-degradable resin in the unexposed areas due to the excess acid.

[0212] The type of acid diffusion control agent is not particularly limited, but examples include compounds selected from basic compounds (CA), low molecular weight compounds (CB) having a nitrogen atom and a group that is eliminated by the action of an acid, and compounds (CC) whose acid diffusion control ability is reduced or lost by irradiation with active light or radiation. It is also preferable that the acid diffusion control agent is a compound that generates an acid with a pKa of 0 or more upon irradiation with active light or radiation.

[0213] (Basic compound (CA)) As the basic compound (CA), a compound having a structure represented by any of the following formulas (A) to (E) is preferred. In formulas (B), (C), (D), and (E), * represents the bond position.

[0214]

[0215] In formula (A), R ２００ ~R ２０２Each of these independently represents a hydrogen atom, an alkyl group (preferably having 1 to 20 carbon atoms), a cycloalkyl group (preferably having 3 to 20 carbon atoms), or an aryl group (6 to 20 carbon atoms). ２００ ~R ２０２ At least two of them may be joined to form a ring. In formula (E), R ２０３ ~R ２０６ Each of these independently represents an alkyl group having 1 to 20 carbon atoms.

[0216] R in equations (A) and (E) ２００ , R ２０１ , R ２０２ , R ２０３ , R ２０４ , R ２０５ and R ２０６ The alkyl group or cycloalkyl group represented by may have substituents. Preferred substituent alkyl groups include C1-C20 aminoalkyl groups, C1-C20 hydroxyalkyl groups, or C1-C20 cyanoalkyl groups. In formulas (A) and (E), R ２００ , R ２０１ , R ２０２ , R ２０３ , R ２０４ , R ２０５ and R ２０６ The alkyl group or cycloalkyl group represented by is preferably unsubstituted.

[0217] Examples of basic compounds (CA) include guanidine, aminopyrrolidine, pyrazole, pyrazoline, piperazine, aminomorpholine, aminoalkylmorpholine, and piperidine. The basic compound (CA) may also be a compound having at least one selected from the group consisting of an imidazole structure, a diazabicyclo structure, an onium hydroxide structure, an onium carboxylate structure, a trialkylamine structure, an aniline structure, and a pyridine structure. The basic compound (CA) may also be an alkylamine derivative having at least one selected from the group consisting of a hydroxyl group and an ether bond, or an aniline derivative having at least one selected from the group consisting of a hydroxyl group and an ether bond.

[0218] The difference between the pKa of the conjugate acid of the basic compound (CA) and the pKa of the acid generated from the specified salt compound or the photoacid generator (the value obtained by subtracting the pKa of the acid generated from the specified salt compound or the photoacid generator from the pKa of the conjugate acid of the basic compound (CA)) is preferably 1.00 or higher, more preferably 1.00 to 14.00, and even more preferably 2.00 to 13.00. Furthermore, the pKa of the conjugate acid of the basic compound (CA) is preferably, for example, 1.00 to 14.00, more preferably 3.00 to 13.00, and even more preferably 3.50 to 12.50.

[0219] Specific examples of basic compounds (CA) include, for example, the compounds described in paragraphs

[0132] to

[0136] of International Publication No. 2020 / 066824, which are incorporated herein by reference. Specific examples of low molecular weight compounds (CB) having a nitrogen atom and a group that is eliminated by the action of an acid include the compounds described in paragraphs

[0156] to

[0163] of International Publication No. 2020 / 066824, which are incorporated herein by reference.

[0220] (Compounds (CC) whose acid diffusion control ability is reduced or lost by irradiation with active light or radiation) Specifically, examples of compounds (CC) include onium salt compounds (CD) of acids that are relatively weak acids with respect to the above-mentioned specific salt compounds and the above-mentioned photoacid generator, and basic compounds (CE) whose basicity is reduced or lost by irradiation with active light or radiation.

[0221] The compound (CD) may be a compound that generates acid upon exposure. Preferably, the compound (CD) is a compound that generates an acid whose pKa is 1.00 or greater than the acid generated from the specified salt compound or the photoacid generator. The difference between the pKa of the acid generated from the compound (CD) and the pKa of the acid generated from the specified salt compound or the photoacid generator (the value obtained by subtracting the pKa of the acid generated from the specified salt compound or the photoacid generator from the pKa of the acid generated from the compound (CD)) is preferably 1.00 or greater, more preferably 1.00 to 10.00, even more preferably 1.00 to 5.00, and particularly preferably 1.00 to 3.00. Furthermore, the pKa of the acid generated from the compound (CD) is preferably, for example, 0.50 to 10.00, more preferably 0.80 to 5.00, and even more preferably 1.00 to 5.00.

[0222] The compound (CD) is preferably an onium salt compound consisting of an anion and a cation. Examples of the compound (CD) include "M ＋ X － Examples include compounds represented by " (onium salts). ＋ represents a cation, preferably an organic cation. ＋ As for M, which was described in the above explanation of the photoacid generator ＋ The same thing can be cited as X － X represents an anion, preferably an organic anion. － Examples include the anions represented by formulas (d1-1) to (d1-4) described in the above explanation of the photoacid generator.

[0223] In particular, when the above compound (CC) is an onium salt compound (CD) that is relatively weak acid with respect to the above specific salt compound, it is preferable that the onium salt (CD) is a compound containing an anion part represented by any of the following formulas (BB-1) to (BB-7).

[0224]

[0225] Specific examples of onium salt compounds (CDs) include, for example, the compounds described in paragraphs

[0305] to

[0314] of International Publication No. 2020 / 158337, which are incorporated herein by reference. Specific examples of basic compounds (CEs) include those described in paragraphs

[0137] to

[0155] and paragraph

[0164] of International Publication No. 2020 / 066824, which are incorporated herein by reference.

[0226] In addition to the compounds described above, other known compounds disclosed in paragraphs

[0627] to

[0664] of U.S. Patent Application Publication 2016 / 0070167A1, paragraphs

[0095] to

[0187] of U.S. Patent Application Publication 2015 / 0004544A1, paragraphs

[0403] to

[0423] of U.S. Patent Application Publication 2016 / 0237190A1, and paragraphs

[0259] to

[0328] of U.S. Patent Application Publication 2016 / 0274458A1 can also be suitably used as acid diffusion control agents, and such descriptions are incorporated herein by reference.

[0227] The molecular weight of the acid diffusion control agent is not particularly limited, but is preferably 100 to 3000, more preferably 150 to 2500, and even more preferably 200 to 2000.

[0228] When the resist composition of the present invention contains an acid diffusion control agent, the content of the acid diffusion control agent is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and even more preferably 1.0% by mass or more, based on the total solid content of the resist composition. Furthermore, the content of the acid diffusion control agent is preferably 30.0% by mass or less, more preferably 20.0% by mass or less, and even more preferably 10.0% by mass or less, based on the total solid content of the resist composition. Only one type of acid diffusion control agent may be used, or two or more types may be used. When two or more types are used, it is preferable that their total content is within the range of the above preferred content.

[0229] [Resin] The resist composition of the present invention includes a resin. Examples of resins include resins whose polarity increases with the action of an acid (hereinafter also simply referred to as "acid-degradable resins") and hydrophobic resins. The resist composition preferably contains an acid-degradable resin, and more preferably contains both an acid-degradable resin and a hydrophobic resin. Acid-degradable resins will be described in detail below.

[0230] <Acid-degradable resin> (Repeating unit having an acid-degradable group) The acid-degradable resin contains a repeating unit having an acid-degradable group (hereinafter also simply referred to as "repeating unit A1"). The acid-degradable group is a group that decomposes and increases in polarity upon the action of an acid, and is typically a group that decomposes upon the action of an acid to produce a polar group. It is preferable that the acid-degradable group has a structure in which the polar group is protected by a group that is left behind upon the action of an acid (leaving group). It is preferable that the acid-degradable resin increases in polarity upon the action of an acid and decreases in solubility in organic solvents. Examples of the above polar groups include acidic groups such as carboxyl groups, phenolic hydroxyl groups, fluorinated alcohol groups, sulfonic acid groups, phosphoric acid groups, sulfonamide groups, sulfonylimide groups, (alkylsulfonyl)(alkylcarbonyl)methylene groups, (alkylsulfonyl)(alkylcarbonyl)imide groups, bis(alkylcarbonyl)methylene groups, bis(alkylcarbonyl)imide groups, bis(alkylsulfonyl)methylene groups, bis(alkylsulfonyl)imide groups, tris(alkylcarbonyl)methylene groups, and tris(alkylsulfonyl)methylene groups, as well as alcoholic hydroxyl groups. Among these, carboxyl groups, phenolic hydroxyl groups, fluorinated alcohol groups (preferably hexafluoroisopropanol groups), or sulfonic acid groups are preferred as polar groups.

[0231] Examples of groups that are eliminated by the action of an acid include the group represented by any of the following formulas: (Y1), (Y2), and (Y3). Formula (Y1): -C(Rx １ ) (Rx ２ ) (Rx ３ ) Formula (Y2): -C(R ３６ ) (Caution ３７ ) ( OR ３８) Formula (Y3): -C(Rn)(H)(Ar)

[0232] In formula (Y1), Rx １ ~Rx ３ Each of these independently represents an alkyl group (linear or branched), a cycloalkyl group (monocyclic or polycyclic), an alkenyl group (linear or branched), an alkynyl group, or an aryl group (monocyclic or polycyclic). １ ~Rx ３ If all of them are alkyl groups (linear or branched), then Rx １ ~Rx ３ Preferably, at least two of them are methyl groups. Among them, Rx １ ~Rx ３ Each preferably independently represents a linear or branched alkyl group, and Rx １ ~Rx ３ It is more preferable that each of these independently represents a linear alkyl group. １ ~Rx ３ These two may combine to form a monocycle or polycycle. Rx １ ~Rx ３ Preferred alkyl groups include C1-C5 alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, and t-butyl groups. １ ~Rx ３ Preferred cycloalkyl groups include monocyclic cycloalkyl groups such as cyclopentyl and cyclohexyl groups, and polycyclic cycloalkyl groups such as norbornyl, tetracyclodecanyl, tetracyclododecanyl, and adamantyl groups. １ ~Rx ３ A vinyl group is preferred as the alkenyl group. Rx １ ~Rx ３ The alkynyl group is preferably an ethynyl group or a propargyl group. Rx １ ~Rx ３ The aryl group is preferably an aryl group having 6 to 10 carbon atoms, such as a phenyl group, a naphthyl group, and an anthyl group.

[0233] Rx １~Rx ３ A cycloalkyl group is preferred as the ring formed by the bonding of these two. Rx １ ~Rx ３ The cycloalkyl group formed by the bonding of these two groups is preferably a monocyclic cycloalkyl group such as a cyclopentyl group or a cyclohexyl group, or a polycyclic cycloalkyl group such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, or an adamantyl group, with a monocyclic cycloalkyl group having 5 to 6 carbon atoms being more preferred. １ ~Rx ３ The cycloalkyl group formed by the bonding of these two groups may have one of the methylene groups constituting the ring replaced by a heteroatom such as an oxygen atom, a group containing a heteroatom such as a carbonyl group, or a vinylidene group. In these cycloalkyl groups, one or more of the ethylene groups constituting the cycloalkane ring may be replaced by vinylene groups. The group represented by formula (Y1) is, for example, Rx １ is a methyl group or an ethyl group, and Rx ２ and Rx ３ A preferred embodiment is one in which the two are bonded together to form the aforementioned cycloalkyl group.

