Active-ray-sensitive or radiation-sensitive resin composition, resist film, pattern formation method, method for manufacturing electronic device

Abstract

This invention provides a photosensitive radioactive or radioactive linear resin composition that can reduce the LWR of the formed pattern, a resist film, a pattern forming method, and a method for manufacturing an electronic device. The photosensitive radioactive or radioactive linear resin composition of this invention is a photosensitive radioactive or radioactive linear resin composition comprising a resin (A) having a repeating unit (a), wherein the repeating unit (a) is a repeating unit having an ionic group that generates an acid by irradiation with photosensitive rays or radiation, and wherein the repeating unit formed by replacing the repeating group with a hydrogen atom has a molecular weight of 300 or less, and the repeating unit (a) is in a predetermined amount or more relative to the total solids content of the photosensitive radioactive or radioactive linear resin composition.

Description

Technical Field

[0001] The present invention relates to a photosensitive radiation-curable or radiation-sensitive resin composition, a resist film, a patterning method, and a method for manufacturing an electronic device. Prior Art

[0002] As a patterning method, various methods have been studied, and for example, the following methods can be cited.

[0003] That is, a photosensitive radiation-curable or radiation-sensitive resin film (hereinafter also referred to as "resist film") formed using a photosensitive radiation-curable or radiation-sensitive resin composition is exposed, and a change in solubility of the resist film with respect to a developer occurs in a region reflecting the exposed pattern. Thereafter, development is performed using a developer (alkali developer, organic solvent-based developer, etc.), and the exposed portion or non-exposed portion in the resist film is removed to obtain a desired pattern.

[0004] For example, Patent Document 1 discloses a patterning method in which a pattern is formed according to a prescribed procedure using a material containing a high molecular compound as a base resin. The high molecular compound contains a repeating unit having an aromatic group in a range of 10 mol% or more and 100 mol% or less of all repeating units, and contains a repeating unit having a sulfonium salt acid generator group in a range of 1 mol% or more and 30 mol% or less, and can be dissolved in an alkali developer due to the action of an acid. [Prior Art Documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-140268 Summary of the Invention Problems to be Solved by the Invention

[0006] The inventors of the present invention studied the materials (photosensitive radiation-curable or radiation-sensitive resin composition, resist composition) described in Patent Document 1, and as a result, found that it is difficult to reduce the line width roughness (LWR) when forming a pattern using a photosensitive radiation-curable or radiation-sensitive resin composition.

[0007] <​​​​Furthermore, the present invention aims to provide a resist film, a patterning method, and a method for manufacturing electronic devices relating to the aforementioned photosensitive or radiosensitive linear resin composition. The means to solve the problem

[0009] The inventors have discovered that the aforementioned problem can be solved by the following structure.

[0010] [1]

[0011] A photosensitive or radiosensitive linear resin composition comprising a resin (A) having a repeating unit (a), wherein the repeating unit (a) in the photosensitive or radiosensitive linear resin composition has an ionic group that generates an acid by irradiation with photochemical rays or radiation, and the repeating unit formed by replacing the detaching group with a hydrogen atom has a molecular weight of 300 or less. When the photosensitive or radiosensitive linear resin composition does not contain a compound that generates an acid by irradiation with photochemical rays or radiation, the molar amount of the repeating unit (a) relative to the total solids content of the photosensitive or radiosensitive linear resin composition is 0.50 mmol / g or more. When the photosensitive or radiosensitive linear resin composition contains a compound that generates an acid by irradiation with photochemical rays or radiation, the combined molar amount of the repeating unit (a) and the compound relative to the total solids content of the photosensitive or radiosensitive linear resin composition is 0.50 mmol / g or more.

[0012] [2]

[0013] As described in [1], the repeating unit formed by replacing the desiccant in the repeating unit (a) with a hydrogen atom has a molecular weight of 200 or less.

[0014] [3]

[0015] The photosensitive radioactive or radiosensitive linear resin composition as described in [1] or [2] contains the compound as a low molecular weight compound.

[0016] [4]

[0017] As described in [3], the photosensitive radioactive or radiosensitive linear resin composition, wherein the compound is an ionic compound.

[0018] [5]

[0019] As described in any one of [1] to [4], the photosensitive radioactive or radiosensitive linear resin composition, wherein the repeating unit (a) is a repeating unit represented by general formula (1).

[0020] [Chemistry 1]

[0021] In general formula (1), A represents the base that constitutes the main chain of the resin.

[0022] L represents a single bond or a divalent linker.

[0023] Z+ represents an organic cation.

[0024] [6]

[0025] As described in [5], the photosensitive radioactive or radiosensitive linear resin composition, wherein A is a base containing only atoms selected from the group consisting of hydrogen atoms and carbon atoms, and L is a single bond or a base containing only atoms selected from the group consisting of hydrogen atoms and carbon atoms.

[0026] [7]

[0027] As described in any one of [1] to [6], the photosensitive radioactive or radiosensitive linear resin composition, wherein the resin (A) is a resin whose solubility in alkaline developing solution is enhanced by the action of acid.

[0028] [8]

[0029] As described in any one of [1] to [7], the photosensitive radioactive or radiosensitive linear resin composition, wherein the resin (A) has repeating units represented by the general formula (A2).

[0030] [Chemistry 2]

[0031] In general formula (A2), R101, R102, and R103 each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group, or an alkyloxycarbonyl group.

[0032] LA represents a single bond or a divalent linker.

[0033] ArA represents an aromatic cyclic group.

[0034] k represents an integer from 1 to 5.

[0035] R102 can also be bonded to ArA, in which case R102 represents a single bond or an alkyl group.

[0036] [9]

[0037] As described in any one of [1] to [8], the photosensitive radioactive or radiosensitive linear resin composition, wherein the resin (A) contains repeating units having acid-degradable groups, wherein the repeating units having acid-degradable groups decompose under the action of acid to produce one or more groups selected from the group consisting of carboxyl groups and aromatic hydroxyl groups.

[0038]

[10]

[0039] As described in [9], the photosensitive radioactive or radiosensitive linear resin composition, wherein the repeating unit having an acid-degradable group is a repeating unit represented by any one of general formulas (3) to (7).

[0040] [Chemistry 3]

[0041] In general formula (3), R5 to R7 each independently represent a hydrogen atom, alkyl group, cycloalkyl group, halogen atom, cyano group, or alkoxycarbonyl group.

[0042] L2 represents a single bond or a divalent linker.

[0043] R8 to R10 each independently represent an alkyl, cycloalkyl, aryl, aralkyl, or alkenyl group. Furthermore, two of R8 to R10 can bond together to form a ring.

[0044] In general formula (4), R11 to R14 each independently represent a hydrogen atom or an organic group. Among them, at least one of R11 and R12 represents an organic group.

[0045] X1 represents -CO-, -SO-, or -SO2-.

[0046] Y1 represents -O-, -S-, -SO-, -SO2-, or -NR34-. R34 represents a hydrogen atom or an organic group.

[0047] L3 represents a single bond or a divalent linker.

[0048] R15 through R17 each independently represent an alkyl, cycloalkyl, aryl, aralkyl, or alkenyl group. Furthermore, two of R15 through R17 can bond together to form a ring.

[0049] In general formula (5), R18 and R19 each independently represent a hydrogen atom or an organic group.

[0050] R20 and R21 each independently represent a hydrogen atom, alkyl group, cycloalkyl group, aryl group, aralkyl group, or alkenyl group. Furthermore, R20 and R21 can bond together to form a ring.

[0051] In general formula (6), R22 to R24 each independently represent a hydrogen atom, alkyl group, cycloalkyl group, halogen atom, cyano group, or alkoxycarbonyl group.

[0052] L4 represents a single bond or a divalent linker.

[0053] Ar1 represents an aromatic cyclic group.

[0054] R25 to R27 each independently represent a hydrogen atom, alkyl group, cycloalkyl group, aryl group, aralkyl group, or alkenyl group.

[0055] Furthermore, R26 and R27 can bond together to form a ring.

[0056] Additionally, R24 or R25 can be bonded to Ar1.

[0057] In general formula (7), R28 to R30 each independently represent a hydrogen atom, alkyl group, cycloalkyl group, halogen atom, cyano group, or alkoxycarbonyl group.

[0058] L5 represents a single bond or a divalent linker.

[0059] R31 and R32 each independently represent a hydrogen atom, alkyl, cycloalkyl, aryl, aralkyl, or alkenyl.

[0060] R33 represents alkyl, cycloalkyl, aryl, aralkyl, or alkenyl. Furthermore, R32 and R33 can bond together to form a ring.

[0061]

[11]

[0062] As described in

[10] , the photosensitive radioactive or radiosensitive linear resin composition, wherein the repeating unit having an acid-degradable group is a repeating unit represented by any of the general formulas (6) to (7).

[0063]

[12]

[0064] As described in any one of [1] to

[11] , wherein, in the case that the photosensitive radioactive or radioactive linear resin composition does not contain compounds that generate acid upon irradiation by photosensitive rays or radiation, the molar amount of the repeating unit (a) relative to the total solids content of the photosensitive radioactive or radioactive linear resin composition is 0.70 mmol / g or more.

[0065] In the case where the photosensitive or radiosensitive linear resin composition contains a compound that produces acid by irradiation with photosensitive rays or radiation, the total molar amount of the repeating unit (a) and the compound relative to the total solid content of the photosensitive or radiosensitive linear resin composition is 0.70 mmol / g or more.

[0066]

[13]

[0067] The radiation-sensitive or radiation-responsive resin composition according to any one of [1] to

[12] , wherein when the radiation-sensitive or radiation-responsive resin composition does not contain a compound that generates an acid upon irradiation with actinic radiation or radiation, the molar amount of the repeating unit (a) is 1.00 mmol / g or more relative to the total solid content of the radiation-sensitive or radiation-responsive resin composition; and when the radiation-sensitive or radiation-responsive resin composition contains a compound that generates an acid upon irradiation with actinic radiation or radiation, the total molar amount of the repeating unit (a) and the compound is 1.00 mmol / g or more relative to the total solid content of the radiation-sensitive or radiation-responsive resin composition.

[0068] 〔14〕 <统一格式保留原标签

[0069] The radiation-sensitive or radiation-responsive resin composition according to any one of [1] to

[13] , wherein the radiation-sensitive or radiation-responsive resin composition contains the compound, and the compound contains a photo-degradable base compound.

[0070] 〔15〕

[0071] A resist film formed using the radiation-sensitive or radiation-responsive resin composition according to any one of [1] to

[14] .

[0072] 〔16〕 <统一格式保留原标签

[0073] A method of forming a pattern, comprising: a step of forming a resist film on a substrate using the radiation-sensitive or radiation-responsive resin composition according to any one of [1] to

[14] ; a step of exposing the resist film; and a step of developing the exposed resist film using a developer.

[0074] 〔17〕

[0075] A method of manufacturing an electronic device, including the pattern forming method according to

[16] . Advantages of the Invention

[0076] According to the present invention, there is provided a radiation-sensitive or radiation-responsive resin composition capable of reducing the LWR of the formed pattern.

[0077] In addition, the present invention can provide a resist film, a patterning method, and a method for manufacturing electronic devices related to the aforementioned photosensitive radioactive or radiosensitive linear resin composition. Simple Explanation of the Diagram

[0078] none Implementation

[0079] The present invention will now be described in detail.

[0080] The following description of the structural elements is sometimes based on representative embodiments of the present invention, but the present invention is not limited to such embodiments.

[0081] Regarding the use of the term "base" (atomic group) in this specification, as long as it does not violate the spirit of this invention, the description of "unsubstituted" and "unsubstituted" also includes bases without substituents and bases with substituents. For example, the term "alkyl" includes not only alkyls without substituents (unsubstituted alkyls) but also alkyls with substituents (substituted alkyls).

[0082] In addition, the term "organic group" in this specification refers to a group containing at least one carbon atom.

[0083] Unless otherwise specified, the substituent is a monovalent substituent.

[0084] In this specification, "photochemical rays" or "radiation" refers to, for example, the bright-line spectrum of a mercury lamp, the far-ultraviolet radiation represented by an excimer laser, extreme ultraviolet (EUV) radiation, X-rays, and electron beams (EB). In this specification, "light" refers to photochemical rays or radiation.

[0085] Unless otherwise specified, "exposure" in this instruction manual includes not only exposure using the bright-line spectrum of mercury lamps, far-ultraviolet rays represented by excimer lasers, extreme ultraviolet rays, X-rays, and EUV, but also depiction using particle beams such as electron beams and ion beams.

[0086] In this manual, the term "~" is used to indicate the lower and upper limits, including the values ​​before and after it.

[0087] Unless otherwise specified, the bonding orientation of the divalent groups described in this specification is not limited. For example, in the compound represented by the formula "XYZ", where Y is -COO-, Y can be -CO-O- or -O-CO-. Furthermore, the compound can be "X-CO-OZ" or "XO-CO-Z".

[0088] In this specification, (meth)acrylate means acrylate and methacrylate, and (meth)acrylic acid means acrylic acid and methacrylic acid.

[0089] In this specification, the weight-average molecular weight (Mw), number-average molecular weight (Mn), and dispersion (also known as molecular weight distribution) (Mw / Mn) of the resin are defined as polystyrene conversion values ​​obtained by GPC determination using a gel permeation chromatography (GPC) apparatus (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: refractive index detector)

[0090] In this specification, the composition ratio of the resin (molar ratio or mass ratio, etc.) is determined by 13C nuclear magnetic resonance (NMR).

[0091] The acid dissociation constant (pKa) referred to in this specification means the pKa in aqueous solution, specifically obtained by calculation using the software package described below, based on a database of Hammett substituent constants and known literature values. All pKa values ​​described in this specification represent values ​​obtained by calculation using this software package.

[0092] Software Package 1: Advanced Chemistry Development (ACD / Labs) Software V8.14 for Solaris (1994-2007 ACD / Labs).

[0093] On the other hand, pKa is also determined using molecular orbital calculations. One specific method is the calculation of the H+ dissociation free energy in aqueous solution based on thermodynamic cycles. Methods for calculating the H+ dissociation free energy include density functional theory (DFT), and various other methods have been reported in the literature; this is not a limitation. Furthermore, several software programs exist that can perform DFT, such as Gaussian16.

[0094] As described in this specification, pKa refers to the value obtained by using software package 1 to calculate a database based on Hammett substituent constants and known literature values. In cases where pKa cannot be calculated by this method, it is assumed to be the value obtained by using density functional theory (DFT) and Gaussian 16.

[0095] In addition, pKa in this specification refers to "pKa in aqueous solution" as described above. If the pKa in aqueous solution cannot be calculated, it shall be assumed to be "pKa in dimethyl sulfoxide (DMSO) solution".

[0096] In this specification, halogen atoms, for example, include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms.

[0097] [Photosensitive or radiosensitive linear resin composition (resist composition)]

[0098] The photosensitive or radiosensitive linear resin composition of the present invention is a photosensitive or radiosensitive linear resin composition comprising a resin (A) having a repeating unit (a), wherein the repeating unit (a) has an ionic group that generates an acid by irradiation of photochemical rays or radiation, and the repeating unit formed by replacing the detaching group with a hydrogen atom has a molecular weight of 300 or less. When the photosensitive or radiosensitive linear resin composition does not contain a compound that generates an acid by irradiation of photochemical rays or radiation, the molar amount of the repeating unit (a) relative to the total solids content of the photosensitive or radiosensitive linear resin composition is 0.50 mmol / g or more. When the photosensitive or radiosensitive linear resin composition contains a compound that generates an acid by irradiation of photochemical rays or radiation, the total molar amount of the repeating unit (a) and the compound relative to the total solids content of the photosensitive or radiosensitive linear resin composition is 0.50 mmol / g or more.

[0099] Hereinafter, photosensitive or radiosensitive linear resin compositions will also be referred to as "resist compositions".

[0100] Hereinafter, compounds that produce acids through photochemical rays or radiation will also be referred to as "photoacid generators".

[0101] Although the mechanism by which this structure solves the problem of the present invention may not be clear, the inventors speculate as follows.

[0102] The resist composition of the present invention contains at least 0.50 mmol / g of a portion (acid-generating portion) relative to the total solids content that has the function of decomposing to produce acid upon irradiation by photochemical rays or radiation. This increases the acid generation contrast when the resist film formed using the resist composition is exposed.

[0103] Furthermore, in the resist composition of the present invention, part or all of the acid-generating site exists on the resin as an ionic group that detaches to generate acid. The repeating unit having the ionic group is a repeating unit with a molecular weight of 300 or less, formed by replacing the detaching group with a hydrogen atom, and the ionic structure exists near the main chain of the resin. Therefore, the ionic structure is stereomasked, and the ionic structures are difficult to aggregate in the resist film. Furthermore, by loading part or all of the acid-generating site onto the resin, plasticization of the resist film can be suppressed, maintaining good exposure latitude (EL).

[0104] It is believed that the synergistic effect of these properties can improve the LWR of patterns formed using resist compositions.

[0105] Furthermore, the photoresist film formed by the photoresist composition of the present invention as described above also has excellent exposure latitude (EL), and consequently, excellent pattern collapse suppression of the formed pattern.

[0106] The superior effect of the present invention is defined as the ability of the resist composition of the present invention to further reduce the LWR of the formed pattern, to have a better EL of the formed resist film, and to have better pattern collapse inhibition of the formed pattern.

[0107] The resist composition of the present invention will be described in detail below.

[0108] The resist composition of the present invention can be a positive resist composition (a resist composition for positive pattern formation) or a negative resist composition (a resist composition for negative pattern formation). Furthermore, it can be a resist composition for alkaline development or a resist composition for organic solvent development.

[0109] Preferably, the resist composition of the present invention is a positive resist composition. Furthermore, the resist composition of the present invention is preferably a resist composition for alkaline development.

[0110] The resist composition of the present invention is typically a chemically amplified resist composition.

[0111] The following is a detailed description of the various components of the corrosion inhibitor.

[0112] [Resin (A)]

[0113] The resist composition includes resin (A).

[0114] Resin (A) contains repeating units (a) with ionicity of groups that can generate acid by detachment of dereliction groups caused by irradiation with photochemical rays or radiation.

[0115] In repeating unit (a), the acid is typically generated by forming an acidic group on the main chain side of the resin. Alternatively, it can also be generated by a detached detached group becoming an acid.

[0116] That is, resin (A) typically contains repeating units with groups that decompose upon exposure to produce acidic groups. Therefore, resin (A) typically becomes more polar upon exposure and its solubility relative to alkaline developers increases, while its solubility relative to organic solvents decreases.

[0117] That is, in the pattern forming method of the present invention, typically when an alkaline developer is used as the developer, a positive pattern can be formed more preferably, and when an organic developer is used as the developer, a negative pattern can be formed more preferably.

[0118] Furthermore, resin (A) is preferably a resin whose solubility in alkaline developing solution is improved due to the action of acid. For example, by having repeating units with acid-decomposing groups, resin (A) can have the property of improved solubility in alkaline developing solution due to the action of acid.

[0119] Repeating units with acid-decomposable groups will be described later.

[0120] <Repeating Unit (a)>

[0121] Resin (A) has repeating unit (a).

[0122] The repeating unit (a) is a repeating unit that has an ionic property of producing an acid by irradiation of photochemical rays or radiation, which causes the detaching group to detach. (Hereinafter also referred to as "specific functional group")

[0123] Acids produced by specific functional groups include, for example, sulfonic acids, sulfadiazines, carboxylic acids, and phosphonic acids, with sulfonic acids being preferred.

[0124] In a particular functional group, the acid is typically generated by forming an acidic group on the main chain side of the resin.

[0125] That is, specific functional groups are usually decomposed by irradiation with photochemical rays or radiation, producing acidic groups (sulfonic acid groups, sulfonimide groups, carboxylic acid groups, and phosphonic acid groups, etc.) on the main chain side of resin (A), preferably producing sulfonic acid groups on the main chain side of resin (A).

[0126] The specific functional group can be a group with an onium salt structure or a group with a betaine structure, preferably a group with an onium salt structure.

[0127] The repeating unit (a) is preferably the repeating unit represented by general formula (1).

[0128] [Chemistry 4]

[0129] In general formula (1), A represents the base that constitutes the main chain of the resin.

[0130] A is preferably a basis represented by any of the following general formulas (a-1) to (a-6).

[0131] In addition, the base represented by any of the general formulas (a-1) to (a-6) is preferably a base that contains only atoms selected from the group consisting of hydrogen atoms and carbon atoms.

[0132] [Chemistry 5]

[0133] In general formulas (a-1) to (a-6), Ra independently represents a hydrogen atom, an alkyl group, or -CH2-O-Ra2. Ra2 represents a hydrogen atom, an alkyl group, or an acetyl group. When multiple Ra groups exist in the same general formula, two Ra groups can bond to each other to form a ring. The alkyl group can be straight-chain or branched-chain, and the number of carbon atoms is preferably 1 to 6.

[0134] W can independently represent a methylene group, an oxygen atom, or a sulfur atom.

[0135] Rc1 and Rc2 each independently represent a hydrogen atom, an alkyl group, or an alkoxy group. Additionally, two Rc1 or Rc2 atoms bonded to the same carbon atom can also combine to form an oxygen atom.

[0136] That is, -C(Rc1)2- and -C(Rc2)2- can each be -CO-.

[0137] Y represents either a nitrogen atom or a carbon atom. When Y is a nitrogen atom, m is 0; when Y is a carbon atom, m is 1.

[0138] Rc3 represents a hydrogen atom or a substituent.

[0139] Rb represents an organic group independently.

[0140] n1 represents an integer from 0 to 3.

[0141] n2 represents an integer from 0 to 5.

[0142] l represents 0 or 1.

[0143] * indicates the bond position relative to L.

[0144] In addition, A in general formula (1) is preferably a base that contains only atoms selected from the group consisting of hydrogen atoms and carbon atoms.

[0145] In addition, A contains at least one carbon atom, and is preferably a base containing only atoms selected from the group consisting of hydrogen atoms and carbon atoms.

[0146] In general formula (1), L represents a single bond or a divalent linker.

[0147] The divalent linker is preferably an alkyl group, an alkylphenyl group, -CO-, -O-, -S-, -NRd-, or a combination thereof. Rd represents a hydrogen atom or an alkyl group (e.g., having 1 to 6 carbon atoms).

[0148] The alkyl group can be linear or branched, and has, for example, 1 to 6 carbon atoms. The alkyl group and the phenyl group may preferably have halogen atoms (such as fluorine atoms).

[0149] Examples of "bases comprising combinations thereof" include: -CO-O-, -CO-O-extrinyl-, -CO-O-extrinylphenyl-, -CO-NRd-, -CO-NRd-extrinyl-, and -CO-NRd-extrinylphenyl-.

[0150] In addition, L in general formula (1) is preferably a single bond or a base consisting only of atoms selected from the group consisting of hydrogen atoms and carbon atoms.

[0151] Furthermore, L contains at least one carbon atom, and is preferably a base containing only atoms selected from the group consisting of hydrogen atoms and carbon atoms.

[0152] In general formula (1), Z+ represents an organic cation.

[0153] Z+ is typically equivalent to a detached radical in an acidic ionic group, which is produced by the detachment of a detached radical due to irradiation by photochemical rays or radiation.

[0154] The organic cations are preferably organic cations represented by formula (ZaI) (cation (ZaI)) or organic cations represented by formula (ZaII) (cation (ZaII)).

[0155] [Chemistry 6]

[0156] In the formula (ZaI), R201, R202, and R203 each independently represent an organic group.

