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

Abstract

This invention provides a photosensitive or radiosensitive linear resin composition with excellent defect suppression properties, a resist film, a patterning method, and a method for manufacturing electronic devices. The photosensitive or radiosensitive linear resin composition of this invention comprises: resin A, having a repeating unit a1, said repeating unit a1 having a base represented by any one of general formulas (1) to (6) as a nonionic base that decomposes upon irradiation by photosensitive rays or radiation; and additive B, being at least one of an acid having an acid group with a pKa of -3.60 or higher, and a salt with a structure in which hydrogen atoms of an acid group having a pKa of -3.60 or higher are cationically substituted.

Description

Technical Field

[0001] This invention relates to a photosensitive radioactive or radiosensitive linear resin composition, a resist film, a patterning method, and a method for manufacturing electronic devices. Prior Technology

[0002] As a method for pattern formation, various methods have been studied, such as the following methods. That is, a photosensitive or radiosensitive linear resin film (hereinafter also referred to as "resist film") formed using a photosensitive radiosensitive or radiosensitive linear resin composition is exposed, causing a change in the solubility of the resist film relative to the developer in the areas reflecting the exposed pattern. Then, development is performed using a developer (such as an alkaline aqueous solution or an organic solvent-based developer) to remove the exposed or unexposed areas of the resist film, thereby obtaining the desired pattern.

[0003] For example, Patent Document 1 discloses a photoresist composition comprising: a photoresist polymer containing repeating units represented by the following chemical formula; a photoacid generator that generates acid; and an organic solvent, wherein the content of the photoacid generator is 0.1 to 20 parts by weight relative to 100 parts by weight of the photoresist polymer, and the content of the organic solvent is 300 to 5000 parts by weight (Third Invention, Sixth Invention).

[0004] [Chemistry 1] [Existing Technical Documents] [Patent Literature]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2008-111120 Summary of the Invention

[0006] [The problem that the invention aims to solve] The inventors studied the photoresist composition (photosensitive radioactive or radiosensitive linear resin composition) described in Patent Document 1 and found that there is room for improvement in defect suppression when using the photoresist composition to form patterns.

[0007] Therefore, the objective of this invention is to provide a photosensitive or radiosensitive linear resin composition with excellent defect suppression properties. 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. [Methods for solving problems]

[0008] The inventors have discovered that the aforementioned problem can be solved by the following structure.

[0009] [1] A photosensitive or radiosensitive linear resin composition comprising: Resin A, having repeating units a1 of 20 moles or more relative to all repeating units, wherein repeating units a1 have a base represented by any one of general formulas (1) to (6) as a nonionic base that decomposes upon irradiation by photochemical rays or radiation; and Additive B is at least one of an acid having an acid group with a pKa of -3.60 or higher, and a salt having a structure in which the hydrogen atom of an acid group with a pKa of -3.60 or higher is cation-substituted. [Chemistry 2] In general formulas (1) to (6), * indicates the bond position. In general formula (1), R1 and R2 each independently represent an organic group. R1 and R2 can bond together to form a ring. In general formula (2), R3 and R4 each independently represent an organic group. R3 and R4 can bond together to form a ring. In general formula (3), R5 and R6 each independently represent a hydrogen atom or an organic group. R5 and R6 can bond together to form a ring. n represents 0 or 1. Ar represents an aromatic cyclic group that may have substituents. In general formula (4), R7 represents an organic group. X represents -CO- or -SO2-. In general formula (5), R8 and R9 each independently represent an organic group. R8 and R9 can bond together to form a ring. In general formula (6), R10 and R11 each independently represent an organic group. R10 and R11 can bond together to form a ring. [2] The photosensitive radioactive or radiosensitive linear resin composition as described in [1] includes resin A containing the repeating unit a1 in a content of 40 mol% or more relative to all repeating units. [3] As described in [1] or [2], in the resin A, the content of repeating units having acid-degradable groups that are not equivalent to any of the groups represented by general formulas (1) to (6) is 20 mol% or less relative to all repeating units. [4] As described in any one of [1] to [3], the photosensitive radioactive or radiosensitive linear resin composition, wherein the solubility parameter (SP) value of all repeating units constituting the resin A is 18.0 MPa or higher. [5] As described in any one of [1] to [4], the photosensitive radioactive or radiosensitive linear resin composition, wherein the resin A contains repeating units having lactone groups. [6] The photosensitive or radiosensitive linear resin composition as described in any one of [1] to [5], wherein the concentration of the solid component is less than 2% by mass. [7] A photoresist film is formed using a photosensitive radioactive or radiosensitive linear resin composition as described in any one of [1] to [6]. [8] A pattern forming method, comprising: The step of forming a resist film on a substrate using a photosensitive radioactive or radiosensitive linear resin composition as described in any one of [1] to [6]; The step of exposing the resist film; and The step of developing the exposed resist film using a developer. [9] A method for manufacturing an electronic device includes the pattern forming method as described in [8]. [The effects of the invention]

[0010] According to the present invention, photosensitive radioactive or radiosensitive linear resin compositions with excellent defect suppression properties can be provided. 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. Implementation

[0011] The present invention will now be described in detail. 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. 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). In addition, the term "organic group" in this specification refers to a group containing at least one carbon atom. Unless otherwise specified, the substituent is a monovalent substituent. 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) light, X-rays, and electron beams (EB). In this specification, "light" refers to photochemical rays or radiation. Unless otherwise specified, "exposure" in this instruction manual includes not only exposure using the bright-line spectrum of mercury lamps, far-ultraviolet light represented by excimer lasers, extreme ultraviolet light, X-rays, and EUV light, but also depiction using particle beams such as electron beams and ion beams. In this manual, the term "~" is used to indicate the lower and upper limits, including the values ​​before and after it. 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".

[0012] In this specification, (meth)acrylate means acrylate and methacrylate, and (meth)acrylic acid means acrylic acid and methacrylic acid.

