Positive-type resist composition, resist film, pattern formation method, and method for manufacturing electronic devices

Abstract

The present invention provides a positive resist composition, a resist film using the positive resist composition, a pattern formation method, and a method for manufacturing an electronic device, said resist composition containing an ionic compound (A) and a resin (B) that: has a repeating unit (b1) having an interacting group interacting with an ionic group in the ionic compound; and a main chain that decomposes as a result of irradiation by X rays, electron beams, or extreme UV rays.

Description

[Technical Field]

[0001] The present invention relates to a positive-type resist composition, a resist film, a pattern formation method, and a method for manufacturing an electronic device. [Background technology]

[0002] Since the development of resists for KrF excimer lasers (248 nm), pattern formation methods utilizing chemical amplification have been employed to compensate for the decrease in sensitivity due to light absorption. For example, in a positive-type chemical amplification method, first, the photoacid generator contained in the exposure area decomposes upon light irradiation to generate acid. Then, during the post-exposure bake (PEB) process, the generated acid acts as a catalyst to change the alkali-insoluble groups of the resin contained in the photosensitive or radiation-sensitive resin composition to alkali-soluble groups, thereby changing the solubility in the developer. Subsequently, development is performed using, for example, a basic aqueous solution. This removes the exposure area and obtains the desired pattern. On the other hand, there are also known pattern formation methods that do not utilize chemical amplification using acids as described above. Under these circumstances, various compositions have been proposed for photosensitive or radiation-sensitive resin compositions.

[0003] For example, Patent Document 1 discloses a positive-type resist material for forming positive-type patterns by organic solvent development, which includes a base resin containing a polymer having repeating units having ionic groups.

[0004] Patent Document 2 discloses a resist composition used in a specific resist pattern formation method, which contains a substrate component having an acidic group and an ionic compound having a light-absorbing cation that generates an acid with an acid dissociation constant (pKa) of 0 or more upon exposure, wherein the acidic group and the light-absorbing cation can form an associated structure.

[0005] Patent Document 3 discloses a polymer and a positive-type resist composition comprising the polymer and a solvent, which, when used as a main-chain cleavage type positive-type resist, can sufficiently suppress the occurrence of resist pattern collapse and produce a highly clear resist pattern. Furthermore, Patent Document 4 discloses a pattern formation method using a resist made of a copolymer of α-methylstyrene and α-methyl chloroacrylate. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2017-146521 [Patent Document 2] Japanese Patent Application Publication No. 2013-127526 [Patent Document 3] Japanese Patent Application Publication No. 2017-132965 [Patent Document 4] Japanese Patent Application Publication No. 3-132760 [Overview of the project] [Problems that the invention aims to solve]

[0007] In pattern formation methods that utilize chemical amplification using acids, the diffusion of acid from the exposed area to the unexposed area makes it difficult to form a resist pattern that matches the optical image. However, the pattern formation method that does not utilize chemical amplification using acids, as described above, is moving in the direction of eliminating this property. However, in pattern formation methods using X-rays, electron beams (EB), or extreme ultraviolet (EUV) light as exposure sources, there is a demand for ultra-fine patterns, and even with the conventional techniques described above, the resolution was insufficient when forming ultra-fine patterns (for example, 40 nm or less).

[0008] Therefore, the object of the present invention is to provide a positive-type resist composition that can form patterns with extremely excellent resolution when forming ultrafine patterns (for example, 40 nm or less). Furthermore, the present invention aims to provide a resist film using the above-mentioned positive-type resist composition, a pattern formation method, and a method for manufacturing an electronic device. [Means for solving the problem]

[0009] As a result of diligent research to solve the above problems, the inventors have found that the above problems can be solved by the following configuration. <1> (A) Ionic compounds, and (B) A positive-type resist composition containing a resin having repeating units (b1) having interacting groups that interact with the ionic groups in the above-mentioned ionic compound, wherein the main chain decomposes upon irradiation with X-rays, electron beams, or extreme ultraviolet light, The above ionic compound (A) is a compound that generates acid upon irradiation with X-rays, electron beams, or extreme ultraviolet light. The above resin (B) has at least one of the group consisting of a hydroxyl group, a carboxyl group, a carbonate group, a carbonyl group, an amino group, an amide group, a thiol group, an alkoxycarbonyl group, an alkyloxysulfonyl group, a sulfo group, a sulfonyl group, and an alkylsulfonyl group as the interacting group. The above resin (B) has repeating units represented by the following general formula (1), A positive-type resist composition in which the above-mentioned ionic compound (A) and the above-mentioned resin (B) are the same compound. [ka] In general formula (1), X represents a chlorine atom, a bromine atom, or an iodine atom. R represents a hydrogen atom or a monovalent organic group. <2> (A) Ionic compounds, and (B) A positive-type resist composition containing a resin having repeating units (b1) having interacting groups that interact with the ionic groups in the above-mentioned ionic compound, the main chain of which decomposes upon irradiation with X-rays, electron beams, or extreme ultraviolet light (excluding polymers containing structural units represented by the following general formula (1'), polymers represented by the following A-2, copolymers of 1-methyl-1-phenylethyl-α-chloroacrylate and 2-hydroxyethyl methacrylate, copolymers of 1-methyl-1-phenylethyl-α-chloroacrylate and 2-hydroxy-3-phenoxypropyl acrylate, and copolymers of 1-methyl-1-phenylethyl-α-bromoacrylate and 1-hydroxy-1-methylethyl methacrylate), The above ionic compound (A) is a compound that generates acid upon irradiation with X-rays, electron beams, or extreme ultraviolet light. The above resin (B) has at least one of the group consisting of a hydroxyl group, an amino group, an amide group, and a thiol group as the above interacting group. The repeating unit (b1) described above is the repeating unit represented by the following general formula (2), The resin (B) described above is a positive-type resist composition having repeating units represented by the following general formula (1). Here, the ionic compound (A) and the resin (B) described above may be the same compound. [ka] (X' represents a halogen atom or a cyano group. R'' represents an acid-degradable organic group and includes at least one structure represented by the following general formula (2').) [ka] (R in the formula 1 , R 2 Each of these independently represents an alkyl group, an aryl group, an aryl alkyl group, an alkoxyalkyl group, an alkoxyaryl group, an alkoxyaryl alkyl group, a hydroxyalkyl group, a hydroxyaryl group, a hydroxyaryl alkyl group, a haloalkyl group, a haloaryl group, a haloaryl alkyl group, a silylalkyl group, a silylaryl group, a silylaryl alkyl group, a siloxyalkyl group, a siloxyaryl group, and a siloxyaryl alkyl group. Also, R 1 , R 2 It may also form a ring structure by closing the ring. 3 (where m' is 0 or 1, the symbol indicates an organic group with 1 to 12 carbon atoms.) [ka] [ka] In general formula (2), R' represents a hydrogen atom or an alkyl group. C 1 The above represents the interacting group. j represents either 0 or 1. k represents either 0 or 1. n represents an integer from 1 to 9. If n represents an integer from 2 to 9, multiple C 1 They may be the same or different. [Chemistry] In general formula (1), X represents a chlorine atom, a bromine atom, or an iodine atom. R represents a hydrogen atom or a monovalent organic group. <3> (A) Ionic compounds, and (B) A positive-type resist composition containing a resin having repeating units (b1) having interacting groups that interact with the ionic groups in the above-mentioned ionic compound, the main chain of which decomposes upon irradiation with X-rays, electron beams, or extreme ultraviolet light (excluding polymers containing structural units represented by the following general formula (1'), polymers represented by the following A-2, copolymers of 1-methyl-1-phenylethyl-α-chloroacrylate and 2-hydroxyethyl methacrylate, copolymers of 1-methyl-1-phenylethyl-α-chloroacrylate and 2-hydroxy-3-phenoxypropyl acrylate, and copolymers of 1-methyl-1-phenylethyl-α-bromoacrylate and 1-hydroxy-1-methylethyl methacrylate), The above ionic compound (A) is a compound that generates acid upon irradiation with X-rays, electron beams, or extreme ultraviolet light. The above resin (B) has at least one of the group consisting of a hydroxyl group, an amino group, an amide group, and a thiol group as the above interacting group. The above resin (B) has repeating units represented by the following general formula (1), A positive-type resist composition in which the resin (B) has repeating units represented by the following general formula (7) (excluding those corresponding to repeating units represented by the following general formula (2)). Here, the ionic compound (A) and the resin (B) may be the same compound. [Chemistry] (X' represents a halogen atom or a cyano group. R'' represents an acid-degradable organic group and includes at least one structure represented by the following general formula (2').) [Chemistry] z (R in the formula 1 、R 2 Each of these independently represents an alkyl group, an aryl group, an aryl alkyl group, an alkoxyalkyl group, an alkoxyaryl group, an alkoxyaryl alkyl group, a hydroxyalkyl group, a hydroxyaryl group, a hydroxyaryl alkyl group, a haloalkyl group, a haloaryl group, a haloaryl alkyl group, a silylalkyl group, a silylaryl group, a silylaryl alkyl group, a siloxyalkyl group, a siloxyaryl group, and a siloxyaryl alkyl group. Also, R 1 、R 2 It may also form a ring structure by closing the ring. 3 (where m' is 0 or 1, the symbol indicates an organic group with 1 to 12 carbon atoms.) [Chemistry] z [Chemistry] In general formula (1), X represents a chlorine atom, a bromine atom, or an iodine atom. R represents a hydrogen atom or a monovalent organic group. [Chemistry] In general formula (7), R 31 represents a hydrogen atom or an alkyl group. R 32 This represents a monovalent organic group. 's' represents either 0 or 1. t represents either 0 or 1. w represents an integer from 0 to 9. If w represents an integer from 2 to 9, multiple R 32 They may be the same or different.

change

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change

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[16] below) are also described below.

[0010] [1] (A) Ionic compounds, and (B) A positive-type resist composition containing a resin having repeating units (b1) having interacting groups that interact with the ionic groups in the above-mentioned ionic compound, the main chain of which decomposes upon irradiation with X-rays, electron beams, or extreme ultraviolet light. [2] The positive-type resist composition according to [1], wherein the resin (B) has at least one from the group consisting of a hydroxyl group, an amino group, an amide group, and a thiol group as the interacting group.

[0011] [3] The positive-type resist composition according to [1] or [2], wherein the resin (B) has repeating units represented by the following general formula (1).

[0012] [ka]

[0013] In general formula (1), X represents a halogen atom or an alkyl fluoride. R represents a hydrogen atom or a monovalent organic group.

[0014] [4] The positive-type resist composition according to [3], wherein X in the above general formula (1) represents a fluorine atom, a chlorine atom, or a bromine atom. [5] A positive-type resist composition according to any one of [1] to [4], wherein the ionic compound (A) and the resin (B) are the same compound.

[0015] [6] The positive-type resist composition according to [5], wherein the resin (B) comprises a repeating unit represented by the following general formula (3) as the repeating unit (b1), and at least one repeating unit selected from the group consisting of a repeating unit represented by the following general formula (4) and a repeating unit represented by the following general formula (5).

[0016] [ka]

[0017] In general formula (3), A represents a hydrogen atom, a halogen atom, or an alkyl group. L represents a divalent linking group. B represents a single bond or a (m+1) valence linking group. C represents the interacting group mentioned above. m represents an integer greater than or equal to 1. If m represents an integer greater than or equal to 2, then multiple Cs may be the same or different. In general formula (4), A1 represents a hydrogen atom, a halogen atom, or an alkyl group. L1 represents a single bond or a divalent linking group. B1 represents a single bond or a (p+1) valence linking group. D1 represents an anionic group. E1 represents a cation. p represents an integer between 1 and 2. If p represents an integer of 2, then multiple D1 and multiple E1 may be the same or different. In general formula (5), A2 represents a hydrogen atom, a halogen atom, or an alkyl group. L2 represents a divalent linking group. B2 represents a single bond or a (q+1) valence linking group. D2 represents an anion. E2 represents a cationic group. q represents an integer between 1 and 2. If q represents an integer of 2, then multiple D2s and multiple E2s may be the same or different.

[0018] [7] A positive-type resist composition according to any one of items [1] to [6], wherein the repeating unit (b1) is a repeating unit represented by general formula (2).

[0019] [ka]

[0020] In general formula (2), R' represents a hydrogen atom or an alkyl group. C1 represents the interacting group described above. j represents either 0 or 1. k represents either 0 or 1. n represents an integer from 1 to 9. If n represents an integer between 2 and 9, then multiple C1s may be the same or different.

[0021] [8] A positive-type resist composition according to any one of [1] to [7], wherein the content of the repeating unit (b1) is 20 mol% or less relative to the total repeating units of the resin (B).

[0022] [9] A positive-type resist composition according to any one of [1] to [8], wherein the resin (B) has repeating units represented by the following general formula (7) (excluding those corresponding to the repeating units represented by the following general formula (2)).

[0023] [ka]

[0024] In general formula (7), R 31 represents a hydrogen atom or an alkyl group. R 32 This represents a monovalent organic group. 's' represents either 0 or 1. t represents either 0 or 1. w represents an integer from 0 to 9. If w represents an integer from 2 to 9, multiple R 32 They may be the same or different.

[0025]

[10] The positive-type resist composition according to any one of [1] to [9], wherein the ionic compound (A) is a compound represented by the following general formula (6).

[0026] [ka]

[0027] In general formula (6), M3 + This represents an organic cation that is decomposed by irradiation with X-rays, electron beams, or extreme ultraviolet light. A3 - This represents an anionic group. R a represents a hydrogen atom or a monovalent organic group. L a This represents a single bond or a divalent linking group.

[0028]

[11] The above ionic compound (A) and the above resin (B) are the same compound, and the R in the compound represented by the above general formula (6) a The positive-type resist composition according to

[10] , wherein a monovalent organic group as a resin is included in the main chain structure of the resin.

[0029]

[12] A3 in the compound represented by the above general formula (6) -The positive resist composition according to

[10] or

[11] , wherein the group is selected from the group consisting of groups represented by the following general formulas (B-1) to (B-14).