[0157] The number of carbon atoms in the organic groups R201, R202, and R203 is typically 1 to 30, preferably 1 to 20. Furthermore, the two groups in R201 to R203 can bond to form a ring structure, and the ring may contain an oxygen atom, a sulfur atom, an ester group, an amino group, or a carbonyl group. Examples of groups formed by the bonding of the two groups in R201 to R203 include alkyl groups (e.g., butyl and pentyl) and -CH2-CH2-O-CH2-CH2-.

[0158] As preferred examples of organic cations in formula (ZaI), examples include cation (ZaI-1), cation (ZaI-2), organic cation (ZaI-3b) represented by formula (ZaI-3b) and organic cation (ZaI-4b) represented by formula (ZaI-4b).

[0159] First, the cation (ZaI-1) will be explained.

[0160] The cation (ZaI-1) is an aryl strontium cation of formula (ZaI) in which at least one of R201 to R203 is aryl.

[0161] The aryl strontium cation can be entirely composed of aryl groups (R201 to R203), or it can be partially composed of aryl groups and the remainder of alkyl or cycloalkyl groups.

[0162] Alternatively, one of R201 to R203 can be an aryl group, and the other two of R201 to R203 can be bonded to form a ring structure. Alternatively, the ring can contain oxygen atoms, sulfur atoms, ester groups, amino groups, or carbonyl groups.

[0163] Examples of groups formed by two bonds in R201 to R203 include: alkylene AL, -aromatic cyclo-alkylene AL-aromatic cyclo-, -aromatic cyclo-aromatic cyclo-, and -aromatic cyclo-O-aromatic cyclo-. The alkylene AL can be linear or branched. The number of carbon atoms in the alkylene AL is preferably 1 to 6. Furthermore, one or more methylene groups constituting the alkylene AL may be substituted with an oxygen atom, a sulfur atom, an ester group, an amino group, and / or a carbonyl group. Examples of alkylene AL include: butylene, pentylene, and -CH2-CH2-O-CH2-CH2-.

[0164] Examples of aryl strontium cations include: triaryl strontium cations, diarylalkyl strontium cations, aryldialkyl strontium cations, diarylcycloalkyl strontium cations, and aryldicycloalkyl strontium cations.

[0165] In the triarylstrom cation, the diarylalkylstrom cation, and the diarylcycloalkylstrom cation, the two aryl groups can be further bonded via single bonds or divalent linkages (-O-, -S-, alkyl groups, or combinations thereof) in addition to S+ bonds.

[0166] The aryl group contained in the aryl strontium cation is preferably phenyl or naphthyl, and more preferably phenyl. The aryl group can be an aryl group containing a heterocyclic structure having 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. When the aryl strontium cation has two or more aryl groups, the two or more aryl groups can be the same or different.

[0167] The aryl strontium cation preferably has a straight-chain alkyl group having 1 to 15 carbon atoms, a branched-chain alkyl group having 3 to 15 carbon atoms, or a cycloalkyl group having 3 to 15 carbon atoms, and more preferably, for example, methyl, ethyl, propyl, n-butyl, dibutyl, tributyl, cyclopropyl, cyclobutyl, and cyclohexyl.

[0168] The aryl, alkyl, and cycloalkyl groups in R201 to R203 may preferably have substituents that are independently alkyl (e.g., 1 to 15 carbons), cycloalkyl (e.g., 3 to 15 carbons), aryl (e.g., 6 to 14 carbons), alkoxy (e.g., 1 to 15 carbons), cycloalkylalkoxy (e.g., 1 to 15 carbons), cycloalkylsulfonyl (e.g., 1 to 15 carbons), halogen atom (e.g., fluorine atom, iodine atom), hydroxyl, carboxyl, ester group, sulfinyl group, sulfonyl group, alkylthio group, and phenylthio group, etc.

[0169] The substitution may, where possible, further have substituents, and preferably, for example, the alkyl group has halogen atoms as substituents, becoming a trifluoromethyl or other halogenated alkyl group.

[0170] In addition, the substituents are preferably formed by any combination to create acid-degradable groups.

[0171] Furthermore, the so-called acid-decomposable group refers to a group that decomposes due to the action of an acid to produce a polar group. Preferably, it is a structure formed by the polar group being protected by an acid-depleting group that is released due to the action of an acid. Acid-decomposable groups, acid-depleting groups, and polar groups will be discussed later.

[0172] Next, the cation (ZaI-2) will be explained.

[0173] The cation (ZaI-2) is a cation in formula (ZaI) where R201 to R203 each independently represent an organic group without an aromatic ring. The aromatic ring referred to here also includes aromatic rings containing heteroatoms.

[0174] The organic groups that do not have an aromatic ring, which are R201 to R203, generally have 1 to 30 carbons, and preferably 1 to 20 carbons.

[0175] R201 to R203 are preferably alkyl, cycloalkyl, allyl, or vinyl, more preferably straight-chain or branched-chain 2-oxoalkyl, 2-oxocycloalkyl, or alkoxycarbonylmethyl, and even more preferably straight-chain or branched-chain 2-oxoalkyl.

[0176] Alkyl and cycloalkyl groups in R201 to R203 may include, for example, straight-chain alkyl groups having 1 to 10 carbon atoms or branched-chain alkyl groups having 3 to 10 carbon atoms (e.g., methyl, ethyl, propyl, butyl, and pentyl), and cycloalkyl groups having 3 to 10 carbon atoms (e.g., cyclopentyl, cyclohexyl, and norbornyl).

[0177] R201~R203 can also be further substituted by halogen atoms, alkoxy groups (e.g., carbon 1~5), hydroxyl groups, cyano groups, or nitro groups.

[0178] Furthermore, the substituents of R201 to R203 are preferably formed independently by any combination of substituents to create acid-degradable groups. The acid-degradable groups will be discussed later.

[0179] Next, the cation (ZaI-3b) will be explained.

[0180] The cation (ZaI-3b) is the cation represented by the following formula (ZaI-3b).

[0181] [Chemistry 7]

[0182] In formula (ZaI-3b), R1c to R5c each independently represent a hydrogen atom, alkyl, cycloalkyl, aryl, alkoxy, aryloxy, alkoxycarbonyl, alkylcarbonyloxy, cycloalkylcarbonyloxy, halogen atom, hydroxyl, nitro, alkylthio, or arylthio.

[0183] R6c and R7c each independently represent a hydrogen atom, an alkyl group (such as a third butyl group), a cycloalkyl group, a halogen atom, a cyano group, or an aryl group.

[0184] Rx and Ry each independently represent alkyl, cycloalkyl, 2-oxoalkyl, 2-oxocycloalkyl, alkoxycarbonylalkyl, allyl, or vinyl.

[0185] Furthermore, the substituents R1c~R7c, as well as Rx and Ry, are preferably formed independently by any combination of substituents to create acid-degradable groups. Regarding acid-degradable groups, see below.

[0186] Any two or more of R1c to R5c, R5c and R6c, R6c and R7c, R5c and Rx, and Rx and Ry can each bond to each other to form a ring, and each ring can independently contain an oxygen atom, a sulfur atom, a ketone group, an ester bond, or a amide bond.

[0187] Examples of the rings include: aromatic or non-aromatic hydrocarbon rings, aromatic or non-aromatic heterocycles, and polycyclic fused rings formed by combining two or more of these rings. Examples of rings include 3-membered to 10-membered rings, preferably 4-membered to 8-membered rings, and more preferably 5-membered or 6-membered rings.

[0188] Examples of alkyl groups formed by the bonding of any two or more of R1c to R5c, R6c and R7c, and Rx and Ry include alkylene groups such as butylyl and pentylyl. The methylene group in this alkyl group may be substituted with heteroatoms such as oxygen atoms.

[0189] The group formed by the bonding of R5c with R6c and R5c with Rx is preferably a single bond or an alkyl group. Examples of alkyl groups include methylene and ethyl groups.

[0190] Rings formed by the mutual bonding of R1c to R5c, R6c, R7c, Rx, Ry, and any two or more of R1c to R5c, R5c and R6c, R6c and R7c, R5c and Rx, and Rx and Ry may have substituents.

[0191] Next, the cation (ZaI-4b) will be explained.

[0192] The cation (ZaI-4b) is the cation represented by the following formula (ZaI-4b).

[0193] [Chemistry 8]

[0194] In equation (ZaI-4b), l represents an integer from 0 to 2.

[0195] r represents an integer from 0 to 8.

[0196] R13 represents a hydrogen atom, a halogen atom (e.g., a fluorine atom, an iodine atom, etc.), a hydroxyl group, an alkyl group, a haloalkyl group, an alkoxy group, a carboxyl group, an alkoxycarbonyl group, or a group having a cycloalkyl group (which may be the cycloalkyl group itself or a group containing a cycloalkyl group). These groups may have substituents.

[0197] R14 represents a hydroxyl group, a halogen atom (e.g., a fluorine atom, an iodine atom, etc.), an alkyl group, a haloalkyl group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylsulfonyl group, a cycloalkylsulfonyl group, or a group having a cycloalkyl group (which may be the cycloalkyl group itself or a group that partially contains a cycloalkyl group). These groups may have substituents. In the presence of multiple R14 groups, each independently represents one of the aforementioned groups, such as a hydroxyl group.

[0198] R15 can independently represent an alkyl, cycloalkyl, or naphthyl group. Two R15 groups can bond together to form a ring. When two R15 groups bond together to form a ring, the ring skeleton may contain heteroatoms such as oxygen or nitrogen atoms. In a particular case, when two R15 groups bond together to form a ring structure, it is preferable that the two R15 groups bond together to form an alkyl group. Furthermore, the alkyl group, the cycloalkyl group, the naphthyl group, and the ring formed by the bonding of two R15 groups (such as an alkyl group formed by the bonding of two R15 groups) may have substituents.

[0199] In formula (ZaI-4b), the alkyl groups in R13, R14, and R15 are straight-chain or branched-chain. The alkyl groups preferably have 1 to 10 carbon atoms. More preferably, the alkyl groups are methyl, ethyl, n-butyl, or tributyl, etc.

[0200] Furthermore, the substituents of R13~R15, as well as Rx and Ry, are preferably formed independently by any combination of substituents to create acid-degradable groups. The acid-degradable groups will be discussed later.

[0201] Next, we will explain equation (ZaII).

[0202] In formula (ZaII), R204 and R205 each independently represent aryl, alkyl, or cycloalkyl.

[0203] The aryl group in R204 and R205 is preferably phenyl or naphthyl, and more preferably phenyl. The aryl group in R204 and R205 may also be an aryl group containing a heterocycle with an oxygen atom, a nitrogen atom, or a sulfur atom. Examples of heterocyclic aryl groups include: pyrrole, furan, thiophene, indole, benzofuran, and benzothiophene.

[0204] The alkyl and cycloalkyl groups in R204 and R205 are preferably straight-chain alkyl groups having 1 to 10 carbon atoms or branched-chain alkyl groups having 3 to 10 carbon atoms (e.g., methyl, ethyl, propyl, butyl, or pentyl), or cycloalkyl groups having 3 to 10 carbon atoms (e.g., cyclopentyl, cyclohexyl, or norbornyl).

[0205] The aryl, alkyl, and cycloalkyl groups in R204 and R205 may each independently have substituents. Examples of substituents that may be present in the aryl, alkyl, and cycloalkyl groups in R204 and R205 include: alkyl groups (e.g., 1-15 carbon atoms), cycloalkyl groups (e.g., 3-15 carbon atoms), aryl groups (e.g., 6-15 carbon atoms), alkoxy groups (e.g., 1-15 carbon atoms), halogen atoms, hydroxyl groups, and phenylthio groups. Furthermore, the substituents in R204 and R205 are preferably formed independently by any combination of substituents to create acid-degradable groups. Regarding acid-degradable groups, as will be discussed later.

[0206] In the repeating unit (a), the molecular weight of the repeating unit formed by replacing the decomposing radical (e.g., Z+ in general formula (1)) with a hydrogen atom is 300 or less, preferably 200 or less. The lower limit of the molecular weight is preferably 72 or more, more preferably 100 or more.

[0207] The following example illustrates a repeating unit (a).

[0208] In the following examples, a combination of the cation portion (equivalent to the Z+ portion in general formula (1)) and other portions may be appropriately substituted.

[0209] [Chemistry 9]

[0210] [Chemistry 10]

[0211] [Chemistry 11]

[0212] [Chemistry 12]

[0213] [Chemistry 13]

[0214] Repeating unit (a) may be used alone or in more than one form.

[0215] The content of repeating unit (a) relative to all repeating units of resin (A) is preferably 1 mol% to 80 mol%, more preferably 5 mol% to 70 mol%, and even more preferably 7 mol% to 60 mol%.

[0216] <Repeating unit with acid-decomposing group>

[0217] Resin (A) is also preferably a repeating unit containing an acid-decomposable group.

[0218] The repeating unit having an acid-decomposing group is preferably a repeating unit different from the repeating unit.

[0219] Acid-degradable groups refer to groups that decompose under the action of acid to produce polar groups. Preferably, the acid-degradable group is a structure with polar groups protected by acid-free groups that are released from the acid. That is, a resin (A) containing repeating units with acid-degradable groups decomposes under the action of acid to produce polar groups. The resin containing these repeating units becomes more polar due to the action of acid, and its solubility relative to alkaline developing solutions increases, while its solubility relative to organic solvents decreases.

[0220] As a polar group, it is preferably a base-soluble group, such as: carboxyl group, aromatic hydroxyl group (phenolic hydroxyl group, etc.), fluorinated alcohol group, sulfonic acid group, phosphoric acid group, sulfonamide group, sulfonyl imino group, (alkylsulfonyl)(alkylcarbonyl)methylene, (alkylsulfonyl)(alkylcarbonyl)imino, bis(alkylcarbonyl)methylene, bis(alkylcarbonyl)imino, bis(alkylsulfonyl)methylene, bis(alkylsulfonyl)imino, tri(alkylcarbonyl)methylene, and tri(alkylsulfonyl)methylene, as well as acidic groups such as alcoholic hydroxyl group, etc.

[0221] Among them, the polar group is preferably a carboxyl group, an aromatic hydroxyl group (phenolic hydroxyl group, etc.), a fluorinated alcohol group (preferably a hexafluoroisopropanol group), or a sulfonic acid group, and more preferably a carboxyl group or an aromatic hydroxyl group (phenolic hydroxyl group, etc.).

[0222] That is, the repeating unit with an acid-decomposable group is preferably decomposed by the action of an acid to produce one or more groups selected from the group consisting of carboxyl groups, aromatic hydroxyl groups (phenolic hydroxyl groups, etc.), fluorinated alcohol groups, and sulfonic acid groups, and more preferably produces one or more groups selected from the group consisting of carboxyl groups and aromatic hydroxyl groups (phenolic hydroxyl groups, etc.).

[0223] As an acid-free radical that is released due to the action of an acid, such as any of the radicals represented by formulas (Y1) to (Y4) can be listed.

[0224] Equation (Y1): -C(Rx1)(Rx2)(Rx3)

[0225] Equation (Y2): -C(=O)OC(Rx1)(Rx2)(Rx3)

[0226] Equation (Y3): -C(R36)(R37)(OR38)

[0227] Equation (Y4): -C(Rn)(H)(Ar)

[0228] In formulas (Y1) and (Y2), Rx1 to Rx3 each independently represent an alkyl group (straight-chain or branched-chain), a cycloalkyl group (monocyclic or polycyclic), an aryl group (monocyclic or polycyclic), an aralkyl group, or an alkenyl group (straight-chain or branched-chain). Where possible, these are preferably substituents containing or having fluorine atoms.

[0229] Furthermore, when all of Rx1 to Rx3 are alkyl (straight-chain or branched-chain), it is preferable that at least two of Rx1 to Rx3 are methyl.

[0230] Wherein, Rx1 to Rx3 preferably represent straight-chain or branched-chain alkyl groups independently, and Rx1 to Rx3 more preferably represent straight-chain alkyl groups independently.

[0231] Two of Rx1 to Rx3 can be bonded together to form a ring (single ring or multiple rings).

[0232] The alkyl groups in Rx1 to Rx3 are preferably alkyl groups with 1 to 5 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, or tributyl.

[0233] The cycloalkyl groups in Rx1 to Rx3 are preferably monocyclic cycloalkyl groups such as cyclopentyl or cyclohexyl, or polycyclic cycloalkyl groups such as norbornyl, tetracyclic decyl, tetracyclic dodecyl, or adamantyl.

[0234] The aryl groups in Rx1 to Rx3 are preferably aryl groups with 6 to 10 carbon atoms, such as phenyl, naphthyl, and anthracene.

[0235] The aralkyl groups in Rx1 to Rx3 are preferably aralkyl groups with 7 to 20 carbon atoms.

[0236] The alkenyl group in Rx1~Rx3 is preferably vinyl.

[0237] The ring formed by the two bonds in Rx1 to Rx3 is preferably a cycloalkyl group. The cycloalkyl group formed by the two bonds in Rx1 to Rx3 is preferably a monocyclic cycloalkyl group such as cyclopentyl or cyclohexyl, or a polycyclic cycloalkyl group such as norbornyl, tetracyclic decyl, tetracyclic dodecyl, or adamantyl, and more preferably a monocyclic cycloalkyl group with 5 to 6 carbon atoms.

[0238] In the cycloalkyl group formed by the mutual bonding of two bonds in Rx1 to Rx3, for example, one of the methylene groups constituting the ring may be substituted with a heteroatom such as an oxygen atom, a group with a heteroatom such as a carbonyl group, or a vinylene. In addition, one or more (e.g., one to two) of the ethyl groups constituting the cycloalkane ring in such a cycloalkyl group may be substituted with vinylene.

[0239] The group represented by formula (Y1) or formula (Y2) is preferably, for example, Rx1 is methyl or ethyl, and Rx2 and Rx3 are bonded to form the cycloalkyl group.

[0240] In addition, in formula (Y1) or formula (Y2), two bonds of Rx1 to Rx3 form a cycloalkenyl group. In the cycloalkenyl group, if there is an ethene group adjacent to the C (carbon atom) explicitly stated in "C(Rx1)(Rx2)(Rx3)" in formula (Y1) or formula (Y2), the remaining one of Rx1 to Rx3 may be a hydrogen atom.

[0241] In formula (Y3), R36 to R38 each independently represent a hydrogen atom or an organogroup. R37 and R38 can also bond together to form a ring. Examples of organogroups include alkyl, cycloalkyl, aryl, aralkyl, and alkenyl groups. R36 is preferably a hydrogen atom.

[0242] As alkyl, cycloalkyl, aryl, aralkyl, and alkenyl groups represented by R36 to R38 in formula (Y3), similarly, groups described as alkyl, cycloalkyl, aryl, aralkyl, and alkenyl groups represented by Rx1 to Rx3 in formulas (Y1) and (Y2) can be listed.

[0243] R37 and R38 can bond together to form a ring.

[0244] Alternatively, R38 can bond to the main chain of the repeating unit. In this case, R38 is preferably a methylene isoalkyl group.

[0245] As for equation (Y3), it is preferred to use the basis represented by the following equation (Y3-1).

[0246] [Chemistry 14]

[0247] Here, L1 and L2 each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, or a group composed of these (e.g., a group composed of an alkyl group and an aryl group).

[0248] M represents a single bond or a divalent linker.

[0249] Q represents an alkyl group that may contain heteroatoms, a cycloalkyl group that may contain heteroatoms, an aryl group, an amino group, an ammonium group, a mercapto group, a cyano group, an aldehyde group that may contain heteroatoms, or a group composed of these (e.g., a group composed of alkyl and cycloalkyl groups).

[0250] One of the alkyl and cycloalkyl groups, such as the methylene group, may be substituted by a heteroatom such as an oxygen atom or a group with a heteroatom such as a carbonyl group.

[0251] Furthermore, it is preferable that one of L1 and L2 is a hydrogen atom and the other is an alkyl, cycloalkyl, aryl, or a group formed by combining alkyl and aryl groups.

[0252] At least two of Q, M, and L1 can bond to form a ring (preferably a 5-membered or 6-membered ring). Q can bond to a portion of the acid group protected by the group represented by formula (Y3-1) to form a ring. Q can bond to the main chain of the repeating unit to form a ring.

[0253] Regarding the refinement of the pattern, L2 is preferably a secondary or tertiary alkyl group, more preferably a tertiary alkyl group. Examples of secondary alkyl groups include isopropyl, cyclohexyl, or norbornyl, and examples of tertiary alkyl groups include tributyl or adamantyl. In these states, due to the higher Tg (glass transition temperature) and activation energy, fogging can be suppressed in addition to ensuring film strength.

[0254] In formula (Y4), Ar represents an aromatic cyclic group. Rn represents an alkyl, cycloalkyl, or aryl group. Rn and Ar can bond to each other to form a non-aromatic ring. Ar is preferably an aryl group.

[0255] Regarding the excellent acid decomposability of the repeating unit, in the case where the non-aromatic ring in the acid-free group protecting the polar group is directly bonded to the polar group (or its residue), the ring member atom adjacent to the ring member atom in the non-aromatic ring that is directly bonded to the polar group (or its residue) is preferably not a halogen atom such as a fluorine atom as a substituent.

[0256] The acid-free group that is released due to the action of acid can also be 2-cyclopentenyl with substituents (alkyl, etc.) such as 3-methyl-2-cyclopentenyl, and cyclohexyl with substituents (alkyl, etc.) such as 1,1,4,4-tetramethylcyclohexyl.

[0257] The repeating unit having an acid-decomposable group is preferably a repeating unit represented by any one of general formulas (3) to (7), and more preferably a repeating unit represented by any one of general formulas (6) to (7).

[0258] [Chemistry 15]

[0259] In general formula (3), R5 to R7 each independently represent a hydrogen atom, an alkyl group (which can be straight-chain or branched-chain, for example, 1 to 6 carbon atoms), a cycloalkyl group (monocyclic or polycyclic, for example, 3 to 15 ring members), a halogen atom, a cyano group, or an alkoxycarbonyl group (for example, 2 to 7 carbon atoms. The alkyl part can be straight-chain or branched-chain).

[0260] R5 is preferably a hydrogen atom or an alkyl group.

[0261] R6~R7 are preferably each an independent hydrogen atom.

[0262] In general formula (3), L2 represents a single bond or a divalent linker.

[0263] Examples of divalent linking groups include: -CO-, -NR-, -O-, -S-, -SO-, -SO2-, alkyl groups (preferably with 1 to 6 carbon atoms; may be straight-chain or branched-chain), cycloalkyl groups (preferably with 3 to 15 carbon atoms), alkenyl groups (preferably with 2 to 6 carbon atoms), divalent aliphatic heterocyclic groups (preferably rings with 5 to 10 ring members having at least one nitrogen atom, oxygen atom, sulfur atom, or selenium atom as a ring member), divalent aromatic heterocyclic groups (preferably rings with 5 to 10 ring members having at least one nitrogen atom, oxygen atom, sulfur atom, or selenium atom as a ring member), divalent aromatic hydrocarbon cycloalkyl groups (preferably rings with 6 to 10 ring members), and divalent linking groups formed by combining multiple of these. The R in -NR- represents a hydrogen atom or an organic group. The organic group is preferably an alkyl group (e.g., with 1 to 6 carbon atoms).

[0264] In general formula (3), R8 to R10 each independently represent alkyl, cycloalkyl, aryl, aralkyl, or alkenyl.

[0265] As alkyl, cycloalkyl, aryl, aralkyl, and alkenyl groups represented by R8 to R10 in general formula (3), similarly, groups described as alkyl, cycloalkyl, aryl, aralkyl, and alkenyl groups represented by Rx1 to Rx3 in formulas (Y1) and (Y2) can be listed.