[0013] 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)

[0014] In this specification, the composition ratio of the resin (molar ratio or mass ratio, etc.) is determined by 13C nuclear magnetic resonance (NMR).

[0015] 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.

[0016] Software Package 1: Advanced Chemistry Development (ACD / Labs) Software V8.14 for Solaris (1994-2007 ACD / Labs).

[0017] 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, but are not limited to these. Furthermore, several software programs exist that can perform DFT, such as Gaussian16.

[0018] 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. 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".

[0019] In this specification, halogen atoms, for example, include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms.

[0020] [Photosensitive or radiosensitive linear resin composition] The photosensitive or radiosensitive linear resin composition of the present invention comprises: resin A, repeating unit a1 having 20 moles or more of repeating units relative to all repeating units, said repeating unit a1 having a base represented by any one of general formulas (1) to (6) as a nonionic base that decomposes upon irradiation by photosensitive rays or radiation; and Additive B is at least one of an acid having an acid group with a pKa of -3.60 or higher, and a salt having a structure in which the hydrogen atom of an acid group with a pKa of -3.60 or higher is cation-substituted. Hereinafter, photosensitive or radiosensitive linear resin compositions will also be referred to as "resist compositions". The base represented by general formulas (1) to (6) that is a non-ionic base that decomposes by irradiation with photochemical rays or radiation is also called a "specific functional base".

[0021] While the mechanism by which this structure improves the defect suppression of patterns may not be clear, the inventors speculate as follows. First, in a photoresist film formed using a typical chemically amplified photoresist composition, the acid generated by the photoacid generator upon exposure acts on the acid-decomposing resin, causing the decomposition of acid-decomposing groups, thereby changing the polarity of the exposed portion. In this case, since the acid generated by the photoacid generator diffuses within the photoresist film, a deterioration in dissolution contrast is easily caused. Furthermore, it is difficult to suppress the generation of minute defects due to probabilistic factors such as whether the photoacid generator decomposes upon exposure to light to generate acid, whether the generated acid encounters acid-decomposing groups, and even if the generated acid encounters acid-decomposing groups, whether the decomposition of acid-decomposing groups actually occurs. On the other hand, the resist composition of the present invention includes resin A, in which specific functional groups are exposed and chemical bonds are directly broken, causing a change in the polarity of this portion. It is speculated that the low dependence on the elements of general probability theory allows for a more direct realization of the polarity change in the exposed portion, which, in this respect, helps to suppress the generation of defects during pattern formation. Furthermore, the resist composition of the present invention also includes additive B. It is presumed that additive B interacts with resin A, promoting the cleavage of side chains of resin A during exposure, and increasing the difference in solubility between the exposed and unexposed portions of resin A during development, thereby contributing to the excellent defect suppression properties of the resist composition of the present invention. Furthermore, the resist composition of the present invention exhibits excellent resolution when forming patterns. Hereinafter, the superiority of at least one of the defect suppression and resolution properties of the resist composition of the present invention is also referred to as superior effect of the present invention.

[0022] The resist composition of the present invention will be described in detail below. The resist composition can be either a positive or negative type. Furthermore, it can be a resist composition for alkaline development or a resist composition for organic solvent development. The resist composition of the present invention is typically a non-chemically amplified resist composition, but it can also be used in the resist composition of the present invention as a mechanism of a chemically amplified resist composition. The following is a detailed description of the various components of the corrosion inhibitor.

[0023] [Resin A] The resist composition includes resin A. Resin A is a resin containing repeating unit a1, which has a base (specific functional group) represented by general formula (1) to general formula (6) as a non-ionic base that decomposes by irradiation (exposure) of photochemical rays or radiation. Specific functional groups decompose to produce polar groups when exposed to photochemical rays or radiation. That is, resin A contains repeating units with groups that decompose upon exposure to generate polar groups. Resins containing these repeating units typically become more polar upon exposure and have increased solubility relative to alkaline developers, but decreased solubility relative to organic solvents. 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.

[0024] <Repeating unit a1> Resin A contains repeating unit a1. The repeating unit a1 has specific functional groups. The specific functional base is the base represented by any one of the general formulas (1) to (6).

[0025] [Chemistry 3]

[0026] In general formula (1), * indicates the position of the bond. In general formula (1), R1 and R2 each independently represent an organic group. Examples of such organic groups include cyano, alkyl, alkoxy, alkoxycarbonyl, alkenyl, cycloalkyl, and aromatic cycloyl groups. The alkyl group can be straight-chain or branched-chain, and preferably has 1 to 5 carbon atoms. Examples of the alkyl group include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, and tributyl. As the alkyl portion of the alkoxy group and the alkoxycarbonyl group, for example, groups that are the same as the alkyl group can be listed. The alkenyl group can be linear or branched, and preferably has 1 to 5 carbon atoms. Examples of alkenyl groups include vinyl groups. The cycloalkyl group preferably has a ring member number of 3 to 15. The cycloalkyl group is preferably a monocyclic cycloalkyl group such as cyclopentyl or cyclohexyl, or a polycyclic cycloalkyl group such as norbornyl, tetracyclodecyl, tetracyclododecyl, and adamantyl. In the cycloalkyl group, for example, one or more (e.g., one to three) of the methylene group constituting the ring may be substituted with a heteroatom (-O- or -S-, etc.), -SO2-, -SO3-, an ester group, a carbonyl group, or a vinylidene group. Additionally, in these cycloalkyl groups, one or more (e.g., one to two) of the ethyl groups constituting the cycloalkane ring may be substituted with ethylides. The aromatic cyclic group can be monocyclic or polycyclic, and the number of ring member atoms is preferably 5 to 15. The aromatic cyclic group may have one or more (e.g., one to five) heteroatoms (oxygen atom, sulfur atom, and / or nitrogen atom, etc.) as ring member atoms. Examples of the aromatic cyclic group include: benzene cyclic group, naphthyl cyclic group, anthracene cyclic group, thiazole cyclic group, and benzothiazole cyclic group. Substituents that may be present in the alkyl, alkoxy, alkoxycarbonyl, and alkenyl groups include, for example, halogen atoms (fluorine atoms, etc.), hydroxyl groups, nitro groups, cyano groups, cycloalkyl groups, and aromatic cycloalkyl groups. For example, the alkyl group may have a fluorine atom as a substituent, becoming a perfluoroalkyl group. Regarding cycloalkyl and aromatic cycloalkyl groups as substituents, examples of cycloalkyl and aromatic cycloalkyl groups described as preferred forms of organogroups can be cited. Substituents that may be present in the cycloalkyl and aromatic cycloalkanes include, for example, halogen atoms, hydroxyl groups, nitro groups, cyano groups, alkyl groups, alkoxy groups, alkoxy carbonyl groups, and alkenyl groups. Regarding alkyl, alkoxy, alkoxy carbonyl, and alkenyl groups as substituents, examples include alkyl, alkoxy, alkoxy carbonyl, and alkenyl groups described as preferred organic groups. Alkyl, alkoxy, alkoxy carbonyl, and alkenyl groups as substituents may further have substituents as described above.