[0030] [ka]

[0031] In equations (B-1) to (B-14), * indicates a bonding position. In equations (B-1) to (B-5), and (B-12), R X1 Each of these independently represents a monovalent organic group. In formulas (B-7) and (B-11), R X2 Each of these independently represents a hydrogen atom, or a substituent other than a fluorine atom and a perfluoroalkyl group. The two R in formula (B-7) X2 They may be the same or different. In general formula (B-8), R XF1 R represents a hydrogen atom, a fluorine atom, or a perfluoroalkyl group. However, multiple Rs are not allowed. XF1 Of these, at least one represents a fluorine atom or a perfluoroalkyl group. The two R in formula (B-8) XF1 They may be the same or different. In general formula (B-9), R X3 R represents a hydrogen atom, a halogen atom, or a monovalent organic group. n1 represents an integer from 0 to 4. If n1 represents an integer from 2 to 4, multiple R X3 They may be the same or different. In general formula (B-10), R XF2 This represents a fluorine atom or a perfluoroalkyl group. In general formula (B-14), R X4 R represents a hydrogen atom, a halogen atom, or a monovalent organic group. n2 represents an integer from 0 to 4. If n2 represents an integer from 2 to 4, multiple R X4 They may be the same or different.

[0032]

[13] A3 in the compound represented by the above general formula (6)- The positive resist composition according to

[12] , wherein the group is selected from the group consisting of the groups represented by the above general formulas (B-6), (B-7), (B-8), (B-9), and (B-14).

[14] A resist film formed using any one of the positive-type resist compositions described in [1] to

[13] .

[0033]

[15] A step of forming a resist film on a substrate using any one of the positive-type resist compositions described in [1] to

[13] , The above resist film is exposed to X-rays, electron beams, or extreme ultraviolet light, A pattern forming method comprising the steps of developing the exposed resist film using a developing solution to form a pattern.

[16] A method for manufacturing an electronic device, including the pattern formation method described in

[15] . [Effects of the Invention]

[0034] According to the present invention, it is possible to provide a positive-type resist composition that can form patterns with extremely high resolution when forming ultrafine patterns (for example, 40 nm or less). Furthermore, according to the present invention, it is possible to provide a resist film using the above-mentioned positive-type resist composition, a pattern formation method, and a method for manufacturing an electronic device. [Modes for carrying out the invention]

[0035] The resist composition, resist film, pattern formation method, and method for manufacturing electronic devices according to the present invention will be described in detail below. The following description of the constituent elements may be based on typical embodiments of the present invention, but the present invention is not limited to such embodiments.

[0036] 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 substituted and unsubstituted groups. For example, "alkyl group" includes not only unsubstituted alkyl groups but also substituted alkyl groups. Furthermore, in this specification, "organic group" means a group containing at least one carbon atom. Unless otherwise specified, the substituents are preferably monovalent.

[0037] Furthermore, in this specification, the type of substituent, the position of the substituent, and the number of substituents are not particularly limited when we say "may have substituents." The number of substituents may be, for example, one, two, three, or more. Examples of substituents include monovalent nonmetallic atom groups excluding hydrogen atoms, and for example, substituents T can be selected from the following.

[0038] (substituent T) Substituents T include 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, butoxycarbonyl, and phenoxycarbonyl; acyloxy groups such as acetoxy, propionyloxy, and benzoyloxy; acyl groups such as acetyl, benzoyl, isobutyryl, acryloyl, methacryloyl, and methoxalyl; and methyl Alkylsulfanil groups such as sulfanil groups and tert-butylsulfanil groups; arylsulfanil groups such as phenylsulfanil groups and p-tolylsulfanil groups; alkyl groups; cycloalkyl groups; aryl groups; heteroaryl groups; hydroxyl groups; carboxyl groups; formyl groups; sulfo groups; cyano groups; alkylaminocarbonyl groups; arylaminocarbonyl groups; sulfonamide groups; silyl groups; amino groups; monoalkylamino groups; dialkylamino groups; arylamino groups, nitro groups; formyl groups; and combinations thereof.

[0039] 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 light), 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.

[0040] In this specification, "~" is used to mean that the numbers before and after it are included as the lower and upper limits, respectively.

[0041] The bonding direction of divalent groups as expressed herein is not limited unless otherwise specified. For example, in a compound represented by the general formula "XYZ", if Y is -COO-, Y may also be -CO-O- or -O-CO-. Furthermore, the above compound may also be "X-CO-OZ" or "XO-CO-Z".

[0042] In this specification, (meth)acrylate refers to acrylate and methacrylate, and (meth)acrylic refers to acrylic and methacrylic.

[0043] 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).

[0044] 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 herein are those calculated using this software package.

[0045] Software Package 1: Advanced Chemistry Development (ACD / Labs) Software V8.14 for Solaris (1994-2007 ACD / Labs).

[0046] On the other hand, 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 it by calculating the dissociation free energy. + The dissociation free energy can be calculated using, for example, DFT (Density Functional Theory), but various other methods have been reported in the literature and are not limited to this. Several software programs exist that can perform DFT; for example, Gaussian16 is one such program.

[0047] In this specification, pKa refers to a value calculated using software package 1 based on a database of Hammett substituent constants and publicly available literature values, as described above. However, if pKa cannot be calculated using this method, the value obtained by Gaussian16 based on DFT (Density Functional Theory) shall be adopted. Furthermore, as stated above, pKa refers to "pKa in aqueous solution," but if pKa in aqueous solution cannot be calculated, "pKa in dimethyl sulfoxide (DMSO) solution" shall be used.

[0048] In this specification, examples of halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms.

[0049] [Positive-type resist composition] The positive-type resist composition of the present invention (hereinafter also referred to as the "resist composition") will be described below. The resist composition of the present invention is a positive-type resist composition. It may also be a resist composition for alkaline development or a resist composition for organic solvent development. The compositions of the present invention are typically non-chemically amplified resist compositions.

[0050] The positive-type resist composition of the present invention contains (A) an ionic compound and (B) a resin having repeating units (b1) that interact with the ionic groups in the ionic compound, the main chain of which decomposes upon irradiation with X-rays, electron beams, or extreme ultraviolet light.

[0051] With this configuration, it is possible to form ultra-fine patterns (for example, 40 nm or less) with extremely high resolution. The mechanism by which the present invention can produce the above effects is not entirely clear, but the inventors believe it to be as follows.

[0052] The resin (B) of the present invention is a resin whose main chain is first decomposed by irradiation with X-rays, electron beams, or extreme ultraviolet light. When a resist film is formed using the resist composition of the present invention and irradiated with X-rays, electron beams, or extreme ultraviolet light, the main chain is cleaved in the exposed area, and the solubility in the developer increases due to the reduction in molecular weight. That is, a difference in the dissolution rate in the developer (so-called dissolution contrast) occurs between the unexposed and exposed areas. Since the resin (B) has a low molecular weight, it is considered that the solubility in alkaline developers increases in the exposed area, and also increases in organic developers.

[0053] Furthermore, resin (B) contains repeating units (b1) having interacting groups that interact with ionic groups in ionic compounds. In the resist film formed by the resist composition of the present invention, before exposure, since the ionic group and the interaction group interact with each other, it shows poor solubility in the developer. When irradiated with X-rays, electron beams, or extreme ultraviolet rays, in the exposed area, for example, the cation in the ionic compound absorbs the exposure light and decomposes, so that the interaction group is exposed, and the solubility of the exposed area in the developer increases. That is, a dissolution contrast occurs between the unexposed area and the exposed area. In the exposed area, it is considered that the solubility in the alkali developer increases and the solubility in the organic developer also increases. Specific embodiments are shown below. The interaction group is a group that interacts with the ionic group in the ionic compound. Specifically, it is considered that the interaction group interacts with the ionic group to form an association structure in a form close to a salt. When a resist film is formed by the composition of the present invention, in such an associated state, it shows poor solubility in the alkali developer and also shows poor solubility in the organic developer. Expose the resist film with X-rays, electron beams (EB), or extreme ultraviolet rays (EUV light). Examples of the exposure method include irradiating X-rays, electron beams, or extreme ultraviolet rays through a predetermined mask on the formed resist film. By the above exposure, the cation decomposes, etc., and the interaction group forming the above association structure is exposed, and the solubility of the exposed area in the developer increases.

[0054] Thus, the resin (B) contained in the resist composition of the present invention is a resin whose main chain decomposes by irradiation with X-rays, electron beams, or extreme ultraviolet rays, and since it contains the repeating unit (b1), the dissolution contrast between the exposed area and the unexposed area can be greatly improved. Surprisingly, it is considered that even in the formation of ultra-fine patterns (for example, 40 nm or less), patterns with extremely excellent resolution can be formed.

[0055] In contrast, when using only resins whose main chains decompose as described above, or when using only the interaction mechanism described above, the dissolution contrast was still insufficient when forming ultrafine patterns (e.g., 40 nm or less), and sufficient resolution could not be obtained.

[0056] [Components of the resist composition] The components that the resist composition may contain are described in detail below.

[0057] <(A) Ionic compounds> The resist composition contains (A) an ionic compound (hereinafter also referred to as "compound (A)"). Compound (A) is typically a compound having an ionic group. More specifically, as an ionic group, it can be a compound having a cationic group and a counter anion, or a compound having an anionic group and a counter cation. Anionic groups include groups containing an anionic atom, while cationic groups include groups containing a cationic atom. Examples of cations include organic cations. Compound (A) may have both a cationic group and an anionic group in a single molecule.

[0058] The above ionic compound (A) is preferably a compound represented by the following general formula (6).

[0059] [ka]

[0060] In general formula (6), M3 + This represents an organic cation that is decomposed by irradiation with X-rays, electron beams, or extreme ultraviolet light. A3 - This represents an anionic group. R a represents a hydrogen atom or a monovalent organic group. L aThis represents a single bond or a divalent linking group.

[0061] R a The monovalent organic group is not particularly limited, but in a preferred embodiment, it has 1 to 30 carbon atoms, and more preferably 1 to 20 carbon atoms. R a The group is preferably an alkyl group, a cycloalkyl group, or an aryl group.

[0062] The alkyl group may be linear or branched, with C1 to C20 alkyl groups being preferred, C1 to C15 alkyl groups being more preferred, and C1 to C10 alkyl groups being even more preferred. The cycloalkyl group may be monocyclic or polycyclic, with cycloalkyl groups having 3 to 20 carbon atoms being preferred, cycloalkyl groups having 3 to 15 carbon atoms being more preferred, and cycloalkyl groups having 3 to 10 carbon atoms being even more preferred. The aryl group may be monocyclic or polycyclic, with a preferred aryl group having 6 to 20 carbon atoms, a more preferred aryl group having 6 to 15 carbon atoms, and an even more preferred aryl group having 6 to 10 carbon atoms.

[0063] A cycloalkyl group may contain heteroatoms as ring member atoms. Examples of heteroatoms are not particularly limited, but include nitrogen atoms, oxygen atoms, and the like. Furthermore, the cycloalkyl group may include a carbonyl bond (>C=O) as a ring member atom. The alkyl, cycloalkyl, and aryl groups described above may have further substituents. The further substituents are not particularly limited, but substituent T is preferred.

[0064] L a The divalent linking group as is is not particularly limited, but represents alkylene groups, cycloalkylene groups, aromatic groups, -O-, -CO-, -COO-, and groups formed by combining two or more of these. The alkylene group may be linear or branched, and preferably has 1 to 20 carbon atoms, and more preferably has 1 to 10 carbon atoms. The cycloalkylene group may be monocyclic or polycyclic, preferably having 3 to 20 carbon atoms, more preferably 3 to 10 carbon atoms. The aromatic group is a divalent aromatic group, preferably an aromatic group having 6 to 20 carbon atoms, more preferably 6 to 15 carbon atoms. The aromatic ring constituting the aromatic group is not particularly limited, and examples thereof include aromatic rings having 6 to 20 carbon atoms. Specifically, benzene rings, naphthalene rings, anthracene rings, thiophene rings, etc. can be mentioned. A benzene ring or a naphthalene ring is preferable, and a benzene ring is more preferable.

[0065] The alkylene group, cycloalkylene group, and aromatic group may further have a substituent. The further substituent is not particularly limited, and examples thereof include the above-mentioned substituent T, and a halogen atom is preferable. A3 - and R a may be bonded to each other to form a ring.

[0066] M3 + Although not particularly limited, an organic cation represented by the following general formula (ZaI) (cation (ZaI)) or an organic cation represented by the following general formula (ZaII) (cation (ZaII)) is preferable.

[0067]

Chemical formula

[0068] In the above general formula (ZaI), R 201 、R 202 、and R 203 each independently represents an organic group. R 201 、R 202 、and R 203 The number of carbon atoms of the organic group as is usually 1 to 30, preferably 1 to 20. Also, R 201 ~R 203Two of them may combine to form a ring structure, which may contain an oxygen atom, a sulfur atom, an ester group, an amide group, or a carbonyl group within the ring. R 201 ~R 203 Examples of the group formed by the combination of two of R 201 ~R 203 include an alkylene group (e.g., a butylene group and a pentylene group), and -CH2-CH2-O-CH2-CH2-.

[0069] Preferred embodiments of the organic cation in the general formula (ZaI) include the cation (ZaI-1), the cation (ZaI-2), the organic cation represented by the general formula (ZaI-3b) (cation (ZaI-3b)), and the organic cation represented by the general formula (ZaI-4b) (cation (ZaI-4b)) described below.

[0070] First, the cation (ZaI-1) will be described. The cation (ZaI-1) is an arylsulfonium cation in which at least one of R 201 ~R 203 in the above general formula (ZaI) is an aryl group. 201 ~R 203 The arylsulfonium cation may have all of R 201 ~R 203 as aryl groups, or a part of R 201 ~R 203 may be an aryl group and the rest may be an alkyl group or a cycloalkyl group. Also, one of R 201 ~R 203 may be an aryl group, and the remaining two of R 201 ~R 203 may combine to form a ring structure, which may contain an oxygen atom, a sulfur atom, an ester group, an amide group, or a carbonyl group within the ring. 201 ~R 203 Examples of the group formed by the combination of two of R 201 ~R 203 include an alkylene group (e.g., a butylene group, a pentylene group, or -CH2-CH2-O-CH2-CH2-) 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. 201 ~R 203 201 201 201 ~R 203 ​​​​​​​Examples of arylsulfonium cations include triarylsulfonium cations, diarylalkylsulfonium cations, aryldialkylsulfonium cations, diarylcycloalkylsulfonium cations, and aryldicycloalkylsulfonium cations.