[0234] When the resist composition of the present invention is used as an EUV resist, Rx １ ~Rx ３ Alkyl groups, cycloalkyl groups, alkenyl groups, aryl groups, and Rx are represented by １ ~Rx ３ The ring formed by the bonding of these two elements may further preferably have a fluorine atom or an iodine atom as a substituent.

[0235] In formula (Y2), R ３６ ~R ３８ Each of these independently represents a hydrogen atom or a monovalent organic group. ３７ and R ３８ These may bond to each other to form a ring. Examples of monovalent organic groups include alkyl groups, cycloalkyl groups, aryl groups, aralkyl groups, alkenyl groups, and alkynyl groups. ３６It is also preferable that it be a hydrogen atom. Furthermore, the alkyl group, cycloalkyl group, aryl group, alkenyl group, and alkynyl group may include groups containing heteroatoms such as oxygen atoms and / or carbonyl groups. For example, in the alkyl group, cycloalkyl group, aryl group, and aralkyl group, one or more methylene groups may be replaced with groups containing heteroatoms such as oxygen atoms and / or carbonyl groups. ３８ R may bond with other substituents on the repeating main chain to form a ring. ３８ The group formed by the bonding of the repeating unit main chain with another substituent is preferably an alkylene group such as a methylene group. When the resist composition of the present invention is used as an EUV resist, R ３６ ~R ３８ A monovalent organic group represented by, and R ３７ and R ３８ The ring formed by the bonding of these elements may further preferably have a fluorine atom or an iodine atom as a substituent.

[0236] In formula (Y3), Ar represents an aromatic ring group. Rn represents an alkyl group, a cycloalkyl group, or an aryl group. Rn and Ar may bond to each other to form a non-aromatic ring. An aryl group is preferred as Ar. When the resist composition of the present invention is used as an EUV resist, it is also preferable that the aromatic ring group represented by Ar, and the alkyl group, cycloalkyl group, and aryl group represented by Rn, have a fluorine atom or an iodine atom as a substituent.

[0237] From the standpoint of excellent acid decomposition properties of repeating units, in a leaving group that protects a polar group, if a non-aromatic ring is directly bonded to the polar group (or its residue), it is preferable that the ring member atoms in the non-aromatic ring adjacent to the ring member atom directly bonded to the polar group (or its residue) do not have halogen atoms such as fluorine atoms as substituents.

[0238] Other groups that may be removed by the action of an acid include a 2-cyclopentenyl group having a substituent (such as an alkyl group), such as a 3-methyl-2-cyclopentenyl group, and a cyclohexyl group having a substituent (such as an alkyl group), such as a 1,1,4,4-tetramethylcyclohexyl group.

[0239] As the repeating unit A1, the repeating unit represented by formula (A) is also preferred.

[0240]

[0241] L １ R represents a divalent linking group which may have a fluorine atom or an iodine atom. １ R represents a hydrogen atom, a fluorine atom, an iodine atom, an alkyl group which may have a fluorine atom or an iodine atom, or an aryl group which may have a fluorine atom or an iodine atom. ２ This represents a leaving group that is removed by the action of an acid and may have a fluorine atom or an iodine atom. However, L １ , R １ and R ２ At least one of them has a fluorine atom or an iodine atom. １ Divalent linking groups that may have a fluorine atom or an iodine atom, represented by -CO-, -O-, -S-, -SO-, -SO ２ - Hydrocarbon groups which may have a fluorine atom or an iodine atom (for example, alkylene groups, cycloalkylene groups, alkenylene groups, and arylene groups, etc.), and linked groups formed by linking multiple thereof. Among these, L １The alkylene group is preferably -CO-, an arylene group, or an -arylene group-an alkylene group having a fluorine or iodine atom, and more preferably -CO-, or an -arylene group-an alkylene group having a fluorine or iodine atom. The arylene group is preferably a phenylene group. The alkylene group may be linear or branched. The number of carbon atoms in the alkylene group is not particularly limited, but is preferably 1 to 10, and more preferably 1 to 3. The total number of fluorine and iodine atoms in the alkylene group having a fluorine or iodine atom is not particularly limited, but is preferably 2 or more, more preferably 2 to 10, and even more preferably 3 to 6.

[0242] R １ The alkyl group represented by may be linear or branched. The number of carbon atoms in the alkyl group is not particularly limited, but 1 to 10 is preferred, and 1 to 3 is more preferred. １ The total number of fluorine atoms and iodine atoms contained in the alkyl group having a fluorine atom or an iodine atom, represented by R, is not particularly limited, but is preferably 1 or more, more preferably 1 to 5, and even more preferably 1 to 3. １ The alkyl group represented by may contain heteroatoms other than halogen atoms, such as oxygen atoms.

[0243] R ２ Examples of leaving groups that may have a fluorine atom or an iodine atom, represented by formulas (Y1), (Y2), and (Y3) described above, include leaving groups that have a fluorine atom or an iodine atom.

[0244] As the repeating unit A1, the repeating unit represented by formula (AI) is also preferred.

[0245]

[0246] In equation (AI), Xa １ Rx represents a hydrogen atom or an optionally substituted alkyl group. T represents a single bond or a divalent linking group. １ ~Rx ３Each of these independently represents an alkyl group (linear or branched), a cycloalkyl group (monocyclic or polycyclic), an alkenyl group (linear or branched), an alkynyl group, or an aryl group (monocyclic or polycyclic). However, Rx １ ~Rx ３ If all of them are alkyl groups (linear or branched), then Rx １ ~Rx ３ It is preferable that at least two of them are methyl groups. １ ~Rx ３ These two may combine to form a monocyclic or polycyclic (such as a monocyclic or polycyclic cycloalkyl group).

[0247] Xa １ Examples of alkyl groups that may have substituents, represented by , include a methyl group or -CH ２ -R １１ The group represented by R is an example. １１ R represents a halogen atom (such as a fluorine atom), a hydroxyl group, or a monovalent organic group. １１ Examples of monovalent organic groups represented by include alkyl groups having 5 or fewer carbon atoms that may be substituted with halogen atoms, acyl groups having 5 or fewer carbon atoms that may be substituted with halogen atoms, and alkoxy groups having 5 or fewer carbon atoms that may be substituted with halogen atoms, with alkyl groups having 3 or fewer carbon atoms being preferred and methyl groups being more preferred. １ Preferably, the group is a hydrogen atom, a methyl group, a trifluoromethyl group, or a hydroxymethyl group.

[0248] Examples of divalent linking groups for T include alkylene groups, aromatic ring groups, -COO-Rt- groups, and -O-Rt- groups. In the formula, Rt represents an alkylene group or a cycloalkylene group. T is preferably a single bond or a -COO-Rt- group. When T represents a -COO-Rt- group, Rt is preferably an alkylene group having 1 to 5 carbon atoms, and -CH ２ -, - (CH ２ ) ２ - or - (CH ２ ) ３ - is preferable.

[0249] Rx １ ~Rx３ Preferred alkyl groups include C1-C4 alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, and t-butyl groups. １ ~Rx ３ The preferred cycloalkyl group is a monocyclic cycloalkyl group such as a cyclopentyl group and a cyclohexyl group, or a polycyclic cycloalkyl group such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, and an adamantyl group. １ ~Rx ３ A vinyl group is preferred as the alkenyl group. Rx １ ~Rx ３ The alkynyl group is preferably an ethynyl group or a propargyl group. Rx １ ~Rx ３ The aryl group is preferably an aryl group having 6 to 10 carbon atoms, such as a phenyl group, a naphthyl group, and an anthyl group.

[0250] Rx １ ~Rx ３ The cycloalkyl group formed by the bonding of these two groups is preferably a monocyclic cycloalkyl group such as a cyclopentyl group or a cyclohexyl group. Polycyclic cycloalkyl groups such as a norbornyl group, tetracyclodecanyl group, tetracyclododecanyl group, and adamantyl group are also preferred. Among these, monocyclic cycloalkyl groups having 5 to 6 carbon atoms are preferred. Rx １ ~Rx ３ The cycloalkyl group formed by the bonding of these two may have, for example, one of the methylene groups constituting the ring replaced by a heteroatom such as an oxygen atom, a group containing a heteroatom such as a carbonyl group, or a vinylidene group. Furthermore, one or more of the ethylene groups constituting the cycloalkane ring of these cycloalkyl groups may be replaced by vinylene groups. In formula (AI), for example, Rx １ is a methyl group or an ethyl group, and Rx ２ and Rx ３ A preferred embodiment is one in which the two are bonded together to form the aforementioned cycloalkyl group.

[0251] When each of the above groups has substituents, examples of substituents include alkyl groups (1 to 4 carbon atoms), halogen atoms, hydroxyl groups, alkoxy groups (1 to 4 carbon atoms), carboxyl groups, and alkoxycarbonyl groups (2 to 6 carbon atoms). The number of carbon atoms of the substituent is preferably 8 or less.

[0252] The repeating unit represented by formula (AI) is an acid-degradable (meth)acrylate tertiary alkyl ester repeating unit (Xa １ A repeating unit in which represents a hydrogen atom or a methyl group, and T represents a single bond, is preferred.

[0253] The repeating unit A1 may have an acid-degradable group containing an unsaturated bond. The repeating unit represented by formula (B) is preferred as the repeating unit having an acid-degradable group containing an unsaturated bond.

[0254]

[0255] In formula (B), Xb represents a hydrogen atom, a halogen atom, or an optionally substituted alkyl group. L represents a single bond or an optionally substituted divalent linking group. １ ~Ry ３ Each of these independently represents a linear or branched alkyl group, a monocyclic or polycyclic cycloalkyl group, an alkenyl group, an alkynyl group, or a monocyclic or polycyclic aryl group. However, Ry １ ~Ry ３ At least one of these represents an alkenyl group, an alkynyl group, a monocyclic or polycyclic cycloalkenyl group, or a monocyclic or polycyclic aryl group. １ ~Ry ３ These two may combine to form a monocyclic or polycyclic (monocyclic or polycyclic cycloalkyl group, cycloalkenyl group, etc.) structure.

[0256] Examples of alkyl groups that may have substituents, represented by Xb, include a methyl group or -CH ２ -R １１ The group represented by R is an example. １１Xb represents a halogen atom (such as a fluorine atom), a hydroxyl group, or a monovalent organic group. Examples include alkyl groups having 5 or fewer carbon atoms that may be substituted with a halogen atom, acyl groups having 5 or fewer carbon atoms that may be substituted with a halogen atom, and alkoxy groups having 5 or fewer carbon atoms that may be substituted with a halogen atom. Alkyl groups having 3 or fewer carbon atoms are preferred, and methyl groups are more preferred. Xb is preferably a hydrogen atom, a fluorine atom, a methyl group, a trifluoromethyl group, or a hydroxymethyl group.

[0257] Examples of divalent linking groups represented by L include -Rt-, -CO-, -COO-Rt-, -COO-Rt-CO-, -Rt-CO-, and -O-Rt-. Rt represents an alkylene group, a cycloalkylene group, or an aromatic ring group, with an aromatic ring group being preferred. Rt may have substituents such as a halogen atom, a hydroxyl group, or an alkoxy group. As for L, -Rt-, -CO-, -COO-Rt-CO-, or -Rt-CO- are preferred.