[0027] R1 and R2 can bond together to form a ring. The ring formed by the mutual bonding of R1 and R2 can be a monocyclic or polycyclic ring. The ring preferably has 4 to 15 ring members.

[0028] When R1 and R2 are bonded together to form a ring, it is preferable that R1 and R2 are bonded together to form a base represented by the following general formula (LC). *V -LC1 -LL1 -LA1 -LA2 -LL2 -LC2 -*W (LC)

[0029] In the general formula (LC), *V represents the bond position on the R1 side. In other words, *V is the bond position with -CO- as explicitly stated in general formula (1). In the general formula (LC), *W represents the bond position on the R2 side. In other words, *W is the bond position with the nitrogen atom explicitly stated in the general formula (1).

[0030] In the general formula (LC), LC1 and LC2 each independently represent a single bond, -CO-, or -SO2-.

[0031] In the general formula (LC), LL1 and LL2 each independently represent a single bond or an alkyl group. The alkyl group can be linear or branched, and the number of carbon atoms is preferably 1 to 15. One or more (e.g., one to three) methylene groups constituting the alkyl group may be substituted with heteroatoms (-O- or -S-, etc.), -SO2-, -SO3-, ester groups, carbonyl groups, or vinylidenes. The vinylidenes may have substituents, such as organogroups. Examples of organogroups that the vinylidenes may have include organogroups described as represented by R1. In addition, one or more (e.g., one to two) of the ethyl groups constituting the alkyl group may be substituted with vinyl groups. The alkylene group may be, for example, "-methylene or other unsubstituted alkylene-", "-methylene or other unsubstituted alkylene-O-", "-S-ethylene-ethylene-", or "-ethylene-". Furthermore, the term "unsubstituted alkyl groups such as methylene" refers to straight-chain or branched alkyl groups in which the methylene group constituting the alkyl group is not substituted with heteroatoms or the ethyl group constituting the alkyl group is not substituted with vinyl groups. The number of carbon atoms in the unsubstituted alkyl groups such as methylene is preferably 1 to 8.

[0032] In the general formula (LC), LA1 and LA2 each independently represent a single bond or an aromatic ring group. The aromatic cyclic group can be monocyclic or polycyclic, and the number of ring member atoms is preferably 5 to 15. The aromatic cyclic group may have one or more (e.g., one to five) heteroatoms (oxygen atom, sulfur atom, and / or nitrogen atom, etc.) as ring member atoms. Examples of the aromatic cyclic group include: benzene cyclic group (benzene-1,2-diyl, etc.), naphthyl cyclic group (naphthalene-1,2-diyl, etc.), anthracene cyclic group, thiazole cyclic group, and benzothiazole cyclic group.

[0033] In the general formula (LC), preferably at least one of LC1, LL1, LA1, LA2, LL2, and LC2 is a single bond, and at least one of LL1, LA1, LA2, and LL2 is a single bond. Furthermore, if both LA1 and LA2 are single bonds, LL2 is also preferably a single bond. The total number of atoms other than hydrogen atoms in the base represented by the general formula (LC) is preferably 3 to 100, more preferably 4 to 20.

[0034] The group represented by the general formula (LC) formed by the mutual bonding of R1 and R2 in general formula (1) is preferably LC1 as a single bond, LL1 as a single bond, LA1 as an aromatic ring group, LA2 as a single bond, LL2 as a single bond, and LC2 as -CO-.

[0035] In general formula (2), * indicates the bond position. In general formula (2), R3 and R4 each independently represent an organic group. As organic groups represented by R3 and R4 in general formula (2), organic groups represented by R1 and R2 in general formula (1) can be listed similarly. R3 and R4 can bond together to form a ring. The ring formed by the mutual bonding of R3 and R4 can be a monocyclic or polycyclic ring. The ring preferably has 4 to 15 ring members. When R3 and R4 are bonded together to form a ring, it is preferable that R3 and R4 are bonded together to form the base represented by the general formula (LC). In this case, in the general formula (LC), *V represents the bond position on the R3 side, and *W represents the bond position on the R4 side. The group represented by the general formula (LC) formed by the mutual bonding of R3 and R4 in general formula (2) is preferably LC1 as a single bond, LL1 as an alkyl group, LA1 as a single bond or an aromatic cyclic group, LA2 as a single bond, LL2 as a single bond, and LC2 as a single bond.