[0071] The aryl group contained in the arylsulfonium cation is preferably a phenyl group or a naphthyl group, with the phenyl group being more preferred. 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. When the arylsulfonium cation has two or more aryl groups, the two or more aryl groups may be the same or different. The alkyl or cycloalkyl group that the arylsulfonium cation may optionally 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. Examples include methyl, ethyl, propyl, n-butyl, sec-butyl, t-butyl, cyclopropyl, cyclobutyl, and cyclohexyl groups.

[0072] R 201 ~R 203 The substituents that the aryl group, alkyl group, and cycloalkyl group may have are, independently, 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 14 carbon atoms), alkoxy groups (e.g., having 1 to 15 carbon atoms), cycloalkylalkoxy groups (e.g., having 1 to 15 carbon atoms), halogen atoms, hydroxyl groups, and phenylthio groups. The above substituents may have further substituents if possible. For example, the alkyl group may have a halogen atom as a substituent, forming a halogenated alkyl group such as a trifluoromethyl group.

[0073] Next, the cation (ZaI-2) will be described. The cation (ZaI-2) is the R in the formula (ZaI) 201 ~R 203 is a cation in which each independently represents an organic group having no aromatic ring. Here, the aromatic ring includes an aromatic ring containing a heteroatom. R 201 ~R 203 The organic group having no aromatic ring as ~ is generally having 1 to 30 carbon atoms, preferably 1 to 20 carbon atoms. R 201 ~R 203 Each is independently preferably an alkyl group, a cycloalkyl group, an allyl group, or a vinyl group, more preferably a linear or branched 2-oxoalkyl group, a 2-oxocycloalkyl group, or an alkoxycarbonylmethyl group, and even more preferably a linear or branched 2-oxoalkyl group.

[0074] R 201 ~R 203 Examples of the alkyl group and cycloalkyl group of ~ include a linear alkyl group having 1 to 10 carbon atoms or a branched alkyl group having 3 to 10 carbon atoms (for example, a methyl group, an ethyl group, a propyl group, a butyl group, and a pentyl group), and a cycloalkyl group having 3 to 10 carbon atoms (for example, a cyclopentyl group, a cyclohexyl group, and a norbornyl group). R 201 ~R 203 ~ may be further substituted by a halogen atom, an alkoxy group (for example, having 1 to 5 carbon atoms), a hydroxyl group, a cyano group, or a nitro group.

[0075] Next, the cation (ZaI-3b) will be described. The cation (ZaI-3b) is a cation represented by the following general formula (ZaI-3b).

[0076]

Chemical formula

[0077] In the general 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. R 6c and R 7c Each of these independently represents a hydrogen atom, an alkyl group (such as a t-butyl group), a cycloalkyl group, a halogen atom, a cyano group, or an aryl group. R 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.

[0078] 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 may be bonded together to form a ring, which may independently contain an oxygen atom, a sulfur atom, a ketone group, an ester bond, or an amide bond. Examples of the above-mentioned 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, with 4- to 8-membered rings being preferred, and 5- or 6-membered rings being more preferred.

[0079] R 1c ~R 5c Two or more of the following, R 6c and R 7c , and R x and R yExamples of groups formed by the bonding of these atoms include alkylene groups such as butylene and pentylene groups. The methylene group in this alkylene group may be substituted with a heteroatom such as an oxygen atom. R 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.

[0080] Next, we will explain the cation (ZaI-4b). The cation (ZaI-4b) is a cation represented by the following general formula (ZaI-4b).

[0081] [ka]

[0082] In the general formula (ZaI-4b), l represents an integer between 0 and 2. r represents an integer between 0 and 8. R 13 This represents a group having a hydrogen atom, a fluorine atom, a hydroxyl group, an alkyl group, an alkoxy group, an alkoxycarbonyl group, or a cycloalkyl group (which may be a cycloalkyl group itself or a group that partially contains a cycloalkyl group). These groups may have substituents. R 14 R represents a hydroxyl group, alkyl group, alkoxy group, alkoxycarbonyl group, alkylcarbonyl group, alkylsulfonyl group, cycloalkylsulfonyl group, or a group having 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 If multiple instances exist, each independently represents one of the above-mentioned groups, such as a hydroxyl group. R 15 Each of these independently represents an alkyl group, a cycloalkyl group, or a naphthyl group. These groups may have substituents. Two R 15They 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 skeleton may contain heteroatoms such as oxygen atoms or nitrogen atoms. In one embodiment, two R 15 It is preferable that the alkylene group is bonded to each other to form a ring structure.

[0083] In the general formula (ZaI-4b), R 13 , R 14 , and R 15 The alkyl group is linear or branched. The alkyl group preferably has 1 to 10 carbon atoms. Methyl, ethyl, n-butyl, or t-butyl groups are more preferred alkyl groups.

[0084] Next, we will explain the general formula (ZaII). In the general formula (ZaII), R 204 and R 205 Each of these independently represents an aryl group, an alkyl group, or a cycloalkyl group. R 204 and R 205 The aryl group is preferably a phenyl group or a naphthyl group, with the phenyl group being more preferred. 204 and R 205 The aryl group may be an aryl group having a heterocycle containing an oxygen atom, a nitrogen atom, or a sulfur atom, etc. Examples of heterocycle aryl group skeletons include pyrrole, furan, thiophene, indole, benzofuran, and benzothiophene. R 204 and R 205 The alkyl and cycloalkyl groups are preferably 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, or pentyl group), or cycloalkyl groups having 3 to 10 carbon atoms (e.g., cyclopentyl group, cyclohexyl group, or norbornyl group).

[0085] R 204 and R 205The 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.

[0086] A3 - The anionic group is a group having an anionic atom and is not particularly limited, but is preferably a group selected from the group consisting of groups represented by the following general formulas (B-1) to (B-14).

[0087] [ka]

[0088] In equations (B-1) to (B-14), * indicates a bonding position. In equations (B-1) to (B-5), and (B-12), R X1 Each of these independently represents a monovalent organic group. In formulas (B-7) and (B-11), R X2 Each of these independently represents a hydrogen atom, or a substituent other than a fluorine atom and a perfluoroalkyl group. The two R in formula (B-7) X2 They may be the same or different. In general formula (B-8), R XF1 R represents a hydrogen atom, a fluorine atom, or a perfluoroalkyl group. However, multiple Rs are not allowed. XF1 Of these, at least one represents a fluorine atom or a perfluoroalkyl group. The two R in formula (B-8) XF1 They may be the same or different. In general formula (B-9), R X3 R represents a hydrogen atom, a halogen atom, or a monovalent organic group. n1 represents an integer from 0 to 4. If n1 represents an integer from 2 to 4, multiple R X3They may be the same or different. In general formula (B-10), R XF2 This represents a fluorine atom or a perfluoroalkyl group. In general formula (B-14), R X4 R represents a hydrogen atom, a halogen atom, or a monovalent organic group. n2 represents an integer from 0 to 4. If n2 represents an integer from 2 to 4, multiple R X4 They may be the same or different.

[0089] In general formulas (B-1) to (B-5), and (B-12), R X1 Each of these independently represents a monovalent organic group. R X1 Preferred members include alkyl groups (which may be linear or branched; preferably with 1 to 15 carbon atoms), cycloalkyl groups (which may be monocyclic or polycyclic; preferably with 3 to 20 carbon atoms), or aryl groups (which may be monocyclic or polycyclic; preferably with 6 to 20 carbon atoms). In general formula (B-5), R X1 Inside, N - It is also preferable that the atom directly bonded is neither the carbon atom in -CO- nor the sulfur atom in -SO2-.

[0090] R X1 The cycloalkyl group in this can be monocyclic or polycyclic. R X1 Examples of cycloalkyl groups in this context include norbornyl and adamantyl groups. R X1 The substituents that the cycloalkyl group may have are not particularly limited, but include the substituent T mentioned above, and alkyl groups (which may be linear or branched; preferably having 1 to 5 carbon atoms) are preferred. R X1 One or more of the carbon atoms that are ring member atoms of the cycloalkyl group in the compound may be replaced by carbonyl carbon atoms. R X1 The number of carbon atoms in the alkyl group is preferably 1 to 10, and more preferably 1 to 5. R X1The substituents that the alkyl group in the alkyl group may have are not particularly limited, but include the substituent T mentioned above, and cycloalkyl groups, fluorine atoms, or cyano groups are preferred. Examples of cycloalkyl groups as substituents include R X1 The cycloalkyl groups described above are similarly listed when the given group is a cycloalkyl group. R X1 If the alkyl group in has a fluorine atom as the substituent, the alkyl group may be a perfluoroalkyl group. Also, R X1 The alkyl group in this may have one or more -CH2- groups substituted with carbonyl groups. R X1 In this case, the aryl group is preferably a benzene ring group. R X1 The substituents that the aryl group in the above are not particularly limited, but include the substituent T, and alkyl groups, fluorine atoms, or cyano groups are preferred. An example of an alkyl group as the substituent is R X1 The alkyl groups described above are similarly listed when the alkyl group is a cycloalkyl group.

[0091] In general formulas (B-7) and (B-11), R X2 Each of these independently represents a hydrogen atom, or a substituent other than a fluorine atom and a perfluoroalkyl group. The two R in formula (B-7) X2 They may be the same or different. R X2 The substituents other than the fluorine atom and perfluoroalkyl group represented by are preferably alkyl groups other than perfluoroalkyl groups, or cycloalkyl groups. Examples of the alkyl groups mentioned above include R X1 Examples include alkyl groups obtained by removing a perfluoroalkyl group from the alkyl group in the above. Furthermore, it is preferable that the alkyl group does not contain a fluorine atom. Examples of the above cycloalkyl groups include R X1 Examples include cycloalkyl groups in the above. Furthermore, it is preferable that the above cycloalkyl groups do not contain a fluorine atom.

[0092] In general formula (B-8), R XF1 R represents a hydrogen atom, a fluorine atom, or a perfluoroalkyl group. However, multiple Rs are not allowed. XF1 Of these, at least one represents a fluorine atom or a perfluoroalkyl group. The two R in formula (B-8) XF1 They may be the same or different. R XF1 The number of carbon atoms in the perfluoroalkyl group represented by is preferably 1 to 15, more preferably 1 to 10, and even more preferably 1 to 6.

[0093] In general formula (B-9), R X3 R represents a hydrogen atom, a halogen atom, or a monovalent organic group. X3 Examples of halogen atoms include fluorine, chlorine, bromine, and iodine atoms, with fluorine being the preferred choice. R X3 A monovalent organic group as R X1 It is similar to the monovalent organic group described as follows. n1 represents an integer between 0 and 4. n1 is preferably an integer between 0 and 2, and preferably 0 or 1. If n1 represents an integer between 2 and 4, multiple R X3 They may be the same or different.

[0094] In general formula (B-10), R XF2 This represents a fluorine atom or a perfluoroalkyl group. R XF2 The number of carbon atoms in the perfluoroalkyl group represented by is preferably 1 to 15, more preferably 1 to 10, and even more preferably 1 to 6.

[0095] In general formula (B-14), R X4 R represents a hydrogen atom, a halogen atom, or a monovalent organic group. X4 Examples of halogen atoms include fluorine, chlorine, bromine, and iodine atoms, with fluorine being the preferred choice. R X4 A monovalent organic group as RX1 It is similar to the monovalent organic group described as follows. n² represents an integer between 0 and 4. n2 is preferably an integer between 0 and 2, and preferably 0 or 1. If n2 represents an integer between 2 and 4, multiple R X4 They may be the same or different.

[0096] A3 in the compound represented by the above general formula (6) - However, it is preferable that the group is selected from the group consisting of groups represented by the above general formulas (B-6), (B-7), (B-8), (B-9), and (B-14).

[0097] In a preferred embodiment, it is preferable that the ionic compound (A) and the resin (B) are the same compound. That is, in this embodiment, the resin (B) has an ionic group, and the ionic group is one of those described in relation to the ionic compound (A). In the above embodiment, in a preferred embodiment, R in the compound represented by the general formula (6) is a It is preferable that the monovalent organic group is included in the main chain structure of the resin.

[0098] Furthermore, if the ionic compound (A) and the resin (B) are the same compound, the resist composition of the present invention may further contain the ionic compound (A).

[0099] The above-mentioned ionic compound (A) is preferably a compound that generates acid upon irradiation with X-rays, electron beams, or extreme ultraviolet light. The acid dissociation constant (Pka) of the acid generated by irradiation with X-rays, electron beams, or extreme ultraviolet light is not particularly limited, but -15.0 or higher is preferred. Furthermore, the acid dissociation constant (Pka) of the acid generated by irradiation with X-rays, electron beams, or extreme ultraviolet light is not particularly limited, but is preferably 6.5 or less.

[0100] The following are examples of ionic compounds (A), but the present invention is not limited to these.

[0101] [ka]

[0102] [ka]

[0103] The content of ionic compound (A) in the resist composition is not particularly limited, but in terms of achieving superior effects of the present invention, it is preferably 0.1 to 30% by mass, more preferably 0.5 to 25% by mass, and even more preferably 3.0 to 21.5% by mass, relative to the total solid content of the composition. The ionic compound (A) may be used alone or in combination of two or more types.

[0104] <(B) A resin having repeating units (b1) with interacting groups that interact with ionic groups in an ionic compound, and whose main chain decomposes upon irradiation with X-rays, electron beams, or extreme ultraviolet light.> The resist composition contains a resin (hereinafter also referred to as "resin (B)") which has repeating units (b1) having interacting groups that interact with the ionic groups in the (B) ionic compound, and whose main chain decomposes upon irradiation with X-rays, electron beams, or extreme ultraviolet light. Resin (B) is a resin whose main chain decomposes upon irradiation with X-rays, electron beams, or extreme ultraviolet light. Specifically, the main chain is cleaved and decomposed, resulting in a lower molecular weight, upon irradiation with X-rays, electron beams, or extreme ultraviolet light.