[0266] Furthermore, two of R8 to R10 can bond together to form a ring.

[0267] The loop formed by two mutually bonded R8~R10 in general formula (3) can be similarly described as the loop formed by two bonds of Rx1~Rx3 in formulas (Y1) and (Y2).

[0268] In general formula (4), R11 to R14 each independently represent a hydrogen atom or an organic group (preferably with 1 to 6 carbon atoms). Among them, at least one of R11 and R12 represents an organic group.

[0269] In general formula (4), X1 represents -CO-, -SO-, or -SO2-.

[0270] In general formula (4), Y1 represents -O-, -S-, -SO-, -SO2-, or -NR34-. R34 represents a hydrogen atom or an organic group. The organic group is preferably an alkyl group (e.g., having 1 to 6 carbon atoms).

[0271] In general formula (4), L3 represents a single bond or a divalent linker.

[0272] As the binary linking base represented by L3 in general formula (4), similarly, bases that are described as the binary linking base represented by L2 in general formula (3) can be listed.

[0273] In general formula (4), R15 to R17 each independently represent alkyl, cycloalkyl, aryl, aralkyl, or alkenyl.

[0274] As alkyl, cycloalkyl, aryl, aralkyl, and alkenyl groups represented by R15 to R17 in general formula (4), similarly, groups described as alkyl, cycloalkyl, aryl, aralkyl, and alkenyl groups represented by Rx1 to Rx3 in formulas (Y1) and (Y2) can be listed.

[0275] Furthermore, two of R15 to R17 can bond together to form a ring.

[0276] The loop formed by two mutually bonded R15 to R17 in general formula (4) can be similarly described as the loop formed by two bonds Rx1 to Rx3 in formulas (Y1) and (Y2).

[0277] In general formula (5), R18 and R19 each independently represent a hydrogen atom or an organic group (preferably with 1 to 6 carbon atoms).

[0278] In general formula (5), R20 and R21 each independently represent a hydrogen atom, alkyl, cycloalkyl, aryl, aralkyl, or alkenyl.

[0279] As alkyl, cycloalkyl, aryl, aralkyl, and alkenyl groups represented by R20 and R21 in general formula (5), similarly, groups described as alkyl, cycloalkyl, aryl, aralkyl, and alkenyl groups represented by Rx1 to Rx3 in formulas (Y1) and (Y2) can be listed.

[0280] Furthermore, R20 and R21 can bond together to form a ring.

[0281] The ring formed by the mutual bonding of R20 and R21 in general formula (5) can be similarly illustrated as the ring formed by the two bonds of Rx1 to Rx3 in formulas (Y1) and (Y2).

[0282] In general formula (6), R22 to R24 each independently represent a hydrogen atom, an alkyl group (which can be straight-chain or branched-chain, for example, 1 to 6 carbon atoms), a cycloalkyl group (monocyclic or polycyclic, for example, 3 to 15 ring members), a halogen atom, a cyano group, or an alkoxycarbonyl group (for example, 2 to 7 carbon atoms. The alkyl part can be straight-chain or branched-chain).

[0283] In general formula (6), L4 represents a single bond or a divalent linker.

[0284] As the divalent linking base represented by L4 in general formula (6), similarly, bases that are described as the divalent linking base represented by L2 in general formula (3) can be listed.

[0285] In general formula (6), Ar1 represents an aromatic cyclic group. The aromatic cyclic group can be monocyclic or polycyclic, and as ring member atoms, it can have one or more (e.g., one to three) heteroatoms, or it can have no heteroatoms. The number of ring member atoms in the aromatic cyclic group is preferably 5 to 15.

[0286] Ar1 is preferably a benzene ring group.

[0287] In general formula (6), R25 to R27 each independently represent a hydrogen atom, alkyl, cycloalkyl, aryl, aralkyl, or alkenyl.

[0288] As alkyl, cycloalkyl, aryl, aralkyl, and alkenyl groups represented by R25 to R27 in general formula (6), similarly, groups described as alkyl, cycloalkyl, aryl, aralkyl, and alkenyl groups represented by Rx1 to Rx3 in formulas (Y1) and (Y2) can be listed.

[0289] Furthermore, R26 and R27 can bond together to form a ring.

[0290] In the case where R26 and R27 in general formula (6) are bonded together to form a ring, it is preferable that R26 and R27 together form a divalent linker. As such a divalent linker, the groups described as the divalent linker represented by L2 in the general formula (3) can be similarly listed, preferably alkyl groups.

[0291] Additionally, R24 or R25 can be bonded to Ar1.

[0292] In the case where R24 is bonded to Ar1, it is preferable that R24 is a single bond or a divalent linker bonded to the ring member atom of the aromatic ring group represented by Ar1. As such a divalent linker, the groups described as the divalent linker represented by L2 in the general formula (3) can be similarly listed, preferably alkyl groups.

[0293] Furthermore, in the case where R25 is bonded to Ar1, it is preferable that R25 becomes a divalent linker and bonds to the ring member atom of the aromatic ring group represented by Ar1. As such a divalent linker, the groups described as the divalent linker represented by L2 in the general formula (3) can be similarly listed, preferably alkyl groups.

[0294] In general formula (7), R28 to R30 each independently represent a hydrogen atom, an alkyl group (which can be straight-chain or branched-chain, for example, 1 to 6 carbon atoms), a cycloalkyl group (monocyclic or polycyclic, for example, 3 to 15 ring members), a halogen atom, a cyano group, or an alkoxycarbonyl group (for example, 2 to 7 carbon atoms. The alkyl part can be straight-chain or branched-chain).

[0295] In general formula (7), L5 represents a single bond or a divalent linker.

[0296] As the divalent linking base represented by L5 in general formula (7), similarly, bases that are described as the divalent linking base represented by L2 in general formula (3) can be listed.

[0297] R31 and R32 each independently represent a hydrogen atom, alkyl, cycloalkyl, aryl, aralkyl, or alkenyl.

[0298] R33 indicates alkyl, cycloalkyl, aryl, aralkyl, or alkenyl.

[0299] As alkyl, cycloalkyl, aryl, aralkyl, and alkenyl groups represented by R31 to R33 in general formula (7), similarly, groups described as alkyl, cycloalkyl, aryl, aralkyl, and alkenyl groups represented by Rx1 to Rx3 in formulas (Y1) and (Y2) can be listed.

[0300] Furthermore, R32 and R33 can bond together to form a ring.

[0301] In the case where R32 and R33 in general formula (7) are bonded together to form a ring, it is preferable that R32 and R33 together form a divalent linker. As such a divalent linker, the groups described as the divalent linker represented by L2 in the general formula (3) can be similarly listed, preferably alkyl groups.

[0302] The following examples illustrate repeating units with acid-decomposing groups.

[0303] Furthermore, in the following formula, Xa1 represents any one of H, CH3, CF3, and CH2OH, and Rxa and Rxb each independently represent a straight-chain or branched alkyl group (methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, or tributyl, etc.) with 1 to 5 carbon atoms.

[0304] [Chemistry 16]

[0305] [Chemistry 17]

[0306] [Chemistry 18]

[0307] [Chemistry 19]

[0308] [Chemistry 20]

[0309] [Chemistry 21]

[0310] Repeating units with acid-decomposing groups can be used alone or in two or more forms.

[0311] The content of repeating units with acid-degradable groups is preferably 5 mol% to 80 mol% relative to all repeating units of resin (A), more preferably 10 mol% to 70 mol%, and even more preferably 15 mol% to 60 mol%.

[0312] <Repeating unit with acid group>

[0313] Resin (A) may contain repeating units with acid groups.

[0314] The repeating unit having an acid group is preferably a repeating unit different from the repeating unit.

[0315] As an acid group, it is preferred to have a pKa of 13 or less. As described above, the acid dissociation constant of the acid group is preferably 13 or less, more preferably 3 to 13, and even more preferably 5 to 10.

[0316] When resin (A) contains acid groups with a pKa of 13 or less, the content of acid groups in resin (A) is not particularly limited, and is mostly between 0.2 mmol / g and 6.0 mmol / g. Preferably, it is between 0.8 mmol / g and 6.0 mmol / g, more preferably between 1.2 mmol / g and 5.0 mmol / g, and even more preferably between 1.6 mmol / g and 4.0 mmol / g. If the content of acid groups is within the aforementioned range, development proceeds well, and the resulting pattern shape and resolution are excellent.

[0317] As an acid group, it is preferably, for example, a carboxyl group, a hydroxyl group, an aromatic hydroxyl group (phenolic hydroxyl group), a fluorinated alcohol group (preferably a hexafluoroisopropanol group), a sulfonic acid group, a sulfonamide group, or an isopropanol group.

[0318] Furthermore, one or more (preferably one to two) fluorine atoms in the hexafluoroisopropanol group may be substituted with a group other than the fluorine atom (such as an alkoxycarbonyl group). The resulting -C(CF3)(OH)-CF2- is also preferably an acid group. Alternatively, one or more fluorine atoms may be substituted with a group other than the fluorine atom to form a ring containing -C(CF3)(OH)-CF2-.

[0319] Repeating units with acid groups may also have fluorine or iodine atoms.

[0320] The repeating unit having an acid group is preferably the repeating unit represented by general formula (B).

[0321] [Chemistry 22]

[0322] R3 represents a hydrogen atom, or an organic group that may have a fluorine or iodine atom.

[0323] The organic group that may have a fluorine atom or an iodine atom is preferably a group represented by -L4-R8. As L4, it represents a single bond or an ester group. R8 may include: alkyl groups that may have a fluorine atom or an iodine atom, cycloalkyl groups that may have a fluorine atom or an iodine atom, aryl groups that may have a fluorine atom or an iodine atom, or groups formed by combinations of these.

[0324] R4 and R5 each independently represent a hydrogen atom, a fluorine atom, an iodine atom, or an alkyl group that may have a fluorine atom or an iodine atom.

[0325] L2 represents a divalent group composed of a single bond, an ester group, or -CO-, -O-, and an alkyl group (preferably with 1 to 6 carbon atoms. It can be a straight chain or a branched chain. In addition, -CH2- can be substituted by a halogen atom).

[0326] L3 represents an aromatic hydrocarbon cyclic group with a valence of (n+m+1) or an alicyclic hydrocarbon cyclic group with a valence of (n+m+1). Examples of aromatic hydrocarbon cyclic groups include benzene cyclic groups and naphthyl cyclic groups. Examples of alicyclic hydrocarbon cyclic groups include monocyclic and polycyclic groups, such as cycloalkyl cyclic groups, norbornene cyclic groups, and adamantane cyclic groups.

[0327] R6 represents a hydroxyl group or a fluorinated alcohol group. The fluorinated alcohol group is preferably represented by the group in the following formula (3L).

[0328] *-L6X-R6X (3L)

[0329] L6X represents a single bond or a divalent linkage. There are no particular limitations on the divalent linkage; examples include -CO-, -O-, -SO-, -SO2-, -NRA-, alkyl groups (preferably with 1 to 6 carbon atoms; they can be straight-chain or branched-chain), and divalent linkages formed by combining multiple of these. RA can be a hydrogen atom or an alkyl group with 1 to 6 carbon atoms. Furthermore, the alkyl group may have substituents. Examples of substituents include halogen atoms (preferably fluorine atoms) and hydroxyl groups. R6X represents a hexafluoroisopropanol group.

[0330] Furthermore, when R6 is a hydroxyl group, L3 is also preferably an aromatic hydrocarbon cyclic group with a (n+m+1) valence.

[0331] R7 represents a halogen atom.

[0332] m represents an integer greater than or equal to 1. m is preferably an integer between 1 and 3, and even more preferably an integer between 1 and 2.

[0333] n represents an integer greater than or equal to 1 or 0. Ideally, n should be an integer between 1 and 4.

[0334] Furthermore, (n+m+1) is preferably an integer between 1 and 5.

[0335] The repeating unit having an acid group is preferably a repeating unit represented by the general formula (A2), and the resin (A) is preferably a repeating unit represented by the general formula (A2).

[0336] The repeating unit represented by the general formula (A2) is a repeating unit with an aromatic hydroxyl group as an acid group.

[0337] [Chemistry 23]

[0338] In general formula (A2), R101, R102, and R103 each independently represent a hydrogen atom, an alkyl group (which can be straight-chain or branched-chain, for example, 1 to 6 carbon atoms), a cycloalkyl group (monocyclic or polycyclic, for example, 3 to 15 ring members), a halogen atom, a cyano group, or an alkoxycarbonyl group (for example, 2 to 7 carbon atoms; the alkyl part can be straight-chain or branched-chain).

[0339] In general formula (A2), LA represents a single bond or a divalent linker.

[0340] As the divalent linking base represented by LA in general formula (A2), similarly, bases that are described as the divalent linking base represented by L2 in general formula (3) can be listed.

[0341] ArA represents an aromatic cyclic group (such as a benzene cyclic group).

[0342] The aromatic ring group can be monocyclic or polycyclic. As ring member atoms, it can have one or more (e.g., one to three) heteroatoms, or it can have no heteroatoms. The number of ring member atoms in the aromatic ring group is preferably 5 to 15.

[0343] In general formula (A2), k represents an integer from 1 to 5.

[0344] R102 can be bonded to ArA. In this case, R102 represents a single bond or an alkyl group (which can be straight-chain or branched-chain, with the number of carbon atoms being, for example, 1 to 6).

[0345] In this case, the aromatic cyclic group represented by ArA is bonded to the carbon atom constituting the main chain (the carbon atom bonded by R101) via the single bond or the alkyl group.

[0346] The following are examples of repeating units with acid groups.

[0347] [Chemistry 24]

[0348] In the following examples, a represents 1 or 2.

[0349] [Chemistry 25]

[0350] [Chemistry 26]

[0351] [Chemistry 27]

[0352] [Chemistry 28]

[0353] Furthermore, the repeating unit is preferably the repeating unit specifically described below. In the formula, R represents a hydrogen atom or a methyl group, and a represents 2 or 3.

[0354] [Chemistry 29]

[0355] [Chemistry 30]

[0356] [Chemistry 31]

[0357] Repeating units with acid groups can be used alone or in more than one type.

[0358] The content of repeating units with acid groups is preferably 1 mol% to 80 mol% relative to all repeating units of resin (A), more preferably 5 mol% to 60 mol%, and even more preferably 10 mol% to 50 mol%.

[0359] <Repeating unit with lactone group>

[0360] Resin (A) is also preferably a repeating unit containing a lactone group.

[0361] The repeating unit having a lactone group is preferably a repeating unit different from the repeating unit.

[0362] In addition, repeating units with lactone groups can also serve as repeating units (e.g., repeating units with acid-degrading groups).

[0363] As a lactone group, it is acceptable to have a lactone structure. The lactone structure is preferably a 5-membered to 7-membered ring lactone structure. More preferably, it is formed by ring condensation of other ring structures within the 5- to 7-membered ring lactone structure to form a bicyclic or spirocyclic structure.

[0364] The resin (A) preferably contains repeating units having lactone groups formed by removing one or more (e.g., one to two) hydrogen atoms from the lactone structure represented by any of the following formulas (LC1-1) to (LC1-21).

[0365] In addition, the lactone group can be directly bonded to the main chain. For example, the ring-membered atoms of the lactone group can form the main chain of resin (A).

[0366] [Chemistry 32]

[0367] The lactone structure may have substituents (Rb2). Examples of substituents (Rb2) include: alkyl groups having 1 to 8 carbon atoms, cycloalkyl groups having 4 to 7 carbon atoms, alkoxy groups having 1 to 8 carbon atoms, alkoxycarbonyl groups having 1 to 8 carbon atoms, carboxyl groups, halogen atoms, hydroxyl groups, cyano groups, groups containing acid-degradable groups (or the acid-degradable group itself), groups containing specific functional groups (or the specific functional group itself), and groups containing combinations of these. n2 represents an integer from 0 to 4. When n2 is 2 or more, the multiple Rb2 groups may be different, and the multiple Rb2 groups may bond together to form a ring.

[0368] One or more (e.g., one to two) methylene groups not adjacent to -COO- or -O- in the ring member atom of the lactone structure may also be substituted with heteroatoms such as -O- or -S-.

[0369] Repeating units having a lactone group include, for example, repeating units represented by the following general formula (AI).

[0370] [Chemistry 33]

[0371] In the general formula (AI), Rb0 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms.

[0372] Preferred substituents that can be present in alkyl groups of Rb0 include hydroxyl groups and halogen atoms.

[0373] Examples of halogen atoms in Rb0 include fluorine, chlorine, bromine, and iodine. Rb0 is preferably composed of hydrogen or methyl atoms.

[0374] Ab represents a single bond, an alkyl group, a divalent linker having a monocyclic or polycyclic alicyclic hydrocarbon structure, an ether group, an ester group, a carbonyl group, a carboxyl group, or a divalent group formed by combining these. Preferably, it is a single bond or a linker represented by -Ab1-CO2-. Ab1 is a straight-chain or branched alkyl group, or a monocyclic or polycyclic cycloalkyl group, preferably methylene, ethyl, cyclohexyl, adamantyl, or norbornyl.

[0375] V represents a group formed by removing a hydrogen atom from the ring member atom of the lactone structure represented by any of formulas (LC1-1) to (LC1-21).

[0376] As a repeating unit having a lactone group, it can be, for example, a repeating unit represented by general formula (AII) or general formula (AIII).

[0377] [Chemistry 34]

[0378] In general formulas (AII) and (AIII), RIII independently represents a hydrogen atom or a substituent.

[0379] RIII is preferably a hydrogen atom.

[0380] In general formula (AII), ahd1 represents a group formed by removing one hydrogen atom from each of the adjacent ring members of the lactone structure represented by any of formulas (LC1-1) to (LC1-21).

[0381] In general formula (AIII), ahd2 represents a group formed by removing two hydrogen atoms from one of the ring members of the lactone structure represented by any of formulas (LC1-1) to (LC1-21).

[0382] The following examples illustrate repeating units with lactone groups.

[0383] [Chemistry 35] (where Rx represents H and CH) [3] [、CH] [2] [OH, or CF] [3] [)]

[0384] [Chemistry 36] (where Rx represents H and CH) [3] [、CH] [2] [OH, or CF] [3] [)]

[0385] When an optical isomer is present in a repeating unit having a lactone group, any optical isomer may be used. Alternatively, a single optical isomer may be used alone, or multiple optical isomers may be used in combination. When primarily using one optical isomer, its optical purity (ee) is preferably 90 or higher, more preferably 95 or higher.

[0386] Repeating units with lactone groups can be used alone or in two or more forms.

[0387] The content of repeating units with lactone groups is preferably 1 mol% to 70 mol% relative to all repeating units in resin (A), more preferably 3 mol% to 60 mol%, and even more preferably 5 mol% to 50 mol%.

[0388] <Repeating units with sulfonyl lactone or carbonate groups>

[0389] The resin (A) is also preferably a repeating unit containing a sulfonyl lactone group or a carbonate group.

[0390] The repeating unit having a sulfonyl lactone group or a carbonate group is preferably a repeating unit different from the repeating unit.

[0391] As for the sulfonyl group, it is sufficient to have a sulfonyl structure. The sulfonyl structure is preferably a 5-membered to 7-membered cyclic sulfonyl structure. More preferably, it is formed by cyclic condensation of other ring structures within the 5- to 7-membered cyclic sulfonyl structure to form a bicyclic or spirocyclic structure.

[0392] In addition, the sulfonyl group can be directly bonded to the main chain. For example, the ring-membered atoms of the sulfonyl group can form the main chain of resin (A).

[0393] The resin (A) preferably contains repeating units having a sulfonolactone group formed by removing one or more (e.g., one or two) hydrogen atoms from the ring member atoms of the sulfonolactone structure represented by any of the following formulas (SL1-1) to (SL1-3).

[0394] [Chemistry 37]

[0395] The sulfonyl lactone structure may have a substituent (Rb2). The substituent (Rb2) in formulas (SL1-1) to (SL1-3) can be described in the same way as the substituent (Rb2) in the lactone structures represented by formulas (LC1-1) to (LC1-21).

[0396] One or more (e.g., one to two) methylene groups not adjacent to -COO- or -O- in the ring member atom of the sulfonyl lactone structure may also be substituted with heteroatoms such as -O- or -S-.

[0397] Examples of repeating units having a sulfonyl group include: repeating units in which V is substituted to a group formed by removing one hydrogen atom from a ring member atom of a sulfonyl structure represented by any of formulas (SL1-1) to (SL1-3) in repeating units represented by general formula (AII); repeating units in which ahd1 is substituted to a group formed by removing one hydrogen atom from each adjacent ring member atom of a sulfonyl structure represented by any of formulas (SL1-1) to (SL1-3) in repeating units represented by general formula (AIII); and repeating units in which ahd2 is substituted to a group formed by removing two hydrogen atoms from one ring member atom of a sulfonyl structure represented by any of formulas (SL1-1) to (SL1-3) in repeating units represented by repeating formula (AIII).

[0398] As a carbonate group, a cyclic carbonate group is preferred.

[0399] As a repeating unit having a cyclic carbonate group, it is preferably a repeating unit represented by the following formula (A-1).

[0400] [Chemistry 38]

[0401] In formula (A-1), RA1 represents a hydrogen atom, a halogen atom, or a monovalent organic group (preferably methyl).

[0402] n represents an integer greater than or equal to 0.

[0403] RA2 represents a substituent. When n is 2 or more, there can be multiple RA2s, which can be the same or different.

[0404] A represents a single bond or a divalent linker. Preferably, the divalent linker is an alkyl group, a divalent linker having a monocyclic or polycyclic alicyclic hydrocarbon structure, an ether group, an ester group, a carbonyl group, a carboxyl group, or a divalent group formed by combining these.

[0405] Z represents a group of atoms that, together with the radical represented by -O-CO-O- in the formula, form a monocyclic or polycyclic atom.

[0406] The following examples illustrate repeating units having sulfonyl lactone or carbonate groups.

[0407] [Chemistry 39] (where Rx represents H and CH) [3] [、CH] [2] [OH, or CF] [3] [)]

[0408] The content of repeating units having sulfonyl groups or carbonate groups is preferably 1 mol% or more, more preferably 10 mol% or more, relative to all repeating units in resin (A). Furthermore, as an upper limit, it is preferably 85 mol% or less, more preferably 80 mol% or less, more preferably 70 mol% or less, and particularly preferably 60 mol% or less.

[0409] <Repeating units containing fluorine or iodine atoms>

[0410] Resin (A) may contain repeating units with fluorine or iodine atoms.

[0411] The repeating unit having fluorine or iodine atoms is preferably a repeating unit different from the repeating unit.

[0412] As a repeating unit having fluorine or iodine atoms, it is preferably the repeating unit represented by formula (C).

[0413] [Chemistry 40]

[0414] L5 represents a single bond or an ester group.

[0415] R9 represents a hydrogen atom, or an alkyl group that may have a fluorine atom or an iodine atom.

[0416] R10 represents a hydrogen atom, an alkyl group that may have a fluorine atom or an iodine atom, a cycloalkyl group that may have a fluorine atom or an iodine atom, an aryl group that may have a fluorine atom or an iodine atom, or a group composed of these.

[0417] The following examples illustrate repeating units that have fluorine or iodine atoms.

[0418] [Chemistry 41]

[0419] The content of repeating units having fluorine or iodine atoms is preferably 0 mol% or more, more preferably 5 mol% or more, and even more preferably 10 mol% or more, relative to all repeating units in resin (A). Furthermore, as an upper limit, it is preferably 50 mol% or less, more preferably 45 mol% or less, and even more preferably 40 mol% or less.