[0036] In general formula (3), * indicates the bond position. In general formula (3), R5 and R6 each independently represent a hydrogen atom or an organic group. As organic groups represented by R5 and R6 in general formula (3), organic groups represented by R1 and R2 in general formula (1) can be listed similarly. R5 and R6 can bond together to form a ring. The ring formed by the mutual bonding of R5 and R6 can be a monocyclic or polycyclic ring. The number of ring members is preferably 4 to 15. When R5 and R6 are bonded together to form a ring, it is preferable that R5 and R6 are bonded together to form the base represented by the general formula (LC). In this case, in the general formula (LC), *V represents the bond position on the R5 side, and *W represents the bond position on the R6 side. The group represented by the general formula (LC) formed by the mutual bonding of R5 and R6 in general formula (3) is preferably LC1 as a single bond, LL1 as an alkyl group, LA1 as a single bond, LA2 as a single bond, LL2 as a single bond, and LC2 as a single bond. In general formula (3), n represents 0 or 1. In general formula (3), Ar represents an aromatic cyclic group that may have substituents. As the aromatic ring group represented by Ar in general formula (3), aromatic ring groups can also be described in the same way as the form of the organic groups represented by R1 and R2 in general formula (1). In addition, the group represented by general formula (3) is preferably an acid-decomposing group formed by protecting the sulfonic acid group, which is a polar group, with "-CR5 R6 -(CO)n -Ar" as a protecting group.

[0037] In general formula (4), * indicates the bond position. In general formula (4), R7 represents an organic group. As the organic group represented by R7 in general formula (4), the organic groups represented by R1 and R2 in general formula (1) can be listed similarly. In general formula (4), X represents -CO- or -SO2-.

[0038] In general formula (5), * indicates the bond position. In general formula (5), R8 and R9 each independently represent an organic group. As organic groups represented by R8 and R9 in general formula (5), organic groups represented by R1 and R2 in general formula (1) can be similarly listed. R8 and R9 can bond together to form a ring. The ring formed by the mutual bonding of R8 and R9 can be a monocyclic or polycyclic ring. The ring preferably has 4 to 15 ring members. When R8 and R9 are bonded together to form a ring, it is preferable that R8 and R9 are bonded together to form a base represented by the general formula (LC). In this case, in the general formula (LC), *V represents the bond position on the R8 side, and *W represents the bond position on the R9 side. The group represented by the general formula (LC) formed by the mutual bonding of R8 and R9 in general formula (5) is preferably LC1 as a single bond, LL1 as an alkyl group, LA1 as a single bond or an aromatic cyclic group, LA2 as a single bond or an aromatic cyclic group, LL2 as a single bond, and LC2 as a single bond.

[0039] In general formula (6), * indicates the bond position. In general formula (6), R10 and R11 each independently represent an organic group. As organic groups represented by R10 and R11 in general formula (6), similarly, organic groups represented by R1 and R2 in general formula (1) can be listed. R10 and R11 can bond together to form a ring. The ring formed by the mutual bonding of R10 and R11 can be a monocyclic or polycyclic ring. The ring preferably has 4 to 15 ring members. When R10 and R11 are bonded together to form a ring, it is preferable that R10 and R11 are bonded together to form the base represented by the general formula (LC). In the general formula (LC) under this case, *V represents the bond position on the R10 side, and *W represents the bond position on the R11 side. The group represented by the general formula (LC) formed by the mutual bonding of R10 and R11 in general formula (6) is preferably LC1 as -CO-, LL1 as a single bond, LA1 as an aromatic ring group, LA2 as a single bond, LL2 as a single bond, and LC2 as a single bond.

[0040] The repeating unit a1 only needs to have at least one specific functional group, and may have more than two (e.g., two to four). When the repeating unit a1 has more than two specific functional groups, the two or more specific functional groups may each be the same structure or different structures. In addition, the two or more specific functional groups may be specific functional groups represented by the same general formula, or they may be specific functional groups represented by different general formulas.

[0041] The repeating unit a1 is preferably a repeating unit represented by, for example, the general formula (aa). The repeating unit represented by the general formula (aa) is a repeating unit a1 having the basis represented by the general formulas (1) to (3), (5), or (6).

[0042] [Chemistry 4]

[0043] In the general formula (aa), Ra1 ~ Ra3 each independently represent a hydrogen atom or a substituent. The substituent is preferably a halogen atom or an alkyl group, and more preferably a methyl group.

[0044] In the general formula (aa), La1 represents -COO-, aromatic cyclic group, or a combination of these groups. The aromatic ring group can be monocyclic or polycyclic, and the number of ring members is preferably 5 to 15. The aromatic ring group may have one or more (e.g., one to five) heteroatoms (oxygen atom, sulfur atom, and / or nitrogen atom, etc.) as ring members. The aromatic ring group is preferably a benzene ring group (benzene-1,4-diyl, etc.). Examples of bases that form the combination include -COO-aromatic cycloalgyl- and -aromatic cycloalgyl-COO-.

[0045] In the general formula (aa), La2 represents a single bond or a divalent linker. Examples of divalent linking groups include: -CO-, -O-, -S-, -SO-, -SO2-, hydrocarbon groups (e.g., alkyl, cycloalkyl, alkenyl, aryl, etc.), and linking groups formed by linking multiple of these. Halogen atoms are preferred as substituents that may be present in the hydrocarbon group. The alkyl group can be linear or branched, and the number of carbon atoms is preferably 1 to 4. The cycloalkyl group can be monocyclic or polycyclic, and the number of carbon atoms is preferably 3 to 15. One or more (preferably one to two) of the -CH2- group constituting the cycloalkyl group may be substituted with heteroatoms (-O- or -S-, etc.), -SO2-, -SO3-, ester groups, or carbonyl groups. In this way, the cycloalkyl group can become a lactone group. For example, a lactone group can be formed by removing two hydrogen atoms from the lactone structure represented by any of the formulas (LC1-1) to (LC1-21) described below. The divalent linker is preferably an enylalkyl group or an enylcycloalkyl-O- group.

[0046] In the general formula (aa), Za represents any one of the bases represented by the general formulas (1) to (3), (5) and (6). Among them, the groups directly bonded by the general formulas (1) to (3) are preferably other than oxygen atoms, and are preferably alkyl groups (e.g., alkyl groups constituting La2) or aromatic cyclic groups (e.g., aromatic cyclic groups constituting La1). The preferred direct bond of the base represented by general formulas (5) to (6) is an oxygen atom (e.g., an oxygen atom in -COO- constituting La1, or an oxygen atom in -O- constituting La2).