[0105] The resin (B) preferably has repeating units represented by the following general formula (1), which allows the main chain to be decomposed by irradiation with X-rays, electron beams, or extreme ultraviolet light.

[0106] [ka]

[0107] In general formula (1), X represents a halogen atom or an alkyl fluoride. R represents a hydrogen atom or a monovalent organic group.

[0108] The halogen atom X is not particularly limited, but examples include fluorine, chlorine, bromine, and iodine atoms. Fluorine, chlorine, or bromine atoms are preferred as halogen atoms, fluorine and chlorine atoms are more preferred, and chlorine atoms are particularly preferred. The alkyl fluoride group X is an alkyl group substituted with a fluorine atom, and examples include linear or branched alkyl groups having 1 to 10 carbon atoms substituted with a fluorine atom. A trifluoromethyl group is preferred as the alkyl fluoride group.

[0109] The monovalent organic group R is not particularly limited, but specific examples include alkyl groups, cycloalkyl groups, aryl groups, and aralkyl groups.

[0110] The alkyl group may be linear or branched, and preferably has 1 to 20 carbon atoms, and more preferably has 1 to 15 carbon atoms. The cycloalkyl group may be monocyclic or polycyclic, preferably having 3 to 20 carbon atoms, and more preferably 5 to 15 carbon atoms. The cycloalkyl group may also have heteroatoms such as oxygen atoms as ring members. The aryl group preferably has 6 to 20 carbon atoms, and more preferably 6 to 15 carbon atoms. The aralkyl group preferably has 7 to 21 carbon atoms, and more preferably has 7 to 16 carbon atoms.

[0111] The alkyl, cycloalkyl, aryl, and aralkyl groups may have further substituents. The further substituents are not particularly limited, but substituent T is preferred, and alkyl groups, halogen atoms, and carboxyl groups are more preferred.

[0112] If the alkyl group, cycloalkyl group, aryl group, and aralkyl group described above have further substituents that correspond to the interacting groups described below, then the repeating unit represented by the general formula (1) described above corresponds to the repeating unit (b1) described below.

[0113] The content of the repeating units represented by general formula (1) in resin (B) is preferably 10 to 50 mol%, more preferably 20 to 50 mol%, and particularly preferably 25 to 50 mol%, relative to the total repeating units of resin (B).

[0114] In resin (B), the repeating unit represented by general formula (1) may be used alone or in combination of two or more types.

[0115] The following are examples of repeating units that correspond to the repeating unit represented by general formula (1), but the present invention is not limited to these.

[0116] [ka]

[0117] (A repeating unit having an interacting group that interacts with an ionic group in an ionic compound (b1)) The resin (B) has repeating units (b1) having interacting groups that interact with the ionic groups in the above-mentioned ionic compound. The interacting group described above interacts with the ionic group in the ionic compound. Specifically, as stated above, the interacting group is thought to interact with the ionic group to form an associated structure similar to a salt.

[0118] Resin (B) preferably has at least one of the group consisting of hydroxyl group, carboxyl group, carbonate group, carbonyl group, amino group, amide group, thiol group, alkoxycarbonyl group, alkyloxysulfonyl group, sulfo group, sulfonyl group, and alkylsulfonyl group as the interacting group, and more preferably has at least one of the group consisting of hydroxyl group, amino group, amide group, and thiol group.

[0119] Examples of amino groups include -NH2 or -NHR1 (where R1 represents an alkyl group having 1 to 5 carbon atoms). Examples of amide groups include -C(=O)-NHR2 (where R2 is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms). A thiol group is represented by the -SH denomination.

[0120] The alkyl group in the alkoxycarbonyl group may be linear or branched, and preferably has 1 to 5 carbon atoms, and more preferably has 1 to 3 carbon atoms. The alkyl group in the alkyloxysulfonyl group may be linear or branched, and preferably has 1 to 5 carbon atoms, and more preferably has 1 to 3 carbon atoms. The alkyl group in the alkylsulfonyl group may be linear or branched, and preferably has 1 to 5 carbon atoms, and more preferably has 1 to 3 carbon atoms.

[0121] In one preferred embodiment, the interacting group is preferably a group having proton donor properties. Proton donor properties are exhibited by having a free hydrogen atom. Furthermore, in a preferred embodiment, the interacting group is preferably a group having proton-accepting properties. Proton-accepting properties are exhibited by having substituents with lone pairs of electrons, such as fluorine, nitrogen, or oxygen atoms, which have relatively high electronegativity.

[0122] The repeating unit (b1) described above is preferably a repeating unit represented by the following general formula (3).

[0123] [ka]

[0124] In general formula (3), A represents a hydrogen atom, a halogen atom, or an alkyl group. L represents a divalent linking group. B represents a single bond or a (m+1) valence linking group. C represents the interacting group mentioned above. m represents an integer greater than or equal to 1. If m represents an integer greater than or equal to 2, then multiple Cs may be the same or different.

[0125] The halogen atom A is not particularly limited, but examples include fluorine, chlorine, bromine, and iodine atoms. The alkyl group A is not particularly limited, but may be linear or branched, and preferably has 1 to 5 carbon atoms, and more preferably has 1 to 2 carbon atoms.

[0126] The divalent linking group L is not particularly limited, but represents alkylene groups, cycloalkylene groups, aromatic groups, -CO-, -COO-, and groups formed by combining two or more of these. The alkylene group may be linear or branched, and preferably has 1 to 20 carbon atoms, and more preferably has 1 to 10 carbon atoms. The cycloalkylene group may be monocyclic or polycyclic, preferably having 3 to 20 carbon atoms, and more preferably having 3 to 10 carbon atoms. The aromatic group is a divalent aromatic group, preferably having 6 to 20 carbon atoms, and more preferably having 6 to 15 carbon atoms. The aromatic ring constituting the aromatic group is not particularly limited, but examples include aromatic rings having 6 to 20 carbon atoms, specifically benzene rings, naphthalene rings, anthracene rings, thiophene rings, etc. A benzene ring or a naphthalene ring is preferred, and a benzene ring is more preferred.

[0127] The alkylene group, cycloalkylene group, and aromatic group may have further substituents. The further substituents are not particularly limited, but substituent T is preferred.

[0128] B represents a single bond or a (m+1) valence linking group. As an example of a (m+1) valence linking group of B, one can refer to a group obtained by removing (m-1) hydrogen atoms from the divalent linking group of L described above.

[0129] C represents the interacting group described above. The interacting group of C is not particularly limited as long as it is a group that interacts with the ionic group in the ionic compound, but for example, at least one of the group consisting of hydroxyl group, carboxyl group, carbonate group, carbonyl group, amino group, amide group, thiol group, alkoxycarbonyl group, alkyloxysulfonyl group, sulfo group, sulfonyl group, and alkylsulfonyl group is preferred, and at least one of the group consisting of hydroxyl group, amino group, amide group, and thiol group is more preferred. Examples of amino groups include -NH2 or -NHR1 (where R1 represents an alkyl group having 1 to 5 carbon atoms). Examples of amide groups include -C(=O)-NHR2 (where R2 is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms). A thiol group is represented by the -SH denomination.

[0130] The alkyl group in the alkoxycarbonyl group may be linear or branched, and preferably has 1 to 5 carbon atoms, and more preferably has 1 to 3 carbon atoms. The alkyl group in the alkyloxysulfonyl group may be linear or branched, and preferably has 1 to 5 carbon atoms, and more preferably has 1 to 3 carbon atoms. The alkyl group in the alkylsulfonyl group may be linear or branched, and preferably has 1 to 5 carbon atoms, and more preferably has 1 to 3 carbon atoms.

[0131] m represents an integer greater than or equal to 1. While there is no particular upper limit to m, it is preferably 5 or less. m is more preferably an integer between 1 and 2. If m represents an integer greater than or equal to 2, then multiple Cs may be the same or different.

[0132] The repeating unit (b1) described above is preferably a repeating unit represented by the following general formula (2).

[0133] [ka]

[0134] In general formula (2), R' represents a hydrogen atom or an alkyl group. C1 represents the interacting group described above. j represents either 0 or 1. k represents either 0 or 1. n represents an integer from 1 to 9. If n represents an integer between 2 and 9, then multiple C1s may be the same or different.

[0135] The alkyl group as R' is not particularly limited, but may be linear or branched, and preferably has 1 to 5 carbon atoms, and more preferably has 1 to 2 carbon atoms. The interacting group described as C1 is the same as the interacting group described as C.

[0136] n is preferably an integer between 1 and 3, and more preferably 1 or 2. If n represents an integer between 2 and 9, then multiple C1s may be the same or different.

[0137] The content of repeating units (b1) in resin (B) is preferably 1 to 50 mol%, more preferably 1 to 40 mol%, and particularly preferably 1 to 30 mol%, relative to the total repeating units of resin (B). In a preferred embodiment, the content of repeating units (b1) in resin (B) is preferably 20 mol% or less relative to the total repeating units of resin (B).

[0138] In resin (B), the repeating unit (b1) may be used alone or in combination of two or more types.

[0139] The following are examples of repeating units that correspond to the repeating unit (b1), but the present invention is not limited to these.

[0140] [ka]

[0141] (Other repeating units) The resin (B) may include repeating units other than the repeating unit (b1) represented by the general formula (1) above.

[0142] In a preferred embodiment, it is preferable that the ionic compound (A) and the resin (B) are the same compound. That is, in this embodiment, the resin (B) has an ionic group, and the ionic group is one of those described in relation to the ionic compound (A).

[0143] In the above embodiment, the resin (B) may have at least one repeating unit selected from the group consisting of repeating units represented by the following general formula (4) and repeating units represented by the following general formula (5).

[0144] (At least one repeating unit selected from the group consisting of repeating units represented by general formula (4) and repeating units represented by general formula (5)) <Repeating unit represented by general formula (4)>

[0145] [ka]

[0146] In general formula (4), A1 represents a hydrogen atom, a halogen atom, or an alkyl group. L1 represents a single-bonded, divalent linking group. B1 represents a single bond or a (p+1) valence linking group. D1 represents an anionic group. E1 represents a cation. p represents an integer between 1 and 2. If p represents an integer of 2, then multiple D1s and multiple E1s may be the same or different.

[0147] The halogen atom as A1 is not particularly limited, but examples include fluorine, chlorine, bromine, and iodine. The alkyl group A1 is not particularly limited, but may be linear or branched, and preferably has 1 to 5 carbon atoms, and more preferably has 1 to 2 carbon atoms.

[0148] The divalent linking group as L1 is not particularly limited, but can represent alkylene groups, cycloalkylene groups, aromatic groups, -CO-, -COO-, and groups formed by combining two or more of these. The alkylene group may be linear or branched, and preferably has 1 to 20 carbon atoms, and more preferably has 1 to 10 carbon atoms. The cycloalkylene group may be monocyclic or polycyclic, preferably having 3 to 20 carbon atoms, and more preferably having 3 to 10 carbon atoms. The aromatic group is a divalent aromatic group, preferably having 6 to 20 carbon atoms, and more preferably having 6 to 15 carbon atoms. The aromatic ring constituting the aromatic group is not particularly limited, but examples include aromatic rings having 6 to 20 carbon atoms, specifically benzene rings, naphthalene rings, anthracene rings, thiophene rings, etc. A benzene ring or a naphthalene ring is preferred, and a benzene ring is more preferred.

[0149] The alkylene group, cycloalkylene group, and aromatic group may have further substituents. The further substituents are not particularly limited, but substituent T is preferred.

[0150] B1 represents a single bond or a (p+1) valence linking group. As an example of a (p+1) valence linking group of B1, one can refer to a group obtained by removing (p-1) hydrogen atoms from the divalent linking group L1 described above.

[0151] D1 represents an anionic group. The anionic group D1 is a group having an anionic atom and is not particularly limited, but it is preferably a group selected from the group consisting of groups represented by the general formulas (B-1) to (B-14) above. The anionic group of D1 is preferably a group selected from the group consisting of the groups represented by the general formulas (B-6), (B-7), (B-8), (B-9), and (B-14).

[0152] E1 represents a cation. (E1)p means that there are p cations E1. The cation as E1 is preferably an organic cation that decomposes upon irradiation with X-rays, electron beams, or extreme ultraviolet light, and is preferably an organic cation represented by the above general formula (ZaI) (cation(ZaI)) or an organic cation represented by the above general formula (ZaII) (cation(ZaII)).

[0153] p represents an integer between 1 and 2. If p represents an integer of 2, then multiple D1s and multiple E1s may be the same or different.

[0154] The content of the repeating units represented by general formula (4) in resin (B) is preferably 1 to 20 mol%, more preferably 1 to 15 mol%, and particularly preferably 1 to 10 mol%, relative to the total repeating units of resin (B).

[0155] In resin (B), the repeating unit represented by general formula (4) may be used alone or in combination of two or more types.

[0156] The following are examples of repeating units that correspond to the repeating unit represented by general formula (4), but the present invention is not limited to these.

[0157] [ka]

[0158] <Repeating unit represented by general formula (5)> The resin (B) may have at least one repeating unit selected from the group consisting of repeating units represented by general formula (4) and repeating units represented by general formula (5), which is the repeating unit represented by the following general formula (5).

[0159] [ka]

[0160] In general formula (5), A2 represents a hydrogen atom, a halogen atom, or an alkyl group. L2 represents a divalent linking group. B2 represents a single bond or a (q+1) valence linking group. D2 represents an anion. E2 represents a cationic group. q represents an integer between 1 and 2. If q represents an integer of 2, then multiple D2s and multiple E2s may be the same or different.

[0161] The halogen atom as A2 is not particularly limited, but examples include fluorine, chlorine, bromine, and iodine. The alkyl group as A2 is not particularly limited, but may be linear or branched, and preferably has 1 to 5 carbon atoms, and more preferably has 1 to 2 carbon atoms.