[0420] <The repeating unit represented by equation (V-1) or equation (V-2) below>

[0421] Resin (A) may have repeating units represented by the following formula (V-1) or the following formula (V-2).

[0422] The repeating units represented by the following formulas (V-1) and (V-2) are preferably different from the repeating units.

[0423] [Chemistry 42]

[0424] In the formula, R6 and R7 each independently represent a hydrogen atom, hydroxyl group, alkyl group, alkoxy group, acetoxy group, cyano group, nitro group, amino group, halogen atom, ester group (-OCOR or -COOR: R is an alkyl group or fluorinated alkyl group with 1 to 6 carbon atoms), or carboxyl group. As an alkyl group, it is preferred to be a straight-chain, branched-chain, or cyclic alkyl group with 1 to 10 carbon atoms.

[0425] n3 represents an integer from 0 to 6.

[0426] n4 represents an integer from 0 to 4.

[0427] X4 represents a methylene group, an oxygen atom, or a sulfur atom.

[0428] The following examples illustrate the repeating units represented by equation (V-1) or equation (V-2).

[0429] As a repeating unit represented by formula (V-1) or formula (V-2), for example, the repeating unit described in paragraph

[0100] of International Publication No. 2018 / 193954 can be cited.

[0430] The content of the repeating unit represented by formula (V-1) or formula (V-2) below is preferably 1 mol% to 65 mol% relative to all repeating units in resin (A), and more preferably 5 mol% to 45 mol%.

[0431] <Repetitive units used to reduce the dynamism of the main chain>

[0432] Resin (A) may contain repeating units that reduce the mobility of the main chain as repeating units different from repeating unit a1.

[0433] From the viewpoint of suppressing excessive diffusion of acid or pattern degradation during development, resin (A) preferably has a high glass transition temperature (Tg). Tg is preferably greater than 90°C, more preferably greater than 100°C, further preferably greater than 110°C, and especially preferably greater than 125°C. Furthermore, excessively high Tg leads to a decrease in the dissolution rate in the developer; therefore, Tg is preferably below 400°C, and more preferably below 350°C.

[0434] Furthermore, in this specification, the glass transition temperature (Tg) of polymers such as resin (A) is calculated using the following method. First, the Tg of the homopolymer containing only each repeating unit in the polymer is calculated individually using the Bicerano method. The calculated Tg will be referred to as the "Tg of the repeating unit". Second, the mass ratio (%) of each repeating unit relative to all repeating units in the polymer is calculated. Next, the Tg of each mass ratio is calculated using the Fox formula (described in Materials Letters 62 (2008) 3152, etc.), and these are summed to be set as the Tg (°C) of the polymer.

[0435] The Bicerano method is described in "Prediction of polymer properties," Marcel Dekker Inc., New York (1993), etc. Furthermore, the Tg calculated using the Bicerano method can be performed using polymer property estimation software such as MDL Polymer (MDL Information Systems, Inc.).

[0436] In order to increase the Tg of resin (A) (preferably setting Tg to exceed 90°C), it is preferable to reduce the mobility of the main chain of resin (A). Methods for reducing the mobility of the main chain of resin (A) are listed below (a) to (e).

[0437] (a) Introducing large substituents into the main chain

[0438] (b) Introducing multiple substituents into the main chain

[0439] (c) Introducing substituents into the vicinity of the main chain to induce interactions between resins (A).

[0440] (d) Forming a main chain with a ring structure

[0441] (e) Connection between the ring structure and the main chain

[0442] Furthermore, resin (A) is preferably a repeating unit with a Tg of 130°C or higher, which is a homopolymer.

[0443] Furthermore, there are no particular restrictions on the types of repeating units with a Tg of 130°C or higher in the homopolymer, as long as the repeating unit has a Tg of 130°C or higher as calculated by the Bicerano method. Moreover, the types of functional groups in the repeating units represented by equations (A) to (E) described later correspond to repeating units with a Tg of 130°C or higher in the homopolymer.

[0444] (The repeating unit represented by equation (A))

[0445] As an example of a specific method of achieving (a), a method of introducing the repeating unit represented by formula (A) into the resin (A) can be cited.

[0446] [Chemistry 43]

[0447] In formula (A), RA represents a group with a polycyclic structure. Rx represents a hydrogen atom, a methyl group, or an ethyl group. A group with a polycyclic structure is a group with multiple ring structures, which may or may not be condensed.

[0448] As a specific example of the repeating unit represented by formula (A), those described in paragraphs

[0107] to

[0119] of International Publication No. 2018 / 193954 can be cited.

[0449] The content of the repeating unit represented by formula (A) is preferably 1 mol% to 65 mol% relative to all repeating units in resin (A), and more preferably 5 mol% to 45 mol%.

[0450] (The repeating unit represented by equation (B))

[0451] As an example of a specific method of achieving (b), the method of introducing the repeating unit represented by formula (B) into the resin (A) can be cited.

[0452] [Chemistry 44]

[0453] In formula (B), Rb1 to Rb4 each independently represent a hydrogen atom or an organic group, and at least two of Rb1 to Rb4 represent organic groups.

[0454] Furthermore, there are no particular restrictions on the types of other organic groups, provided that at least one of the organic groups is a group whose main chain in the repeating unit is directly linked to a ring structure.

[0455] In addition, if none of the organic groups are groups with a ring structure directly linked to the main chain of the repeating unit, then at least two of the organic groups are substituents with a number of three or more structural atoms other than hydrogen atoms.

[0456] As a specific example of the repeating unit represented by formula (B), those described in paragraphs

[0113] to

[0115] of International Publication No. 2018 / 193954 can be cited.

[0457] The content of the repeating unit represented by formula (B) is preferably 1 mol% to 65 mol% relative to all repeating units in resin (A), and more preferably 5 mol% to 45 mol%.

[0458] (The repeating unit represented by equation (C))

[0459] As an example of a specific method of achieving (c), the method of introducing the repeating unit represented by formula (C) into the resin (A) can be cited.

[0460] [Chemistry 45]

[0461] In formula (C), Rc1 to Rc4 each independently represent a hydrogen atom or an organic group, and at least one of Rc1 to Rc4 is a group in which a hydrogen atom with hydrogen bonding at least 3 atoms originating from a carbon atom in the main chain. Preferably, the hydrogen atom with hydrogen bonding at least 2 atoms (closer to the main chain) is used to induce the interaction between the main chains of resin (A).

[0462] As a specific example of the repeating unit represented by formula (C), those described in paragraphs

[0119] to

[0121] of International Publication No. 2018 / 193954 can be cited.

[0463] The content of the repeating unit represented by formula (C) is preferably 1 mol% to 65 mol% relative to all repeating units in resin (A), and more preferably 5 mol% to 45 mol%.

[0464] (The repeating unit represented by equation (D))

[0465] As an example of a specific method of achieving (d), the method of introducing the repeating unit represented by formula (D) into the resin (A) can be cited.

[0466] [Chemistry 46]

[0467] In formula (D), "cyclic" means that the main chain is formed in a ring structure. There is no particular restriction on the number of atoms in the ring structure.

[0468] As a specific example of the repeating unit represented by formula (D), those described in paragraphs

[0126] to

[0127] of International Publication No. 2018 / 193954 can be cited.

[0469] The content of the repeating unit represented by formula (D) is preferably 1 mol% to 65 mol% relative to all repeating units in resin (A), and more preferably 5 mol% to 45 mol%.

[0470] (The repeating unit represented by equation (E))

[0471] As an example of a specific method of achieving (e), the method of introducing the repeating unit represented by formula (E) into the resin (A) can be cited.

[0472] [Chemistry 47]

[0473] In formula (E), Re independently represents either a hydrogen atom or an organic group. Examples of organic groups include alkyl, cycloalkyl, aryl, aralkyl, and alkenyl groups, which may have substituents.

[0474] A "cyclic" is a cyclic group that contains carbon atoms in the main chain. There is no particular limit to the number of atoms contained in a cyclic group.

[0475] As a specific example of the repeating unit represented by formula (E), those described in paragraphs

[0131] to

[0133] of International Publication No. 2018 / 193954 can be cited.

[0476] The content of the repeating unit represented by formula (E) is preferably 1 mol% to 65 mol% relative to all repeating units in resin (A), and more preferably 5 mol% to 45 mol%.

[0477] <Repeating units with hydroxyl or cyano groups>

[0478] Resin (A) may contain repeating units with hydroxyl or cyano groups. This improves substrate adhesion and developer affinity.

[0479] The repeating unit having a hydroxyl or cyano group is preferably a repeating unit different from the repeating unit (especially the repeating unit having an acid group).

[0480] The repeating unit having a hydroxyl or cyano group is preferably a repeating unit having an alicyclic hydrocarbon structure substituted with a hydroxyl or cyano group.

[0481] The repeating unit having a hydroxyl or cyano group is preferably free of acid-degradable groups. Examples of repeating units having a hydroxyl or cyano group include those described in paragraphs

[0153] to

[0158] of International Publication No. 2020 / 004306.

[0482] The content of repeating units having hydroxyl or cyano groups is preferably 1 mol% to 65 mol% relative to all repeating units in resin (A), and more preferably 5 mol% to 45 mol%.

[0483] <Repeating unit with an alicyclic hydrocarbon structure that does not exhibit acid decomposition properties>

[0484] Resin (A) may contain repeating units with an alicyclic hydrocarbon structure that do not exhibit acid decomposition properties.

[0485] The repeating unit having an alicyclic hydrocarbon structure and not exhibiting acid decomposition properties is preferably a repeating unit different from the repeating unit.

[0486] This reduces the leaching of low-molecular-weight components from the resist film into the immersion solution during immersion exposure. Examples of such repeating units include repeating units derived from 1-adamantyl (meth)acrylate, disadamantyl (meth)acrylate, tricyclodecane (meth)acrylate, or cyclohexyl (meth)acrylate.

[0487] The content of repeating units having an alicyclic hydrocarbon structure and not exhibiting acid decomposition ability is preferably 1 mol% to 65 mol% relative to all repeating units in resin (A), and more preferably 5 mol% to 45 mol%.

[0488] <The repeating unit represented by formula (III) that does not contain either a hydroxyl or a cyano group>

[0489] Resin (A) may contain repeating units represented by formula (III) that do not have either hydroxyl or cyano groups.

[0490] [Chemistry 48]

[0491] In formula (III), R5 represents a hydrocarbon group having at least one cyclic structure and not having either a hydroxyl or a cyano group.

[0492] Ra represents a hydrogen atom, an alkyl group, or a -CH2-O-Ra2 group. In the formula, Ra2 represents an alkyl or acetyl group.

[0493] R5 has a cyclic structure that includes both monocyclic and polycyclic hydrocarbon groups. Examples of monocyclic hydrocarbon groups include cycloalkyl groups with 3 to 12 carbon atoms (more preferably 3 to 7 carbon atoms) or cycloalkenyl groups with 3 to 12 carbon atoms.

[0494] For detailed definitions of each basis in equation (III) and specific examples of repeating units, see paragraphs

[0169] to

[0173] of International Publication No. 2020 / 004306.

[0495] The content of the repeating unit represented by formula (III) that does not have either hydroxyl or cyano groups, relative to all repeating units in resin (A), is preferably 1 mol% to 65 mol%, more preferably 5 mol% to 45 mol.

[0496] <Other repeating units>

[0497] Furthermore, resin (A) may have repeating units other than the repeating units mentioned above.

[0498] For example, resin (A) may contain repeating units selected from the group consisting of repeating units having an oxathiane ring group, repeating units having an oxazolone ring group, repeating units having a dioxane ring group, repeating units having a hydantoin ring group, and repeating units having a cyclobutane ring group.

[0499] The content of other repeating units relative to all repeating units in resin (A) is preferably 1 mol% to 65 mol%, more preferably 5 mol% to 45 mol%.

[0500] The following are examples of such repeating units.

[0501] [Chemistry 49]

[0502] In addition to having the aforementioned repeating structural units, resin (A) may also have various repeating structural units for purposes such as adjusting dry etching resistance, standard developer compatibility, substrate adhesion, resist profile, resolution, heat resistance, and sensitivity.

[0503] Resin (A) can be synthesized by conventional methods (e.g., free radical polymerization).

[0504] Using the GPC method, the weight-average molecular weight of resin (A), converted to polystyrene, is preferably 1,000 to 200,000, more preferably 3,000 to 20,000, and even more preferably 5,000 to 15,000. By setting the weight-average molecular weight of resin (A) within the aforementioned range, the degradation of heat resistance and dry etching resistance can be further suppressed. Furthermore, the degradation of developability and the degradation of film-forming properties due to increased viscosity can also be further suppressed.

[0505] The dispersion (molecular weight distribution) of resin (A) is typically 1.0 to 5.0, preferably 1.0 to 3.0, more preferably 1.2 to 3.0, and even more preferably 1.2 to 2.0. The smaller the dispersion, the better the resolution and resist shape, resulting in smoother sidewalls and better roughness of the resist pattern.

[0506] Resin (A) can be used alone or in combination with two or more.

[0507] In the resist composition, the content of resin (A) is preferably 10% to 99.9% by mass, more preferably 40% to 99.5% by mass, and even more preferably 65% ​​to 99% by mass, relative to the total solid content of the composition.

[0508] In the resist composition, the molar amount of repeating unit (a) relative to the total solid content of the resist composition is preferably 0.05 mmol / g to 5.00 mmol / g, more preferably 0.15 mmol / g to 4.00 mmol / g, even more preferably 0.50 mmol / g to 2.50 mmol / g, and particularly preferably 0.70 mmol / g to 1.50 mmol / g.

[0509] The molar amount of the repeating unit (a) can be appropriately adjusted by setting the content of resin (A) relative to the total solids content of the resist composition and the content of repeating unit (a) relative to all repeating units of resin (A).

[0510] Furthermore, the term "solid component" refers to the components that form the resist film and does not include solvents. Additionally, any component that forms the resist film is considered a solid component, even if it is in liquid form.

[0511] When the resist composition does not contain a photoacid generator, the molar amount of the repeating unit (a) relative to the total solid content of the resist composition is 0.50 mmol / g or more, preferably 0.70 mmol / g or more, and more preferably 1.00 mmol / g or more. The upper limit of the molar amount is, for example, 5.00 mmol / g or less, preferably 3.00 mmol / g or less, and more preferably 2.50 mmol / g or less.

[0512] When the resist composition includes a photoacid generator, the total molar amount of the repeating unit (a) and the photoacid generator relative to the total solid content of the resist composition is 0.50 mmol / g or more, preferably 0.70 mmol / g or more, and more preferably 1.00 mmol / g or more. The upper limit of the total molar amount is, for example, 5.00 mmol / g or less, preferably 3.00 mmol / g or less, and more preferably 2.50 mmol / g or less.

[0513] In the resist composition, the molar amount of the repeating unit (a) relative to the total molar amount of the repeating unit (a) and the photoacid generator is preferably 5 mol% to 100 mol, more preferably 15 mol% to 99 mol, and even more preferably 25 mol% to 90 mol.

[0514] The photoacid generator will be discussed later.

[0515] [Photoacid generators (compounds that produce acids through exposure to photochemical rays or radiation)]

[0516] The resist composition of the present invention may include a photoacid generator (a compound that produces acid by irradiation with photochemical rays or radiation) as a component different from the stated component.

[0517] Photoacid generators are components that produce acid through exposure to photochemical rays or radiation.

[0518] Furthermore, the acid produced by the compound that generates acid through irradiation by photochemical rays or radiation is an acid produced separately from the acid produced by the repeating unit (a) in the resin (A).

[0519] In addition, repeating units other than repeating units (a) in the resin (or resin (A)) contained in the resist composition that generate acid by irradiation with photochemical rays or radiation can also be used as photoacid generators.

[0520] The photoacid generator is preferably a low-molecular-weight compound, and the resist composition preferably includes a photoacid generator as a low-molecular-weight compound.

[0521] The molecular weight of the photoacid generator, which is a low-molecular-weight compound, is preferably 3000 or less, more preferably 2000 or less, and even more preferably 1000 or less. The lower limit of the molecular weight is, for example, 100 or more.

[0522] The content of the photoacid generator as a low molecular weight compound is preferably 10% to 100% by mass, more preferably 60% to 100% by mass, and even more preferably 90% to 100% by mass, relative to all photoacid generators.

[0523] As will be described later, part or all of the photoacid generator (preferably a low molecular weight photoacid generator) may also be a photodegradable alkaline compound as described later.

[0524] There are no particular limitations on the photoacid generator, but it is preferred to be a compound that produces organic acids by irradiation with photochemical rays or radiation (preferably an electron beam or extreme ultraviolet radiation).

[0525] The organic acid is preferably, for example, at least one of sulfonic acid, bis(alkylsulfonyl)imidin, and tri(alkylsulfonyl)methylation.

[0526] Photoacid generators can be ionic or nonionic compounds, but are preferably ionic compounds.

[0527] As an ionic compound, the photoacid generator can be either a photoacid generator of onium salt or an intramolecular salt (betaine compound).

[0528] (As a photoacid generator for onium salts)

[0529] Photoacid generators that are onium salts typically have both cationic and anionic sites.

[0530] Examples of photoacid generators for onium salts include compounds represented by "Mp+m Xq-n".

[0531] In “Mp+m Xq-n”, p, q, m, and n each independently represent an integer greater than or equal to 1 (preferably an integer from 1 to 8).

[0532] Mp+ represents an organic cation with a p-valence. An organic cation may include a cation site as part of itself, or it may be the cation site itself. Preferably, the organic cation is the cation site itself.

[0533] Xq- represents an organic anion with a charge of q. An organic anion may include the anionic site as a part, or the anionic site itself. Preferably, an organic anion includes the anionic site as a part.

[0534] When multiple Mp+ and Xq- exist, they can be the same or different.

[0535] The value obtained by multiplying the average of p in multiple Mp+ groups by m is the same as the value obtained by multiplying the average of q in multiple Xq- groups by n.

[0536] Among them, the preferred value is p = 1.

[0537] For example, it is preferable that p, q, m, and n are all 1.

[0538] Alternatively, it is preferable to have p = 1, q = 2~8, m = the same value as q, and n = 1.

[0539] Organic cations

[0540] As organic cations, the organic cations described in the description of repeating unit (a) can be used in the same way.

[0541] Organic anions

[0542] Examples of organic anions include: phenolic hydroxyl anions, sulfonate anions (aliphatic sulfonate anions, aromatic sulfonate anions, and camphor sulfonate anions, etc.), carboxylate anions (aliphatic carboxylate anions, aromatic carboxylate anions, aralkyl carboxylate anions, formate anions, and bicarbonate anions, etc.), carbonylsulfonylimide anions, bis(sulfonylimide)imide anions (bis(alkylsulfonylimide)imide anions, etc.), bis(carbonyl)imide anions, and tri(alkylsulfonylimide)methyl anions.

[0543] The aliphatic portion of the aliphatic sulfonate anion and the aliphatic carboxylate anion can be alkyl or cycloalkyl, preferably a straight-chain or branched alkyl with 1 to 30 carbon atoms, or a cycloalkyl with 3 to 30 carbon atoms.

[0544] The alkyl group may be, for example, a fluoroalkyl group (which may or may not have substituents other than fluorine atoms. It may also be a perfluoroalkyl group).

[0545] The cycloalkyl group can be monocyclic or polycyclic, and one or more (preferably one to two) of the -CH2- group constituting the ring structure can be substituted with heteroatoms (-O- or -S-, etc.), -SO2-, -SO3-, ester group, or carbonyl group.

[0546] The aryl group in the aromatic sulfonate anion and the aromatic carboxylate anion is preferably an aryl group with 6 to 14 carbon atoms, such as phenyl, tolyl, and naphthyl.

[0547] The listed alkyl, cycloalkyl, and aryl groups may have substituents. There are no particular limitations on the substituents, but examples include: nitro, halogen atoms such as fluorine or chlorine atoms, carboxyl, hydroxyl, amino, cyano, alkoxy (preferably 1-15 carbon atoms), alkyl (preferably 1-10 carbon atoms), cycloalkyl (preferably 3-15 carbon atoms), aryl (preferably 6-14 carbon atoms), alkoxycarbonyl (preferably 2-7 carbon atoms), acetyl (preferably 2-12 carbon atoms), alkoxycarbonyloxy (preferably 2-7 carbon atoms), alkylthio (preferably 1-15 carbon atoms), alkylsulfonyl (preferably 1-15 carbon atoms), alkyliminosulfonyl (preferably 1-15 carbon atoms), and aryloxysulfonyl (preferably 6-20 carbon atoms), etc.

[0548] The aralkyl group in the aralkyl carboxylate anion is preferably an aralkyl group with 7 to 14 carbon atoms, such as benzyl, phenethyl, naphthylmethyl, naphthylethyl, and naphthylbutyl.

[0549] Examples of sulfonylimid anions include, for instance, saccharin anion.

[0550] The alkyl group in the bis(alkylsulfonyl)imine anion and the tri(alkylsulfonyl)methyl anion is preferably an alkyl group having 1 to 5 carbon atoms. Examples of substituents for these alkyl groups include: halogen atoms, alkyl groups substituted with halogen atoms, alkoxy groups, alkylthio groups, alkyloxysulfonyl groups, aryloxysulfonyl groups, and cycloalkylaryloxysulfonyl groups, preferably fluorine atoms or alkyl groups substituted with fluorine atoms.

[0551] In addition, the alkyl groups in the bis(alkylsulfonyl)imidin anion can bond with each other to form a ring structure.

[0552] As an organic anion, it is also preferred to be an aliphatic sulfonate anion in which at least α-position of sulfonic acid is substituted with a fluorine atom (such as an aliphatic sulfonate anion in which one or two fluorine atoms are substituted at α-position), an aliphatic sulfonate anion in which α-position of sulfonic acid is not substituted with a fluorine atom (such as an aliphatic sulfonate anion in which fluorine atom is not substituted at α-position, or substituted with zero to three fluorine atoms or perfluoroalkyl at β-position), an aromatic sulfonate anion substituted with a fluorine atom or a group having a fluorine atom, a bis(alkylsulfonyl)imidin anion in which an alkyl atom is substituted with a fluorine atom, or a tri(alkylsulfonyl)methyl anion in which an alkyl atom is substituted with a fluorine atom.

[0553] In addition, the organic anion is preferably the anion represented by the following formula (AN).

[0554] [Transformation 50]

[0555] In equation (AN), o represents an integer from 0 to 5. p represents an integer from 0 to 10. q represents an integer from 0 to 10.

[0556] In formula (AN), AX represents -SO3- or -COO-.

[0557] In formula (AN), Xf represents a fluorine atom or an alkyl group substituted with at least one fluorine atom. The alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 4. Furthermore, the alkyl group substituted with at least one fluorine atom is preferably a perfluoroalkyl group.

[0558] Xf is preferably a fluorine atom or a perfluoroalkyl group having 1 to 4 carbon atoms, more preferably a fluorine atom or CF3. In particular, it is even more preferably that Xf is a fluorine atom in both cases.

[0559] In formula (AN), R4 and R5 each independently represent a hydrogen atom, a fluorine atom, an alkyl group, or an alkyl group substituted with at least one fluorine atom. In the presence of multiple R4 and R5 groups, R4 and R5 may be the same or different.

[0560] The alkyl groups represented by R4 and R5 may have substituents other than fluorine atoms, preferably having 1 to 4 carbon atoms.