[0047] The repeating unit a1 is also preferably a repeating unit represented by, for example, general formulas (ab) to (ad). The repeating units represented by general formulas (ab) to (ad) are repeating units a1 with the basis represented by general formula (4).

[0048] [Chemistry 5]

[0049] In the general formula (ab), p represents an integer greater than or equal to 0, preferably an integer between 0 and 2. When p is an integer greater than 2, there exist multiple Rb3, Rb4, Lb1, Lb2, and Lb3 that can be the same or different from each other. In the general formula (ab), Rb1 ~ Rb4 each independently represent a hydrogen atom or a substituent. Examples of substituents include halogen atoms and alkyl groups. Among them, Rb1 to Rb4 are preferably hydrogen atoms. In the general formula (ab), Lb1 ~ Lb5 each independently represent a single bond or a divalent linker. Examples of divalent linking groups include: -CO-, -O-, -S-, -SO-, -SO2-, hydrocarbon groups (e.g., alkyl, cycloalkyl, alkenyl, aryl, etc.), and linking groups formed by linking multiple of these. Halogen atoms are preferred as substituents that may be present in the hydrocarbon group. The alkyl group can be linear or branched, and the number of carbon atoms is preferably 1 to 4. Among them, Lb1, Lb2, and Lb4 are preferably single bonds. Lb3 is preferably a single bond or an alkyl group, and more preferably a single bond or a methylene group. Lb5 is preferably -CO-. In the general formula (ab), Zb is the basis represented by the general formula (4). The -CO- explicitly stated in general formula (4) is preferably bonded to Lb4.

[0050] In the general formula (ac), Rc1 and Rc2 each independently represent a hydrogen atom or a substituent. Examples of substituents include halogen atoms and alkyl groups. Among them, Rc1 and Rc2 are preferably hydrogen atoms. In the general formula (ac), Lc1 and Lc2 each independently represent a single bond or a divalent linker. Examples of divalent linking groups include: -CO-, -O-, -S-, -SO-, -SO2-, hydrocarbon groups (e.g., alkyl, cycloalkyl, alkenyl, aryl, etc.), and linking groups formed by linking multiple of these. Halogen atoms are preferred as substituents that may be present in the hydrocarbon group. The alkyl group can be linear or branched, and the number of carbon atoms is preferably 1 to 4. The divalent linker is preferably one or more groups selected from the group consisting of alkylene, -O-, and -CO-, more preferably "*p-alkylene-O-alkylene-*q" or "*p-alkylene-CO-*q". *p and *q are the bonding positions, where *p can be a bonding position on the Zc side, and *q can also be a bonding position on the Zc side. The alkylene groups on the *p and / or *q sides of "*p-alkylene-O-alkylene-*q" and the alkylene groups in "*p-alkylene-CO-*q" are preferably substituents with halogen atoms, and can also be perhalogenated alkylene groups (perfluoroalkylene groups, etc.). Among them, Lc1 is preferably a single bond. Lc2 is preferably a divalent linkage, and more preferably "*p-extinyl-O-extinyl-*q" or "*p-extinyl-CO-*q". In the general formula (ac), Zc is the basis represented by the general formula (4). The preferred configuration is the -CO- and Lc1 bond as explicitly stated in general formula (4).

[0051] In the general formula (ad), Rd1 ~ Rd4 each independently represent a hydrogen atom or a substituent. Examples of substituents include halogen atoms and alkyl groups. Rd1 is preferably a hydrogen atom or an alkyl group, and more preferably a hydrogen atom or a methyl group. Rd2 ~ Rd4 are preferably hydrogen atoms. In the general formula (ad), Ld1 ~ Ld3 each independently represent a single bond or a divalent linkage. Examples of divalent linking groups include: -CO-, -O-, -S-, -SO-, -SO2-, hydrocarbon groups (e.g., alkyl, cycloalkyl, alkenyl, aryl, etc.), and linking groups formed by linking multiple of these. Halogen atoms are preferred as substituents that may be present in the hydrocarbon group. The alkyl group can be linear or branched, and the number of carbon atoms is preferably 1 to 4. Among them, Ld1 is preferably an ester group (-COO-). Ld2 is preferably a single bond. Ld3 is preferably "*p-extrinyl-CO-*q". *p and *q are the bonding positions. *p can be a bonding position on the Zd side, and *q can also be a bonding position on the Zd side. It is preferred that *q is a bonding position on the Zd side. In the general formula (ad), Zd is the basis represented by the general formula (4). The preferred configuration is the -CO- and Ld2 bond as explicitly stated in general formula (4).

[0052] The following example illustrates the repeating unit a1.

[0053] [Chemistry 6]

[0054] [Chemistry 7]

[0055] The content of repeating unit a1 is 20 mol% or more, preferably 40 mol% or more, relative to all repeating units in resin A. Alternatively, it can be 100 mol% or less as an upper limit. Repeating unit a1 can be used alone or in two or more ways. When using two or more, it is preferable that their total content is within the range of the preferred content. When there are two or more types of resin A, the resist composition is preferably resin A in which the content of one or more repeating units a1 is 40 mol% or more relative to all repeating units. In this case, the resist composition is preferably resin A in which the content of repeating units a1 is 30% to 100% by mass relative to the total content of resin A, and the content is 40 mol% or more relative to all repeating units; more preferably, it contains 60% to 100% by mass; and even more preferably, it contains 80% to 100% by mass.

[0056] <Repeating unit with non-equivalent acid decomposition group> Resin A may contain repeating units having acid-degradable groups (also called "non-equivalent acid-degradable groups") that are not equivalent to the groups represented by the general formulas (1) to (6). The term "non-acid-decomposable group" does not refer to the groups represented by general formulas (1) to (6). For example, even if the groups represented by general formulas (1) to (6) are polar groups that decompose due to the action of an acid, such groups are not included in the non-acid-decomposable group. In addition, the non-acid-decomposable group does not include the groups represented by general formulas (1) to (6) as part of it. In addition to having a non-acid-decomposable group, the repeating unit may have a group (specific functional group) represented by the general formula (1) to general formula (6), or it may not have one, preferably it does not have one.