[0258] Ry １ ~Ry ３ The alkyl group represented is preferably an alkyl group having 1 to 4 carbon atoms, such as a methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, or t-butyl group. １ ~Ry ３ The cycloalkyl group represented by is preferably a monocyclic cycloalkyl group such as a cyclopentyl group and a cyclohexyl group, or a polycyclic cycloalkyl group such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, and an adamantyl group. １ ~Ry ３ A vinyl group is preferred as the alkenyl group represented by Ry. １ ~Ry ３ As the alkynyl group represented by , an ethynyl group is preferred. １ ~Ry ３ The cycloalkenyl group represented by is preferably a cyclopentyl group and a monocyclic cycloalkyl group such as a cyclohexyl group that contains a double bond in part. １ ~Ry３ The aryl group represented by is preferably an aryl group having 6 to 10 carbon atoms, such as a phenyl group, a naphthyl group, and an anthyl group.

[0259] Ry １ ~Ry ３ The cycloalkyl group formed by the bonding of these two groups is preferably a monocyclic cycloalkyl group such as a cyclopentyl group and a cyclohexyl group, or a polycyclic cycloalkyl group such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, and an adamantyl group. Among these, a monocyclic cycloalkyl group having 5 to 6 carbon atoms is more preferred. １ ~Ry ３ A cycloalkyl group or cycloalkenyl group formed by the bonding of these two elements may, for example, have one of the methylene groups constituting the ring be a heteroatom such as an oxygen atom, a carbonyl group, or -SO ２ -Base and -SO ３ - These groups may be replaced by groups containing heteroatoms such as - groups, vinylidene groups, or combinations thereof. Furthermore, in these cycloalkyl or cycloalkenyl groups, one or more ethylene groups constituting the cycloalkane or cycloalkene ring may be replaced by vinylene groups. The repeating unit represented by formula (B) is, for example, Ry １ is a methyl group, ethyl group, vinyl group, allyl group, or aryl group, R ２ and Ry ３ A preferred embodiment is one in which the two are bonded together to form the aforementioned cycloalkyl group or cycloalkenyl group.

[0260] When each of the above groups has substituents, examples of substituents include alkyl groups (1 to 4 carbon atoms), halogen atoms, hydroxyl groups, alkoxy groups (1 to 4 carbon atoms), carboxyl groups, and alkoxycarbonyl groups (2 to 6 carbon atoms). The number of carbon atoms of the substituent is preferably 8 or less.

[0261] The repeating units represented by formula (B) are preferably acid-degradable (meth)acrylic acid tertiary ester repeating units (a repeating unit in which Xb represents a hydrogen atom or a methyl group and L represents a -CO- group), acid-degradable hydroxystyrene tertiary alkyl ether repeating units (a repeating unit in which Xb represents a hydrogen atom or a methyl group and L represents a phenyl group), or acid-degradable styrene carboxylic acid tertiary ester repeating units (a repeating unit in which Xb represents a hydrogen atom or a methyl group and L represents a -Rt-CO- group (Rt is an aromatic group)).

[0262] Specific examples of repeating units having an acid-degradable group containing an unsaturated bond include, for example, the repeating units described in

[0067] to

[0071] of International Publication No. 2022 / 024928, which are incorporated herein by reference.

[0263] Specific examples of repeating unit A1 (a repeating unit having an acid-degradable group) are shown below, but are not limited to these. Repeating units having an acid-degradable group described in the examples later are also preferred. Furthermore, for specific examples of repeating unit A1, one can refer to, for example, the descriptions in

[0029] to

[0071] of International Publication No. 2022 / 024928, which are incorporated herein by reference.

[0264]

[0265] The content of repeating unit A1 is preferably 15 mol% or more, more preferably 40 mol% or more, and even more preferably 60 mol% or more, relative to the total repeating units in the acid-degradable resin. Furthermore, the content of repeating unit A1 is preferably less than 100 mol%, more preferably 95 mol% or less, and even more preferably 90 mol% or less, relative to the total repeating units in the acid-degradable resin. The acid-degradable resin may contain one type of repeating unit A1 or two or more types. If the acid-degradable resin contains two or more types of repeating unit A1, it is preferable that their total content is within the range of the above preferred content.

[0266] (Repeating units having acidic groups) Acid-degradable resins preferably contain repeating units having acidic groups (hereinafter also simply referred to as "repeating unit A2"). Repeating unit A2 is preferably a different repeating unit from the above repeating unit A1 (repeating unit having an acid-degradable group). Repeating unit A2 may also have a fluorine atom or an iodine atom. Preferred acidic groups are carboxyl groups, phenolic hydroxyl groups, fluorinated alcohol groups (preferably hexafluoroisopropanol groups), sulfonic acid groups, sulfonamide groups, or isopropanol groups. Among these, repeating unit A2 is preferably a repeating unit having a phenolic hydroxyl group. The above hexafluoroisopropanol group may have one or more fluorine atoms (preferably 1 to 2) substituted with a group other than a fluorine atom (such as an alkoxycarbonyl group). As for the acidic group, the -C(CF) formed in this way ３ ) (OH)-CF ２ - is also preferable. In addition, one or more fluorine atoms are substituted with a group other than a fluorine atom, -C(CF ３ ) (OH)-CF ２ A ring containing - may be formed.

[0267] The repeating unit A2 is preferably a repeating unit represented by the following formula (Pa1), and the acid-degradable resin preferably contains the repeating unit represented by the following formula (Pa1).

[0268]

[0269] In formula (Pa1), R ａ１ and R ａ２ Each of these independently represents a hydrogen atom or a substituent. ａ１ Ar represents a single bond or a divalent linking group. ａ１ Ar represents an aromatic ring group with (m+n+1) valency. ａ１ And, R ａ２ or L ａ１ This may be a single bond or a bond via a linking group. Ｘ represents a substituent other than a hydroxyl group. n represents an integer between 1 and 9 (inclusive). m represents an integer between 0 and 8 (inclusive).

[0270] In the above formula (Pa1), R ａ１ and R ａ２ Each of these independently represents a hydrogen atom or a substituent. ａ１ and R ａ２ The substituent represented by is not particularly limited, but is preferably an alkyl group, a cycloalkyl group, a halogen atom, a cyano group, or an alkoxycarbonyl group. ａ１ and R ａ２ The alkyl group represented by may be linear or branched, and may have substituents. The number of carbon atoms in the alkyl group is not particularly limited, but is preferably 1 to 10, more preferably 1 to 5, and even more preferably 1 to 3. Examples of alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, and t-butyl groups. ａ１ and R ａ２ The number of carbon atoms in the cycloalkyl group represented by is not particularly limited, but is preferably 3 to 20, and more preferably 5 to 15. The cycloalkyl group may be a monocyclic cycloalkyl group such as a cyclopentyl group and a cyclohexyl group, or a polycyclic cycloalkyl group such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, and an adamantyl group. The cycloalkyl group may have substituents. ａ１ and R ａ２ Examples of halogen atoms represented by include fluorine, chlorine, bromine, and iodine atoms, with fluorine or iodine atoms being preferred. ａ１ and R ａ２ The alkyl group contained in the alkoxycarbonyl group represented by may be linear or branched. The number of carbon atoms in the alkyl group contained in the alkoxycarbonyl group is not particularly limited, but 1 to 5 is preferred, and 1 to 3 is more preferred. The alkoxycarbonyl group may have substituents.

[0271] In the above formula (Pa1), L ａ１ L represents a single bond or a divalent linking group. ａ１ Examples of divalent linking groups represented by include -COO- and -CONR ａ３-, alkylene groups, or groups formed by combining two or more of these groups. ａ３ R represents a hydrogen atom or an alkyl group. Preferred alkylene groups include C1-C8 alkylene groups such as methylene, ethylene, propylene, butylene, hexylene, and octylene. The alkylene group may have substituents. ａ３ Examples of alkyl groups that represent an alkyl group include alkyl groups having 20 or fewer carbon atoms, such as methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, sec-butyl group, hexyl group, 2-ethylhexyl group, octyl group, and dodecyl group, with alkyl groups having 8 or fewer carbon atoms being preferred.

[0272] In the above formula (Pa1), Ar ａ１ Ar represents an aromatic ring group with (m+n+1) valency. ａ１ The aromatic ring group represented by may be either an aromatic hydrocarbon group or an aromatic heterocyclic group. Preferred aromatic hydrocarbon groups include groups containing aromatic hydrocarbons having 6 to 18 carbon atoms, such as benzene, naphthalene, anthracene, and naphthacene. Preferred aromatic heterocyclic groups include groups containing aromatic heterocyclic rings with 4 to 20 ring member atoms, such as thiophene, furan, pyridine, pyrrole, benzothiophene, benzofuran, benzopyrrole, triazine, imidazole, benzimidazole, triazole, thiadiazole, and thiazole.

[0273] Ar ａ１ And, R ａ２ or L ａ１ These may be bonded via single bonds or linking groups. Examples of linking groups include -O-, -S-, -CO-, and -CO ２ -, -SO-, -SO ２ - Examples include alkylene groups (preferably having 1 to 5 carbon atoms), alkenylene groups (preferably having 2 to 5 carbon atoms), and groups formed by combining two or more of these. The alkylene groups and alkenylene groups may have substituents.

[0274] In the above formula (Pa1), R Ｘ represents a substituent other than a hydroxy group. As the substituent represented by R Ｘ , for example, a carboxy group, a sulfo group, a cyano group, a halogen atom, a hydrocarbon group, an amino group, a nitro group, and a group formed by combining two or more of these can be mentioned. As the hydrocarbon group represented by R Ｘ , for example, an alkyl group (preferably having 1 to 10 carbon atoms), a cycloalkyl group (preferably having 5 to 15 carbon atoms), and an alkenyl group (preferably having 2 to 10 carbon atoms) can be mentioned. The hydrocarbon group represented by R Ｘ may have a substituent. Further, when the hydrocarbon group represented by R Ｘ contains ‑CH ２ ‑, at least one of ‑CH ２ ‑ may be replaced by at least one selected from the group consisting of ‑O‑, ‑CO‑, ‑S‑, and ‑SO ２ ‑. The substituent represented by R Ｘ preferably has a halogen atom. As the halogen atom, a fluorine atom or an iodine atom is preferable.

[0275] In the above formula (Pa1), n represents an integer of 1 or more and 9 or less, preferably represents an integer of 1 or more and 5 or less, and more preferably represents an integer of 1 or more and 4 or less. m represents an integer of 0 or more and 8 or less, preferably represents an integer of 0 or more and 4 or less, and more preferably represents an integer of 0 or more and 3 or less.

[0276] The repeating unit A2 is preferably a repeating unit represented by the following formula (Pa2), and the acid-decomposable resin preferably contains a repeating unit represented by the following formula (Pa2).

[0277]

[0278] In the formula (Pa2), R ａ４ represents a hydrogen atom or an alkyl group. L ａ２ represents a single bond or ‑COO‑. r represents an integer of 0 or more and 3 or less. R Ｘ１ represents a halogen atom or a hydrocarbon group. n1 represents an integer of 1 or more and 5 or less. m1 represents an integer of 0 or more and 4 or less.

[0279] In the above formula (Pa2), R ａ４ represents a hydrogen atom or an alkyl group. The alkyl group represented by R ａ４ may be either linear or branched and may have a substituent. The number of carbon atoms of the alkyl group is not particularly limited, but is preferably 1 to 10, more preferably 1 to 5, and particularly preferably 1 to 3. Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, and a t-butyl group.