[0561] Specific examples and preferred states of alkyl groups substituted with at least one fluorine atom are the same as those of Xf.

[0562] R4 and R5 are preferably hydrogen atoms.

[0563] Furthermore, it is also preferable that one of R4 and R5 bonded to the same carbon atom is a hydrogen atom, and the other is a fluorine atom or an alkyl group substituted with at least one fluorine atom. Preferably, in the -C(R4)(R5)- position closest to and / or second closest to AX, one of R4 and R5 bonded to the same carbon atom is a hydrogen atom, and the other is a fluorine atom or an alkyl group substituted with at least one fluorine atom. Additionally, it is also preferable that in the -C(R4)(R5)- position closest to and / or second closest to AX, R4 and R5 are each independently a hydrogen atom or an alkyl group (which may have substituents other than fluorine atoms).

[0564] In equation (AN), L represents a divalent linkage base. When there are multiple Ls, they can be the same or different.

[0565] Examples of divalent linkers include: -O-CO-O-, -COO-, -OCO-, -CONH-, -NHCO-, -CO-, -O-, -S-, -SO-, -SO2-, alkylene groups (preferably with 1 to 6 carbon atoms), cycloalkylene groups (preferably with 3 to 15 carbon atoms), alkenylene groups (preferably with 2 to 6 carbon atoms), and divalent linkers formed by combining multiple of these. Preferably, the alkyl group is -O-CO-O-, -COO-, -OCO-, -CONH-, -NHCO-, -CO-, -O-, -SO2-, -O-CO-O-alkyl-, -alkyl-O-CO-O-, -COO-alkyl-, -OCO-alkyl-, -CONH-alkyl-, or -NHCO-alkyl-, and more preferably -O-CO-O-, -O-CO-O-alkyl-, -alkyl-O-CO-O-, -COO-, -OCO-, -CONH-, -SO2-, -COO-alkyl-, or -OCO-alkyl-.

[0566] In formula (AN), W represents an organic group containing a cyclic structure. Preferably, the organic group is cyclic.

[0567] Examples of cyclic organic groups include alicyclic groups, aryl groups, and heterocyclic groups.

[0568] Alicyclic groups can be monocyclic or polycyclic. Examples of monocyclic alicyclic groups include cyclopentyl, cyclohexyl, and cyclooctyl. Examples of polycyclic alicyclic groups include norbornyl, tricyclic decyl, tetracyclic decyl, tetracyclic dodecyl, and adamantyl. Preferably, these are alicyclic groups with a large volumetric structure having 7 or more carbon atoms, such as norbornyl, tricyclic decyl, tetracyclic decyl, tetracyclic dodecyl, and adamantyl.

[0569] The aryl group can be monocyclic or polycyclic. Examples of aryl groups include phenyl, naphthyl, phenanthryl, and anthracene.

[0570] The heterocyclic group can be monocyclic or polycyclic. Furthermore, the heterocyclic group can be aromatic or non-aromatic. Examples of aromatic heterocycles include: furan rings, thiophene rings, benzofuran rings, benzothiophene rings, dibenzofuran rings, dibenzothiophene rings, and pyridine rings. Examples of non-aromatic heterocycles include: tetrahydropyran rings, lactone rings, sulfonyl lactone rings, and decahydroisoquinoline rings. The heterocycle in the heterocyclic group is preferably a furan ring, a thiophene ring, a pyridine ring, or a decahydroisoquinoline ring.

[0571] The cyclic organic group may have substituents. Examples of such substituents include: alkyl groups (which may be linear or branched, preferably with 1 to 12 carbon atoms), cycloalkyl groups (which may be monocyclic, polycyclic, or spirocyclic, preferably with 3 to 20 carbon atoms), aryl groups (preferably with 6 to 14 carbon atoms), hydroxyl groups, alkoxy groups, ester groups, amide groups, carbamate groups, urea groups, thioether groups, sulfonamide groups, and sulfonate groups. Furthermore, the carbon atom constituting the cyclic organic group (the carbon atom that contributes to ring formation) may also be a carbonyl carbon.

[0572] The preferred anion represented by formula (AN) is AX-CF2-CH2-OCO-(L)q'-W, AX-CF2-CHF-CH2-OCO-(L)q'-W, AX-CF2-COO-(L)q'-W, AX-CF2-CF2-CH2-CH2-(L)qW, or AX-CF2-CH(CF3)-OCO-(L)q'-W. Here, AX, L, q, and W are the same as in formula (AN). q' represents an integer from 0 to 10.

[0573] The anion is preferably an anion represented by any one of the general formulas (d1-1) to (d1-3).

[0574] [Chemistry 51]

[0575] In formula (d1-1), R51 represents a hydrocarbon group that may have substituents (e.g., hydroxyl and / or fluorine atoms). Examples of such hydrocarbon groups include alkyl groups (which may be straight-chain or branched-chain, preferably having 6 to 15 carbon atoms) and aryl groups (which may be monocyclic or polycyclic, preferably having 6 to 15 carbon atoms).

[0576] In formula (d1-2), Z2c represents a hydrocarbon group with 1 to 30 carbon atoms that may have substituents. Preferably, in the hydrocarbon group, the α carbon and / or β carbon are not bonded to fluorine atoms relative to the sulfur atom in -SO3-.

[0577] The hydrocarbon group in Z2c can be linear, branched, or cyclic. Furthermore, the carbon atom in the hydrocarbon group (preferably the carbon atom forming the cyclic structure if the hydrocarbon group has a cyclic structure) can be a carbonyl carbon (-CO-). Examples of hydrocarbon groups include those containing norbornyl, which can have substituents. The carbon atom forming the norbornyl group can be substituted with a carbonyl carbon.

[0578] The hydrocarbon group in Z2c is preferably an aryl group. The aryl group can be monocyclic or polycyclic, and the number of carbon atoms is preferably 6 to 15. The aryl group is also preferably a substituent containing a nitrogen atom.

[0579] In addition, "Z2c-SO3-" in general formula (d1-2) is preferably different from the anion represented by general formula (AN).

[0580] In formulas (d1-3), R52 represents an organogroup. The organogroup is preferably an alkyl group, more preferably an alkyl group having 1 to 10 carbon atoms. The alkyl group can be linear, branched, or cyclic. Fluorine atoms are preferred as substituents in the alkyl group. The alkyl group can also be a perfluoroalkyl group.

[0581] Y3 represents a single bond, -CO-, an alkyl group, or an aryl group. The alkyl group can be linear, branched, or cyclic. The alkyl group preferably has 1 to 7 carbon atoms. The aryl group preferably has 6 to 15 carbon atoms.

[0582] Rf represents a hydrocarbon group. The hydrocarbon group preferably has 1 to 30 carbon atoms. It can be a straight chain, a branched chain, or have a cyclic structure. Furthermore, the carbon atom in the hydrocarbon group (preferably the carbon atom forming the cyclic structure when the hydrocarbon group has a cyclic structure) can be a carbonyl carbon (-CO-). Examples of the hydrocarbon group include groups containing norbornyl, which can have substituents. The carbon atom forming the norbornyl group can be a carbonyl carbon. Alkyl groups such as methyl are also preferred.

[0583] Fluorine atoms can be listed as a substituent that the hydrocarbon group may have.

[0584] In addition, the portion other than the organic cation in the compound represented by any of the formulas (Ia-1) to (Ia-5) described below, and the compound represented by any of the formulas (IIa-1) and (IIa-2) below, may also be used as an organic anion.

[0585] Compound (I) and Compound (II)

[0586] The photoacid generator as an onium salt may be one or more selected from the group consisting of compounds (I) and (II) described below.

[0587] Compounds (I) and (II) are also compounds that produce acids by exposure to photochemical rays or radiation (photoacid generators).

[0588] Compound (I)

[0589] Compound (I) is a compound having one or more structural sites X and one or more structural sites Y, and producing an acid by irradiation with photochemical rays or radiation, wherein the acid comprises a first acidic site derived from structural site X and a second acidic site derived from structural site Y.

[0590] Structural site X: A structural site containing an anionic site A1- and a cation site M1+, which forms the first acidic site represented by HA1 through irradiation by photochemical rays or radiation.

[0591] Structural site Y: A structural site containing an anionic site A2- and a cationic site M2+, which forms the second acidic site represented by HA2 through irradiation by photochemical rays or radiation.

[0592] Among them, compound (I) satisfies the following condition I.

[0593] Condition I: In the compound (I), the compound PI formed by replacing the cation M1+ in the structural site X and the cation M2+ in the structural site Y with H+ has an acid dissociation constant a1 and an acid dissociation constant a2. The acid dissociation constant a1 originates from the acidic site represented by HA1, which is formed by replacing the cation M1+ in the structural site X with H+. The acid dissociation constant a2 originates from the acidic site represented by HA2, which is formed by replacing the cation M2+ in the structural site Y with H+. The acid dissociation constant a2 is greater than the acid dissociation constant a1.

[0594] The following is a more detailed explanation of condition I.

[0595] In the case of compound (I), for example, a compound that produces an acid having a first acidic site derived from the structural site X and a second acidic site derived from the structural site Y, compound PI is equivalent to "a compound having HA1 and HA2".

[0596] To explain the acid dissociation constants a1 and a2 of this compound PI in more detail, when the acid dissociation constants of compound PI are determined, the pKa of compound PI as "a compound having A1- and HA2" is the acid dissociation constant a1, and the pKa of "a compound having A1- and HA2" as "a compound having A1- and A2-" is the acid dissociation constant a2.

[0597] Furthermore, in the case of compound (I), for example, a compound that produces an acid having two first acidic sites derived from the structural site X and one second acidic site derived from the structural site Y, compound PI is equivalent to "a compound having two HA1 and one HA2".

[0598] When the acid dissociation constant of compound PI is determined, the acid dissociation constant when compound PI is "a compound having one Al-, one HA1, and one HA2", and the acid dissociation constant when "a compound having one Al-, one HA1, and one HA2" is "a compound having two Al- and one HA2", are equivalent to the acid dissociation constant a1. Furthermore, the acid dissociation constant when "a compound having two Al- and one HA2" is "a compound having two Al- and A2-", is equivalent to the acid dissociation constant a2. That is, in the case of compound PI, when it has multiple acid dissociation constants derived from the acidic sites represented by HA1 formed by replacing the cation site M1+ in the structural site X with H+, the value of acid dissociation constant a2 is larger than the largest value among the multiple acid dissociation constants a1. Furthermore, when the acid dissociation constant of compound PI is defined as "aa" for a compound having "one Al-, one HA1, and one HA2", and the acid dissociation constant of "ab" for a compound having "two Al- and one HA2", the relationship between aa and ab satisfies aa <ab。

[0599] The acid dissociation constants a1 and a2 are determined by the method for determining the acid dissociation constant.

[0600] The compound PI is equivalent to the acid produced when compound (I) is irradiated with photochemical rays or radiation.

[0601] When compound (I) has two or more structural sites X, the structural sites X may be the same or different. In addition, the two or more Al- and the two or more M1+ may be the same or different.

[0602] In addition, A1- and A2-, as well as M1+ and M2+ in compound (I) may be the same or different, and A1- and A2- are preferably different.

[0603] Regarding the aspect of further reducing the LWR of the formed pattern, in the compound PI, the difference between the acid dissociation constant a1 (which is the maximum value when multiple acid dissociation constants a1 exist) and the acid dissociation constant a2 is preferably 0.1 or more, more preferably 0.5 or more, and even more preferably 1.0 or more. Furthermore, there is no particular limitation on the upper limit of the difference between the acid dissociation constant a1 (which is the maximum value when multiple acid dissociation constants a1 exist) and the acid dissociation constant a2, for example, it is 16 or less.

[0604] Furthermore, in terms of further reducing the LWR of the formed pattern, the acid dissociation constant a2 in the compound PI is, for example, 20 or less, preferably 15 or less. Moreover, as a lower limit value for the acid dissociation constant a2, it is preferably -4.0 or more.

[0605] Furthermore, regarding the potential to further reduce the LWR of the formed pattern, the acid dissociation constant a1 in the compound PI is preferably 2.0 or less, and more preferably 0 or less. Moreover, as a lower limit value for the acid dissociation constant a1, it is preferably -20.0 or more.

[0606] Anionic sites A1- and A2- are structural sites containing negatively charged atoms or groups of atoms. Examples include structural sites selected from the group consisting of formulas (AA-1) to (AA-3) and (BB-1) to (BB-6) shown below. As anionic site A1-, it is preferable to form an acidic site with a small acid dissociation constant, preferably any one of formulas (AA-1) to (AA-3). Furthermore, as anionic site A2-, it is preferable to form an acidic site with a larger acid dissociation constant than anionic site A1-, and preferably selected from any one of formulas (BB-1) to (BB-6). Moreover, in the following formulas (AA-1) to (AA-3) and (BB-1) to (BB-6), * indicates a bonding position.

[0607] In formula (AA-2), RA represents a monovalent organic group. Examples of monovalent organic groups represented by RA include cyano, trifluoromethyl, and methanesulfonyl.

[0608] [Chemistry 52]

[0609] Furthermore, the cation sites M1+ and M2+ are structural sites containing positively charged atoms or groups of atoms, such as monovalent organic cations. Moreover, there are no particular limitations on the organic cations; the aforementioned organic cations can be listed, with preferred examples being organic cations represented by formula (ZaI) (cation (ZaI)) or organic cations represented by formula (ZaII) (cation (ZaII)).

[0610] There are no particular limitations on the specific structure of compound (I), for example, the compounds represented by formulas (Ia-1) to (Ia-5) described later can be listed.

[0611] The compounds represented by formula (Ia-1) will be described below. The compounds represented by formula (Ia-1) are as follows.

[0612] M11+ A11--L1-A12- M12+ (Ia-1)

[0613] The compound (Ia-1) produces an acid represented by HA11-L1-A12H by exposure to photochemical rays or radiation.

[0614] In formula (Ia-1), M11+ and M12+ each independently represent organic cations.

[0615] A11- and A12- each independently represent monovalent anionic functional groups.

[0616] L1 represents a binary linkage base.

[0617] M11+ and M12+ can be the same or different.

[0618] A11- and A12- can be the same or different, but it is better for them to be different from each other.

[0619] In the compound PIa (HA11-L1-A12H) formed by replacing the organic cations represented by M11+ and M12+ with H+ in formula (Ia-1), the acid dissociation constant a2 derived from the acidic site represented by A12H is greater than the acid dissociation constant a1 derived from the acidic site represented by HA11. Furthermore, preferred values ​​for acid dissociation constants a1 and a2 are as described above. Additionally, compound PIa is the same acid produced from the compound represented by formula (Ia-1) by irradiation with photochemical rays or radiation.

[0620] In addition, at least one of M11+, M12+, A11-, A12-, and L1 may have an acid-degradable group as a substituent.

[0621] In formula (Ia-1), the organic cations represented by M1+ and M2+ can be listed above, with the organic cations represented by formula (ZaI) (cation (ZaI)) or the organic cations represented by formula (ZaII) (cation (ZaII)) being more preferred.

[0622] The monovalent anionic functional group represented by A11- refers to a monovalent group containing the anionic site A1-. Similarly, the monovalent anionic functional group represented by A12- refers to a monovalent group containing the anionic site A2-.

[0623] As the monovalent anionic functional group represented by A11- and A12-, it is preferably a monovalent anionic functional group comprising the anionic site of any one of formulas (AA-1) to (AA-3) and (BB-1) to (BB-6), and more preferably a monovalent anionic functional group selected from the group consisting of formulas (AX-1) to (AX-3) and (BX-1) to (BX-7). As the monovalent anionic functional group represented by A11-, it is preferably a monovalent anionic functional group represented by any one of formulas (AX-1) to (AX-3). Furthermore, as the monovalent anionic functional group represented by A12-, it is preferably a monovalent anionic functional group represented by any one of formulas (BX-1) to (BX-7), and more preferably a monovalent anionic functional group represented by any one of formulas (BX-1) to (BX-6).

[0624] [Chemistry 53]

[0625] In equations (AX-1) to (AX-3), RA1 and RA2 each independently represent a monovalent organic group. * indicates the bond position.

[0626] Examples of monovalent organic groups represented by RA1 include cyano, trifluoromethyl, and methanesulfonyl.

[0627] The monovalent organic group represented by RA2 is preferably a straight-chain, branched-chain, or cyclic alkyl group or an aryl group.

[0628] The alkyl group preferably has 1 to 15 carbon atoms, more preferably 1 to 10, and even more preferably 1 to 6.

[0629] The alkyl group may have substituents. Preferred substituents are fluorine atoms or cyano groups, and more preferably fluorine atoms. When the alkyl group has a fluorine atom as a substituent, it may be a perfluoroalkyl group.

[0630] The aryl group is preferably phenyl or naphthyl, and more preferably phenyl.

[0631] The aryl group may have substituents. Preferred substituents are fluorine atoms, iodine atoms, perfluoroalkyl groups (e.g., preferably having 1 to 10 carbon atoms, more preferably having 1 to 6 carbon atoms), or cyano groups, more preferably fluorine atoms, iodine atoms, or perfluoroalkyl groups.

[0632] In equations (BX-1) to (BX-4) and (BX-6), RB represents a monovalent organic group. * indicates the bond position.

[0633] The monovalent organic group represented by RB is preferably a straight-chain, branched-chain, or cyclic alkyl group or an aryl group.

[0634] The alkyl group preferably has 1 to 15 carbon atoms, more preferably 1 to 10, and even more preferably 1 to 6.

[0635] The alkyl group may have substituents. There are no particular limitations on the substituents, but fluorine or cyano groups are preferred, and fluorine atoms are even more preferred. When the alkyl group has a fluorine atom as a substituent, it may be a perfluoroalkyl group.

[0636] Furthermore, when the carbon atom at the bonding position in the alkyl group (for example, in the case of formula (BX-1) and formula (BX-4), it corresponds to the carbon atom in the alkyl group that is directly bonded to -CO- as stated in the formula; in the case of formula (BX-2) and formula (BX-3), it corresponds to the carbon atom in the alkyl group that is directly bonded to -SO2- as stated in the formula; and in the case of formula (BX-6), it corresponds to the carbon atom in the alkyl group that is directly bonded to N- as stated in the formula) has a substituent, it is preferably a substituent other than a fluorine atom or a cyano group.

[0637] In addition, the carbon atoms in the alkyl group may be substituted with carbonyl carbons.

[0638] The aryl group is preferably phenyl or naphthyl, and more preferably phenyl.

[0639] The aryl group may have substituents. Preferred substituents are fluorine atoms, iodine atoms, perfluoroalkyl groups (e.g., preferably having 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms), cyano groups, alkyl groups (e.g., preferably having 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms), alkoxy groups (e.g., preferably having 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms), or alkoxycarbonyl groups (e.g., preferably having 2 to 10 carbon atoms, more preferably 2 to 6 carbon atoms), and more preferably fluorine atoms, iodine atoms, perfluoroalkyl groups, alkyl groups, alkoxy groups, or alkoxycarbonyl groups.

[0640] In formula (Ia-1), the divalent linker represented by L1 is not particularly limited and can include: -CO-, -NR-, -O-, -S-, -SO-, -SO2-, alkyl groups (preferably with 1 to 6 carbon atoms, which can be straight-chain or branched-chain), cycloalkyl groups (preferably with 3 to 15 carbon atoms), alkenyl groups (preferably with 2 to 6 carbon atoms), and divalent aliphatic heterocyclic groups (preferably having at least one N atom, O atom, S atom, or Se atom within the ring structure). The rings can be 5- to 10-membered rings, more preferably 5- to 7-membered rings, and even more preferably 5- to 6-membered rings; divalent aromatic heterocyclic groups (preferably 5- to 10-membered rings having at least one N, O, S, or Se atom within the ring structure, more preferably 5- to 7-membered rings, and even more preferably 5- to 6-membered rings); divalent aromatic hydrocarbon cyclic groups (preferably 6- to 10-membered rings, and even more preferably 6-membered rings); and divalent linking groups formed by combining multiple of these. R can be a hydrogen atom or a monovalent organic group. There are no particular limitations on the monovalent organic group; for example, it is preferably an alkyl group (preferably having 1 to 6 carbon atoms).

[0641] Furthermore, the alkyl group, the cycloalkyl group, the alkenyl group, the divalent aliphatic heterocyclic group, the divalent aromatic heterocyclic group, and the divalent aromatic hydrocarbon cycloalkyl group may have substituents. Examples of substituents include halogen atoms (preferably fluorine atoms).

[0642] As the divalent linking base represented by L1, the divalent linking base represented by equation (L1) is preferred.

[0643] [Chemistry 54]

[0644] In equation (L1), L111 represents a single bond or a divalent linker.

[0645] The divalent linker represented by L111 is not particularly limited, and examples include: -CO-, -NH-, -O-, -SO-, -SO2-, alkyl groups with substituents (preferably 1 to 6 carbons, which can be either straight-chain or branched-chain), cycloalkyl groups with substituents (preferably 3 to 15 carbons), aryl groups with substituents (preferably 6 to 10 carbons), and divalent linkers formed by combining multiple of these. The substituents are not particularly limited, and examples include halogen atoms.

[0646] p represents an integer from 0 to 3, preferably an integer from 1 to 3.

[0647] v represents an integer of 0 or 1.

[0648] Xf1 each independently represents a fluorine atom or an alkyl group substituted with at least one fluorine atom. The alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 4. Furthermore, as an alkyl group substituted with at least one fluorine atom, a perfluoroalkyl group is preferred.

[0649] Xf2 can independently represent a hydrogen atom, an alkyl group that may have a fluorine atom as a substituent, or a fluorine atom. The alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 4. Among them, Xf2 is preferably an alkyl group that represents a fluorine atom, or an alkyl group substituted with at least one fluorine atom, more preferably a fluorine atom, or a perfluoroalkyl group.

[0650] Preferably, Xf1 and Xf2 are each independently a fluorine atom or a perfluoroalkyl group having 1 to 4 carbon atoms, more preferably a fluorine atom or CF3. In particular, it is even more preferable that both Xf1 and Xf2 are fluorine atoms.

[0651] * indicates the location of the bond.

[0652] In the case where L1 in formula (Ia-1) represents the divalent linker represented by formula (L1), it is preferred to be the bonding bond (*) on the L111 side of formula (L1) and the A12- bond in formula (Ia-1).

[0653] Next, equations (Ia-2) to (Ia-4) will be explained.

[0654] [Chemistry 55]

[0655] In formula (Ia-2), A21a- and A21b- each independently represent a monovalent anionic functional group. Here, the monovalent anionic functional group represented by A21a- and A21b- refers to a monovalent group containing the anionic site A1-. There are no particular limitations on the monovalent anionic functional groups represented by A21a- and A21b-, for example, monovalent anionic functional groups selected from the group consisting of formulas (AX-1) to (AX-3) can be listed.

[0656] A22- represents a divalent anionic functional group. Here, the divalent anionic functional group represented by A22- refers to a divalent group containing the anionic site A2-. Examples of divalent anionic functional groups represented by A22- include those represented by formulas (BX-8) to (BX-11) shown below.

[0657] [Chemistry 56]

[0658] M21a+, M21b+, and M22+ each independently represent an organic cation. The organic cations represented by M21a+, M21b+, and M22+ have the same meaning as M1+, and the preferred state is also the same.

[0659] L21 and L22 each independently represent a divalent organic group.

[0660] Furthermore, in formula (Ia-2), in compound PIa-2 formed by replacing the organic cations represented by M21a+, M21b+, and M22+ with H+, the acid dissociation constant a2 originating from the acidic site represented by A22H is greater than the acid dissociation constant a1-1 originating from A21aH and the acid dissociation constant a1-2 originating from the acidic site represented by A21bH. Moreover, the acid dissociation constants a1-1 and a1-2 are equivalent to the acid dissociation constant a1.