[0057] An acid-decomposable group refers to a group that decomposes under the action of an acid to produce a polar group. Preferably, an acid-decomposable group is a structure with a polar group that has been released from its protective group by the action of an acid. An acid-decomposable group can decompose under the action of an acid to produce a polar group.

[0058] As a polar group, it is preferably a base-soluble group, such as: carboxyl group, phenolic hydroxyl group, fluorinated alcohol group, sulfonic acid group, phosphoric acid group, sulfonamide group, sulfonylimido group, (alkylsulfonyl)(alkylcarbonyl)methylene, (alkylsulfonyl)(alkylcarbonyl)imido, bis(alkylcarbonyl)methylene, bis(alkylcarbonyl)imido, bis(alkylsulfonyl)methylene, bis(alkylsulfonyl)imido, tri(alkylcarbonyl)methylene, and tri(alkylsulfonyl)methylene, as well as acidic groups such as alcoholic hydroxyl group, etc. As a detaching group that is released due to the action of acid, examples can be listed as the groups represented by formulas (Y1) to (Y4). Equation (Y1): -C(Rx1)(Rx2)(Rx3) Equation (Y2): -C(=O)OC(Rx1)(Rx2)(Rx3) Equation (Y3): -C(R36)(R37)(OR38) Equation (Y4): -C(Rn)(H)(Ar)

[0059] In formulas (Y1) and (Y2), Rx1 to Rx3 each independently represent an alkyl group (straight-chain or branched-chain, preferably with 1 to 6 carbon atoms), a cycloalkyl group (monocyclic or polycyclic, preferably with 3 to 15 carbon atoms), an alkenyl group (straight-chain or branched-chain, preferably with 2 to 6 carbon atoms), an aryl group (monocyclic or polycyclic, preferably with 6 to 15 carbon atoms), or a heteroaryl group (monocyclic or polycyclic, preferably with 5 to 15 ring members). Two of Rx1 to Rx3 can be bonded to form a monocyclic or polycyclic ring. Examples of such monocyclic or polycyclic rings include cycloalkane rings. Preferably, the cycloalkane rings are monocyclic cycloalkane rings such as cyclopentane and cyclohexane rings, and polycyclic cycloalkane rings such as norbornene, tetracyclic decane, tetracyclic dodecane, and adamantane rings. In the cycloalkane ring, for example, one or more (e.g., one to three) methylene groups constituting the ring may be substituted with heteroatoms (-O- or -S-, etc.), -SO2-, -SO3-, ester groups, carbonyl groups, or vinylidenes. Furthermore, in these cycloalkane rings, one or more (e.g., one to two) ethyl groups constituting the cycloalkane ring may be substituted with ethylidenes. In formula (Y1), a cycloalkane ring is formed by two bonds in Rx1 to Rx3, and when the cycloalkane ring forms an eindustrial group with the α carbon and γ carbon relative to the C (carbon) atom specified in formula (Y1), the remaining one in Rx1 to Rx3 can be a hydrogen atom. In formula (Y3), R36 to R38 each independently represent a hydrogen atom or an organic group. The organic group is preferably an alkyl group (linear or branched, preferably with 1 to 6 carbon atoms), a cycloalkyl group (monocyclic or polycyclic, preferably with 3 to 15 carbon atoms), an aryl group (monocyclic or polycyclic, preferably with 6 to 15 carbon atoms), an aralkyl group (preferably with 7 to 18 carbon atoms), or an alkenyl group (linear or branched, preferably with 2 to 6 carbon atoms). R37 and R38 can be bonded together to form a loop. Examples of such loops include single or multiple loops formed by two bonds of Rx1 to Rx3. In formula (Y4), Ar represents an aromatic cyclic group. Rn represents an alkyl group (straight-chain or branched-chain, preferably with 1 to 6 carbon atoms), a cycloalkyl group (monocyclic or polycyclic, preferably with 3 to 15 carbon atoms), or an aryl group (monocyclic or polycyclic, preferably with 6 to 15 carbon atoms). Rn and Ar can bond to each other to form a non-aromatic ring. Ar is preferably an aryl group (monocyclic or polycyclic, preferably with 6 to 15 carbon atoms).

[0060] The content of repeating units having non-acid-degradable groups (acid-degradable groups not equivalent to those represented by general formulas (1) to (6)) is preferably 60 mol% or less, more preferably 50 mol% or less, and even more preferably 20 mol% or less, relative to all repeating units in resin A. Furthermore, the lower limit may also be 0 mol% or more. That is, resin A may also not contain repeating units having non-acid-degradable groups. The repeating unit having a non-acid-decomposing group may be used alone or in two or more forms. When two or more are used, it is preferable that their total content be within the range of the preferred content.

[0061] <Repeating unit with lactone group> Resin A is also preferably a repeating unit containing a lactone group. A repeating unit having a lactone group may or may not be equivalent to the repeating unit. For example, a repeating unit with a lactone group may or may not be equivalent to a repeating unit a1, and may or may not be equivalent to a repeating unit with a non-equivalent acid-decomposing group.

[0062] As a lactone group, it is acceptable to have either a lactone structure or a sulfonolactone structure. The lactone structure is preferably a 5-membered to 7-membered ring lactone structure. More preferably, it is formed by ring condensation within a 5- to 7-membered ring lactone structure to create a bicyclic or spirocyclic structure. Resin A preferably contains repeating units having lactone groups formed by removing one or more (e.g., one to two) hydrogen atoms from a lactone structure represented by any of the following formulas (LC1-1) to (LC1-21). 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.

[0063] [Chemistry 8]

[0064] 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 an integer greater than 2, the multiple Rb2 groups may be different, and the multiple Rb2 groups may bond together to form a ring. 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-.

[0065] Repeating units having a lactone group can be exemplified by repeating units represented by the following general formula (AI).