[0162] The divalent linking group as L2 is not particularly limited, but represents alkylene groups, cycloalkylene groups, aromatic groups, -CO-, -COO-, and groups formed by combining two or more of these. The alkylene group may be linear or branched, and preferably has 1 to 20 carbon atoms, and more preferably has 1 to 10 carbon atoms. The cycloalkylene group may be monocyclic or polycyclic, preferably having 3 to 20 carbon atoms, and more preferably having 3 to 10 carbon atoms. The aromatic group is a divalent aromatic group, preferably having 6 to 20 carbon atoms, and more preferably having 6 to 15 carbon atoms. The aromatic ring constituting the aromatic group is not particularly limited, but examples include aromatic rings having 6 to 20 carbon atoms, specifically benzene rings, naphthalene rings, anthracene rings, thiophene rings, etc. A benzene ring or a naphthalene ring is preferred, and a benzene ring is more preferred.

[0163] The alkylene group, cycloalkylene group, and aromatic group may have further substituents. The further substituents are not particularly limited, but substituent T is preferred.

[0164] B2 represents a single bond or a (q+1) valence linking group. As an example of a (q+1) valence linking group of B2, one can refer to a group obtained by removing (q-1) hydrogen atoms from the divalent linking group L2 described above.

[0165] D2 represents an anion. (D2)q means that it represents q anions D2. While there are no particular limitations on the D2 anion, an anion represented by the following general formula (DA) is preferred.

[0166] [ka]

[0167] In the general formula (DA), A 31 - This represents an anionic group. R a1 represents a hydrogen atom or a monovalent organic group. L a1 This represents a single bond or a divalent linking group.

[0168] A 31 - represents an anionic group. 31 - The anionic group is a group having an anionic atom and is not particularly limited, but is preferably a group selected from the group consisting of groups represented by the general formulas (B-1) to (B-14) above.

[0169] R a1 The monovalent organic group is not particularly limited, but generally has 1 to 30 carbon atoms, with 1 to 20 carbon atoms being preferred. R a1 The group is preferably an alkyl group, a cycloalkyl group, or an aryl group.

[0170] The alkyl group may be linear or branched, with C1 to C20 alkyl groups being preferred, C1 to C15 alkyl groups being more preferred, and C1 to C10 alkyl groups being even more preferred. The cycloalkyl group may be monocyclic or polycyclic, with cycloalkyl groups having 3 to 20 carbon atoms being preferred, cycloalkyl groups having 3 to 15 carbon atoms being more preferred, and cycloalkyl groups having 3 to 10 carbon atoms being even more preferred. The aryl group may be monocyclic or polycyclic, with a preferred aryl group having 6 to 20 carbon atoms, a more preferred aryl group having 6 to 15 carbon atoms, and an even more preferred aryl group having 6 to 10 carbon atoms.

[0171] A cycloalkyl group may contain heteroatoms as ring member atoms. Examples of heteroatoms are not particularly limited, but include nitrogen atoms, oxygen atoms, and the like. Furthermore, the cycloalkyl group may include a carbonyl bond (>C=O) as a ring member atom. The alkyl, cycloalkyl, and aryl groups described above may have further substituents. The further substituents are not particularly limited, but substituent T is preferred.

[0172] L a1 The divalent linking group as is is not particularly limited, but represents alkylene groups, cycloalkylene groups, aromatic groups, -O-, -CO-, -COO-, and groups formed by combining two or more of these. The alkylene group may be linear or branched, and preferably has 1 to 20 carbon atoms, and more preferably has 1 to 10 carbon atoms. The cycloalkylene group may be monocyclic or polycyclic, preferably having 3 to 20 carbon atoms, and more preferably having 3 to 10 carbon atoms. The aromatic group is a divalent aromatic group, preferably having 6 to 20 carbon atoms, and more preferably having 6 to 15 carbon atoms. The aromatic ring constituting the aromatic group is not particularly limited, but examples include aromatic rings having 6 to 20 carbon atoms, specifically benzene rings, naphthalene rings, anthracene rings, thiophene rings, etc. A benzene ring or a naphthalene ring is preferred, and a benzene ring is more preferred.

[0173] The alkylene group, cycloalkylene group, and aromatic group may have further substituents. The further substituents are not particularly limited, but examples include the substituent T, and halogen atoms are preferred. A 31 - Ra1 may bond to each other to form a ring.

[0174] E2 represents a cationic group. The cationic group as E2 is a group having a cationic atom, and is preferably an organic cationic group that decomposes upon irradiation with X-rays, electron beams, or extreme ultraviolet light, and is preferably an organic cationic group represented by the following general formula (ZBI) or an organic cationic group represented by the following general formula (ZBII).

[0175] [ka]

[0176] In the above general formula (ZBI), R 301 , and R 302 Each of these independently represents an organic group. R 301 , and R 302 The number of carbon atoms in the organic group is usually 1 to 30, and preferably 1 to 20. R 303 This represents a divalent linking group. Also, R 301 ~R 303 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. 301 ~R 303 Examples of groups formed by the bonding of two of these include alkylene groups (e.g., butylene and pentylene groups) and -CH2-CH2-O-CH2-CH2-.

[0177] R 301 , and R 302 The organic group used is not particularly limited, but is preferably an alkyl group, a cycloalkyl group, or an aryl group. The aryl group is preferably a phenyl group or a naphthyl group, and more preferably a phenyl group. The aryl group may also be an aryl group having a heterocyclic structure containing an oxygen atom, a nitrogen atom, or a sulfur atom. Examples of heterocyclic structures include pyrrole residues, furan residues, thiophene residues, indole residues, benzofuran residues, and benzothiophene residues. The alkyl or cycloalkyl group 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. Examples include methyl group, ethyl group, propyl group, n-butyl group, sec-butyl group, t-butyl group, cyclopropyl group, cyclobutyl group, and cyclohexyl group.

[0178] R 301 ~R 302 The substituents that the aryl group, alkyl group, and cycloalkyl group may have are, independently, 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 14 carbon atoms), alkoxy groups (e.g., having 1 to 15 carbon atoms), cycloalkylalkoxy groups (e.g., having 1 to 15 carbon atoms), halogen atoms, hydroxyl groups, and phenylthio groups.

[0179] R 303 The divalent linking group as is is not particularly limited, but represents alkylene groups, cycloalkylene groups, aromatic groups, and groups formed by combining two or more of these. The alkylene group may be linear or branched, and preferably has 1 to 20 carbon atoms, and more preferably has 1 to 10 carbon atoms. The cycloalkylene group may be monocyclic or polycyclic, preferably having 3 to 20 carbon atoms, and more preferably having 3 to 10 carbon atoms. The aromatic group is a divalent aromatic group, preferably having 6 to 20 carbon atoms, and more preferably having 6 to 15 carbon atoms. The aromatic ring constituting the aromatic group is not particularly limited, but examples include aromatic rings having 6 to 20 carbon atoms, specifically benzene rings, naphthalene rings, anthracene rings, thiophene rings, etc. A benzene ring or a naphthalene ring is preferred, and a benzene ring is more preferred.

[0180] The alkylene group, cycloalkylene group, and aromatic group may have further substituents. The further substituents are not particularly limited, but substituent T is preferred.

[0181] In the above general formula (ZBII), R 304 This represents an aryl group, an alkyl group, or a cycloalkyl group. R 305 This represents a divalent linking group. R 304 The aryl group is preferably a phenyl group or a naphthyl group, with the phenyl group being more preferred. 304 The aryl group may be an aryl group having a heterocycle containing an oxygen atom, a nitrogen atom, or a sulfur atom, etc. Examples of heterocycle aryl group skeletons include pyrrole, furan, thiophene, indole, benzofuran, and benzothiophene. R 304 The alkyl and cycloalkyl groups are preferably 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, or pentyl group), or cycloalkyl groups having 3 to 10 carbon atoms (e.g., cyclopentyl group, cyclohexyl group, or norbornyl group).

[0182] R 304 The aryl group, alkyl group, and cycloalkyl group may each independently have substituents. 304 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.

[0183] R 305 The divalent linking group as is is not particularly limited, but represents alkylene groups, cycloalkylene groups, aromatic groups, and groups formed by combining two or more of these. The alkylene group may be linear or branched, and preferably has 1 to 20 carbon atoms, and more preferably has 1 to 10 carbon atoms. The cycloalkylene group may be monocyclic or polycyclic, preferably having 3 to 20 carbon atoms, and more preferably having 3 to 10 carbon atoms. The aromatic group is a divalent aromatic group, preferably having 6 to 20 carbon atoms, and more preferably having 6 to 15 carbon atoms. The aromatic ring constituting the aromatic group is not particularly limited, but examples include aromatic rings having 6 to 20 carbon atoms, specifically benzene rings, naphthalene rings, anthracene rings, thiophene rings, etc. A benzene ring or a naphthalene ring is preferred, and a benzene ring is more preferred.

[0184] The alkylene group, cycloalkylene group, and aromatic group may have further substituents. The further substituents are not particularly limited, but substituent T is preferred.

[0185] q represents an integer between 1 and 2. If q represents an integer of 2, then multiple D2s and multiple E2s may be the same or different.

[0186] The content of the repeating units represented by general formula (5) in resin (B) is preferably 1 to 20 mol%, more preferably 1 to 15 mol%, and particularly preferably 1 to 10 mol%, relative to the total repeating units of resin (B).

[0187] In resin (B), the repeating unit represented by general formula (5) may be used alone or in combination of two or more types.

[0188] The following are examples of repeating units that correspond to the repeating unit represented by general formula (5), but the present invention is not limited to these.

[0189] [ka]

[0190] Preferably, the resin (B) has a repeating unit represented by the general formula (3) as the repeating unit (b1), and at least one repeating unit selected from the group consisting of the repeating unit represented by the general formula (4) and the repeating unit represented by the general formula (5).

[0191] In another preferred embodiment, the resin (B) comprises a repeating unit represented by the general formula (2) as the repeating unit (b1), and at least one repeating unit selected from the group consisting of the repeating unit represented by the general formula (4) and the repeating unit represented by the general formula (5).

[0192] If the ionic compound (A) and the resin (B) are the same compound, the resist composition of the present invention may further contain resin (B).

[0193] (The repeating unit represented by general formula (7)) The resin (B) may have repeating units represented by the following general formula (7) (except for those equivalent to the repeating units represented by the above general formula (2)).

[0194] [ka]

[0195] In general formula (7), R 31 represents a hydrogen atom or an alkyl group. R 32 This represents a monovalent organic group. 's' represents either 0 or 1. t represents either 0 or 1. w represents an integer from 0 to 9. If w represents an integer from 2 to 9, multiple R 32 They may be the same or different.

[0196] R 31The alkyl group is not particularly limited, but may be linear or branched, and preferably has 1 to 5 carbon atoms, and more preferably has 1 to 2 carbon atoms. R 32 A monovalent organic group as R X1 It is similar to the monovalent organic group described as follows.

[0197] w is preferably an integer between 1 and 3, and more preferably 1 or 2. If w represents an integer from 2 to 9, multiple R 32 They may be the same or different.

[0198] The content of the repeating units represented by general formula (7) in resin (B) is preferably 1 to 50 mol%, more preferably 20 to 50 mol%, and particularly preferably 30 to 50 mol%, relative to the total repeating units of resin (B).

[0199] In resin (B), the repeating unit represented by general formula (7) may be used alone or in combination of two or more types.

[0200] (Repeating unit with acid-degradable group) The resin (B) may further contain repeating units having acid-degradable groups. Acid-degradable groups preferably have a structure in which a polar group is protected by a leaving group that is removed by the action of an acid. Examples of polar groups include acidic groups such as carboxyl groups, phenolic hydroxyl groups, fluorinated alcohol groups, sulfonic 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 (typically groups that dissociate in a 2.38% by mass aqueous solution of tetramethylammonium hydroxide), as well as alcoholic hydroxyl groups.

[0201] Alcoholic hydroxyl groups refer to hydroxyl groups bonded to a hydrocarbon group, excluding hydroxyl groups directly bonded to an aromatic ring (phenolic hydroxyl groups), and exclude aliphatic alcohols (e.g., hexafluoroisopropanol groups) in which the α-position of the hydroxyl group is substituted with an electron-withdrawing group such as a fluorine atom. Preferably, the alcoholic hydroxyl group has a pKa (acid dissociation constant) of 12 or more and 20 or less.

[0202] Among these, carboxyl groups, phenolic hydroxyl groups, fluorinated alcohol groups (preferably hexafluoroisopropanol groups), or sulfonic acid groups are preferred as polar groups.

[0203] Examples of groups that are eliminated by the action of an acid (leaving groups) include those represented by formulas (Y1) to (Y4). Formula (Y1):-C(Rx1)(Rx2)(Rx3) Formula (Y2):-C(=O)OC(Rx1)(Rx2)(Rx3) Formula (Y3):-C(R 36 )(R 37 )(OR 38 ) Formula (Y4):-C(Rn)(H)(Ar)

[0204] In formulas (Y1) and (Y2), Rx1 to Rx3 each independently represent an alkyl group (linear or branched), a cycloalkyl group (monocyclic or polycyclic), or an aryl group (monocyclic or polycyclic). In particular, it is preferable that Rx1 to Rx3 each independently represent a linear or branched alkyl group, and it is more preferable that Rx1 to Rx3 each independently represent a linear alkyl group. Two of Rx1 to Rx3 may combine to form a monocycle or polycycle. The alkyl groups Rx1 to Rx3 are not particularly limited, but include alkyl groups having 1 to 20 carbon atoms, with alkyl groups having 1 to 4 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, and t-butyl groups being preferred. The cycloalkyl groups Rx1 to Rx3 are not particularly limited, but include cycloalkyl groups having 3 to 20 carbon atoms, with monocyclic cycloalkyl groups such as cyclopentyl and cyclohexyl groups, and polycyclic cycloalkyl groups such as norbornyl, tetracyclodecanyl, tetracyclododecanyl, and adamantyl groups being preferred. The aryl groups Rx1 to Rx3 are preferably aryl groups having 6 to 14 carbon atoms, such as phenyl groups, naphthyl groups, and anthyl groups. Alkyl, cycloalkyl, and aryl groups may have substituents.