[0280] In the above formula (Pa2), L ａ２ represents a single bond or -COO-, and a single bond is preferred. r represents an integer of 0 or more and 3 or less, preferably an integer of 0 or more and 2 or less, more preferably 0 or 1, and even more preferably 0. When r represents 0 in formula (Pa2), the aromatic ring is benzene; when r represents 1, it is naphthalene; when r represents 2, it is anthracene; and when r represents 3, it is naphthacene. n1 represents an integer of 1 or more and 5 or less, preferably an integer of 1 or more and 4 or less. m1 represents an integer of 0 or more and 4 or less, preferably an integer of 0 or more and 3 or less.

[0281] In the above formula (Pa2), R Ｘ１ represents a halogen atom or a hydrocarbon group. As the halogen atom represented by R Ｘ１ a fluorine atom, a chlorine atom, a bromine atom or an iodine atom is preferred, and a fluorine atom or an iodine atom is more preferred. Examples of the hydrocarbon group represented by R Ｘ１ include an alkyl group (preferably having 1 to 10 carbon atoms), a cycloalkyl group (preferably having 5 to 15 carbon atoms), and an alkenyl group (preferably having 2 to 10 carbon atoms). The hydrocarbon group represented by R Ｘ１ may have a substituent. Also, when the hydrocarbon group represented by R Ｘ１ contains -CH ２ -, at least one of -CH ２ - may be replaced by at least one selected from the group consisting of -O-, -CO-, -S- and -SO ２ -. R Ｘ１The hydrocarbon group represented by preferably has a halogen atom. The halogen atom is preferably a fluorine atom or an iodine atom.

[0282] Specific examples of repeating unit A2 (a repeating unit having an acid group) are shown below, but the system is not limited to these. In the following structural formulas, G １ and G ２ Each of these independently represents a hydrogen atom, a methyl group, a fluorine atom, a chlorine atom, a trifluoromethyl group, a cyano group, a hydroxyl group, or a hydroxymethyl group. f1 represents an integer from 1 to 3. Repeating unit A2 described in the examples below is also preferred. Specific examples of repeating unit A2 include, for example, the repeating unit described in

[0079] to

[0110] of International Publication No. 2022 / 024928, which is incorporated herein by reference.

[0283] The repeating unit A2 is preferably a repeating unit represented by the following formula (18), and the acid-degradable resin preferably contains the repeating unit represented by the following formula (18).

[0284]

[0285] In formula (18), n1 represents 0 or 1. When n1 is 0, the aromatic ring explicitly shown in formula (18) represents a benzene ring. When n1 is 1, the aromatic ring explicitly shown in formula (18) represents a naphthalene ring. n2 represents an integer from 1 to 5. n3 represents an integer from 0 to 4, provided that 1 ≤ n2 + n3 ≤ 5. X represents a halogen atom or an organic group. Y and Z each independently represent a hydrogen atom, a halogen atom, or an organic group. Note that Y or Z and X may bond to each other to form a ring structure.

[0286] In formula (18) above, examples of halogen atoms represented by Y and Z include fluorine, chlorine, bromine, and iodine atoms, with fluorine or iodine atoms being preferred. The organic groups represented by Y and Z are not particularly limited, but are preferably alkyl groups, cycloalkyl groups, or alkoxycarbonyl groups. The alkyl groups represented by Y and Z may be linear or branched, and may have substituents. The number of carbon atoms in the alkyl group is not particularly limited, but is preferably 1 to 10, more preferably 1 to 5, and even more preferably 1 to 3. Examples of alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, and t-butyl groups. The number of carbon atoms in the cycloalkyl group represented by Y and Z is not particularly limited, but is preferably 3 to 20, and more preferably 5 to 15. The cycloalkyl group may be a monocyclic cycloalkyl group such as a cyclopentyl group and a cyclohexyl group, or a polycyclic cycloalkyl group such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, and an adamantyl group. The cycloalkyl group may have substituents. The alkyl group contained in the alkoxycarbonyl group represented by Y and Z may be linear or branched. The number of carbon atoms in the alkyl group contained in the alkoxycarbonyl group is not particularly limited, but 1 to 5 is preferred, and 1 to 3 is more preferred. The alkoxycarbonyl group may have substituents.

[0287] In the above formula (18), the halogen atom represented by X includes a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, with a fluorine atom or an iodine atom being preferred. The organic group represented by X is not particularly limited, but -CH ２ - At least one of is -O-, -CO-, -S-, and -SO ２Examples of hydrocarbon groups that may be replaced by at least one selected from the group consisting of - include alkyl groups (preferably having 1 to 10 carbon atoms), cycloalkyl groups (preferably having 5 to 15 carbon atoms), alkenyl groups (preferably having 2 to 10 carbon atoms), and alkoxycarbonyl groups (preferably having 2 to 10 carbon atoms). The hydrocarbon group may also have substituents. There are no particular restrictions on substituents, but for example, halogen atoms are preferred, and fluorine atoms or iodine atoms are preferred. In formula (18) above, Y or Z and X may be bonded to each other to form a ring structure. The ring structure may be either an aliphatic ring or an aromatic ring. The ring structure may also be, for example, a five-membered ring.

[0288] In the above formula (18), n2 preferably represents an integer from 2 to 5. n3 preferably represents an integer from 0 to 3.

[0289] When the acid-degradable resin contains repeating units A2, the content of repeating units A2 is preferably 10 mol% or more, and more preferably 15 mol% or more, relative to the total repeating units in the acid-degradable resin. Furthermore, the content of repeating units A2 is preferably less than 40 mol%, and more preferably 35 mol% or less, relative to the total repeating units in the acid-degradable resin.

[0290] (Repeating units that do not have either an acid-degradable group or an acid group, but have a fluorine atom, a bromine atom, or an iodine atom) In addition to the repeating units A1 and A2 described above, the acid-degradable resin may also have repeating units that do not have either an acid-degradable group or an acid group, but have a fluorine atom, a bromine atom, or an iodine atom (hereinafter also simply referred to as "repeating unit X"). It is preferable that repeating unit X is different from repeating units Y and P described later. The repeating unit X is preferably the repeating unit represented by formula (C).

[0291]

[0292] In formula (C), L ５ R represents a single bond or an ester group. ９R represents an alkyl group which may have a hydrogen atom, or a fluorine atom or an iodine atom. １０ This represents an alkyl group which may have a hydrogen atom, a fluorine atom, or an iodine atom, a cycloalkyl group which may have a fluorine atom or an iodine atom, an aryl group which may have a fluorine atom or an iodine atom, or a group which is a combination thereof.

[0293] The content of repeating units X is preferably 0 mol% or more, more preferably 5 mol% or more, and even more preferably 10 mol% or more, relative to the total repeating units in the acid-degradable resin. Furthermore, the upper limit is preferably less than 40 mol%, and more preferably 35 mol% or less, relative to the total repeating units in the acid-degradable resin.

[0294] Furthermore, the acid-degradable resin may have repeating units having at least one of a fluorine atom, a bromine atom, and an iodine atom. Examples of repeating units having at least one of a fluorine atom, a bromine atom, and an iodine atom include repeating units having a fluorine atom, a bromine atom, or an iodine atom and having an acid-degradable group, repeating units having a fluorine atom, a bromine atom, or an iodine atom and having an acid group, and repeating units having a fluorine atom, a bromine atom, or an iodine atom. The total content of repeating units having at least one of a fluorine atom, a bromine atom, and an iodine atom among the repeating units of the acid-degradable resin is preferably 10 mol% or more, more preferably 20 mol% or more, even more preferably 30 mol% or more, and particularly preferably 40 mol% or more, relative to the total repeating units of the acid-degradable resin. There is no particular upper limit, but for example, it is 100 mol% or less relative to the total repeating units of the acid-degradable resin.

[0295] Specific examples of repeating units having fluorine atoms or iodine atoms include, for example, the repeating units described in

[0116] to

[0117] of International Publication No. 2022 / 024928, which are incorporated herein by reference.

[0296] (Repeating units having lactone groups, sultone groups, or carbonate groups) Acid-degradable resins may have repeating units (hereinafter also simply referred to as "repeating unit Y") having at least one selected from the group consisting of lactone groups, sultone groups, and carbonate groups. It is also preferable that repeating unit Y does not have acidic groups such as hydroxyl groups and hexafluoropropanol groups.

[0297] The lactone group or sultone group may have a lactone structure or a sultone structure. The lactone structure or sultone structure is preferably a 5-7 membered ring lactone structure or a 5-7 membered ring sultone structure. More preferably, the 5-7 membered ring lactone structure is fused with another ring structure in the form of a bicyclo or spiro structure, or the 5-7 membered ring sultone structure is fused with another ring structure in the form of a bicyclo or spiro structure. For units containing a lactone group or sultone group, refer to, for example, the descriptions in International Publication No. 2022 / 024928

[0119] to

[0126] and

[0132] to

[0133] , which are incorporated herein by reference.

[0298] A cyclic carbonate ester group is preferred as the carbonate group. For repeating units having a cyclic carbonate ester group, see, for example, the descriptions in

[0127] to

[0133] of International Publication No. 2022 / 024928, which are incorporated herein by reference.

[0299] When the acid-degradable resin contains repeating units Y, the content of repeating units Y is preferably 1 mol% or more, and more preferably 10 mol% or more, relative to the total repeating units in the acid-degradable resin. Furthermore, the upper limit is preferably less than 40 mol%, and more preferably 35 mol% or less, relative to the total repeating units in the acid-degradable resin.

[0300] (Repeating units having photoacid generating groups) Acid-degradable resins may contain repeating units having groups that generate acid upon irradiation with active light or radiation (also called "photoacid generating groups"), but it is also preferable that acid-degradable resins do not contain repeating units having photoacid generating groups (hereinafter also simply called "repeating unit P"). An example of repeating unit P is the repeating unit represented by formula (4).

[0301]

[0302] R ４１ L represents a hydrogen atom or a methyl group. ４１ L represents a single bond or a divalent linking group. ４２ R represents a divalent linking group. ４０ This represents a structural site that decomposes upon irradiation with active light or radiation, generating acid in the side chain.

[0303] L ４１ L represents a single bond or a divalent linking group, preferably a single bond or an ester bond (-COO-). ４２ These are alkylene groups, cycloalkylene groups, arylene groups, -O-, -CO-, -S-, -SO-, -SO ２ It is preferable that the linking group consists of at least one selected from the group consisting of - and -NR-. R represents a hydrogen atom or an organic group (preferably an organic group having 1 to 10 carbon atoms, such as an alkyl group, cycloalkyl group, or aryl group). The alkylene group may be linear or branched. The number of carbon atoms in the alkylene group is not particularly limited, but 1 to 10 is preferred. The cycloalkylene group may be a monocyclic or polycyclic cycloalkylene group. The number of carbon atoms in the cycloalkylene group is not particularly limited, but 3 to 20 is preferred, and 5 to 15 is more preferred. The number of carbon atoms in the arylene group is not particularly limited, but 6 to 20 is preferred, and 6 to 10 is more preferred. The alkylene group, cycloalkylene group and arylene group may have substituents, and the substituent T mentioned above is an example of a substituent.

[0304] R ４０ Preferably, the group is represented by the following formula (S4-1).

[0305]

[0306] In equation (S4-1), Q － represents an acid residue, M ＋ * represents a cation. * represents L ４１ This indicates the bonding position. An acid residue is a group formed when a proton dissociates from an acid. Q － is a carboxylate anion group (COO － ), sulfonate anion group (SO ３ － ), or sulfonamide group (N － -SO ２ R Ｎ１ It is represented by R Ｎ１ represents an organic group, and examples include organic groups having 1 to 10 carbon atoms, with alkyl groups, fluoroalkyl groups, or aryl groups being preferred. A sulfonate anion group is more preferred. ＋ For further explanation, specific examples, and preferred ranges, please refer to the M section in the above description of the photoacid generator. ＋ It is the same as this.