[0066] [Chemistry 9]

[0067] In the general formula (AI), Rb0 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms. Preferred substituents that can be present in alkyl groups in Rb0 include hydroxyl groups and halogen atoms. Examples of halogen atoms in Rb0 include fluorine, chlorine, bromine, and iodine. Rb0 is preferably a hydrogen atom or a methyl atom. 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. 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).

[0068] 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).

[0069] [Chemistry 10]

[0070] In general formulas (AII) and (AIII), RIII independently represents a hydrogen atom or a substituent. RIII is preferably a hydrogen atom. 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). 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).

[0071] The following examples illustrate repeating units with lactone groups.

[0072] [Chemistry 11]

[0073] [Chemistry 12]

[0074] 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.

[0075] The content of repeating units with lactone groups is preferably 5 mol% to 100 mol% relative to all repeating units in resin A, more preferably 10 mol% to 80 mol%, and even more preferably 15 mol% to 65 mol%. In the repeating unit having a lactone group, the preferred content can be satisfied by the sum of repeating units with lactone groups that are equivalent to repeating unit a1 and repeating units with lactone groups that are not equivalent to repeating unit a1, the preferred content can be satisfied by repeating units with lactone groups that are equivalent to repeating unit a1 alone, and the preferred content can be satisfied by repeating units with lactone groups that are not equivalent to repeating unit a1 alone. The repeating unit having a lactone group may be used alone or in two or more forms. When two or more are used, it is preferable that their total content be within the range of the preferred content.

[0076] <Repeating units with sulfonyl lactone or carbonate groups> Resin A is also preferably a repeating unit containing a sulfonyl group. 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. 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. 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 a sulfonolactone structure represented by any of the following formulas (SL1-1) to (SL1-3).

[0077] [Chemistry 13]

[0078] 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). 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-.

[0079] 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 general formula (AIII).

[0080] As a carbonate group, a cyclic carbonate group is preferred. As a repeating unit having a cyclic carbonate group, it is preferably a repeating unit represented by the following formula (A-1).

[0081] [Chemistry 14]

[0082] In formula (A-1), RA 1 represents a hydrogen atom, a halogen atom, or a monovalent organic group (preferably methyl). n represents an integer greater than or equal to 0. RA 2 represents a substituent. When n is 2 or more, there can be multiple RA 2s, which can be the same or different. 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. 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.

[0083] The following examples illustrate repeating units having sulfonyl lactone or carbonate groups.

[0084] [Chemistry 15]

[0085] 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, further preferably 70 mol% or less, and particularly preferably 60 mol% or less.

[0086] <Repeating unit with acid group> Resin A may contain repeating units with acid groups. The repeating unit having an acid group is preferably different from the repeating unit. 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. 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. As an acid group, it is preferably, for example, a carboxyl group, a hydroxyl group, a phenolic hydroxyl group, a fluorinated alcohol group (preferably a hexafluoroisopropanol group), a sulfonic acid group, a sulfonamide group, or an isopropanol group. Furthermore, one or more (preferably one to two) fluorine atoms in the hexafluoroisopropanol group may be substituted with groups other than fluorine atoms (such as alkoxycarbonyl groups). The resulting -C(CF3)(OH)-CF2- is also preferably an acid group. Alternatively, one or more fluorine atoms may be substituted with groups other than fluorine atoms to form a ring containing -C(CF3)(OH)-CF2-. Repeating units with acid groups may also have fluorine or iodine atoms.

[0087] As a repeating unit with an acid group, it is preferably the repeating unit represented by formula (B).

[0088] [Chemistry 16]

[0089] R3 represents a hydrogen atom, or a monovalent organic group that may have a fluorine or iodine atom. As a monovalent organic group that may have fluorine or iodine atoms, it is preferably represented by -L4-R8. L4 represents a single bond or an ester group. R8 can be exemplified by: alkyl groups that may have fluorine or iodine atoms, cycloalkyl groups that may have fluorine or iodine atoms, aryl groups that may have fluorine or iodine atoms, or groups composed of combinations thereof.

[0090] 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.

[0091] 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). 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.

[0092] R6 represents a hydroxyl group or a fluorinated alcohol group. Preferably, the fluorinated alcohol group is a monovalent group represented by the following formula (3L). *-L6X -R6X (3L) 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; 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. Moreover, when R6 is a hydroxyl group, L3 is preferably an aromatic hydrocarbon cyclic group with an (n+m+1) valence.

[0093] R7 represents a halogen atom. Examples of halogen atoms include fluorine, chlorine, bromine, and iodine. 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. n represents an integer greater than or equal to 1 or 0. Ideally, n should be an integer between 1 and 4. Furthermore, (n+m+1) is preferably an integer between 1 and 5.

[0094] The repeating unit having an acid group is preferably the repeating unit represented by the following formula (I).

[0095] [Chemistry 17]

[0096] In formula (I), R41, R42, and R43 each independently represent a hydrogen atom, alkyl group, cycloalkyl group, halogen atom, cyano group, or alkoxycarbonyl group. Among them, R42 can bond with Ar4 to form a ring, in which case R42 represents a single bond or an extended alkyl group. X4 represents a single bond, -COO-, or -CONR64-, where R64 represents a hydrogen atom or an alkyl group. L4 indicates a single bond or an alkyl group. Ar4 represents an aromatic ring group with a valence of (n+1), and an aromatic ring group with a valence of (n+2) when it is bonded to R42 to form a ring. n represents an integer from 1 to 5.

[0097] The alkyl groups in R41, R42, and R43 of formula (I) are preferably alkyl groups with 20 or fewer carbon atoms, such as methyl, ethyl, propyl, isopropyl, n-butyl, dibutyl, hexyl, 2-ethylhexyl, octyl, and dodecyl, more preferably alkyl groups with 8 or fewer carbon atoms, and even more preferably alkyl groups with 3 or fewer carbon atoms.