[0205] The cycloalkyl group formed by the bonding of two Rx1 to Rx3 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 monocyclic cycloalkyl groups having 5 to 6 carbon atoms being more preferred. The cycloalkyl group formed by the bonding of two Rx1 to Rx3 may, for example, have one of the methylene groups constituting the ring replaced by a heteroatom such as an oxygen atom, or a group having a heteroatom such as a carbonyl group. The cycloalkyl group formed by the bonding of two Rx1 to Rx3 may have substituents.

[0206] In formula (Y3), 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, and alkenyl groups. 36It is also preferable that it be a hydrogen atom.

[0207] In formula (Y4), Ar represents an aromatic ring group. Rn represents an alkyl group, a cycloalkyl group, or an aryl group. Rn and Ar may be bonded to each other to form a non-aromatic ring. Ar is more preferably an aryl group.

[0208] The content of repeating units having acid-degradable groups in resin (B) is preferably 10 mol% or less, more preferably 5 mol% or less, relative to the total repeating units of resin (B), and even more preferably resin (B) is substantially free of repeating units having acid-degradable groups. Here, substantially free of repeating units having acid-degradable groups means that the content of repeating units having acid-degradable groups is 3 mol% or less relative to the total repeating units of resin (B).

[0209] The resin (B) may contain further repeating units, to the extent that it does not impair the effects of the present invention.

[0210] Resin (B) can be synthesized according to conventional methods (e.g., radical polymerization). According to the GPC method, the weight-average molecular weight of resin (B), expressed as polystyrene equivalent, is preferably 1,000 to 200,000, more preferably 10,000 to 100,000, and even more preferably 20,000 to 100,000. Setting the weight-average molecular weight of resin (B) to 1,000 to 200,000 prevents deterioration of dry etching resistance, and further prevents deterioration of developability and deterioration of film-forming ability due to increased viscosity. In addition, the larger the weight-average molecular weight of resin (B), the greater the change in molecular weight when the main chain is decomposed by irradiation with X-rays, electron beams, or extreme ultraviolet light, resulting in a pattern with good resolution. The degree of dispersion (molecular weight distribution) of resin (B) is usually 1 to 5, preferably 1 to 3, more preferably 1.2 to 3.0, and even more preferably 1.2 to 2.0. The lower the degree of dispersion, the better the resolution and resist shape, and furthermore, the smoother the sidewalls of the resist pattern and the better the roughness.

[0211] In a resist composition, it is preferable that the ratio of the number of moles of the ionic compound (A) to the number of moles of the interacting groups in the resin (B) ((number of moles of interacting groups in resin (B)) / (number of moles of ionic compound (A))) is 1 or greater. That is, it is preferable that the number of moles of the interacting groups in resin (B) is greater than the number of moles of the ionic compound (A), or that the number of moles of the ionic compound (A) and the number of moles of the interacting groups in resin (B) are the same.

[0212] In the resist composition, the content of resin (B) is preferably 50 to 99.9% by mass, and more preferably 60 to 99.0% by mass, of the total solid content. Furthermore, resin (B) may be used alone or two or more types may be used.

[0213] <Solvent> The resist composition may contain a solvent. The solvent preferably contains at least one selected from the group consisting of (M1) propylene glycol monoalkyl ether carboxylate (such as propylene glycol monomethyl ether acetate (PGMEA)) and (M2) propylene glycol monoalkyl ether (such as propylene glycol monomethyl ether (PGME) or propylene glycol monoethyl ether (PGEE)), lactate ester (such as ethyl lactate), acetate ester, alkoxypropionic acid ester, linear ketone, cyclic ketone (such as 2-heptanone, cyclohexanone, or cyclopentanone), lactone (such as γ-butyrolactone), and alkylene carbonate (such as propylene carbonate). The solvent may further contain components other than components (M1) and (M2).

[0214] The solvent preferably contains component (M1). More preferably, the solvent consists substantially only of component (M1), or is a mixed solvent of component (M1) and other components. In the latter case, it is even more preferable that the solvent contains both component (M1) and component (M2).

[0215] The mass ratio (M1 / M2) of component (M1) to component (M2) is preferably "100 / 0" to "0 / 100", more preferably "100 / 0" to "15 / 85", even more preferably "100 / 0" to "40 / 60", and particularly preferably "100 / 0" to "60 / 40".

[0216] As described above, the solvent may further contain components other than components (M1) and (M2). In this case, the content of components other than components (M1) and (M2) is preferably 5 to 30% by mass relative to the total amount of the solvent.

[0217] 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. This further improves the coatability of the resist composition. Note that "solids" refers to all components other than the solvent. "Total solids" refers to the total mass of the components of the resist composition excluding the solvent. Furthermore, "solids" refers to the components excluding the solvent, and may be solid or liquid at 25°C, for example.

[0218] <Acid diffusion control agent> The resist composition may further contain an acid diffusion control agent. The acid diffusion control agent acts, for example, as a quencher that traps the acid generated from the ionic compound (A) and plays a role in controlling the diffusion phenomenon of the acid in the resist film. The acid diffusion control agent may be, for example, a basic compound. If the resist composition contains an acid diffusion control agent, the amount of acid diffusion control agent used is preferably 0.0001 to 2% by mass, and more preferably 0.0005 to 1% by mass, relative to the total solid content of the resist composition.

[0219] <Surfactants> The resist composition may or may not contain a surfactant. The surfactant is preferably a fluorine-based and / or silicone-based surfactant (fluorine-based surfactant, silicone-based surfactant, or surfactant having both a fluorine atom and a silicon atom). These surfactants may be used individually or in combination of two or more. If the resist composition contains a surfactant, the amount of surfactant used is preferably 0.0001 to 2% by mass, and more preferably 0.0005 to 1% by mass, relative to the total solid content of the resist composition.

[0220] [Resist film] The present invention also relates to a resist film (also referred to as "resist film") formed by the resist composition of the present invention. Such a film is formed, for example, by coating the composition of the present invention onto a support such as a substrate. The thickness of this film is preferably 0.02 to 0.1 μm. The coating is applied to the substrate by various methods, including spin coating, roll coating, flow coating, dip coating, spray coating, and doctor coating. Spin coating is preferred, with a preferred rotation speed of 1000 to 3000 rpm (rotations per minute). The coated film is pre-baked at 60 to 150°C for 1 to 20 minutes, preferably at 80 to 120°C for 1 to 10 minutes, to form a thin film. The materials constituting the substrate to be processed and its outermost layer can, for example, be silicon wafers in the case of semiconductor wafers. Examples of materials for the outermost layer include Si, SiO2, SiN, SiON, TiN, WSi, BPSG, SOG, and organic anti-reflective coatings.

[0221] [Pattern formation method] The procedure for pattern formation using the above-mentioned resist composition is not particularly limited, but it is preferable to have the following steps. Step 1: A step of forming a resist film on a substrate using a resist composition. Step 2: Exposing the resist film with X-rays, electron beams (EB), or extreme ultraviolet (EUV) light. Step 3: A process to develop the exposed resist film using a developer solution and form a pattern. The following details the steps for each of the above processes.

[0222] <Step 1: Resist film formation process> Step 1 is the process of forming a resist film on a substrate using a resist composition. The definition of the resist composition is as described above.

[0223] One method for forming a resist film on a substrate using a resist composition is to coat the resist composition onto the substrate. Furthermore, it is preferable to filter the resist composition before coating, if necessary. The pore size of the filter is preferably 0.1 μm or less, more preferably 0.05 μm or less, and even more preferably 0.03 μm or less. The filter is preferably made of polytetrafluoroethylene, polyethylene, or nylon.

[0224] The resist composition can be applied to a substrate (e.g., silicon, silicon dioxide coated) 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 rotation speed when spin coating using a spinner is preferably 1000 to 3000 rpm. 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) may be formed beneath the resist film.

[0225] As for drying methods, one example is drying by heating. Heating can be carried out using means provided in a normal exposure machine and / or developing machine, or it may be carried out using a hot plate or the like. The heating temperature is preferably 80 to 150°C, more preferably 80 to 140°C, and even more preferably 80 to 130°C. The heating time is preferably 30 to 1000 seconds, more preferably 60 to 800 seconds, and even more preferably 60 to 600 seconds.

[0226] The thickness of the resist film is not particularly limited, but 10 to 65 nm is preferred, and 10 to 50 nm is more preferred, as it allows for the formation of finer, more precise patterns.

[0227] Alternatively, a topcoat may be formed on the upper layer of the resist film using a topcoat composition. Preferably, the topcoat composition does not need to be mixed with the resist film and can be uniformly applied to the upper layer of the resist film. Furthermore, it is preferable to dry the resist film before forming the topcoat. Next, the topcoat composition can be applied to the obtained resist film by means similar to the resist film formation method described above, and then dried to form the topcoat. The thickness of the topcoat is preferably 10 to 200 nm, more preferably 20 to 100 nm, and even more preferably 40 to 80 nm. The top coat is not particularly limited, and conventionally known top coats can be formed by conventionally known methods. For example, a top coat can be formed based on the description in paragraphs

[0072] to

[0082] of Japanese Patent Application Publication No. 2014-059543. For example, it is preferable to form a topcoat containing a basic compound, such as that described in Japanese Patent Publication No. 2013-61648, on the resist film. Specific examples of basic compounds that the topcoat may contain include basic compounds that may be included in the resist composition described later. Furthermore, the top coat preferably contains a compound comprising at least one group or bond selected from the group consisting of ether bonds, thioether bonds, hydroxyl groups, thiol groups, carbonyl bonds, and ester bonds.

[0228] <Step 2: Exposure Process> Step 2 is the process of exposing the resist film with X-rays, electron beams (EB), or extreme ultraviolet (EUV) light. One method of exposure is to irradiate the formed resist film with X-rays, electron beams, or extreme ultraviolet light through a predetermined mask.

[0229] It is preferable to bake (heat) the image after exposure but before developing. Baking accelerates the reaction in the exposed areas, resulting in better sensitivity and pattern shape. The heating temperature is preferably 80 to 150°C, more preferably 80 to 140°C, and even more preferably 80 to 130°C. The heating time is preferably 10 to 1000 seconds, more preferably 10 to 180 seconds, and even more preferably 30 to 120 seconds. Heating can be performed using the means provided in a standard exposure and / or developing machine, or it may be done using a hot plate or the like. This process is also called post-exposure baking.

[0230] <Process 3: Development process> Step 3 is the process of developing the exposed resist film using a developer solution to form a pattern. The developer may be an alkaline developer or a developer containing an organic solvent (hereinafter also referred to as an organic developer).

[0231] Examples of development methods include immersing the substrate in a tank filled with developer solution for a certain period of time (dip method), puddling the developer solution onto the substrate surface using surface tension and leaving it still for a certain period of time for development (paddle method), spraying the developer solution onto the substrate surface (spray method), and continuously dispensing the developer solution while scanning a developer solution dispensing nozzle at a constant speed onto a substrate rotating at a constant speed (dynamic dispensing method). Alternatively, after the developing process, a step may be performed to stop the development process while substituting with another solvent. The development time is not particularly limited as long as it is enough time for the resin in the unexposed areas to dissolve sufficiently, but 10 to 300 seconds is preferred, and 20 to 120 seconds is more preferred. The temperature of the developer is preferably 0 to 50°C, and more preferably 15 to 35°C.

[0232] 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 0.1 to 20% by mass. The pH of the alkaline developer is usually 10.0 to 15.0.

[0233] 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.

[0234] Examples of ketone solvents include 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, acetone, 2-heptanone (methylamyl ketone), 4-heptanone, 1-hexanone, 2-hexanone, diisobutyl ketone, cyclohexanone, methylcyclohexanone, phenylacetone, methyl ethyl ketone, methyl isobutyl ketone, acetylacetone, acetonylacetone, ionone, diacetonyl alcohol, acetylcarbinol, acetophenone, methyl naphthyl ketone, isophorone, and propylene carbonate.

[0235] Examples of ester solvents include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, pentyl acetate, isopentyl acetate, amyl acetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl-3-ethoxypropionate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate, butyl butanoate, methyl 2-hydroxyisobutyrate, isoamyl acetate, isobutyl isobutyrate, and butyl propionate.

[0236] As alcohol-based solvents, amide-based solvents, ether-based solvents, and hydrocarbon-based solvents, for example, the solvents disclosed in paragraphs

[0715] to

[0718] of U.S. Patent Application Publication 2016 / 0070167A1 can be used.

[0237] The above solvents may be mixed in multiple quantities, or mixed with other solvents or water. The water content of the 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% to 100% by mass, more preferably 80% to 100% by mass, even more preferably 90% to 100% by mass, and particularly preferably 95% to 100% by mass, based on the total amount of the developer.

[0238] <Other processes> The above pattern forming method preferably includes a step of washing with a rinsing solution after step 3.

[0239] Examples of rinsing solutions used in the rinsing step after the development process using an alkaline developer include pure water. A suitable amount of surfactant may be added to the pure water. A suitable amount of surfactant may also be added to the rinsing solution.

[0240] The rinsing solution used in the rinsing step after the development step using an organic developer is not particularly limited as long as it does not dissolve the resist pattern, and a solution containing a general organic solvent can be used. Preferably, the rinsing solution 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. Examples of hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents, and ether solvents are the same as those described for developing solutions containing organic solvents.

[0241] The rinsing process is not particularly limited and can be performed by continuously discharging rinsing solution onto a substrate rotating at a constant speed (rotary coating method), immersing the substrate in a tank filled with rinsing solution for a certain period of time (dip method), or spraying rinsing solution onto the substrate surface (spray method). Furthermore, the pattern formation method of the present invention may include a heating step (Post Bake) after the rinsing step. This step removes the developer and rinsing solution remaining between and inside the patterns due to baking. This step also has the effect of softening the resist pattern and improving the surface roughness of the pattern. The heating step after the rinsing step is usually performed at 40 to 250°C (preferably 90 to 200°C) for 10 seconds to 3 minutes (preferably 30 seconds to 120 seconds).