[0661] Furthermore, A21a- and A21b- can be the same or different. Additionally, M21a+, M21b+, and M22+ can be the same or different.

[0662] In addition, at least one of M21a+, M21b+, M22+, A21a-, A21b-, L21, and L22 may have an acid-degradable group as a substituent.

[0663] In equation (Ia-3), A31a- and A32- each independently represent a monovalent anionic functional group. Furthermore, the definition of the monovalent anionic functional group represented by A31a- is the same as that of A21a- and A21b- in equation (Ia-2), and the preferred state is also the same.

[0664] The monovalent anionic functional group represented by A32- refers to a monovalent group containing the anionic site A2-. There are no particular limitations on the monovalent anionic functional group represented by A32-, and for example, monovalent anionic functional groups selected from the group consisting of formulas (BX-1) to (BX-7) can be listed.

[0665] A31b- represents a divalent anionic functional group. Here, the divalent anionic functional group represented by A31b- refers to a divalent group containing the anionic site A1-. Examples of divalent anionic functional groups represented by A31b- include those represented by formula (AX-4) shown below.

[0666] [Chemistry 57]

[0667] M31a+, M31b+, and M32+ each independently represent a monovalent organic cation. The organic cations represented by M31a+, M31b+, and M32+ have the same meaning as M1+, and the preferred state is also the same.

[0668] L31 and L32 each independently represent a divalent organic group.

[0669] Furthermore, in formula (Ia-3), in compound PIa-3 formed by replacing the organic cations represented by M31a+, M31b+, and M32+ with H+, the acid dissociation constant a2 originating from the acidic site represented by A32H is greater than the acid dissociation constant a1-3 originating from the acidic site represented by A31aH and the acid dissociation constant a1-4 originating from the acidic site represented by A31bH. Moreover, the acid dissociation constants a1-3 and a1-4 are equivalent to the acid dissociation constant a1.

[0670] Furthermore, A31a- and A32- can be the same or different. Additionally, M31a+, M31b+, and M32+ can be the same or different.

[0671] In addition, at least one of M31a+, M31b+, M32+, A31a-, A32-, L31, and L32 may have an acid-degradable group as a substituent.

[0672] In equation (Ia-4), A41a-, A41b-, and A42- each independently represent a monovalent anionic functional group. Furthermore, the definitions of the monovalent anionic functional groups represented by A41a- and A41b- are the same as those for A21a- and A21b- in equation (Ia-2). Additionally, the definition of the monovalent anionic functional group represented by A42- is the same as that for A32- in equation (Ia-3), and the preferred form is also the same.

[0673] M41a+, M41b+, and M42+ each independently represent an organic cation.

[0674] L41 represents a trivalent organic group.

[0675] Furthermore, in formula (Ia-4), in compound PIA-4 formed by replacing the organic cations represented by M41a+, M41b+, and M42+ with H+, the acid dissociation constant a2 originating from the acidic site represented by A42H is greater than the acid dissociation constants a1-5 originating from the acidic site represented by A41aH and a1-6 originating from the acidic site represented by A41bH. Moreover, acid dissociation constants a1-5 and a1-6 are equivalent to the acid dissociation constant a1.

[0676] Furthermore, A41a-, A41b-, and A42- can be the same or different from each other. Additionally, M41a+, M41b+, and M42+ can be the same or different from each other.

[0677] In addition, at least one of M41a+, M41b+, M42+, A41a-, A41b-, A42-, and L41 may have an acid-degradable group as a substituent.

[0678] There are no particular limitations on the divalent organic groups represented by L21 and L22 in formula (Ia-2) and L31 and L32 in formula (Ia-3). Examples include: -CO-, -NR-, -O-, -S-, -SO-, -SO2-, alkyl groups (preferably with 1 to 6 carbon atoms; may be straight-chain or branched-chain), cycloalkyl groups (preferably with 3 to 15 carbon atoms), alkenyl groups (preferably with 2 to 6 carbon atoms), divalent aliphatic heterocyclic groups (preferably 5- to 10-membered rings having at least one N, O, S, or Se atom within the ring structure, more preferably 5- to 7-membered rings, and even more preferably 5- to 6-membered rings), divalent aromatic heterocyclic groups (preferably 5- to 10-membered rings having at least one N, O, S, or Se atom within the ring structure, more preferably 5- to 7-membered rings, and even more preferably 5- to 6-membered rings), divalent aromatic hydrocarbon cyclocyclic groups (preferably 6- to 10-membered rings, and even more preferably 6-membered rings), and divalent organogroups formed by combinations of these. R may include hydrogen atoms or monovalent organogroups. There are no particular restrictions on the type of monovalent organic group; for example, it is preferably an alkyl group (preferably with 1 to 6 carbon atoms).

[0679] Furthermore, the alkyl group, the cycloalkyl group, the alkenyl group, the divalent aliphatic heterocyclic group, the divalent aromatic heterocyclic group, and the divalent aromatic hydrocarbon cycloalkyl group may have substituents. Examples of substituents include halogen atoms (preferably fluorine atoms).

[0680] The divalent organic groups represented by L21 and L22 in formula (Ia-2) and L31 and L32 in formula (Ia-3) are also preferably divalent organic groups represented by, for example, the following formula (L2).

[0681] [Chem.58]

[0682] In equation (L2), q represents an integer from 1 to 3. * indicates the bond position.

[0683] Xf each independently represents a fluorine atom or an alkyl group substituted with at least one fluorine atom. The alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 4. Furthermore, as an alkyl group substituted with at least one fluorine atom, a perfluoroalkyl group is preferred.

[0684] Xf is preferably a fluorine atom or a perfluoroalkyl group having 1 to 4 carbon atoms, more preferably a fluorine atom or CF3. In particular, it is even more preferably that both Xf atoms are fluorine atoms.

[0685] LA represents a single bond or a divalent linker.

[0686] There are no particular limitations on the divalent linker represented by LA, and examples include: -CO-, -O-, -SO-, -SO2-, alkyl groups (preferably with 1 to 6 carbon atoms, which can be straight-chain or branched-chain), cycloalkyl groups (preferably with 3 to 15 carbon atoms), divalent aromatic hydrocarbon cycloalkanes (preferably 6-membered to 10-membered rings, and more preferably 6-membered rings), and divalent linkers formed by combining multiple of these.

[0687] Furthermore, the alkyl group, the cycloalkyl group, and the divalent aromatic hydrocarbon cyclogroup may have substituents. Examples of substituents include halogen atoms (preferably fluorine atoms).

[0688] Examples of divalent organogroups represented by formula (L2) include: *-CF2-*, *-CF2-CF2-*, *-CF2-CF2-CF2-*, *-Ph-O-SO2-CF2-*, *-Ph-O-SO2-CF2-CF2-*, and *-Ph-O-SO2-CF2-CF2-CF2-*, *-Ph-OCO-CF2-*, etc. Furthermore, Ph is an extensophenyl group that may have substituents, preferably 1,4-extensophenyl. There are no particular limitations on the substituents, but alkyl groups (e.g., preferably with 1 to 10 carbon atoms, more preferably with 1 to 6 carbon atoms), alkoxy groups (e.g., preferably with 1 to 10 carbon atoms, more preferably with 1 to 6 carbon atoms), or alkoxycarbonyl groups (e.g., preferably with 2 to 10 carbon atoms, more preferably with 2 to 6 carbon atoms).

[0689] When L21 and L22 in formula (Ia-2) represent the divalent organic groups represented by formula (L2), it is preferred that the bonding bond (*) on the LA side of formula (L2) is bonded to A21a- and A21b- in formula (Ia-2).

[0690] In addition, when L31 and L32 in formula (Ia-3) represent the divalent organic groups represented by formula (L2), it is preferable that the bonding bond (*) on the LA side of formula (L2) is bonded to A31a- and A32- in formula (Ia-3).

[0691] There are no particular limitations on the trivalent organic group represented by L41 in formula (Ia-4). For example, the trivalent organic group represented by formula (L3) can be listed below.

[0692] [Chemistry 59]

[0693] In formula (L3), LB represents a trivalent hydrocarbon cyclic group or a trivalent heterocyclic group. * indicates the bond position.

[0694] The hydrocarbon cyclic group can be an aromatic hydrocarbon cyclic group or an aliphatic hydrocarbon cyclic group. The hydrocarbon cyclic group preferably contains 6 to 18 carbon atoms, more preferably 6 to 14. The heterocyclic group can be an aromatic heterocyclic group or an aliphatic heterocyclic group. The heterocyclic group is preferably a 5- to 10-membered ring having at least one N, O, S, or Se atom within the ring structure, more preferably a 5- to 7-membered ring, and even more preferably a 5- to 6-membered ring.

[0695] As an LB, a trivalent hydrocarbon cyclogroup is preferred, and more preferably a benzene cyclogroup or an adamantane cyclogroup. The benzene cyclogroup or the adamantane cyclogroup may have substituents. There are no particular limitations on the substituents, for example, halogen atoms (preferably fluorine atoms) can be listed.

[0696] Furthermore, in formula (L3), LB1 to LB3 each independently represent a single bond or a divalent linker. There are no particular limitations on the divalent linkers represented by LB1 to LB3; examples include: -CO-, -NR-, -O-, -S-, -SO-, -SO2-, alkyl groups (preferably with 1 to 6 carbon atoms; can be linear or branched), cycloalkyl groups (preferably with 3 to 15 carbon atoms), alkenyl groups (preferably with 2 to 6 carbon atoms), and divalent aliphatic heterocyclic groups (preferably having at least one N, O, S, or Se atom within the ring structure). The following are possible combinations of compounds: 5- to 10-membered rings, more preferably 5- to 7-membered rings, and even more preferably 5- to 6-membered rings; divalent aromatic heterocyclic groups (preferably 5- to 10-membered rings having at least one N, O, S, or Se atom within the ring structure, more preferably 5- to 7-membered rings, and even more preferably 5- to 6-membered rings); divalent aromatic hydrocarbon cyclic groups (preferably 6- to 10-membered rings, and even more preferably 6-membered rings); and divalent linking groups formed by combining multiple of these. R can be a hydrogen atom or a monovalent organic group. There are no particular limitations on the monovalent organic group; for example, it is preferably an alkyl group (preferably having 1 to 6 carbon atoms).

[0697] Furthermore, the alkyl group, the cycloalkyl group, the alkenyl group, the divalent aliphatic heterocyclic group, the divalent aromatic heterocyclic group, and the divalent aromatic hydrocarbon cycloalkyl group may have substituents. Examples of substituents include halogen atoms (preferably fluorine atoms).

[0698] As the divalent linker represented by LB1 to LB3, the preferred ones are -CO-, -NR-, -O-, -S-, -SO-, -SO2-, alkyl groups that may have substituents, and divalent linkers formed by combining a plurality of these.

[0699] The binary linkage bases represented by LB1 to LB3 are preferred, with the binary linkage base represented by equation (L3-1) being more preferred.

[0700] [Transformation 60]

[0701] In equation (L3-1), LB11 represents a single bond or a divalent linker.

[0702] There are no particular limitations on the divalent linker represented by LB11. Examples include: -CO-, -O-, -SO-, -SO2-, alkyl groups with substituents (preferably having 1 to 6 carbon atoms; can be straight-chain or branched-chain), and divalent linkers composed of multiple of these. There are no particular limitations on the substituents either; examples include halogen atoms.

[0703] r represents an integer from 1 to 3.

[0704] Xf has the same meaning as Xf in the above formula (L2), and the better state sample is also the same.

[0705] * indicates the location of the bond.

[0706] Examples of divalent linkages represented by LB1 to LB3 include: *-O-*, *-O-SO2-CF2-*, *-O-SO2-CF2-CF2-*, *-O-SO2-CF2-CF2-CF2-*, and *-COO-CH2-CH2-*.

[0707] In the case where L41 in formula (Ia-4) includes the divalent organic group represented by formula (L3-1) and the divalent organic group represented by formula (L3-1) is bonded to A42-, it is preferable that the bonding bond (*) on the carbon atom side of formula (L3-1) is bonded to A42- in formula (Ia-4).

[0708] Next, the compounds represented by formula (Ia-5) will be explained.

[0709] [Chemistry 61]

[0710] In formula (Ia-5), A51a-, A51b-, and A51c- each independently represent a monovalent anionic functional group. Here, the monovalent anionic functional groups represented by A51a-, A51b-, and A51c- refer to monovalent groups containing the anionic site A1-. There are no particular limitations on the monovalent anionic functional groups represented by A51a-, A51b-, and A51c-, for example, monovalent anionic functional groups selected from the group consisting of formulas (AX-1) to (AX-3) can be listed.

[0711] A52a- and A52b- represent divalent anionic functional groups. Here, the divalent anionic functional groups represented by A52a- and A52b- refer to divalent groups containing the anionic site A2-. Examples of divalent anionic functional groups represented by A52a- and A52b- include divalent anionic functional groups selected from the group consisting of formulas (BX-8) to (BX-11).

[0712] M51a+, M51b+, M51c+, M52a+, and M52b+ each independently represent an organic cation. The organic cations represented by M51a+, M51b+, M51c+, M52a+, and M52b+ have the same meaning as M1+, and the preferred state is also the same.

[0713] L51 and L53 each independently represent a divalent organic group. The divalent organic groups represented by L51 and L53 have the same meaning as L21 and L22 in the above formula (Ia-2), and the preferred state is also the same.

[0714] L52 represents a trivalent organic group. The trivalent organic group represented by L52 has the same meaning as L41 in the above formula (Ia-4), and the preferred state is also the same.

[0715] Furthermore, in formula (Ia-5), in compound PIa-5 formed by replacing the organic cations represented by M51a+, M51b+, M51c+, M52a+, and M52b+ with H+, the acid dissociation constants a2-1 and a2-2 originating from the acidic site represented by A52aH are greater than the acid dissociation constants a1-1, a1-2, and a1-3 originating from the acidic site represented by A51cH. Moreover, acid dissociation constants a1-1 to a1-3 correspond to the acid dissociation constant a1, and acid dissociation constants a2-1 and a2-2 correspond to the acid dissociation constant a2.

[0716] Furthermore, A51a-, A51b-, and A51c- can be the same or different from each other. Additionally, A52a- and A52b- can be the same or different from each other. Furthermore, M51a+, M51b+, M51c+, M52a+, and M52b+ can be the same or different from each other.

[0717] In addition, at least one of M51b+, M51c+, M52a+, M52b+, A51a-, A51b-, A51c-, L51, L52, and L53 may have an acid-degradable group as a substituent.

[0718] ‥Compound (II)

[0719] Compound (II) is a compound having two or more of the structural sites X and one or more of the structural sites Z, and producing an acid by irradiation with photochemical rays or radiation, wherein the acid comprises two or more first acidic sites derived from the structural site X and the structural site Z.

[0720] Structural site Z: The site capable of neutralizing the nonionic nature of acids.

[0721] In compound (II), the definitions of structural site X, A1- and M1+ are the same as those in compound (I), and the preferred state is also the same.

[0722] In compound (II), in compound PII formed by replacing the cation M1+ in structural site X with H+, the preferred range of the acid dissociation constant a1 of the acidic site represented by HA1, formed by replacing the cation M1+ in structural site X with H+, is the same as the acid dissociation constant a1 in compound PI.

[0723] Furthermore, in the case where compound (II) is, for example, a compound that produces an acid having two origins from the first acidic site of structural site X and an acid from structural site Z, compound PII is equivalent to "a compound having two HA1s". When the acid dissociation constant of compound PII is determined, the acid dissociation constant when compound PII is "a compound having one Al- and one HA1", and the acid dissociation constant when "a compound having one Al- and one HA1" is "a compound having two Al-s", are equivalent to the acid dissociation constant a1.

[0724] The acid dissociation constant a1 is determined by the method for determining the acid dissociation constant.

[0725] The compound PII is equivalent to the acid produced when compound (II) is irradiated with photochemical rays or radiation.

[0726] Furthermore, the two or more structural parts X may be the same or different. Additionally, the two or more A1- and the two or more M1+ may be the same or different.

[0727] There are no particular limitations on the nonionicity of the acid in structural site Z, but it is preferred to be a site containing a functional group that has a base or electron that can interact electrostatically with a proton.

[0728] Functional groups that have a base or electrons capable of electrostatic interaction with protons can be exemplified by functional groups with macrocyclic structures such as cyclic polyethers, or functional groups containing nitrogen atoms with non-covalent electron pairs that do not contribute to π-conjugation. A nitrogen atom with non-covalent electron pairs that do not contribute to π-conjugation is, for example, a nitrogen atom with a partial structure as shown in the following formula.

[0729] [Chemistry 62] [Non-covalent electron pairs]

[0730] Examples of partial structures that have functional groups or electrons that can interact electrostatically with protons include: crown ether structures, azacrown ether structures, primary to tertiary amine structures, pyridine structures, imidazole structures, and pyrazine structures, among which primary to tertiary amine structures are preferred.

[0731] There are no particular limitations on the compound (II), for example, compounds represented by the following formulas (IIa-1) and (IIa-2) can be listed.

[0732] [Chemistry 63]

[0733] In formula (IIa-1), A61a- and A61b- each have the same meaning as A11- in formula (Ia-1), and the preferred state is also the same. In addition, M61a+ and M61b+ each have the same meaning as M11+ in formula (Ia-1), and the preferred state is also the same.

[0734] In the above formula (IIa-1), L61 and L62 have the same meaning as L1 in the above formula (Ia-1), and the preferred state is also the same.

[0735] In formula (IIa-1), R2X represents a monovalent organogroup. There are no particular limitations on the monovalent organogroup represented by R2X; examples include: -CH2- alkyl groups (preferably with 1 to 10 carbon atoms, which can be straight-chain or branched-chain), cycloalkyl groups (preferably with 3 to 15 carbon atoms), or alkenyl groups (preferably with 2 to 6 carbon atoms) that can be substituted with one or more of the group consisting of -CO-, -NH-, -O-, -S-, -SO-, and -SO2-.

[0736] Furthermore, the alkyl group, the cycloalkyl group, and the alkenyl group may have substituents. There are no particular limitations on the substituents; for example, halogen atoms (preferably fluorine atoms) can be included.

[0737] Furthermore, in the compound PIIa-1 formed by replacing the organic cations represented by M61a+ and M61b+ with H+ in formula (IIa-1), the acid dissociation constants a1-7 derived from the acidic site represented by A61aH and a1-8 derived from the acidic site represented by A61bH are equivalent to the acid dissociation constant a1.

[0738] Furthermore, the compound PIIa-1, formed by replacing the cation sites M61a+ and M61b+ in the structural site X with H+ in formula (IIa-1), is equivalent to HA61a-L61-N(R2X)-L62-A61bH. Additionally, compound PIIa-1 is the same acid produced from the compound represented by formula (IIa-1) by irradiation with photochemical rays or radiation.

[0739] In addition, at least one of M61a+, M61b+, A61a-, A61b-, L61, L62, and R2X may have an acid-degradable group as a substituent.

[0740] In equation (IIa-2), A71a-, A71b-, and A71c- each have the same meaning as A11- in equation (Ia-1), and the preferred state is also the same. Furthermore, M71a+, M71b+, and M71c+ each have the same meaning as M11+ in equation (Ia-1), and the preferred state is also the same.

[0741] In equation (IIa-2), L71, L72, and L73 each have the same meaning as L1 in equation (Ia-1), and the preferred state is also the same.

[0742] Furthermore, in formula (IIa-2), in the compound PIIa-2 formed by replacing the organic cations represented by M71a+, M71b+, and M71c+ with H+, the acid dissociation constant a1-9 derived from the acidic site represented by A71aH, the acid dissociation constant a1-10 derived from the acidic site represented by A71bH, and the acid dissociation constant a1-11 derived from the acidic site represented by A71cH are equivalent to the acid dissociation constant a1.

[0743] Furthermore, in compound PIIa-2, formed by replacing the cation sites M71a+, M71b+, and M71c+ in structural site X with H+ in formula (IIa-2), the equivalent is HA71a-L71-N(L73-A71cH)-L72-A71bH. Additionally, compound PIIa-2 is the same acid produced from the compound represented by formula (IIa-2) by irradiation with photochemical rays or radiation.

[0744] In addition, at least one of M71a+, M71b+, M71c+, A71a-, A71b-, A71c-, L71, L72, and L73 may have an acid-degradable group as a substituent.

[0745] In addition, the photoacid generator of onium salt can be a compound having two or more of the following structural sites X and generating two acidic sites originating from the following structural sites X by irradiation with photochemical rays or radiation.

[0746] Structural site X: A structural site containing anionic site A1- and cation site M1+, which forms the acidic site represented by HA1 through irradiation by photochemical rays or radiation.

[0747] The two or more structural parts X may be the same or different. Additionally, the two or more A1- and the two or more M1+ may be the same or different.

[0748] The definitions of structural site X, A1- and M1+ are the same as those in compound (I), and are also the same in the preferred form.

[0749] The organic cations shown below and other sites can be appropriately combined to be used as photoacid generators of onium salts.

[0750] First, let's take an example of an organic cation.

[0751] Furthermore, as an organic cation, the cationic portion of the repeating unit exemplified in repeating unit (a) can also be used.

[0752] [Chemistry 64]

[0753] [Chemistry 65]

[0754] [Chemistry 66]

[0755] Secondly, examples are given for sites other than organic cations (organic anions).

[0756] The values ​​shown below for the anionic functional groups in the organic anions are the pKa values ​​of the acid groups formed by hydrogen bonds to each anionic functional group.

[0757] [Chemistry 67]

[0758] [Chemistry 68]

[0759] [Chemistry 69]

[0760] [Chemistry 70]

[0761] [Chemistry 71]

[0762] (As a photoacid generator of intramolecular salts)

[0763] The photoacid generator that serves as an intramolecular salt preferably has a sulfonate anion or a carboxylate anion (preferably an aromatic sulfonate anion or an aromatic carboxylate anion), and even more preferably has a strontium cation or an iodine cation.

[0764] Examples of photoacid generators that are intramolecular salts include compounds (ZbI) and (ZbII).

[0765] The compound (ZbI) is a compound represented by a newly defined general formula such that one of R201 to R203 in the general formula (ZaI) is an aryl group having a substituent containing a group containing -SO3- or -COO-.

[0766] The compound (ZbII) is a compound represented by a newly defined general formula such that one of R204 and R205 in the general formula (ZaII) is an aryl group having a substituent containing a group comprising -SO3- or -COO-.

[0767] The compounds (ZbI) and (ZbII) contain a group of -SO3- or -COO-, for example, the group formed by removing W from the organic anion represented by formula (AN) shown in the description of the organic anion (the group represented by "AX-〔C(Xf)(Xf)〕o-〔C(R4)(R5)〕p-(L)q-").

[0768] Examples include photoacid generators that act as intramolecular salts.

[0769] [Chemistry 72]

[0770] Furthermore, as a photoacid generator, in terms of suppressing the diffusion of acid generated during exposure to non-exposed areas and thus improving resolution, it is preferable to be a compound that generates acid with a volume of 130 ų or more by irradiation with an electron beam or extreme ultraviolet light, and more preferably a compound that generates acid with a volume of 150 ų or more. Additionally, from the viewpoint of sensitivity or solubility in coating solvents, the volume is preferably 2000 ų or less, and more preferably 1500 ų or less.

[0771] 1 Å is 1 × 10⁻¹⁰ m.