[0307] Specific examples of repeating units P include, for example, the repeating units described in paragraphs

[0094] to

[0105] of Japanese Patent Publication No. 2014-041327, the repeating units described in paragraph

[0094] of International Publication No. 2018 / 193954, and the repeating units described in paragraph

[0138] of International Publication No. 2022 / 024928, and these descriptions are incorporated herein by reference. Furthermore, examples of repeating units represented by formula (4) include, for example, the repeating units described in paragraphs

[0094] to

[0105] of Japanese Patent Publication No. 2014-041327, and the repeating units described in paragraph

[0094] of International Publication No. 2018 / 193954, and these descriptions are incorporated herein by reference.

[0308] When the acid-degradable resin contains repeating units P, the content of repeating units P is preferably 1 mol% or more, more preferably 3 mol% or more, and even more preferably 5 mol% or more, relative to the total repeating units in the acid-degradable resin. Furthermore, the content of repeating units P is preferably less than 40 mol%, more preferably 30 mol% or less, and even more preferably 20 mol% or less, relative to the total repeating units in the acid-degradable resin.

[0309] (Repeating units represented by formula (V-1) or formula (V-2)) Acid-degradable resins may have repeating units represented by the following formula (V-1) or formula (V-2). It is preferable that the repeating units represented by formula (V-1) and the following formula (V-2) are different from the repeating units described above.

[0310]

[0311] In equation (V-1) and equation (V-2) below, R ６ and R ７ Each of these independently represents a hydrogen atom, a hydroxyl group, an alkyl group, an alkoxy group, an acyloxy group, a cyano group, a nitro group, an amino group, a halogen atom, an ester group (-OCOR or -COOR: R is an alkyl group having 1 to 6 carbon atoms or a fluorinated alkyl group), or a carboxyl group. As the alkyl group, a linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms is preferred. ３ n represents an integer between 0 and 6. ４ X represents an integer between 0 and 4. ４ represents a methylene group, an oxygen atom, or a sulfur atom. Examples of repeating units represented by formula (V-1) or (V-2) include the repeating units described in paragraph

[0100] of International Publication No. 2018 / 193954, which are incorporated herein by reference.

[0312] (Repeating units to reduce the mobility of the main chain) Acid-degradable resins are preferable to have a high glass transition temperature (Tg) in order to suppress excessive diffusion of generated acid or pattern breakdown during development. For repeating units to reduce the mobility of the main chain, refer to the contents of

[0144] to

[0160] of International Publication No. 2022 / 024928.

[0313] (Repeating units having at least one group selected from lactone groups, sultone groups, carbonate groups, hydroxyl groups, cyano groups, and alkali-soluble groups) Acid-degradable resins may have repeating units having at least one group selected from lactone groups, sultone groups, carbonate groups, hydroxyl groups, cyano groups, and alkali-soluble groups. Examples of repeating units having lactone groups, sultone groups, or carbonate groups in acid-degradable resins include the repeating units described above for repeating unit Y. Preferred content is also as described for repeating unit Y.

[0314] The acid-degradable resin may have repeating units having a hydroxyl group or a cyano group. This improves substrate adhesion. The repeating units having a hydroxyl group or a cyano group are preferably repeating units having a saturated hydrocarbon group having a hydroxyl group or a cyano group (substituted with a hydroxyl group or a cyano group). Alternatively, they may be repeating units having an alicyclic hydrocarbon structure substituted with a hydroxyl group or a cyano group. The repeating units having a hydroxyl group or a cyano group are preferably not having an acid-degradable group. Examples of repeating units having a hydroxyl group or a cyano group include the repeating units described in paragraphs

[0081] to

[0084] of Japanese Patent Application Publication No. 2014-098921, and the above description is incorporated herein by reference.

[0315] The acid-degradable resin may have repeating units having alkali-soluble groups. The inclusion of repeating units having alkali-soluble groups in the acid-degradable resin increases the resolution in contact hole applications. Examples of alkali-soluble groups include carboxyl groups, sulfonamide groups, sulfonylimide groups, bissulfonylimide groups, and aliphatic alcohol groups (e.g., hexafluoroisopropanol group) whose α-position is substituted with an electron-withdrawing group, with carboxyl groups being preferred. Examples of repeating units having alkali-soluble groups include the repeating units described in paragraphs

[0085] and

[0086] of Japanese Patent Application Publication No. 2014-098921, the above description is incorporated herein by reference.

[0316] (Repeating units having an alicyclic hydrocarbon structure and not exhibiting acid decomposition) Acid-degradable resins may have repeating units having an alicyclic hydrocarbon structure and not exhibiting acid decomposition. This reduces the elution of low-molecular-weight components from the resist film into the immersion liquid during immersion exposure. Examples of repeating units having an alicyclic hydrocarbon structure and not exhibiting acid decomposition include repeating units derived from 1-adamantyl (meth)acrylate, diamantyl (meth)acrylate, tricyclodecanyl (meth)acrylate, or cyclohexyl (meth)acrylate.

[0317] (Repeating units represented by formula (III) that do not have either a hydroxyl group or a cyano group) Acid-degradable resins may have repeating units represented by formula (III) that do not have either a hydroxyl group or a cyano group.

[0318]

[0319] In formula (III), R ５ represents a hydrocarbon group having at least one cyclic structure and lacking both a hydroxyl group and a cyano group. Ra represents a hydrogen atom, an alkyl group, or -CH ２ -O-Ra ２ It represents the base. In the formula, Ra ２represents a hydrogen atom, an alkyl group, or an acyl group. Examples of repeating units represented by formula (III) that do not have either a hydroxyl group or a cyano group include the repeating units described in paragraphs

[0087] to

[0094] of Japanese Patent Application Publication No. 2014-098921, which are incorporated herein by reference.

[0320] (Other Repeating Units) Furthermore, the acid-degradable resin may have other repeating units besides those described above. For example, refer to the descriptions in

[0141] to

[0143] and

[0169] to

[0170] of International Publication No. 2022 / 024928, which are incorporated herein by reference.

[0321] In addition to the repeating structural units described above, acid-degradable resins may have various repeating structural units for the purpose of adjusting dry etching resistance, suitability for standard developers, substrate adhesion, resist profile, resolution, heat resistance, and sensitivity.

[0322] A preferred embodiment of the present invention is that the acid-degradable resin has at least one selected from the group consisting of lactone groups, carbonate groups, sultone groups, and saturated hydrocarbon groups having hydroxyl groups. Having at least one selected from the group consisting of lactone groups, carbonate groups, sultone groups, and saturated hydrocarbon groups having hydroxyl groups further improves etching resistance and LWR performance.

[0323] In a preferred embodiment of the present invention, the acid-degradable resin contains repeating units having iodine atoms. By including repeating units having iodine atoms in the acid-degradable resin, the absorption rate of EUV light and the like is increased, the effects of shot noise can be reduced, and the LWR performance is further improved.

[0324] Acid-degradable resins can be synthesized according to conventional methods (e.g., radical polymerization). According to the GPC method, the weight-average molecular weight (Mw) of the acid-degradable resin, expressed as polystyrene equivalent, is preferably 30,000 or less, more preferably 1,000 to 30,000, even more preferably 3,000 to 30,000, and particularly preferably 5,000 to 15,000. The degree of dispersion (molecular weight distribution, Mw / Mn) of the acid-degradable resin is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, even more preferably 1.1 to 2.0, and particularly preferably 1.1 to 1.5. Lower dispersion results in better resolution and resist shape, smoother sidewalls of the resist pattern, and superior roughness.

[0325] The content of the acid-degradable resin in the resist composition is preferably 30.0 to 99.9% by mass, more preferably 40.0 to 99.9% by mass, and even more preferably 60.0 to 90.0% by mass, based on the total solid content of the resist composition. The acid-degradable resin may be used alone or in combination of two or more types. When two or more types are used, it is preferable that their total content is within the above preferred content range.

[0326] <Hydrophobic Resin> The resist composition may contain a hydrophobic resin different from the acid-degradable resin. The hydrophobic resin is preferably designed to be unevenly distributed on the surface of the resist film, but unlike surfactants, it does not necessarily need to have hydrophilic groups in its molecule and does not need to contribute to the uniform mixing of polar and nonpolar substances.

[0327] Hydrophobic resins, in terms of their uneven distribution on the film surface, contain fluorine atoms, silicon atoms, and CH4 atoms in the side chain portion of the resin. ３ It is preferable that the substructure has one or more of these substructures, and more preferably two or more. Furthermore, the hydrophobic resin preferably has a hydrocarbon group having 5 or more carbon atoms. These groups may be present in the main chain of the resin or substituted in the side chain. Examples of hydrophobic resins include the compounds described in paragraphs

[0275] to

[0279] of International Publication No. 2020 / 004306, which are incorporated herein by reference.

[0328] When the resist composition contains a hydrophobic resin, the content of the hydrophobic resin is preferably 0.01 to 20.0% by mass, more preferably 0.1 to 10.0% by mass, and even more preferably 0.1 to 5.0% by mass, based on the total solid content of the resist composition. Only one type of hydrophobic resin may be used, or two or more types may be used. When two or more types are used, it is preferable that their total content is within the above preferred content range.

[0329] [Surfactants] The resist composition of the present invention may contain surfactants. The inclusion of surfactants allows for better adhesion and the formation of patterns with fewer development defects. Fluorine-based and / or silicone-based surfactants are preferred. Examples of fluorine-based and / or silicone-based surfactants include those disclosed in paragraphs

[0218] and

[0219] of International Publication No. 2018 / 193954.

[0330] If the resist composition contains a surfactant, the surfactant content is preferably 0.0001 to 2.0% by mass, more preferably 0.0005 to 1.0% by mass, and even more preferably 0.1 to 1.0% by mass, relative to the total solid content of the resist composition. One type of surfactant may be used, or two or more types may be used. If two or more types are used, it is preferable that their total content is within the range of the above preferred content.

[0331] [Solvent] The resist composition of the present invention preferably contains a solvent. The solvent preferably contains (M1) propylene glycol monoalkyl ether carboxylate and (M2) at least one selected from the group consisting of propylene glycol monoalkyl ether, lactic acid ester, acetate ester, alkoxypropionic acid ester, linear ketone, cyclic ketone, lactone, and alkylene carbonate. The solvent may further contain components other than components (M1) and (M2). Details of components (M1) and (M2) are described in paragraphs

[0218] to

[0226] of International Publication No. 2020 / 004306, and these contents are incorporated herein by reference. The solvent content in the resist composition is preferably set so that the solid content concentration is 0.5 to 30% by mass, and more preferably 1 to 20% by mass. If the solvent further contains components other than components (M1) and (M2), the content of the components other than components (M1) and (M2) is preferably 5 to 30% by mass relative to the total amount of the solvent.

[0332] [Other Additives] The resist composition of the present invention may further contain, as other additives, at least one selected from the group consisting of dissolution-inhibiting compounds, dyes, plasticizers, photosensitizers, light absorbers, and compounds that promote solubility in developer solutions (for example, phenol compounds with a molecular weight of 1000 or less, or alicyclic or aliphatic compounds containing a carboxyl group). The above-mentioned "dissolution-inhibiting compounds" are compounds with a molecular weight of 3000 or less that decompose due to the action of acid, thereby reducing their solubility in organic developer solutions.