[0242] 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 the substrate) to form a pattern on the substrate. The processing method for the substrate (or the underlying film and substrate) is not particularly limited, but a preferred method is to form 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. Dry etching may consist of a single stage or multiple stages. If the etching consists of multiple stages, each stage may be the same or a different process. Etching can be performed using any known method, and various conditions are determined appropriately according to the type of substrate or application. For example, etching can be performed in accordance with the Proceedings of the International Society for Optical and Photonics (Proc. of SPIE) Vol. 6924, 692420 (2008), Japanese Patent Publication No. 2009-267112, etc. Alternatively, it can be performed in accordance with the method described in "Chapter 4 Etching" of "Semiconductor Process Textbook, 4th Edition, published in 2007, publisher: SEMI Japan". Among these, oxygen plasma etching is preferred for dry etching.

[0243] The resist composition and the various materials used in the pattern forming method of the present invention (e.g., solvent, developer, rinse solution, anti-reflective film forming composition, top coat forming composition, etc.) are preferably free of impurities such as metals. The impurity content in these materials is preferably 1 ppm by mass or less, more preferably 10 ppb by mass or less, even more preferably 100 ppt by mass or less, particularly preferably 10 ppt by mass or less, and most preferably 1 ppt by mass or less. 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.

[0244] One method for removing impurities such as metals from various materials is filtration using a filter. The filter pore size is preferably less than 100 nm, more preferably 10 nm or less, and even more preferably 5 nm or less. The filter is preferably made of polytetrafluoroethylene, polyethylene, or nylon. The filter may be composed of a composite material combining the above filter material and an ion exchange medium. The filter may be one that has been pre-washed with an organic solvent. In the filter filtration process, multiple types of filters may be connected in series or in parallel. When using multiple types of filters, filters with different pore sizes and / or materials may be used in combination. In addition, various materials may be filtered multiple times, and the process of filtering multiple times may be a circulating filtration process. In the production of a resist composition, it is preferable to dissolve each component, such as a resin and a photoacid generator, in a solvent, and then perform circulating filtration using multiple filters made of different materials. For example, it is preferable to connect polyethylene filters with a pore size of 50 nm, nylon filters with a pore size of 10 nm, and polyethylene filters with a pore size of 3 nm in sequence and perform circulating filtration 10 or more times. The pressure difference between filters should be as small as possible, generally 0.1 MPa or less, preferably 0.05 MPa or less, and more preferably 0.01 MPa or less. The pressure difference between the filter and the filling nozzle should also be as small as possible, generally 0.5 MPa or less, preferably 0.2 MPa or less, and more preferably 0.1 MPa or less. It is preferable to purify the inside of the resist composition manufacturing apparatus with an inert gas such as nitrogen. This suppresses the dissolution of active gases such as oxygen into the resist composition. The resist composition is filtered and then filled into a clean container. The resist composition filled into the container is preferably stored under refrigeration. This suppresses performance degradation over time. The time between the completion of filling the container with the composition and the start of refrigerated storage should be as short as possible, generally within 24 hours, more preferably within 16 hours, more preferably within 12 hours, and even more preferably within 10 hours. The storage temperature is preferably 0 to 15°C, more preferably 0 to 10°C, and even more preferably 0 to 5°C.

[0245] Furthermore, methods for reducing impurities such as metals contained in various materials include, for example, selecting raw materials with low metal content as constituent materials for various materials, filtering the raw materials constituting 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®.

[0246] 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 manufacturing equipment. The content of metal components in the cleaning solution after use is preferably 100 ppt (parts per trillion) or less, more preferably 10 ppt or less, and even more preferably 1 ppt or less.

[0247] In organic processing solutions such as rinsing solutions, a conductive compound may be added to prevent malfunctions of chemical piping and various parts (filters, O-rings, tubes, etc.) due to electrostatic charging and subsequent electrostatic discharge. The conductive compound is not particularly limited, but methanol is an example. The amount added is not particularly limited, but in terms of maintaining desirable developing or rinsing characteristics, 10% by mass or less is preferred, and 5% by mass or less is more preferred. For chemical piping, various types of piping can be used, such as SUS (stainless steel), or piping coated with antistatic treated polyethylene, polypropylene, or fluororesin (polytetrafluoroethylene or perfluoroalkoxy resin, etc.). Similarly, for filters and O-rings, antistatic treated polyethylene, polypropylene, or fluororesin (polytetrafluoroethylene or perfluoroalkoxy resin, etc.) can be used.

[0248] A method for improving the surface roughness of a pattern may be applied to a pattern formed by the method of the present invention. Examples of methods for improving the surface roughness of a pattern include the method of treating the pattern with a hydrogen-containing gas plasma disclosed in International Publication No. 2014 / 002808. Other known methods include those described in Japanese Patent Application Publication No. 2004-235468, U.S. Patent Application Publication No. 2010 / 0020297, Japanese Patent Application Publication No. 2008-83384, and Proc. of SPIE Vol. 8328 83280N-1 "EUV Resist Curing Technique for LWR Reduction and Etch Selectivity Enhancement".

[0249] Furthermore, the present invention relates to a method for manufacturing an electronic device, including the pattern formation method described above, and to an electronic device manufactured by this manufacturing method. The electronic device of the present invention is preferably mounted on electrical and electronic equipment (such as home appliances, office automation (OA) equipment, media-related equipment, optical equipment, and communication equipment). [Examples]

[0250] 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. Unless otherwise specified, "parts" and "%" refer to mass. Examples 1-4, 1-5, 1-13, 1-16, 1-19, 1-20、 1-21, 1-22, 1-24, 1-25, 1-26, 2-4, 2-5, 2-13, 2-16, 2-19, 2-20、 2-21, 2-22, 2-24, 2-25, and 2-26 are reference examples 1-4, 1-5, 1-13, 1-16, and 1-19, respectively. 1-20、 1-21, 1-22, 1-24, 1-25, 1-26, 2-4, 2-5, 2-13, 2-16, 2-19, 2-20、 Sections 2-21, 2-22, 2-24, 2-25, and 2-26 shall be interpreted as such.

[0251] [Various components of positive-type resist compositions]

[0252] [Resin (B)] <Synthesis of resin A-1> The monomers corresponding to each repeating unit of resin A-1 were dissolved in cyclohexanone (5.37 g) in amounts of 18.7 g, 11.8 g, and 2.60 g respectively (from left to right), along with polymerization initiator V-601 (manufactured by Wako Pure Chemical Industries, Ltd.) (0.0461 g). The resulting solution was used as the monomer solution. Cyclohexanone (2.89 g) was placed in a reaction vessel, and the monomer solution was added dropwise to the vessel, which was adjusted to a temperature of 85°C, under a nitrogen gas atmosphere, over a period of 4 hours. The resulting reaction solution was stirred in the reaction vessel at 85°C for 2 hours, and then allowed to cool to room temperature (23°C). The reaction solution, after cooling, was added dropwise to methanol over 20 minutes, and the precipitated powder was filtered off. The resulting powder was dried to obtain resin A-1 (16.6 g).

[0253] Resins A-1 to A-20 were synthesized according to the synthesis example of resin A-1 described above. Table 1 shows the composition ratio (molar ratio; corresponding from left to right), weight-average molecular weight (Mw), and degree of dispersion (Mw / Mn) of each repeating unit for each resin. The weight-average molecular weight (Mw) and dispersion (Mw / Mn) of resins A-1 to A-20 were measured by GPC (solvent: tetrahydrofuran (THF)) (in polystyrene equivalent). The composition ratio (mol% ratio) of the resins was also determined as follows: 13 The measurement was performed using 1C-NMR (nuclear magnetic resonance). Note that resins (RA-1) to (RA-3) are not resin (B), but are listed in Table 1 for convenience.

[0254] [Table 1]

[0255] The structural formulas of resins A-1 to A-20 and RA-1 to RA-3 shown in Table 1 are shown below.

[0256] [ka]

[0257] [ka]

[0258] [ka]

[0259] [Ionic compound (A)] The structures of the ionic compounds (compounds B-1 to B-15) shown in Table 2 are shown below. Although compound B'-1 is not an ionic compound (A), it is listed below for convenience.

[0260] [ka]

[0261] [ka]

[0262] [Acid diffusion control agent] The structure of the acid diffusion control agent (compound C-1) shown in Table 2 is shown below.

[0263] [ka]

[0264] 〔solvent〕 The solvents shown in Table 2 are listed below. F-1: Propylene glycol monomethyl ether acetate (PGMEA) F-2: Propylene glycol monomethyl ether (PGME) F-3: Cyclohexanone F-4: Ethyl lactate F-5: γ-Butyrolactone F-6: Anisole

[0265] <Developer> The developers used during organic solvent development, as shown in Table 3, are as follows. G-1: n-butyl acetate G-2: Isoamyl acetate G-3: Hexyl acetate

[0266] [Preparation of positive-type resist composition] Each component shown in Table 2 was mixed to a solid content concentration of 2% by mass. Next, the resulting mixture was filtered in the following order: first through a polyethylene filter with a pore size of 50 nm, then through a nylon filter with a pore size of 10 nm, and finally through a polyethylene filter with a pore size of 5 nm, to prepare a positive-type resist composition (hereinafter also referred to as the resist composition). In the resist composition, "solid content" refers to all components except the solvent. The obtained resist composition was used in the examples and comparative examples. In Table 2, the content (mass %) of each component refers to its content relative to the total solids.

[0267] [Table 2]

[0268] <Pattern formation (1): EUV exposure, organic solvent development> A base layer film formation composition AL412 (manufactured by Brewer Science) was applied to a silicon wafer and baked at 205°C for 60 seconds to form a 20 nm thick base layer. On top of this, the resist compositions shown in Table 3 were applied and baked at 100°C for 60 seconds to form a 30 nm thick resist film. A silicon wafer with the obtained resist film was patterned using an EUV lithography system (Exitech Micro Exposure Tool, NA 0.3, Quadrupol, outer sigma 0.68, inner sigma 0.36). A mask with a line size of 22 nm and a line-to-space ratio of 1:1 was used as the rectilation mask. After exposure, the resist film was baked at 90°C for 60 seconds, then developed with the developer listed in Table 3 for 30 seconds, and then spin-dried to obtain a positive-type pattern.

[0269] [evaluation] <Resolution> In the exposure and development conditions for forming the resist pattern described above, the exposure amount that reproduces a mask pattern with a line width of 22 nm was defined as the optimal exposure amount. When the line width of the line-and-space pattern formed by further increasing the exposure amount from the optimal exposure amount was reduced, the minimum line width at which the pattern could be resolved without breaks was defined as the resolution value (nm). A smaller resolution value indicates that finer patterns can be resolved, and thus indicates higher resolution. More specifically, the resolution is preferably 20 nm or less, more preferably 16 nm or less, and even more preferably 15 nm or less.

[0270] (Evaluation results) The results of the above evaluation tests are shown in Table 3 below.

[0271] [Table 3]

[0272] The results in Table 3 show that the positive-type resist composition of the present invention can form patterns with extremely high resolution when forming ultrafine patterns.

[0273] <Pattern formation (2): EUV exposure, alkaline aqueous solution development> A substrate film-forming composition AL412 (manufactured by Brewer Science) was applied to a silicon wafer and baked at 205°C for 60 seconds to form a 20 nm thick substrate film. On top of this, the resist compositions shown in Table 4 were applied and baked at 100°C for 60 seconds to form a 30 nm thick resist film. A silicon wafer with the obtained resist film was patterned using an EUV lithography system (Exitech Micro Exposure Tool, NA 0.3, Quadrupol, outer sigma 0.68, inner sigma 0.36). A mask with a line size of 32 nm and a line-to-space ratio of 1:1 was used as the rectilation mask. The resist film after exposure was 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. Afterward, it was spin-dried to obtain a positive-type pattern.

[0274] [evaluation] <Resolution> In the exposure and development conditions for forming the resist pattern described above, the exposure amount that reproduces a mask pattern with a line width of 32 nm was defined as the optimal exposure amount. When the line width of the line-and-space pattern formed by further increasing the exposure amount from the optimal exposure amount was reduced, the minimum line width at which the pattern could be resolved without breaks was defined as the resolution value (nm). A smaller resolution value indicates that finer patterns can be resolved, and thus indicates higher resolution. More specifically, the resolution is preferably 30 nm or less, more preferably 26 nm or less, and even more preferably 24 nm or less.

[0275] For Examples 2-1 to 2-26, development defects were further evaluated as follows. <Development defect> The pattern formed on a silicon wafer (12-inch diameter) as described above was measured in random mode using a KLA2360 (product name) defect inspection system manufactured by KLA-Tencor, with the pixel size of the defect inspection system set to 0.16 μm and the threshold set to 20. Development defects were detected from the differences resulting from the superposition of the comparison image and the pixel-level pattern, and the number of development defects per unit area (defects / cm²) was calculated. 2 The value was calculated. Note that 1 inch is 0.0254 m. Values ​​less than 0.5 were classified as A, values ​​between 0.5 and 0.7 as B, values ​​between 0.7 and 1.0 as C, and values ​​of 1.0 or more as D. A smaller value indicates better performance.

[0276] (Evaluation results) The results of the above evaluation tests are shown in Table 4 below.

[0277] [Table 4]

[0278] The results in Table 4 show that the positive-type resist composition of the present invention exhibits extremely excellent resolution in the formation of ultrafine patterns. Furthermore, when developed with an alkaline developer, it is found that both extremely excellent resolution and reduced development defects are achieved. [Industrial applicability]

[0279] According to the present invention, it is possible to provide a positive-type resist composition that can form patterns with extremely high resolution when forming ultrafine patterns (for example, 40 nm or less). Furthermore, according to the present invention, it is possible to provide a resist film using the above-mentioned positive-type resist composition, a pattern formation method, and a method for manufacturing an electronic device.

[0280] Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention. This application is based on Japanese Patent Application No. 2020-015892 filed on January 31, 2020, the contents of which are incorporated herein by reference.