[0772] In this specification, the volume of acid generated by the photosensitive acid generator is calculated using the following method.

[0773] Using MOPAC7, which comes with Winmostar (software manufactured by X-Ability), the structure for acid generation was optimized using the Parameterized Model number 3 (PM3) method. For the optimized structure obtained, the van der waals volume was calculated using Winmostar (software manufactured by X-Ability) by the method described in Non-Patent Document 1.

[0774] Non-Patent Literature 1: Improvement of the Formula for Calculating Molecular Surface Area and Volume, by Teruo Nagao, pp. 111-120, No. 27, 1993, Hakodate Higher Vocational School Bulletin.

[0775] As a photoacid generator, paragraphs

[0368] to

[0377] of Japanese Patent Application Publication No. 2014-41328 and paragraphs

[0240] to

[0262] of Japanese Patent Application Publication No. 2013-228681 (corresponding to

[0339] of U.S. Patent Application Publication No. 2015 / 004533) may be cited, and these contents are incorporated into the description of this application.

[0776] A photoacid generator can be used alone or in combination with two or more agents.

[0777] When the resist composition of the present invention contains a photoacid generator, its content relative to the total solid content of the resist composition is preferably more than 0% by mass and less than 70% by mass, more preferably 0.1% by mass to 45% by mass, even more preferably 0.5% by mass to 35% by mass, and particularly preferably 0.6% by mass to 10% by mass.

[0778] When the photoacid generating agent includes photoacid generating agents other than the photodegradable alkaline compounds described later, its content relative to the total solid content of the resist composition is preferably more than 0% by mass and less than 70% by mass, more preferably 0.5% by mass to 45% by mass, even more preferably 0.5% by mass to 35% by mass, and particularly preferably 0.6% by mass to 10% by mass.

[0779] [Acid diffusion control agent]

[0780] The resist composition of the present invention may include an acid diffusion control agent.

[0781] The acid diffusion control agent functions as a quencher to capture the acid generated during exposure from photoacid generators and the like, and to suppress the reaction of the resin (A) in the unexposed portion caused by excess generated acid.

[0782] Examples of acid diffusion control agents include: basic compounds (DA); low molecular weight compounds (DD) having nitrogen atoms and groups that are released by the action of acid; and onium salt compounds (DE) having nitrogen atoms in the cation portion.

[0783] In the composition of the present invention, known acid diffusion control agents may be used appropriately. For example, compounds disclosed in paragraphs

[0627] to

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

[0095] to

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

[0403] to

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

[0259] to

[0328] of U.S. Patent Application Publication 2016 / 0274458A1 may be used as acid diffusion control agents.

[0784] As a basic compound (DA), it is preferably a compound having the structure represented by any one of the following general formulas (A) to (E).

[0785] [Chemistry 73]

[0786] In general formula (A), R200, R201, and R202 each independently represent a hydrogen atom, an alkyl group (preferably with 1 to 20 carbon atoms), a cycloalkyl group (preferably with 3 to 20 carbon atoms), or an aryl group (with 6 to 20 carbon atoms). R201 and R202 can be bonded together to form a ring.

[0787] In general formula (E), R203, R204, R205, and R206 each independently represent an alkyl group having 1 to 20 carbon atoms.

[0788] The alkyl groups in general formulas (A) and (E) may have substituents or may not be substituted.

[0789] Regarding the alkyl group, as an alkyl group having a substituent, it is preferably an aminoalkyl group having 1 to 20 carbon atoms, a hydroxyalkyl group having 1 to 20 carbon atoms, or a cyanoalkyl group having 1 to 20 carbon atoms.

[0790] The alkyl groups in general formulas (A) and (E) are preferably unsubstituted.

[0791] The basic compounds are preferably thiazoles, benzothiazoles, imidazoles, benzimidazoles, oxazoles, benzoxazoles, guanidines, aminopyrrolidines, pyrazoles, pyrazolines, piperazines, morpholines, aminomorpholines, aminoalkylmorpholines, piperidines, anilines, or compounds having these structures. More preferably, compounds having a thiazole structure, a benzothiazole structure, an imidazole structure, a benzimidazole structure, an oxazole structure, a benzoxazole structure, a diazabicyclic structure, a morpholine structure, an onium hydroxide structure, an onium carboxylate structure, a trialkylamine structure, an aniline structure, or a pyridine structure, alkylamine derivatives having a hydroxyl group and / or an ether bond, or aniline derivatives having a hydroxyl group and / or an ether bond, etc.

[0792] Low molecular weight compounds (DD) having nitrogen atoms and having groups that are released due to the action of acids (hereinafter also referred to as "compound (DD)") are preferably amine derivatives having groups that are released due to the action of acids.

[0793] The group that is released due to the action of acid is preferably an acetal group, a carbonate group, a carbamate group, a tertiary ester group, a tertiary hydroxyl group, or a semiamine acetal ether group, and more preferably a carbamate group or a semiamine acetal ether group.

[0794] The molecular weight of the compound (DD) is preferably 100 to 1000, more preferably 100 to 700, and even more preferably 100 to 500.

[0795] The compound (DD) may have a carbamate group with a protecting group on the nitrogen atom. Examples of protecting groups constituting the carbamate group include those represented by the following general formula (d-1).

[0796] [Chemistry 74]

[0797] In general formula (d-1), each Rb independently represents a hydrogen atom, an alkyl group (preferably with 1 to 10 carbon atoms), a cycloalkyl group (preferably with 3 to 30 carbon atoms), an aryl group (preferably with 3 to 30 carbon atoms), an aralkyl group (preferably with 1 to 10 carbon atoms), or an alkoxyalkyl group (preferably with 1 to 10 carbon atoms). Two Rb groups can bond together to form a ring.

[0798] Rb represents alkyl, cycloalkyl, aryl, and aralkyl groups, each of which can be independently substituted with functional groups such as hydroxyl, cyano, amino, pyrrolidyl, piperidinyl, morpholinyl, sideoxy, alkoxy, or halogen atoms. The same applies to Rb represents alkoxyalkyl groups.

[0799] Rb is preferably a straight-chain or branched-chain alkyl, cycloalkyl, or aryl group, and more preferably a straight-chain or branched-chain alkyl or cycloalkyl group.

[0800] As a ring formed by two Rb bonds, examples include alicyclic hydrocarbons, aromatic hydrocarbons, heterocyclic hydrocarbons and their derivatives.

[0801] Specific structures that serve as the basis represented by general formula (d-1) can be exemplified by the structures disclosed in paragraph

[0466] of the specification of U.S. Patent Publication US2012 / 0135348A1, but are not limited thereto.

[0802] The compound (DD) preferably has the structure represented by the following general formula (6).

[0803] [Chemistry 75]

[0804] In general formula (6), l represents an integer from 0 to 2, and m represents an integer from 1 to 3, satisfying l+m=3.

[0805] Ra represents a hydrogen atom, alkyl, cycloalkyl, aryl, or aralkyl group. When l is 2, the two Ra can be the same or different, and the two Ra can be linked together to form a heterocycle with the nitrogen atom in the formula. The heterocycle may also contain heteroatoms other than the nitrogen atom in the formula.

[0806] LN represents a single bond or a divalent linker. The divalent linker is preferably an alkyl group (which can be linear or branched, with 1 to 6 carbon atoms, for example).

[0807] Rb has the same meaning as Rb in the general formula (d-1), and the preferred example is also the same.

[0808] In general formula (6), each of the alkyl, cycloalkyl, aryl and aralkyl groups that are Ra can be independently substituted with the same group as the group that can be substituted with the alkyl, cycloalkyl, aryl and aralkyl groups that are Rb.

[0809] As specific examples of alkyl, cycloalkyl, aryl, and aralkyl groups (which may be substituted by the groups mentioned above) in Ra, the same groups as those mentioned in the specific examples concerning Rb can be listed.

[0810] As a specific example of a particularly desirable compound (DD) in this invention, the compounds disclosed in paragraph

[0475] of U.S. Patent Application Publication No. 2012 / 0135348A1 may be cited, but are not limited thereto.

[0811] Onium salt compounds (DE) having nitrogen atoms in the cation portion (hereinafter also referred to as "compound (DE)") are preferably components that are not equivalent to photoacid generators.

[0812] The compound (DE) is preferably a compound having a basic site containing a nitrogen atom in the cation portion. The basic site is preferably an amino group, more preferably a nitrogen-containing aromatic cyclic group (pyridine cyclic group, etc.), or an aliphatic amino group.

[0813] The nitrogen-containing aromatic cyclic group is an aromatic cyclic group having one or more (e.g., one to three) nitrogen atoms as ring members. It can be monocyclic or polycyclic, and the number of ring members is, for example, 5 to 15. It may or may not have heteroatoms other than nitrogen atoms. Pyridine cyclic groups can be listed as examples of the nitrogen-containing aromatic cyclic group.

[0814] Ideally, the atoms adjacent to the nitrogen atom in the basic region should all be hydrogen or carbon atoms. Furthermore, from the viewpoint of improving basicity, it is preferable that electron-withdrawing functional groups (carbonyl, sulfonyl, cyano, and halogen atoms, etc.) are not directly bonded to the nitrogen atom.

[0815] The cationic portion of compound (DE) is preferably a quaternary ammonium cation.

[0816] As quaternary ammonium cations, the following cations represented by formula (ZaIII) can be listed.

[0817] (RCA)4N+ (ZaIII)

[0818] In the formula, RCA represents an alkyl group. The alkyl group may preferably have a hydroxyl or phenyl substituent. The four RCAs may be the same or different from each other.

[0819] As represented by RCA, the alkyl group is preferably an alkyl group having 1 to 6 carbon atoms.

[0820] The alkyl group represented by RCA is preferably methyl, ethyl, propyl, butyl, 2-hydroxyethyl, or benzyl, more preferably methyl, ethyl, propyl, butyl, or 2-hydroxyethyl, and even more preferably methyl, ethyl, or 2-hydroxyethyl.

[0821] Preferably, compound (DE) is ammonium hydroxide having the quaternary ammonium cation as the cation part and OH- as the anion part.

[0822] As a preferred specific example of a compound (DE), one may cite the compound disclosed in paragraph

[0203] of the specification of U.S. Patent Application Publication 2015 / 0309408A1, but is not limited thereto.

[0823] As an acid diffusion control agent, any compound described in paragraphs

[0204] to

[0206] of International Publication No. 2018 / 193954 may also be used, as long as it is equivalent to the acid diffusion control agent in the resist composition of the present invention.

[0824] In addition, the compound used as a photoacid generator can also be used as an acid diffusion control agent.

[0825] Photoacid generators that also act as acid diffusion control agents are also known as photodegradable alkaline compounds.

[0826] Photodegradable alkaline compounds include, for example, onium salts and photoacid generators whose anions are represented by the general formulas (d1-1) to (d1-3).

[0827] As a photodegradable alkaline compound, examples can also be listed as photoacid generators that are intramolecular salts and have a carboxylate anion (for example, the compound (ZbII) is a compound represented by a newly defined general formula such that one of R204 and R205 in the general formula (ZaII) is an aryl group having a group containing -COO- as a substituent).

[0828] The resist composition preferably includes a photodegradable alkaline compound. That is, at least a portion of the photoacid generator and / or acid diffusion control agent is also preferably a photodegradable alkaline compound.

[0829] The content of photodegradable alkaline compounds relative to the total mass of the acid diffusion control agent is preferably 10% to 100% by mass, more preferably 60% to 100% by mass, and even more preferably 90% to 100% by mass.

[0830] The content of photodegradable alkaline compounds is preferably 5% to 100% by mass, more preferably 20% to 100% by mass, and even more preferably 40% to 100% by mass, relative to the total mass of the photoacid generator.

[0831] Acid diffusion control agents can be used alone or in combination with two or more.

[0832] The content of acid diffusion control agent is preferably 0.01% to 30% by mass, more preferably 0.1% to 20% by mass, and even more preferably 0.5% to 15% by mass, relative to the total solid content of the resist composition.

[0833] When the acid diffusion control agent includes an acid diffusion control agent other than a photodegradable alkaline compound, its content relative to the total solid content of the resist composition is preferably 0.01% to 30% by mass, more preferably 0.05% to 20% by mass, even more preferably 0.1% to 15% by mass, and particularly preferably 0.2% to 5% by mass.

[0834] When the resist composition contains a photodegradable alkaline compound, its content relative to the total solid content of the resist composition is preferably 0.01% to 30% by mass, more preferably 0.1% to 20% by mass, even more preferably 0.5% to 15% by mass, and particularly preferably 0.6% to 10% by mass.

[0835] [Surfactants]

[0836] The resist composition may include surfactants. If surfactants are included, patterns with better adhesion and fewer development defects can be formed.

[0837] Fluorine-based and / or silicone-based surfactants are preferred.

[0838] As a fluorinated and / or silicone surfactant, for example, the surfactants disclosed in paragraphs

[0218] and

[0219] of International Publication No. 2018 / 19395 may be used.

[0839] When the resist composition contains a surfactant, the content of the surfactant 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 composition.

[0840] A surfactant may be used alone or in combination with two or more. When using two or more surfactants, it is preferable that their total content be within the range of the preferred content.

[0841] [Solvent]

[0842] The composition of the resist may contain solvent.

[0843] The solvent is preferably one of (M1) propylene glycol monoalkyl ether carboxylate and (M2), wherein (M2) is at least one selected from the group consisting of propylene glycol monoalkyl ether, lactate, acetate, alkoxypropionate, chain ketone, cyclic ketone, lactone, and alkyl carbonate. Furthermore, the solvent may further contain components other than (M1) and (M2).

[0844] The inventors have discovered that when such a solvent is used in combination with the resin, the coatability of the composition is improved, and patterns with fewer development defects can be formed. While the reason may not be entirely clear, the inventors believe it is because these solvents, due to the good balance of the resin's solubility, boiling point, and viscosity, can suppress uneven film thickness and the formation of precipitates during spin coating.

[0845] Details of ingredients (M1) and (M2) are set out in paragraphs

[0218] to

[0226] of International Publication No. 2020 / 004306.

[0846] When the solvent further includes components other than component (M1) and component (M2), the content of components other than component (M1) and component (M2) is preferably 5% to 30% by mass relative to the total amount of solvent.

[0847] Solvents can be used alone or in combination.

[0848] The solvent content in the resist composition is preferably set such that the solid component concentration is 30% by mass or less, more preferably 10% by mass or less, and even more preferably 2% by mass or less. As a lower limit, it is preferably set to 0.05% by mass or more, more preferably 0.1% by mass or more, and even more preferably 0.5% by mass or more.

[0849] This can further improve the coatability of the resist composition.

[0850] In other words, the solvent content in the resist composition is preferably 70% to 99.95% by mass, more preferably 90% to 99.9% by mass, and even more preferably 98% to 99.5% by mass, relative to the total mass of the resist composition.

[0851] [Other additives]

[0852] The resist composition may further include other resins (such as hydrophobic resins) that are not equivalent to resin (A), dissolution inhibiting compounds, dyes, plasticizers, photosensitizers, light absorbers, and / or compounds that promote solubility relative to the developer (alicyclic or aliphatic compounds containing carboxylic acid groups).

[0853] The resist composition may further include solubility-inhibiting compounds. Here, "soil-inhibiting compounds" refers to compounds with a molecular weight of less than 3000 that decompose due to the action of acids and thus have reduced solubility in organic developers.

[0854] The resist composition of the present invention can also be preferably used as a photosensitive composition for EUV exposure or an electron beam exposure.

[0855] The "photon shot noise," caused by the random dispersion of photons in EUV light and electron beams, has a significant impact and can easily lead to LWR degradation and bridging defects. To reduce photon shot noise, one method is to increase the exposure to increase the number of incident photons, but this is difficult to trade off with the requirements of high sensitivity.

[0856] When the value of A obtained using the following formula (1) is high, the absorption efficiency of the resist film formed from the resist composition for EUV and electron beams becomes higher, which is effective in reducing photon shot noise. The value of A represents the absorption efficiency of the resist film for EUV and electron beams by mass ratio.

[0857] Formula (1): A=([H]×0.04+[C]×1.0+[N]×2.1+[O]×3.6+[F]×5.6+[S]×1.5+[I]×39.5) / ([H]×1+[C]×12+[N]×14+[O]×16+[F]×19+[S]×32+[I]×127)

[0858] The A value is preferably 0.120 or higher. There is no particular upper limit. However, if the A value is too high, the EUV and electron beam transmittance of the resist film will decrease, the optical image profile in the resist film will deteriorate, and it will be difficult to obtain a good pattern shape. Therefore, it is preferably 0.240 or lower, and more preferably 0.220 or lower.

[0859] Furthermore, in formula (1), [H] represents the molar ratio of hydrogen atoms originating from the total solids component to all atoms of the total solids component in the photosensitive or radiosensitive linear resin composition; [C] represents the molar ratio of carbon atoms originating from the total solids component to all atoms of the total solids component in the photosensitive or radiosensitive linear resin composition; [N] represents the molar ratio of nitrogen atoms originating from the total solids component to all atoms of the total solids component in the photosensitive or radiosensitive linear resin composition; and [O] represents the molar ratio of oxygen atoms originating from the total solids component to all atoms of the photosensitive or radiosensitive linear resin composition. The molar ratio of all atoms of the total solids component in a linear or radiosensitive linear resin composition, [F] represents the molar ratio of fluorine atoms originating from the total solids component relative to all atoms of the total solids component in the photosensitive or radiosensitive linear resin composition, [S] represents the molar ratio of sulfur atoms originating from the total solids component relative to all atoms of the total solids component in the photosensitive or radiosensitive linear resin composition, and [I] represents the molar ratio of iodine atoms originating from the total solids component relative to all atoms of the total solids component in the photosensitive or radiosensitive linear resin composition.

[0860] For example, when the resist composition comprises resin (A), an alkaline compound, and a solvent, the resin (A) and the alkaline compound are equivalent to the solid components. That is, the total number of atoms in the total solid components is equivalent to the sum of all atoms originating from the resin (A) and all atoms originating from the alkaline compound. For example, [H] represents the molar ratio of hydrogen atoms originating from the total solid components to the total number of atoms in the total solid components. If explained based on the above example, then [H] represents the molar ratio of the sum of hydrogen atoms originating from the resin (A) and the hydrogen atoms originating from the alkaline compound to the sum of all atoms originating from the resin (A) and all atoms originating from the alkaline compound.

[0861] When the structure and content of the total solid components in the resist composition are known, the A value can be calculated by determining the atomic ratio. Furthermore, even when the structural components are unknown, the atomic ratio can be calculated using analytical methods such as elemental analysis for resist films obtained by evaporating the solvent components of the resist composition.

[0862] [Resist film and pattern formation method]

[0863] The procedure for patterning using the resist composition is not particularly limited, but it is preferred to include the following steps.

[0864] Step 1: Forming a resist film on the substrate using a resist composition.

[0865] Step 2: Exposure of the resist film

[0866] Step 3: Developing the exposed resist film using a developer.

[0867] Furthermore, it is preferable to use an alkaline developer as the developer in step 3, and to implement the pattern forming method as a positive pattern forming method.

[0868] The procedures for each step are described in detail below.

[0869] <Step 1: Resist Film Formation Steps>

[0870] Step 1 is the step of forming a resist film on the substrate using a resist composition.

[0871] The composition of the resist is defined as described above.

[0872] As a method for forming a resist film on a substrate using a resist composition, for example, a method of coating a resist composition on a substrate can be cited.

[0873] Furthermore, it is preferable to filter the resist composition using a filter before coating, depending on the requirements. 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. Additionally, the filter is preferably made of polytetrafluoroethylene, polyethylene, or nylon.

[0874] The resist composition can be applied to the substrate (e.g., silicon, silicon dioxide film) used in the manufacture of integrated circuit components by a suitable coating method such as a spin coater or a coater. Spin coating using a spin coater is preferred. The preferred rotation speed for spin coating using a spin coater is 1000 rpm to 3000 rpm.

[0875] After the resist composition is coated, the substrate can be dried to form a resist film. Furthermore, various substrate films (inorganic films, organic films, anti-reflective films) can be formed under the resist film as needed.

[0876] As a drying method, methods involving heating can be cited as an example. Heating can be carried out using mechanisms included in conventional exposure machines and / or developing machines, or using heating plates, etc. The heating temperature is preferably 80°C to 150°C, more preferably 80°C to 140°C, and even more preferably 80°C to 130°C. The heating time is preferably 30 seconds to 1000 seconds, more preferably 60 seconds to 800 seconds, and even more preferably 60 seconds to 600 seconds.

[0877] There are no particular limitations on the thickness of the resist film, but it is preferably 10 nm to 120 nm in terms of forming higher precision micro-patterns. Among these, when EUV exposure or electron beam exposure is used, the thickness of the resist film is more preferably 10 nm to 65 nm, and even more preferably 15 nm to 50 nm.

[0878] Furthermore, a topcoat can be formed by applying a topcoat composition over the resist film.

[0879] The composition of the top coating is preferably unmixed with the resist film, so that it can be uniformly coated on the upper layer of the resist film. The top coating is not particularly limited, and a previously known top coating can be formed by a previously known method, for example, the top coating can be formed based on paragraphs

[0072] to

[0082] of Japanese Patent Application Publication No. 2014-059543.

[0880] For example, it is preferable to form a top coating on the resist film containing an alkaline compound as described in Japanese Patent Application Publication No. 2013-61648. Specific examples of alkaline compounds that may be contained in the top coating include alkaline compounds that may be contained in the resist composition.

[0881] In addition, the top coating is preferably a compound containing at least one group or bond selected from the group consisting of ether, thioether, hydroxyl, thiol, carbonyl and ester bonds.

[0882] <Step 2: Exposure Step>

[0883] Step 2 is the step of exposing the resist film.

[0884] As a method of exposure, one example is irradiating the formed resist film with photochemical rays or radiation through a prescribed mask.

[0885] Examples of photochemical rays or radiation include: infrared light, visible light, ultraviolet light, far ultraviolet light, extreme ultraviolet light, X-rays, and electron beams. Far ultraviolet light with wavelengths below 250 nm, more preferably below 220 nm, and especially preferably 1 nm to 200 nm can be listed. Specifically, examples include KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), F2 excimer laser (wavelength 157 nm), EUV (wavelength 13 nm), X-rays, and electron beams.

[0886] Among them, EUV or electron beams are preferred for photochemical rays or radiation used in exposure.

[0887] It is preferable to bake (heat) the exposed area after exposure and before development. Baking promotes the reaction of the exposed area, resulting in better sensitivity and pattern shape.

[0888] The preferred heating temperature is 80℃~150℃, more preferably 80℃~140℃, and even more preferably 80℃~130℃.

[0889] The heating time is preferably 10 seconds to 1000 seconds, more preferably 10 seconds to 180 seconds, and even more preferably 30 seconds to 120 seconds.

[0890] Heating can be performed using mechanisms included in conventional exposure and / or developing machines, or using heating plates, etc.

[0891] This step is also known as Post Exposure Bake (PEB).

[0892] <Step 3: Development Step>

[0893] Step 3 is the step of developing the exposed resist film with a developer to form a pattern.

[0894] The developer can be an alkaline developer or a developer containing organic solvents (hereinafter also referred to as an organic developer), but an alkaline developer is preferred.

[0895] When using an alkaline developer, a positive pattern is usually formed. When using an organic developer, a negative pattern is usually formed.

[0896] Examples of development methods include: immersing a substrate in a tank filled with developer for a fixed time (immersion method); using surface tension to accumulate developer on the substrate surface and allowing it to stand still for a fixed time for development (puddle method); spraying developer onto the substrate surface (spraying method); and continuously spraying developer onto a substrate rotating at a fixed speed while scanning the developer nozzle at a fixed speed (dynamic distribution method).