[0333] The content of other additives is not particularly limited, but may be 20.0% by mass or less, 10.0% by mass or less, or 5.0% by mass or less, relative to the total solid content of the resist composition. Only one type of other additive may be used, or two or more types may be used. When two or more types are used, it is preferable that their total content is within the range of the above preferred content.

[0334] Furthermore, the resist composition of the present invention may contain water as an impurity. When water is present as an impurity, a smaller amount of water is preferable, but it may be present in an amount of 1 to 30,000 ppm by mass relative to the total resist composition. Furthermore, the resist composition may contain residual monomers as impurities (for example, monomers derived from raw material monomers used in the synthesis of the resin). When residual monomers are present as impurities, a smaller amount of residual monomers is preferable, but it may be present in an amount of 1 to 30,000 ppm by mass relative to the total solid content of the resist composition.

[0335] [Pattern Forming Method] The pattern forming method of the present invention comprises the steps of: (1) forming a resist film on a substrate using the photosensitive or radiation-sensitive resin composition (resist composition) of the present invention; (2) exposing the resist film to light; and (3) developing the exposed resist film using a developer. Each of the above steps will be described in detail below.

[0336] [Step (1)] Step (1) is a step of forming a resist film on a substrate using the resist composition of the present invention. Details of the resist composition of the present invention used in step (1) are as described above.

[0337] One method for forming a resist film on a substrate using a resist composition is to coat the resist composition onto the substrate. If necessary, it is preferable to filter the resist composition before coating. The pore size of the filter is preferably 0.1 μm or less, more preferably 0.03 μm or less, even more preferably 0.01 μm or less, and particularly preferably 0.005 μm or less. The lower limit of the filter pore size is not particularly limited, but it may be 0.001 μm or more. The material of the filter is not particularly limited, but if it is a polymer, it is preferably made of polyolefins such as polyethylene (PE) and polypropylene (PP) (including high density and ultra-high molecular weight); polyamides such as nylon 6 and nylon 66; polyimide (PI); polyamideimide; polyesters such as polyethylene terephthalate; polyethersulfone; cellulose; polyfluorocarbons such as polytetrafluoroethylene (PTFE) and perfluoroalkoxyalkanes; derivatives of the above polymers; and more preferably at least one selected from the group consisting of polyolefins, polyamides, polyimides, polyamideimide, polyesters, polysulfones, cellulose, polyfluorocarbons and their derivatives. In addition to resins, diatomaceous earth, glass, etc. may also be used.

[0338] The resist composition may be filtered using one filter or a combination of two or more filters. If two or more filters are used, they may be the same filter or different filters. The resist composition may also be circulated and filtered repeatedly using the same filter.

[0339] The resist composition can be applied to a substrate (e.g., silicon, silicon coated with silicon dioxide, etc.) used in the manufacture of integrated circuit elements by a suitable coating method such as a spinner or coater. Spin coating using a spinner is preferred. The preferred rotation speed when spin coating using a spinner is 1000 to 3000 rpm (rotations per minute). After applying the resist composition, the substrate may be dried to form a resist film. If necessary, various undercoats (inorganic films, organic films, anti-reflective films, etc.) may be formed in the layer below the resist film.

[0340] As for drying methods, one example is drying by heating. Heating can be carried out using means provided in at least one of a normal exposure machine and a developer machine, and may also be carried out using a hot plate or the like. The heating temperature is not particularly limited, but is preferably 80 to 150°C, more preferably 80 to 140°C, and even more preferably 80 to 130°C. The heating time is not particularly limited, but is preferably 30 to 1000 seconds, more preferably 60 to 800 seconds, and even more preferably 60 to 600 seconds.

[0341] The present invention also includes a resist film obtained in step (1). The thickness of the resist film is not particularly limited, but 10 to 120 nm is preferred in that it is possible to form finer patterns with higher precision. In particular, when EUV exposure is used, the thickness of the resist film is more preferably 10 to 65 nm, and even more preferably 15 to 50 nm. When ArF immersion exposure is used, the thickness of the resist film is more preferably 10 to 120 nm, and even more preferably 15 to 90 nm.

[0342] A topcoat may be formed on the upper layer of the resist film using a topcoat composition. For example, it is preferable to form a topcoat containing a basic compound, such as that described in Japanese Patent Application Publication No. 2013-61648, on the resist film. Specific examples of basic compounds that the topcoat may contain include basic compounds that may be contained in the resist composition.

[0343] [Step (2)] Step (2) is a step of exposing the resist film formed in step (1). Methods of exposure include irradiating the formed resist film with active light or radiation through a predetermined mask. Examples of active light or radiation include infrared light, visible light, ultraviolet light, far ultraviolet light, extreme ultraviolet light, X-rays, and electron beams, preferably with a wavelength of 250 nm or less, more preferably 220 nm or less, and particularly preferably far ultraviolet light with a wavelength of 1 to 200 nm, specifically KrF excimer laser (248 nm), ArF excimer laser (193 nm), F ２ Examples include excimer lasers (157 nm), EUV (13.5 nm), X-rays, and electron beams.

[0344] It is preferable to bake (heat) the image after exposure but before developing. This step is also called post-exposure baking. Baking promotes the reaction of the exposed area, resulting in better sensitivity and pattern shape. The baking temperature is not particularly limited, but is preferably 80 to 150°C, more preferably 80 to 140°C, and even more preferably 80 to 130°C. The baking time is not particularly limited, but is preferably 10 to 1000 seconds, more preferably 10 to 180 seconds, and even more preferably 30 to 120 seconds. Heating can be carried out using means provided in at least one of a normal exposure machine and a developer, and may also be done using a hot plate or the like.

[0345] [Step (3)] Step (3) is a step in which the resist film exposed in step (2) is developed using a developer. By performing step (3), a resist pattern (also simply called a "pattern") is formed. The developer used in step (3) may be an alkaline developer or a developer containing an organic solvent (hereinafter also called an organic developer). Examples of development methods include immersing the substrate in a tank filled with developer for a certain period of time (dip method), puddling the developer on the substrate surface using surface tension and letting it stand for a certain period of time to develop (paddle method), spraying the developer onto the substrate surface (spray method), and continuously dispensing the developer while scanning a developer dispensing nozzle at a constant speed onto a substrate rotating at a constant speed (dynamic dispensing method). The development time is preferably 10 to 300 seconds, and more preferably 20 to 120 seconds. The temperature of the developer is preferably 0 to 50°C, and more preferably 15 to 35°C. In step (3), a step of stopping development while substituting with another solvent may be performed.

[0346] It is preferable to use an alkaline aqueous solution containing alkali as the alkaline developer. The type of alkaline aqueous solution is not particularly limited, but examples include alkaline aqueous solutions containing quaternary ammonium salts represented by tetramethylammonium hydroxide, inorganic alkalis, primary amines, secondary amines, tertiary amines, alcohol amines, or cyclic amines. Among these, it is preferable that the alkaline developer be an aqueous solution of a quaternary ammonium salt represented by tetramethylammonium hydroxide (TMAH). Appropriate amounts of alcohols, surfactants, etc., may be added to the alkaline developer. The alkali concentration of the alkaline developer is usually preferably 0.1 to 20% by mass. The pH of the alkaline developer is usually preferably 10.0 to 15.0.

[0347] The organic developer is preferably a developer containing at least one organic solvent selected from the group consisting of ketone solvents, ester solvents, alcohol solvents, amide solvents, ether solvents, and hydrocarbon solvents.

[0348] The above organic solvents may be mixed in multiple quantities, or mixed with solvents other than the above organic solvents or with water. The water content of the organic developer as a whole is preferably less than 50% by mass, more preferably less than 20% by mass, even more preferably less than 10% by mass, and particularly preferably substantially water-free. The content of the organic solvent in the organic developer is preferably 50% by mass or more and 100% by mass or less, more preferably 80% by mass or more and 100% by mass or less, even more preferably 90% by mass or more and 100% by mass or less, and particularly preferably 95% by mass or more and 100% by mass or less, based on the total amount of the organic developer.

[0349] The organic developer preferably contains butyl acetate (n-butyl acetate), and more preferably contains butyl acetate and a hydrocarbon having 9 to 12 carbon atoms. The hydrocarbon having 9 to 12 carbon atoms contained in the organic treatment solution may be just one type or two or more types. The hydrocarbon having 9 to 12 carbon atoms is preferably at least one selected from the group consisting of alkanes, alkenes, alkynes and cycloalkanes, more preferably an alkane, even more preferably at least one selected from the group consisting of nonanes, decanes, undecanes and dodecanes, particularly preferably at least one selected from the group consisting of undecanes and dodecanes, and most preferably undecanes. The hydrocarbon having 9 to 12 carbon atoms may also contain structural isomers.

[0350] The butyl acetate content in the organic developer is preferably 65% ​​to 99% by mass, more preferably 70% to 95% by mass, and even more preferably 75% to 90% by mass, based on 100% by mass of the entire organic developer. The hydrocarbon content (total amount if multiple hydrocarbons with 9 to 12 carbon atoms are included) in the organic developer is preferably 1% to 35% by mass, more preferably 5% to 30% by mass, and even more preferably 10% to 25% by mass, based on 100% by mass of the entire organic developer.

[0351] The mass ratio of butyl acetate to hydrocarbons having 9 to 12 carbon atoms in the organic developer (butyl acetate content / hydrocarbon content having 9 to 12 carbon atoms) is preferably 60 / 40 to 95 / 5, more preferably 70 / 30 to 95 / 5, even more preferably 80 / 20 to 90 / 10, and particularly preferably 90 / 10.

[0352] Organic developers may contain other components in addition to butyl acetate and hydrocarbons having 9 to 12 carbon atoms. Examples of other components include water, organic solvents other than butyl acetate and hydrocarbons having 9 to 12 carbon atoms, surfactants, antioxidants, and basic compounds.

[0353] [Rinsing Step] After step (3), rinsing may be performed. The rinsing solution is not particularly limited as long as it does not dissolve the pattern, and a solution containing a general solvent can be used. The rinsing solution preferably contains at least one organic solvent selected from the group consisting of hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents, and ether solvents.

[0354] The rinsing method is not particularly limited and includes, for example, a method of continuously discharging rinsing liquid onto a substrate rotating at a constant speed (rotary coating method), a method of immersing the substrate in a tank filled with rinsing liquid for a certain period of time (dip method), and a method of spraying rinsing liquid onto the surface of the substrate (spray method).

[0355] Furthermore, the pattern formation method of the present invention may include a heating step (Post Bake) after step (3). This step removes any developer and rinse solution remaining between and inside the patterns. This step also has the effect of mellowing the resist pattern and improving the surface roughness of the pattern. The heating step after step (3) may be performed, for example, at 40 to 250°C (preferably 90 to 200°C) for, for example, 10 seconds to 3 minutes (preferably 30 seconds to 120 seconds).

[0356] Alternatively, the formed pattern may be used as a mask to perform an etching process on the substrate. In other words, the pattern formed in step (3) may be used as a mask to process the substrate (or the underlying film and substrate) to form a pattern on the substrate. The method of processing the substrate (or the underlying film and substrate) is not particularly limited, but a method of forming a pattern on the substrate by performing dry etching on the substrate (or the underlying film and substrate) using the pattern formed in step (3) as a mask is preferred. Dry etching is not particularly limited, but oxygen plasma etching is preferred.