Claims

1. (A) Ionic compounds, and (B) A positive-type resist composition containing a resin having repeating units (b1) having interacting groups that interact with the ionic groups in the ionic compound, the main chain of which decomposes upon irradiation with X-rays, electron beams, or extreme ultraviolet light, The aforementioned ionic compound (A) is a compound that generates acid upon irradiation with X-rays, electron beams, or extreme ultraviolet light. The resin (B) has at least one of the group consisting of a hydroxyl group, a carboxyl group, a carbonate group, a carbonyl group, an amino group, an amide group, a thiol group, an alkoxycarbonyl group, an alkyloxysulfonyl group, a sulfo group, a sulfonyl group, and an alkylsulfonyl group as the interacting group. The resin (B) has repeating units represented by the following general formula (1): A positive-type resist composition in which the ionic compound (A) and the resin (B) are the same compound. 【Chemistry 1】 In general formula (1), X represents a chlorine atom, a bromine atom, or an iodine atom. R represents a hydrogen atom or a monovalent organic group.

2. (A) Ionic compounds, and (B) A positive-type resist composition containing a resin having repeating units (b1) having interacting groups that interact with the ionic groups in the ionic compound, the main chain of which decomposes upon irradiation with X-rays, electron beams, or extreme ultraviolet light (excluding polymers containing structural units represented by the following general formula (1'), polymers represented by the following A-2, copolymers of 1-methyl-1-phenylethyl-α-chloroacrylate and 2-hydroxyethyl methacrylate, copolymers of 1-methyl-1-phenylethyl-α-chloroacrylate and 2-hydroxy-3-phenoxypropyl acrylate, and copolymers of 1-methyl-1-phenylethyl-α-bromoacrylate and 1-hydroxy-1-methylethyl methacrylate), The aforementioned ionic compound (A) is a compound that generates acid upon irradiation with X-rays, electron beams, or extreme ultraviolet light. The resin (B) has at least one of the group consisting of a hydroxyl group, an amino group, an amide group, and a thiol group as the interacting group. The repeating unit (b1) is a repeating unit represented by the following general formula (2), The resin (B) is a positive-type resist composition having repeating units represented by the following general formula (1). Here, the ionic compound (A) and the resin (B) may be the same compound. 【Chemistry 2】 (X' represents a halogen atom or a cyano group. R'' represents an acid-degradable organic group and includes at least one structure represented by the following general formula (2').) 【Transformation 3】 (In the formula R １ , R ２ Each of these independently represents an alkyl group, an aryl group, an aryl alkyl group, an alkoxyalkyl group, an alkoxyaryl group, an alkoxyaryl alkyl group, a hydroxyalkyl group, a hydroxyaryl group, a hydroxyaryl alkyl group, a haloalkyl group, a haloaryl group, a haloaryl alkyl group, a silylalkyl group, a silylaryl group, a silylaryl alkyl group, a siloxyalkyl group, a siloxyaryl group, and a siloxyaryl alkyl group. Also, R １ , R ２ It may also form a ring structure by closing the ring. ３ (where m' represents an organic group with 1 to 12 carbon atoms; m' is 0 or 1.) 【Chemistry 4】 【Transformation 5】 In general formula (2), R' represents a hydrogen atom or an alkyl group. C1 represents the interacting group. j represents either 0 or 1. k represents either 0 or 1. n represents an integer between 1 and 9. When n represents an integer between 2 and 9, multiple C1s may be the same or different. 【Transformation 6】 In general formula (1), X represents a chlorine atom, a bromine atom, or an iodine atom. R represents a hydrogen atom or a monovalent organic group.

3. (A) an ionic compound, (B) A positive-type resist composition containing a resin having repeating units (b1) having interacting groups that interact with the ionic groups in the ionic compound, the main chain of which decomposes upon irradiation with X-rays, electron beams, or extreme ultraviolet light (excluding polymers containing structural units represented by the following general formula (1'), polymers represented by the following A-2, copolymers of 1-methyl-1-phenylethyl-α-chloroacrylate and 2-hydroxyethyl methacrylate, copolymers of 1-methyl-1-phenylethyl-α-chloroacrylate and 2-hydroxy-3-phenoxypropyl acrylate, and copolymers of 1-methyl-1-phenylethyl-α-bromoacrylate and 1-hydroxy-1-methylethyl methacrylate), The aforementioned ionic compound (A) is a compound that generates acid upon irradiation with X-rays, electron beams, or extreme ultraviolet light. The resin (B) has at least one of the group consisting of a hydroxyl group, an amino group, an amide group, and a thiol group as the interacting group. The resin (B) has repeating units represented by the following general formula (1): A positive-type resist composition wherein the resin (B) has repeating units represented by the following general formula (7) (excluding those corresponding to repeating units represented by the following general formula (2)). Here, the ionic compound (A) and the resin (B) may be the same compound. 【Transformation 7】 (X' represents a halogen atom or a cyano group. R'' represents an acid-degradable organic group and includes at least one structure represented by the following general formula (2').) 【Transformation 8】 (In the formula, R1 and R2 each independently represent an alkyl group, an aryl group, an arylalkyl group, an alkoxyalkyl group, an alkoxyaryl group, an alkoxyarylalkyl group, a hydroxyalkyl group, a hydroxyaryl group, a hydroxyarylalkyl group, a haloalkyl group, a haloaryl group, a haloarylalkyl group, a silylalkyl group, a silylaryl group, a silylarylalkyl group, a siloxyalkyl group, a siloxyaryl group, or a siloxyarylalkyl group. R1 and R2 may also be cyclized to form a ring structure. R3 represents an organic group having 1 to 12 carbon atoms. m' is 0 or 1.) 【Chemistry 9】 【Chemistry 10】 In general formula (1), X represents a chlorine atom, a bromine atom, or an iodine atom. R represents a hydrogen atom or a monovalent organic group. 【Chemistry 11】 In general formula (7), R 31 represents a hydrogen atom or an alkyl group. R 32 represents a monovalent organic group. 's' represents either 0 or 1. t represents either 0 or 1. w represents an integer from 0 to 9. If w represents an integer between 2 and 9, multiple R32s may be the same or different. 【Chemistry 12】 In general formula (2), R' represents a hydrogen atom or an alkyl group. C1 represents the interacting group. j represents either 0 or 1. k represents either 0 or 1. n represents an integer between 1 and 9. When n represents an integer between 2 and 9, multiple C1s may be the same or different.

4. (A) an ionic compound, and (B) A positive-type resist composition containing a resin having repeating units (b1) having interacting groups that interact with the ionic groups in the ionic compound, the main chain of which decomposes upon irradiation with X-rays, electron beams, or extreme ultraviolet light (excluding polymers containing structural units represented by the following general formula (1'), polymers represented by the following A-2, copolymers of 1-methyl-1-phenylethyl-α-chloroacrylate and 2-hydroxyethyl methacrylate, copolymers of 1-methyl-1-phenylethyl-α-chloroacrylate and 2-hydroxy-3-phenoxypropyl acrylate, and copolymers of 1-methyl-1-phenylethyl-α-bromoacrylate and 1-hydroxy-1-methylethyl methacrylate), The aforementioned ionic compound (A) is a compound that generates acid upon irradiation with X-rays, electron beams, or extreme ultraviolet light. The resin (B) has at least one of the group consisting of an amino group, an amide group, and a thiol group as the interacting group. The resin (B) is a positive-type resist composition having repeating units represented by the following general formula (1). Here, the ionic compound (A) and the resin (B) may be the same compound. 【Chemistry 13】 (X' represents a halogen atom or a cyano group. R'' represents an acid-degradable organic group and includes at least one structure represented by the following general formula (2').) 【Chemistry 14】 (In the formula, R1 and R2 each independently represent an alkyl group, an aryl group, an arylalkyl group, an alkoxyalkyl group, an alkoxyaryl group, an alkoxyarylalkyl group, a hydroxyalkyl group, a hydroxyaryl group, a hydroxyarylalkyl group, a haloalkyl group, a haloaryl group, a haloarylalkyl group, a silylalkyl group, a silylaryl group, a silylarylalkyl group, a siloxyalkyl group, a siloxyaryl group, or a siloxyarylalkyl group. R1 and R2 may also be cyclized to form a ring structure. R3 represents an organic group having 1 to 12 carbon atoms. m' is 0 or 1.) 【Chemistry 15】 【Chemistry 16】 In general formula (1), X represents a chlorine atom, a bromine atom, or an iodine atom. R represents a hydrogen atom or a monovalent organic group.

5. The positive-type resist composition according to claim 1, 3, or 4, wherein the repeating unit (b1) is a repeating unit represented by general formula (2). 【Chemistry 17】 In general formula (2), R' represents a hydrogen atom or an alkyl group. C １ represents the aforementioned interacting group. j represents either 0 or 1. k represents either 0 or 1. n represents an integer between 1 and 9. If n represents an integer from 2 to 9, multiple C １ They may be the same or different.

6. The positive-type resist composition according to claim 1, 2, or 4, wherein the resin (B) has repeating units represented by the following general formula (7) (excluding those corresponding to the repeating units represented by the general formula (2)). [Chemistry 18] In general formula (7), R ３１ represents a hydrogen atom or an alkyl group. R ３２ represents a monovalent organic group. 's' represents either 0 or 1. t represents either 0 or 1. w represents an integer from 0 to 9. If w represents an integer from 2 to 9, multiple R ３２ They may be the same or different.

7. The positive-type resist composition according to any one of claims 2 to 4, wherein the ionic compound (A) and the resin (B) are the same compound.

8. The positive-type resist composition according to claim 1 or 7, wherein the resin (B) comprises a repeating unit represented by the following general formula (3) as the repeating unit (b1), and at least one repeating unit selected from the group consisting of a repeating unit represented by the following general formula (4) and a repeating unit represented by the following general formula (5). 【Chemistry 19】 In general formula (3), A represents a hydrogen atom, a halogen atom, or an alkyl group. L represents a divalent linking group. B represents a single bond or a (m+1) valence linking group. C represents the aforementioned interacting group. m represents an integer greater than or equal to 1. If m represents an integer greater than or equal to 2, then multiple Cs may be the same or different. In general formula (4), A １ represents a hydrogen atom, a halogen atom, or an alkyl group. L １ represents a single bond or a divalent linking group. B １ represents a single bond or a (p+1) valence linking group. D １ The symbol represents an anionic group. E １ represents a cation. p represents an integer between 1 and 2. If p represents an integer of 2, then multiple D １ and multiple E １ These may be the same or different. In general formula (5), A ２ represents a hydrogen atom, a halogen atom, or an alkyl group. L ２ This represents a divalent linking group. B ２ represents a single bond or a (q+1) valence linking group. D ２ This represents an anion. E ２ This represents a cationic group. q represents an integer between 1 and 2. If q represents an integer of 2, then multiple D ２ and multiple E ２ These may be the same or different.

9. The positive-type resist composition according to any one of claims 1 to 6, wherein the ionic compound (A) is a compound represented by the following general formula (6). 【Chemistry 20】 In general formula (6), M ３ ＋ This represents an organic cation that is decomposed by irradiation with X-rays, electron beams, or extreme ultraviolet light. A ３ － This represents an anionic group. R ａ represents a hydrogen atom or a monovalent organic group. L ａ This represents a single bond or a divalent linking group.

10. A in the compound represented by the general formula (6) ３ － The positive-type resist composition according to claim 9, wherein the group is selected from the group consisting of groups represented by the following general formulas (B-1) to (B-14). 【Chemistry 21】 In formulas (B-1) to (B-14), * indicates the bonding position. In equations (B-1) to (B-5) and (B-12), R Ｘ１ Each of these independently represents a monovalent organic group. In formulas (B-7) and (B-11), R Ｘ２ Each of these independently represents a hydrogen atom, or a fluorine atom and a substituent other than a perfluoroalkyl group. The two R in formula (B-7) Ｘ２ They may be the same or different. In general formula (B-8), R ＸＦ１ R represents a hydrogen atom, a fluorine atom, or a perfluoroalkyl group. However, multiple Rs are not allowed. ＸＦ１ Of these, at least one represents a fluorine atom or a perfluoroalkyl group. The two R in formula (B-8) ＸＦ１ They may be the same or different. In general formula (B-9), R Ｘ３ n1 represents a hydrogen atom, a halogen atom, or a monovalent organic group. n1 represents an integer from 0 to 4. If n1 represents an integer between 2 and 4, multiple R Ｘ３ They may be the same or different. In general formula (B-10), R ＸＦ２ This represents a fluorine atom or a perfluoroalkyl group. In general formula (B-14), R Ｘ４ n² represents a hydrogen atom, a halogen atom, or a monovalent organic group. n² represents an integer from 0 to 4. If n² represents an integer between 2 and 4, then multiple R Ｘ４ They may be the same or different.

11. A in the compound represented by the general formula (6) ３ － The positive-type resist composition according to claim 10, wherein the group is selected from the group consisting of groups represented by the general formulas (B-6), (B-7), (B-8), (B-9), and (B-14).

12. The ionic compound (A) and the resin (B) are the same compound, and R in the compound represented by the general formula (6) ａ A positive-type resist composition according to any one of claims 9 to 11, wherein the monovalent organic group as a resist is included in the main chain structure of the resin.

13. The positive-type resist composition according to claim 1, wherein the resin (B) has at least one of the group consisting of a hydroxyl group, an amino group, an amide group, and a thiol group as the interacting group.

14. The positive-type resist composition according to any one of claims 1 to 13, wherein the content of the repeating unit (b1) is 20 mol% or less relative to the total repeating units of the resin (B).

15. A resist film formed using the positive-type resist composition described in any one of claims 1 to 14.

16. A step of forming a resist film on a substrate using the positive-type resist composition according to any one of claims 1 to 14, The process involves exposing the resist film with X-rays, electron beams, or extreme ultraviolet light. A pattern forming method comprising the steps of developing the exposed resist film using a developing solution to form a pattern.

17. A method for manufacturing an electronic device, comprising the pattern forming method described in claim 16.

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