[0897] Alternatively, after the developing step, a step can be performed where the solvent is replaced with another solvent while the developing process is stopped.

[0898] There are no particular limitations on the development time, as long as it is the time required for the resin in the unexposed areas to fully dissolve. It is preferably 10 to 300 seconds, and more preferably 20 to 120 seconds.

[0899] The optimal temperature for the developer is 0℃~50℃, and more preferably 15℃~35℃.

[0900] Alkaline developing solutions are preferably alkaline aqueous solutions containing alkali. There are no particular limitations on the type of alkaline aqueous solution; examples include alkaline aqueous solutions containing quaternary ammonium salts (represented by tetramethylammonium hydroxide), inorganic bases, primary amines, secondary amines, tertiary amines, alkanolamines, or cyclic amines. Among these, the alkaline developing solution is preferably an aqueous solution of a quaternary ammonium salt, represented by tetramethylammonium hydroxide (TMAH). Appropriate amounts of alcohols and surfactants may also be added to the alkaline developing solution. The alkali concentration of the alkaline developing solution is typically 0.1% to 20% by mass. Furthermore, the pH of the alkaline developing solution is typically 10.0 to 15.0. The water content of the alkaline developing solution is preferably 51% to 99.95% by mass.

[0901] 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.

[0902] The solvent can be mixed with multiple solvents, or 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, and even more preferably less than 10% by mass, and most preferably substantially free of water.

[0903] The content of organic solvent relative to the total amount of developer is preferably 50% to 100% by mass, more preferably 80% to 100% by mass, further preferably 90% to 100% by mass or less, and especially preferably 95% to 100% by mass or less.

[0904] <Other Steps>

[0905] The pattern forming method preferably includes a cleaning step using a rinsing solution after step 3.

[0906] As a rinsing solution used in the rinsing step following the development step with an alkaline developer, pure water can be cited as an example. Alternatively, an appropriate amount of surfactant can be added to the pure water.

[0907] An appropriate amount of surfactant can also be added to the rinsing solution.

[0908] The rinsing solution used in the rinsing step following the developing step with an organic developer is not particularly limited, as long as it does not dissolve the pattern; a solution containing common organic solvents can be used. Preferably, the rinsing solution is one containing at least one organic solvent selected from the group consisting of hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents, and ether solvents.

[0909] There are no particular limitations on the method of rinsing. For example, the following methods can be listed: continuously spraying rinsing liquid onto a substrate rotating at a fixed speed (spin coating method), immersing the substrate in a tank filled with rinsing liquid for a fixed time (immersion method), and spraying rinsing liquid onto the surface of the substrate (spraying method).

[0910] Alternatively, the pattern forming method of the present invention may include a post-bake step after the rinsing step. This step removes residual developer and rinsing solution between and within the pattern using baking. Furthermore, this step also forms a resist pattern and improves the surface roughness of the pattern. The post-rinsing step is typically performed at 40°C to 250°C (preferably 90°C to 200°C) for a duration of 10 seconds to 3 minutes (preferably 30 seconds to 120 seconds).

[0911] Alternatively, the formed pattern can be used as a mask to perform etching on the substrate. That is, the pattern formed in step 3 can also be used as a mask to process the substrate (or the bottom film and substrate) to form a pattern on the substrate.

[0912] There is no particular limitation on the processing method of the substrate (or the underlying film and the substrate), but it is preferable to form a pattern on the substrate by dry etching using the pattern formed in step 3 as a mask. Dry etching is preferably oxygen plasma etching.

[0913] The resist composition and various materials used in the pattern forming method of the present invention (e.g., solvents, developers, rinse solutions, compositions for forming antireflective films, compositions for forming topcoats, etc.) are preferably free of impurities such as metals. The content of impurities in these materials is preferably less than 1 ppm by mass, more preferably less than 10 ppb by mass, even more preferably less than 100 ppt by mass, particularly preferably less than 10 ppt by mass, and most preferably less than 1 ppt by mass. Examples of metallic impurities include, for instance, Na, K, Ca, Fe, Cu, Mg, Al, Li, Cr, Ni, Sn, Ag, As, Au, Ba, Cd, Co, Pb, Ti, V, W, and Zn.

[0914] As a method for removing impurities such as metals from various materials, filtration using a filter can be cited as an example. Details of filtration using a filter are described in paragraph

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

[0915] In addition, as a method to reduce impurities such as metals contained in various materials, the following methods can be listed: selecting raw materials with low metal content as raw materials for various materials, filtering the raw materials for various materials with filters, and lining the device with Teflon (registered trademark) and distilling under conditions that suppress contamination as much as possible.

[0916] Besides filtration, impurities can also be removed using adsorbent materials, or a combination of filtration and adsorbent materials can be used. As adsorbent materials, known adsorbent materials can be used, such as inorganic adsorbent materials like silicone and zeolite, and organic adsorbent materials like activated carbon. To reduce impurities such as metals contained in these materials, it is necessary to prevent the introduction of metal impurities during the manufacturing process. The content of metal components in the cleaning solution used to clean the manufacturing apparatus can be measured to confirm whether metal impurities have been sufficiently removed from the manufacturing apparatus. The content of metal components in the used cleaning solution is preferably less than 100 parts per trillion (ppt), more preferably less than 10 ppt, and even more preferably less than 1 ppt.

[0917] To prevent malfunctions in chemical piping and various components (filters, O-rings, tubes, etc.) caused by static electricity and subsequent electrostatic discharge, conductive compounds can be added to organic processing solutions such as rinsing solutions. There are no particular limitations on the conductive compounds; methanol is an example. There are no particular limitations on the amount added, but for maintaining better developing or rinsing properties, it is preferably 10% by mass or less, and more preferably 5% by mass or less.

[0918] For pharmaceutical piping, various pipes coated with SUS (stainless steel), or antistatic treated polyethylene, polypropylene, or fluoropolymers (polytetrafluoroethylene, or perfluoroalkoxy resins, etc.) can be used, for example. Similarly, filters and O-rings can also be made of antistatic treated polyethylene, polypropylene, or fluoropolymers (polytetrafluoroethylene, or perfluoroalkoxy resins, etc.).

[0919] Manufacturing methods for electronic devices

[0920] In addition, the present invention also relates to a method for manufacturing an electronic device including the pattern forming method (preferably a method for forming a positive pattern), and an electronic device manufactured by the manufacturing method.

[0921] The electronic device of the present invention can be preferably mounted in electrical and electronic machines (home appliances, office automation (OA), media-related machines, optical machines, and communication machines, etc.). [Example]

[0922] The present invention will be further described in detail below based on embodiments. The materials, amounts, proportions, processing contents, and processing procedures shown in the following embodiments can be appropriately modified without departing from the spirit of the invention. Therefore, the scope of the present invention should not be interpreted as limited by the embodiments shown below.

[0923] [Various components of photosensitive or radiosensitive linear resin compositions (resist compositions)]

[0924] The following describes the components contained in the resist composition used in the experiments provided for the examples.

[0925] [Resin]

[0926] Regarding the resin used in the preparation of the resist composition, the following shows the types of repeating units of the resin and their molar ratios, the weight average molecular weight (Mw) of the resin, and the dispersion of the resin (Pd(Mw / Mn)).

[0927] Furthermore, the resins shown in the table below are synthesized according to the synthesis method of resin A-1 described later (synthesis example 1).

[0928] [Chemistry 76]

[0929] [Chemistry 77]

[0930] [Chemistry 78]

[0931] [Chemistry 79]

[0932] [Chemistry 80]

[0933] [Chemistry 81]

[0934] [Chemistry 82]

[0935] [Chemistry 83]

[0936] <Synthesis Example 1: Synthesis of Resin A-1>

[0937] Cyclohexanone (70 g) was heated to 85°C under a nitrogen atmosphere. While stirring the liquid, a mixed solution of monomers represented by formula M-1 (28.8 g), monomers represented by formula M-2 (55.7 g), monomers represented by formula M-3 (23.7 g), cyclohexanone (130 g), and dimethyl 2,2'-azobisisobutyrate [V-601, manufactured by Fujifilm and Koichi Chemical Co., Ltd.] (6.0 g) was added dropwise over 3 hours to obtain a reaction solution. After the addition was complete, the reaction solution was stirred at 85°C for another 3 hours. After cooling, the obtained reaction solution was precipitated again using 5000 g of ethyl acetate / heptane (mass ratio 1:9), filtered, and the obtained solid was vacuum dried to obtain resin A-1 (86 g). All operations were performed under yellow light.

[0938] [Chemistry 84]

[0939] 〔additive〕

[0940] The following shows the structure of the additives (photoacid generators or acid diffusion controllers) used in the preparation of the resist composition.

[0941] Below, B-1 to B-6 are equivalent to photoacid generators. Furthermore, B-1 to B-6 are not equivalent to acid diffusion control agents.

[0942] D-1, D-4, and D-6~D-8 are equivalent to acid diffusion control agents (photodegradable alkaline compounds) that also act as photoacid generators.

[0943] D-2, D-3, and D-5 are equivalent to acid diffusion control agents other than photodegradable alkaline compounds.

[0944] [Chemistry 85]

[0945] [Chemistry 86]

[0946] [Surfactants]

[0947] The following shows the surfactants used in the preparation of the resist composition.

[0948] W-1: Megafac F176 (manufactured by Dai Nippon Ink & Chemical Co., Ltd.; fluorine-based)

[0949] W-2: Megafac R08 (manufactured by Dai Nippon Ink & Chemical Co., Ltd.; fluorine and silicon based)

[0950] W-3: Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.; silicon-based)

[0951] W-4: Troysol S-366 (manufactured by Troy Chemical Company)

[0952] W-5:KH-20 (manufactured by AGC Seimi Chemical Co., Ltd.)

[0953] W-6: PolyFox PF-6320 (manufactured by OMNOVA Solutions; fluorine-based)

[0954] [Solvent]

[0955] The following shows the solvents used in the preparation of the resist composition.

[0956] SL-1: Propylene glycol monomethyl ether acetate (PGMEA)

[0957] SL-2: Propylene glycol monomethyl ether propionate

[0958] SL-3:2-Heptanone

[0959] SL-4: Ethyl lactate

[0960] SL-5: Propylene Glycol Monomethyl Ether (PGME)

[0961] SL-6: Cyclohexanone

[0962] SL-7: γ-Butyrolactone

[0963] SL-8: Propylene carbonate

[0964] [Preparation of the resist composition]

[0965] The components (resin, photoacid generator, basic compound, surfactant) of the types and amounts shown in Table 1 are dissolved in the solvents shown in Table 1. The obtained solution is filtered using a polyethylene filter with a fine pore size of 0.02 μm to obtain the resist composition of each embodiment or comparative example.

[0966] Furthermore, the amount of solvent used to dissolve each component is adjusted so that the final solid component concentration of the resist composition is 3.0 by mass.

[0967] Furthermore, the term "solid components" refers to all components other than the solvent.

[0968] [test]

[0969] [Preparation of resist film]

[0970] Using a Mark 8 spin coater manufactured by Tokyo Electron, the resist compositions of each example or comparative example were coated onto a 6-inch silicon (Si) wafer that had been pretreated with hexamethyldisilazane (HMDS), and dried on a hot plate at 130°C for 300 seconds to obtain a resist film with a thickness of 100 nm.

[0971] Here, 1 inch is 0.0254m.

[0972] [EB (Electron Beam) Exposure Test]

[0973] On a wafer configured with a resist film obtained by the method described above, pattern irradiation is performed using an electron beam lithography apparatus (manufactured by Advantest Corporation; F7000S, acceleration voltage 50 keV). At this time, the pattern is drawn in such a manner that the line / space ratio is 1 / 1. After the electron beam lithography (pattern irradiation), the wafer is heated on a hot plate at 100 °C for 60 seconds, and then immersed in a 2.38 mass% aqueous solution of tetramethylammonium hydroxide (TMAH) for 60 seconds. Next, the wafer is rinsed with water for 30 seconds. After that, the wafer is rotated at a speed of 4000 rpm for 30 seconds, and then baked and dried at 95 °C for 60 seconds.

[0974] <Evaluation of LWR>

[0975] Using a length measurement scanning electron microscope (SEM (S-9380II manufactured by Hitachi, Ltd.)), a line / space pattern (line / space = 1 / 1) with a line width of 50 nm, which is analyzed by the method shown in the above [EB (electron beam) exposure test], is observed from above the pattern. The line width of the pattern is measured at an arbitrary point (160 points), and the 3σ (nm) of the measurement deviation is evaluated as the value of LWR. The smaller the value, the better the performance.

[0976] In addition, the exposure dose of the electron beam used to form the pattern is set to the optimal exposure dose for reproducing the irradiated pattern.

[0977] <Evaluation of EL (Exposure Latitude)>

[0978] Using a length measurement scanning electron microscope (S-9380II manufactured by Hitachi, Ltd.), a line / space pattern analyzed by the method shown in the above [EB (electron beam) exposure test] is observed, and the exposure dose for reproducing the irradiated pattern (a line / space pattern with a line width of 50 nm (line / space = 1 / 1)) is confirmed. The exposure dose is set as the optimal exposure dose (Eopt) (mJ / cm2). Based on the obtained optimal exposure dose (Eopt), the exposure doses when it becomes ±10% of the target value of 50 nm (i.e., 45 nm and 55 nm) are then obtained. Then, the exposure latitude (EL, unit: %) defined by the following formula is calculated. The larger the value of EL, the smaller the performance change caused by the exposure dose change, and the better.

[0979] Exposure latitude (%): the smaller value of "|Eopt - exposure dose when the line width of the pattern becomes 45 nm| ÷ Eopt × 100" and "|Eopt - exposure dose when the line width of the pattern becomes 55 nm| ÷ Eopt × 100"

[0980] <Evaluation of collapse margin (pattern collapse inhibition)>

[0981] For the line and space pattern analyzed by the method shown in the above [EB (electron beam) exposure test], the exposure dose for analyzing the pattern with a pitch of 150 nm and a line / space = 1 / 1 is set as E0. The space width (unit: nm) when the line pattern starts to collapse when increasing the exposure dose from the exposure dose E0 is used as an index of "collapse margin (pattern collapse inhibition)". The larger the value, the better the performance.

[0982] 〔EUV (extreme ultraviolet) exposure test〕

[0983] For the wafer configured with the resist film obtained by the above method, use an EUV exposure device (Micro Exposure Tool manufactured by Exitech, numerical aperture (NA) 0.3, Quadrupole, outer sigma 0.68, inner sigma 0.36), and use an exposure mask (line / space = 1 / 1) to perform pattern exposure.

[0984] After exposure, heat the wafer on a hot plate at 100 °C for 90 seconds, and then immerse it in a 2.38 mass% aqueous solution of tetramethylammonium hydroxide (TMAH) for 60 seconds. Next, rinse the wafer with water for 30 seconds. After that, rotate the wafer at a speed of 4000 rpm for 30 seconds, and then bake it at 95 °C for 60 seconds and dry it.

[0985] <Evaluation of LWR>

[0986] Use a length measurement scanning electron microscope (SEM (S-9380II manufactured by Hitachi, Ltd.)) to observe the line and space pattern (line / space = 1 / 1) with a line width of 50 nm analyzed by the above method from the top of the pattern. Observe the line width of the pattern at any point (160 points), and evaluate the 3σ (nm) of the measurement deviation as the value of LWR. The smaller the value, the better the performance.

[0987] [result]

[0988] The formulation, characteristics, and evaluation results of the resist compositions of each embodiment or comparative example are shown in the table below.

[0989] In the table, the "Amount (g)" column indicates the amount (g) of each solid component (resin, additive, surfactant) added.

[0990] The "Mass Ratio" column for solvents indicates the mixing ratio (mass ratio) of each solvent.

[0991] The "Molecular weight of the repeating unit (a) after decomposition" column indicates the molecular weight of the repeating unit formed by replacing the decomposition group of the repeating unit (a) in each resin with a hydrogen atom.

[0992] The "Acid Production (mmol / g)" column indicates the total mmol of repeating unit (a) and photoacid generator relative to the total solid content of each resist composition.

[0993]

[0994] The results shown in the table confirm that the resist composition of the present invention can reduce the LWR of the formed pattern, and also has excellent exposure latitude and pattern collapse suppression of the formed pattern.

[0995] Furthermore, the same result can be obtained even if the substrate for forming the resist film is changed from a Si wafer to a chromium substrate.

[0996] It has been confirmed that the greater the number of repeating units (a) and photoacid generators relative to the total solids content of the resist composition, the greater the reduction in the LWR of the formed pattern and the better the exposure latitude.

[0997] In addition, it has been confirmed that when resin (A) contains repeating units with aromatic hydroxyl groups (preferably repeating units represented by formula (A2)), pattern collapse during pattern formation can be further suppressed.

[0998] In addition, regarding Example 6, the resin A-6 used in the resist composition was changed to an equivalent mixture of A-6 and A-10, and the resist composition was prepared in the same manner otherwise. Using this resist composition, tests were conducted in the same manner as in Example 6, and the results were evaluated in the same way as in Example 6, yielding the same results as in Example 6.

[0999] Regarding Example 6, the B-5 used in the resist composition was changed to an equivalent mixture of B-5 and B-2, and the resist composition was prepared in the same manner otherwise. The same evaluation was performed as in Example 6, and the same results were obtained.

[1000] Regarding Example 6, the D-4 used in the resist composition was changed to an equivalent mixture of D-4 and D-8, and the resist composition was prepared in the same manner otherwise. Using this resist composition, tests were conducted in the same manner as in Example 6, and the results were evaluated in the same way as in Example 6, yielding the same results as in Example 6.

[1001] none

Claims

1. A photosensitive or radiosensitive linear resin composition comprising a resin (A) having a repeating unit (a) and repeating units having an acid-decomposing group, wherein the repeating unit (a) has an ionic group that generates an acid by irradiation with photochemical rays or radiation, and the repeating unit formed by replacing the detaching group with a hydrogen atom has a molecular weight of 300 or less; when the photosensitive or radiosensitive linear resin composition does not contain a compound that generates an acid by irradiation with photochemical rays or radiation, the molar amount of the repeating unit (a) relative to the total solids content of the photosensitive or radiosensitive linear resin composition is 0.50 mmol / g or more; when the photosensitive or radiosensitive linear resin composition contains a compound that generates an acid by irradiation with photochemical rays or radiation, the total molar amount of the repeating unit (a) and the compound relative to the total solids content of the photosensitive or radiosensitive linear resin composition is 0.50 mmol / g. mmol / g or higher, the repeating unit with acid-decomposable group decomposes under the action of acid, producing one or more groups selected from the group consisting of carboxyl and aromatic hydroxyl groups, wherein the repeating unit with acid-decomposable group is a repeating unit represented by any of general formulas (6) to (7), wherein in general formula (6), R22 to R24 each independently represent a hydrogen atom, alkyl, cycloalkyl, halogen atom, cyano, or alkoxycarbonyl; L4 represents a single bond or a divalent linked group; Ar1 ​​represents an aromatic cycloalgyl group; R25 to R27 each independently represent a hydrogen atom, alkyl, cycloalkyl, aryl, aralkyl, or alkenyl; furthermore, R26 and R27 can be bonded to each other to form a ring; in addition, R24 or R25 can be bonded to Ar1; wherein in general formula (7), R28 to R30 each independently represent a hydrogen atom, alkyl, cycloalkyl, halogen atom, cyano, or alkoxycarbonyl; L5 represents a single bond or a divalent linked group; R31 and R32 each independently represent a hydrogen atom, alkyl, cycloalkyl, aryl, aralkyl, or alkenyl; R33 represents an alkyl, cycloalkyl, aryl, aralkyl, or alkenyl; furthermore, R32 and R33 can bond together to form a ring.

2. The photosensitive radioactive or radiosensitive linear resin composition as claimed in claim 1, wherein the molecular weight of the repeating unit formed by replacing the desiccant in the repeating unit (a) with a hydrogen atom is 200 or less.

3. The photosensitive radioactive or radiosensitive linear resin composition as described in claim 1 or claim 2, comprising the compound as a low molecular weight compound.

4. The photosensitive radioactive or radiosensitive linear resin composition as claimed in claim 3, wherein the compound is an ionic compound.

5. The photosensitive radioactive or radiosensitive linear resin composition as claimed in claim 1 or claim 2, wherein the repeating unit (a) is a repeating unit represented by general formula (1), in which A represents a group constituting the main chain of the resin; L represents a single bond or a divalent linker; and Z+ represents an organic cation.

6. The photosensitive radioactive or radiosensitive linear resin composition as claimed in claim 5, wherein A is a base containing only atoms selected from the group consisting of hydrogen atoms and carbon atoms, and L is a single bond or a base containing only atoms selected from the group consisting of hydrogen atoms and carbon atoms.

7. The photosensitive radioactive or radiosensitive linear resin composition as claimed in claim 1 or claim 2, wherein the resin (A) is a resin whose solubility in an alkaline developing solution is enhanced by the action of an acid.

8. A photosensitive radioactive or radiosensitive linear resin composition as claimed in claim 1 or claim 2, wherein the resin (A) has repeating units represented by general formula (A2), in which R101, R102, and R103 each independently represent a hydrogen atom, alkyl, cycloalkyl, halogen atom, cyano, or alkyloxycarbonyl; LA represents a single bond or divalent linkage; ArA represents an aromatic cycloalloy; k represents an integer from 1 to 5; wherein, R102 can also be bonded to ArA, in which case R102 represents a single bond or an alkyl group.

9. A photosensitive or radiosensitive linear resin composition as claimed in claim 1 or claim 2, wherein, when the photosensitive or radiosensitive linear resin composition does not contain a compound that produces acid upon irradiation by photosensitive rays or radiation, the molar amount of the repeating unit (a) is 0.70 mmol / g or more relative to the total solids content of the photosensitive or radiosensitive linear resin composition; and when the photosensitive or radiosensitive linear resin composition contains a compound that produces acid upon irradiation by photosensitive rays or radiation, the combined molar amount of the repeating unit (a) and the compound is 0.70 mmol / g or more relative to the total solids content of the photosensitive or radiosensitive linear resin composition.

10. A photosensitive or radiosensitive linear resin composition as claimed in claim 1 or claim 2, wherein, when the photosensitive or radiosensitive linear resin composition does not contain a compound that produces acid upon irradiation by photosensitive rays or radiation, the molar amount of the repeating unit (a) is 1.00 mmol / g or more relative to the total solids content of the photosensitive or radiosensitive linear resin composition; and when the photosensitive or radiosensitive linear resin composition contains a compound that produces acid upon irradiation by photosensitive rays or radiation, the combined molar amount of the repeating unit (a) and the compound is 1.00 mmol / g or more relative to the total solids content of the photosensitive or radiosensitive linear resin composition.

11. The photosensitive radioactive or radiosensitive linear resin composition as claimed in claim 1 or claim 2, wherein the photosensitive radioactive or radiosensitive linear resin composition comprises the compound, wherein the compound comprises a photodegradable alkaline compound.

12. A resist film formed using a photosensitive radioactive or radiosensitive linear resin composition as described in any one of claims 1 to 11.

13. A pattern forming method comprising: forming a resist film on a substrate using a photosensitive radioactive or radiosensitive linear resin composition as described in any one of claims 1 to 11; exposing the resist film; and developing the exposed resist film using a developer.

14. A method for manufacturing an electronic device, comprising the pattern forming method as described in claim 13.