[0357] In the pattern forming method of the present invention, the developer, resist composition, and other various materials (e.g., solvent, rinse solution, anti-reflective film forming composition, top coat forming composition, etc.) used are preferably free of impurities such as metals. The impurity content in these materials is preferably 1 ppm (parts per million) or less, more preferably 10 ppb (parts per billion) or less, even more preferably 100 ppt (parts per trillion) or less, particularly preferably 10 ppt or less, and most preferably 1 ppt or less. The lower limit of the impurity content is not particularly limited and may be 0 ppt or more. Examples of metal impurities include Na, K, Ca, Fe, Cu, Mg, Al, Li, Cr, Ni, Sn, Ag, As, Au, Ba, Cd, Co, Pb, Ti, V, W, and Zn.

[0358] Methods for reducing impurities such as metals contained in various materials include, for example, selecting raw materials with a low metal content as constituent materials for various materials, performing filter filtration on the constituent materials of various materials, and performing distillation under conditions that suppress contamination as much as possible, such as by lining the inside of the apparatus with Teflon®. Details of filtration using filters are described in paragraph

[0321] of International Publication No. 2020 / 004306.

[0359] In addition to filter filtration, impurities may be removed using adsorbents, or a combination of filter filtration and adsorbents may be used. Known adsorbents can be used, such as inorganic adsorbents like silica gel and zeolite, and organic adsorbents like activated carbon. To reduce impurities such as metals contained in the above materials, it is necessary to prevent the introduction of metal impurities during the manufacturing process. Whether metal impurities have been sufficiently removed from the manufacturing equipment can be confirmed by measuring the content of metal components in the cleaning solution used to clean the equipment. The content of metal components in the cleaning solution after use is preferably 100 ppt by mass or less, more preferably 10 ppt by mass or less, and even more preferably 1 ppt by mass or less. There is no particular lower limit, but 0 ppt by mass or more is preferred.

[0360] [Method for Manufacturing Electronic Devices] This specification relates to a method for manufacturing electronic devices, including the pattern forming method of the present invention described above, and to electronic devices manufactured by this manufacturing method. Preferred embodiments of the electronic devices of this specification include those mounted on electrical and electronic equipment (home appliances, OA (Office Automation), media-related equipment, optical equipment, and communication equipment, etc.).

[0361] The present invention will be described in more detail below based on the following examples. The materials, amounts used, proportions, processing content, and processing procedures shown in the following examples can be modified as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be interpreted as being limited by the following examples.

[0362] [Various Components of Photosensitive or Radiation-Sensitive Resin Compositions] [Resin A] Resin A (Resins A-1 to A-37) shown in Table 3 are described below. Resin A is used that has been synthesized according to the synthesis method of Resin A-1 described later (Synthesis Example 1). Table 1 shows the composition ratio (mol % ratio; corresponding from left to right), weight-average molecular weight (Mw), and dispersion (Mw / Mn) of each repeating unit shown below. The weight-average molecular weight (Mw) and dispersion (Mw / Mn) of Resins A-1 to A-37 can be measured by GPC (carrier: tetrahydrofuran (THF)) (polystyrene equivalent). The composition ratio (weight % ratio) of the resins is １３ It can be measured using C-NMR (nuclear magnetic resonance).

[0363]

[0364] The structures of the repeating units MA-1 to MA-26 and MB-1 to MB-34 shown in Table 1 are described below.

[0365]

[0366]

[0367]

[0368] <Synthesis Example 1: Synthesis of Resin A-1> Propylene glycol monomethyl ether acetate (28 g) is heated to 80°C under a nitrogen atmosphere. While stirring this liquid, a mixed solution of monomer represented by MA-16 (30 g), monomer represented by MB-10 (38 g), propylene glycol monomethyl ether acetate (112 g), and dimethyl 2,2'-azobisisobutyrate [V-601, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.] (5.7 g) is added dropwise over 6 hours to obtain a reaction solution. After the dropwise addition is complete, the reaction solution is stirred at 80°C for a further 2 hours. After the obtained reaction solution is allowed to cool, it is reprecipitated with a large amount of heptane and ethyl acetate mixed solvent (heptane:ethyl acetate = 9:1, mass ratio), filtered, and the resulting solid is vacuum dried to obtain 58 g of resin A-1. The weight-average molecular weight (Mw: polystyrene equivalent) of the obtained resin A-1, determined from the GPC (carrier: tetrahydrofuran (THF)), was 8500, and the degree of dispersion (Mw / Mn) was 1.60. １３ The molar ratio of repeating units, as measured by C-NMR, is 50 / 50.

[0369] Other resins (A) used in the examples are synthesized in the same manner as described above.

[0370] <Salt Compound B> The structures of salt compounds B (compounds B-1 to B-15, B'-1 to B'-2) shown in Table 3 are shown below.

[0371]

[0372]

[0373]

[0374] <Synthesis Example 2: Synthesis of Compound B-1> <Synthesis of Compound B-1-b> B-1-a (50.0 g) was dissolved in tetrahydrofuran (500.0 g), and while stirring at 25°C under a nitrogen stream, sodium bicarbonate (12.9 g) was added, and the mixture was stirred for 30 minutes. Methyl p-toluenesulfonate (28.7 g) was added dropwise, and the mixture was stirred at 70°C for 24 hours. The temperature was lowered to 25°C, distilled water (400.0 g) and ethyl acetate (1000.0 g) were added, and after stirring, the organic layer was extracted. The organic layer was washed three times with distilled water (400.0 g), concentrated, n-hexane (260.0 g) was added and stirred, and the precipitated solid was filtered to obtain B-1-b (26.2 g).

[0375]

[0376] <Synthesis of Compound B-1-c> B-1-b (26.0 g), tetrahydrofuran (208.0 g), and cesium carbonate (22.0 g) were mixed and stirred at 25°C, to which t-butyl bromoacetate (13.2 g) was added dropwise. The reaction mixture was stirred at 60°C for 10 hours, then distilled water (100.0 g) and ethyl acetate (300.0 g) were added and stirred for 1 hour. The organic layer was extracted, washed three times with distilled water (100.0 g), and the organic layer was concentrated to obtain B-1-c (28.6 g).

[0377]

[0378] <Synthesis of Compound B-1-d> B-1-c (28.6 g) and trifluoroacetic acid (290.0 g) were mixed and stirred at 40°C for 1 hour. Distilled water (580.0 g) was added and stirred at 25°C for 1 hour, then filtered and washed with distilled water (580.0 g) to obtain a solid. The obtained solid was mixed with ethyl acetate (165.0 g) and n-hexane (200.0 g), stirred at 25°C for 1 hour, then filtered, and the obtained solid was vacuum dried at 40°C for 8 hours to obtain B-1-d (20.0 g).

[0379]

[0380] <Synthesis of Compound B-1-e> B-1-d (5.0 g), toluene (15.0 g), and N,N-dimethylformamide (0.2 g) were mixed and stirred at 50°C for 1 hour. Thionyl chloride (3.2 g) was added dropwise at 50°C, and the mixture was stirred at 60°C for 3 hours. B-1-e (5.2 g) was obtained by distilling off the solvent.

[0381]

[0382] <Synthesis of Compound B-1-g> B-1-f (3.0 g), dichloromethane (20.0 g), and distilled water (15.0 g) were mixed and stirred at 0°C. N,N,N-trimethyladamantane-1-aminium hydroxide 25% aqueous solution (16.4 g) was added dropwise, followed by the addition of B-1-e (4.2 g) in portions. The reaction mixture was stirred at 0°C for 1 hour, then dichloromethane (20.0 g) and distilled water (10.0 g) were added and the mixture was stirred at 25°C for another 1 hour. The organic layer was extracted and washed three times with distilled water (20.0 g), and the organic layer was filtered. The filtrate was concentrated. The obtained solid was mixed with dichloromethane (32.0 g) and stirred at 25°C. t-butyl methyl ether (64.0 g) was added dropwise and the mixture was stirred for another 1 hour. The supernatant was removed, and t-butyl methyl ether (64.0 g) was added to the resulting residue and stirred for 3 hours. The supernatant was removed, and the resulting residue was concentrated to obtain B-1-g (7.3 g).

[0383]

[0384] <Synthesis of Compound B-1> B-1-g (7.0 g), B-1-h (6.5 g), dichloromethane (70.0 g), and distilled water (70.0 g) were mixed and stirred at 25°C for 1 hour. The organic layer was extracted and washed eight times with distilled water (70.0 g). After concentrating the organic layer, diisopropyl ether (100.0 g) was added to the residue and stirred, and the precipitated solid was filtered to obtain compound B-1 (9.2 g).

[0385]

[0386] Regarding the obtained compound B-1 １ H-NMR was measured. １H NMR (400MHz, (CD ３ ) ２ SO); 3.78 (s, 3H), 4.31 (s, 2H), 7.91 (d, 1H), 8.12-8.21 (m, 24H), 8.30 (d, 1H)

[0387] Other compounds (B) used in the examples are synthesized in the same manner as described above.

[0388] <Photoacid Generator C other than salt compound B> The structures of photoacid generator C (compounds C-1 to C-42) shown in Table 3 are shown below.

[0389]

[0390]

[0391]

[0392]

[0393]

[0394]

[0395] <Photo-decaying Quencher D> The structures of photo-decaying quenchers D (compounds D-1 to D-30) shown in Table 3 are shown below.

[0396]

[0397]

[0398]

[0399]

[0400]

[0401] [Non-photodecayable quencher G] The structures of the non-photodecayable quencher G (compounds G-1 to G-5) shown in Table 3 are shown below.

[0402]

[0403] [Resin I] Resins I (Resins I-1 to I-8) shown in Table 3 are described below. Resins I-1 to I-8 are synthesized according to the synthesis method of Resin A1 described above (Synthesis Example 1). Table 2 shows the composition ratio (mass % ratio; corresponding from left to right), weight-average molecular weight (Mw), and dispersion (Mw / Mn) of each repeating unit shown below. The weight-average molecular weight (Mw) and dispersion (Mw / Mn) of Resins I-1 to I-8 are measured by GPC (carrier: tetrahydrofuran (THF)) (polystyrene equivalent). The composition ratio (weight % ratio) of the resins is as follows: １３ Measurement is performed using C-NMR.

[0404]

[0405] The structural formulas of resins I-1 to I-8 shown in Table 2 are shown below.

[0406]

[0407] [Surfactants] The surfactants shown in Table 3 are as follows: H-1: Megafac F176 (manufactured by DIC Corporation, fluorine-based surfactant) H-2: Megafac R08 (manufactured by DIC Corporation, fluorine and silicone-based surfactant) H-3: PF656 (manufactured by OMNOVA, fluorine-based surfactant)

[0408] [Solvents] The solvents shown in Table 3 are as follows: F-1: Propylene glycol monomethyl ether acetate (PGMEA) F-2: Propylene glycol monomethyl ether (PGME) F-3: Propylene glycol monoethyl ether (PGEE) F-4: Cyclohexanone F-5: Cyclopentanone F-6: 2-Heptanone F-7: Ethyl lactate F-8: γ-Butyrolactone F-9: Propylene carbonate

[0409] [Preparation of Resist Composition] Mix each component shown in Table 3 so that the solid content concentration is 2.0% by mass. Then, filter the resulting mixture by passing it through a polyethylene filter with a pore size of 50 nm, a nylon filter with a pore size of 10 nm, and finally a polyethylene filter with a pore size of 5 nm, in that order to prepare the resist compositions (Re-1 to Re-53, CRE-1 to CRE-2). Note that solid content refers to all components other than the solvent. The obtained resist compositions are used in the examples and comparative examples. In the table, the "Quantity" column indicates the content (by mass) of each component relative to the total solid content in the resist composition.

[0410]

[0411]

[0412]

[0413]

[0414] [Pattern Formation] [EUV Exposure, Organic Solvent Development (1)] A base layer formation composition AL412 (manufactured by Brewer Science) is applied to a 12-inch diameter silicon wafer and baked at 205°C for 60 seconds to form a 20 nm thick base layer. A resist composition shown in Table 3 is then applied on top of this and baked at 100°C for 60 seconds to form a 30 nm thick resist film. An EUV exposure apparatus (Exitech Micro Exposure Tool, NA 0.3, Quadrupol, outer sigma 0.68, inner sigma 0.36) is used to irradiate the silicon wafer with the obtained resist film with a pattern so that the average line width of the resulting pattern is 14 nm. A mask with a line size of 16 nm and a line:space ratio of 1:1 is used as the reticle. After exposure, the resist film is baked at 90°C for 60 seconds, then developed with n-butyl acetate for 30 seconds, and finally spin-dried to obtain a negative-type pattern.

[0415] [Evaluation] <Defect Evaluation (Defect Suppression)> The patterns obtained by the method described above are evaluated by counting the number of defects per silicon wafer using UVision5 (AMAT) and SEMVisionG4 (AMAT), according to the following evaluation criteria. The fewer the number of defects, the better the defect suppression, and a rating of "C" or higher is considered acceptable.

[0416] "A": Number of defects is 50 or less "B": Number of defects is between 50 and 100 "C": Number of defects is between 100 and 200 "D": Number of defects is more than 200

[0417] <Roughness Performance> Roughness performance was evaluated using line width roughness (LWR performance, nm). The pattern obtained by the method described above was observed from above using a length-measuring scanning electron microscope (SEM (Hitachi, Ltd. S-9380II)). The line width of the pattern was observed at 250 points, and its standard deviation (σ) was determined. The measurement variability of the line width was evaluated using 3σ, and the value of 3σ was taken as the LWR (nm). The obtained LWR was evaluated according to the following evaluation criteria. The smaller the LWR value, the better the LWR performance, and a rating of "C" or higher is considered acceptable.

[0418] "A": 2.00nm or less "B": More than 2.00nm, 2.40nm or less "C": More than 2.40nm, 2.80nm or less "D": More than 2.80nm

[0419]

[0420]

[0421]

[0422] As shown in the table above, the resist compositions of the examples exhibit excellent LWR performance and defect suppression when patterns are formed by organic solvent development (butyl acetate development). On the other hand, the resist compositions of the comparative examples exhibit insufficient performance in this regard. Furthermore, the resist compositions of the examples exhibit excellent LWR performance and defect suppression of the formed patterns when at least one of the following requirements A to C is met (preferably at least two, more preferably all of them are met). Requirement A: In the specific salt compound contained in the resist composition, the aromatic ring group represented by Wa in the specific anionic portion (the anionic portion represented by formula (1)) is a benzene ring group. Requirement B: In the specific salt compound contained in the resist composition, the specific cation portion is a cation portion represented by formula (X-1). Requirement C: The resin contained in the resist composition has repeating units represented by formula (18).

[0423] [EUV exposure, organic solvent development (2)] A base layer film formation composition AL412 (manufactured by Brewer Science) is applied to a 12-inch diameter silicon wafer and baked at 205°C for 60 seconds to form a 20 nm thick base layer. A resist composition shown in Table 3 is then applied on top of this and baked at 100°C for 60 seconds to form a 30 nm thick resist film. An EUV exposure apparatus (Exitech, Micro Exposure Tool, NA 0.3, Quadrupol, outer sigma 0.68, inner sigma 0.36) is used to irradiate the silicon wafer with the obtained resist film with a pattern so that the average line width of the resulting pattern is 14 nm. A mask with a line size of 14 nm and a line:space ratio of 1:1 is used as the reticle. After exposure, the resist film is baked at 90°C for 60 seconds, then developed with an n-butyl acetate / undecane mixture (weight ratio: n-butyl acetate / undecane = 10 / 90) for 30 seconds, and then spin-dried to obtain a negative-type pattern. Using the obtained pattern, the LWR performance and defect suppression are evaluated in the same manner as described above.

[0424] The evaluation results are shown in the table below.

[0425]

[0426]

[0427]

[0428] As shown in the table above, the resist compositions of the examples exhibit excellent LWR performance and defect suppression when patterns are formed by organic solvent development (butyl acetate / undecane development). On the other hand, the resist compositions of the comparative examples exhibit insufficient performance in this regard. Furthermore, the resist compositions of the examples exhibit excellent LWR performance and defect suppression of the formed patterns when at least one of the following requirements A to C is met (preferably at least two, more preferably all of them are met). Requirement A: In the specific salt compound contained in the resist composition, the aromatic ring group represented by Wa in the specific anionic portion (the anionic portion represented by formula (1)) is a benzene ring group. Requirement B: In the specific salt compound contained in the resist composition, the specific cation portion is a cation portion represented by formula (X-1). Requirement C: The resin contained in the resist composition has repeating units represented by formula (18).

[0429] [EUV exposure, alkaline aqueous solution development] A base layer film formation composition AL412 (manufactured by Brewer Science) is applied to a 12-inch diameter silicon wafer and baked at 205°C for 60 seconds to form a 20 nm thick base layer. A resist composition shown in Table 3 is then applied on top of this and baked at 100°C for 60 seconds to form a 30 nm thick resist film. An EUV exposure apparatus (Exitech Micro Exposure Tool, NA 0.3, Quadrupol, outer sigma 0.68, inner sigma 0.36) is used to irradiate the silicon wafer with the obtained resist film with a pattern so that the average line width of the resulting pattern is 14 nm. A mask with a line size of 14 nm and a line:space ratio of 1:1 is used as the reticle. After exposure, the resist film is baked at 90°C for 60 seconds, then developed with an aqueous solution of tetramethylammonium hydroxide (2.38% by mass) for 30 seconds, followed by rinsing with pure water for 30 seconds. This is then spin-dried to obtain a positive pattern. The obtained positive pattern is used to evaluate the LWR performance and defect suppression in the same manner as described above.

[0430] The evaluation results are shown in the table below.

[0431]

[0432]

[0433]

[0434] As shown in the table above, the resist compositions of the examples exhibit excellent LWR performance and defect suppression even when patterns are formed by alkaline development. On the other hand, the resist compositions of the comparative examples exhibit insufficient performance in this regard. Furthermore, if the resist compositions of the examples satisfy at least one of the following requirements A to C (preferably satisfying at least two, more preferably satisfying all), the LWR performance and defect suppression of the formed patterns are excellent. Requirement A: In the specific salt compound contained in the resist composition, the aromatic ring group represented by Wa in the specific anionic portion (the anionic portion represented by formula (1)) is a benzene ring group. Requirement B: In the specific salt compound contained in the resist composition, the specific cation portion is a cation portion represented by formula (X-1). Requirement C: The resin contained in the resist composition has repeating units represented by formula (18).

Claims

resin and A photosensitive or radiation-sensitive resin composition comprising a salt containing an anionic portion represented by formula (1) and a cation portion represented by formula (X-1) or formula (X-2). In formula (1), Wa represents an aromatic ring group. １ This represents a monovalent organic group. A ２ represents a monovalent substituent. n represents an integer greater than or equal to 1. m represents an integer greater than or equal to 0. However, if m is 0, A １ A monovalent organic group represented by contains at least one structural site selected from the group consisting of formulas (Y-1) and (Y-2). When m is 1 or greater, A １ A monovalent organic group represented by m A ２ At least one of the monovalent substituents represented by includes at least one structural site selected from the group consisting of formulas (Y-1) and (Y-2). In the formula, A ２ If there are multiple A ２ They may be the same or different from one another. In equations (Y-1) and (Y-2), *1 and *2 represent the bonding positions. R ｘ１ each independently represents a monovalent organic group, provided that at least one of R ｘ１ is a monovalent organic group having a halogen atom. Two of the three R ｘ１ may combine to form a ring structure. R ｘ２ Each of these independently represents a monovalent organic group. However, R ｘ２ At least one of them is a monovalent organic group having a halogen atom. 　 The photosensitive or radiation-sensitive resin composition according to claim 1, wherein the anionic portion of the salt is an anionic portion represented by formula (3-1) or formula (3-2). In formula (3-1), Wa represents an aromatic ring group. １ X represents a single bond or a divalent linking group. １ R represents a divalent group selected from the group consisting of formulas (Y-1) and (Y-2). １ This represents a monovalent organic group. A １ R represents a monovalent organic group. １ａ represents a monovalent substituent. n represents an integer greater than or equal to 1. m1 represents an integer greater than or equal to 1. y represents an integer greater than or equal to 0. In the ceremony, L １ If there are multiple L １ They may be the same or different from each other. １ If there are multiple X １ They may be the same or different from each other. １ If multiple R １ They may be the same or different from each other. １ａ If multiple R １ａ They may be the same or different from one another. In formula (3-2), Wa represents an aromatic ring group. ２ X represents a single bond or a divalent linking group. ２ R represents a divalent group selected from the group consisting of formulas (Y-1) and (Y-2). ２ This represents a monovalent organic group. A ２ A represents a monovalent substituent. n represents an integer greater than or equal to 1. m represents an integer greater than or equal to 0. In the formula, A ２ If there are multiple A ２ They may be the same or different from one another. In equations (Y-1) and (Y-2), *1 and *2 represent the bonding positions. 　 In the above formula (3-2), X ２ This represents the above formula (Y-1), and *1 is L ２ When bonded to the side, L ２ The photosensitive or radiation-sensitive resin composition according to claim 2, wherein represents a divalent linking group having 6 or fewer carbon atoms. 　 In the above formula (3-2), X ２ This represents the above formula (Y-1), and *1 is R ２ The photosensitive or radiation-sensitive resin composition according to claim 2, which is bonded to the side. 　 The photosensitive or radiation-sensitive resin composition according to claim 1 or 2, wherein Wa represents a benzene ring group. 　 The photosensitive or radiation-sensitive resin composition according to claim 1 or 2, wherein the salt comprises a cation portion represented by formula (X-1). 　 The photosensitive or radiation-sensitive resin composition according to claim 1 or 2, wherein the resin comprises a repeating unit represented by formula (18). In formula (18), n1 represents 0 or 1. n2 represents an integer from 1 to 5. n3 represents an integer from 0 to 4, provided that 1 ≤ n2 + n3 ≤ 5. X represents a halogen atom or an organic group. Y and Z each independently represent a hydrogen atom, a halogen atom, or an organic group. Note that Y or Z and X may bond to each other to form a ring structure. 　 The photosensitive or radiation-sensitive resin composition according to claim 7, wherein in formula (18), n2 represents an integer from 2 to 5. 　 The photosensitive or radiation-sensitive resin composition according to claim 1 or 2, wherein the resin comprises repeating units having acid-degradable groups in which polar groups are protected by groups that are removed by the action of an acid. Furthermore, the photosensitive or radiation-sensitive resin composition according to claim 1 or 2, comprising a photoacid generator. 　 A photosensitive or radiation-sensitive film formed from the photosensitive or radiation-sensitive resin composition described in claim 1 or 2. 　 A step of forming a photosensitive or radiation-sensitive film on a substrate using the photosensitive or radiation-sensitive resin composition according to claim 1 or 2, A step of exposing the aforementioned photosensitive or radiation-sensitive film, A pattern forming method comprising the steps of developing the exposed photosensitive or radiation-sensitive film using a developing solution to form a pattern. 　 A method for manufacturing an electronic device, comprising the pattern forming method described in claim 12.

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