[0098] The cycloalkyl groups in formula (I) R41, R42, and R43 can be monocyclic or polycyclic. Preferably, they are monocyclic cycloalkyl groups with three to eight carbon atoms, such as cyclopropyl, cyclopentyl, and cyclohexyl. Halogen atoms in R41, R42, and R43 of formula (I) can be listed as fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms, with fluorine atoms being preferred. The alkyl group contained in the alkoxycarbonyl group of R41, R42 and R43 in formula (I) is preferably the same as the alkyl group in R41, R42 and R43.

[0099] Preferred substituents among the aforementioned groups include, for example, alkyl, cycloalkyl, aryl, amino, amide, urea, carbamate, hydroxyl, carboxyl, halogen, alkoxy, thioether, acetyl, acetoxy, alkoxycarbonyl, cyano, and nitro. The substituent preferably has 8 or fewer carbon atoms.

[0100] Ar4 represents an aromatic cyclic group with an (n+1) valence. When n is 1, the divalent aromatic cyclic group is preferably an aryl group with 6 to 18 carbons, such as phenylene, methylphenylene, naphthyl, and anthraceneyl, or a divalent aromatic cyclic group containing heterocycles such as thiophene rings, furan rings, pyrrole rings, benzothiophene rings, benzofuran rings, benzopyrrole rings, triazine rings, imidazole rings, benzimidazole rings, triazole rings, thiadiazole rings, and thiazole rings. Furthermore, the aromatic cyclic group may have substituents.

[0101] Specific examples of (n+1) valence aromatic cyclic groups when n is an integer greater than 2 can be listed as groups formed by removing (n-1) arbitrary hydrogen atoms from the specific examples of divalent aromatic cyclic groups. (n+1) valence aromatic cyclic groups can further have substituents.

[0102] Substituents that can be present as the alkyl, cycloalkyl, alkoxycarbonyl, alkylene, and (n+1) valence aromatic cycloalcosyl groups include, for example, alkyl, methoxy, ethoxy, hydroxyethoxy, propoxy, hydroxypropoxy, and butoxy alkoxy groups listed in R41, R42, and R43 of formula (I); aryl groups such as phenyl groups. Examples of alkyl groups with 20 or fewer carbon atoms include methyl, ethyl, propyl, isopropyl, n-butyl, dibutyl, hexyl, 2-ethylhexyl, octyl, and dodecyl, with a preference for alkyl groups with 8 or fewer carbon atoms. As for X4, it is preferred to use a single key, -COO-, or -CONH-, and even more preferably a single key or -COO-.

[0103] The alkyl group in L4 is preferably an alkyl group having 1 to 8 carbons, such as methylene, ethyl alkyl, propyl alkyl, butyl alkyl, hexyl alkyl, and octyl alkyl. Ar4 is preferably an aromatic ring group with 6 to 18 carbon atoms, and more preferably a benzene ring group, a naphthyl ring group, or a biphenyl ring group. The repeating unit represented by formula (I) preferably includes a hydroxystyrene structure. That is, Ar4 is preferably a benzene ring group.

[0104] The repeating unit represented by equation (I) is preferably the repeating unit represented by equation (1) below.

[0105] [Chemistry 18]

[0106] In equation (1), A represents a hydrogen atom, alkyl group, cycloalkyl group, halogen atom, or cyano group. R represents a halogen atom, alkyl, cycloalkyl, aryl, alkenyl, aralkyl, alkoxy, alkylcarbonyloxy, alkylsulfonoxy, alkyloxycarbonyl, or aryloxycarbonyl, which may be the same or different when multiple Rs are present. When multiple Rs are present, they may combine to form a ring. Preferably, R is a hydrogen atom. a represents an integer from 1 to 3. b represents an integer from 0 to (5-a).

[0107] The following examples illustrate repeating units with acid groups.

[0108] [Chemistry 19]

[0109] In the following examples, 'a' represents 1 or 2.

[0110] [Chemistry 20]

[0111] [Chemistry 21]

[0112] [Chemistry 22]

[0113] [Chemistry 23]

[0114] 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.

[0115] [Chemistry 24]

[0116] [Chemistry 25]

[0117] [Chemistry 26]

[0118] The content of repeating units having acid groups is preferably 5 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 70 mol% or less, more preferably 65 mol% or less, and even more preferably 60 mol% or less.

[0119] <Repeating units containing fluorine or iodine atoms> Resin A may contain repeating units with fluorine or iodine atoms. The repeating unit having fluorine or iodine atoms is preferably different from the repeating unit.

[0120] As a repeating unit having fluorine or iodine atoms, it is preferably the repeating unit represented by formula (C).

[0121] [Chemistry 27]

[0122] L5 represents a single bond or an ester group. R9 represents a hydrogen atom, or an alkyl group that may have a fluorine atom or an iodine atom. 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.

[0123] The following examples illustrate repeating units that have fluorine or iodine atoms.

[0124] [Chemistry 28]

[0125] 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.

[0126] <The repeating unit represented by equation (V-1) or equation (V-2) below> Resin A may have repeating units represented by the following formula (V-1) or the following formula (V-2). The repeating units represented by the following formulas (V-1) and (V-2) are preferably different from the repeating units.

[0127] [Chemistry 29]

[0128] 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 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. n3 represents an integer from 0 to 6. n4 represents an integer from 0 to 4. X4 represents a methylene group, an oxygen atom, or a sulfur atom. The following examples illustrate the repeating units represented by equation (V-1) or equation (V-2). 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. The content of the repeating unit represented by formula (V-1) or the following formula (V-2) is preferably 1 mol% to 65 mol% relative to all repeating units in resin A, and more preferably 5 mol% to 45 mol%.

[0129] <Repetitive units used to reduce the dynamism of the main chain> Resin A may contain repeating units that reduce the mobility of the main chain as repeating units different from repeating unit a1. From the viewpoint of suppressing excessive diffusion of acid or pattern collapse during development, resin A preferably has a high glass transition temperature (Tg). A 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, a Tg is preferably below 400°C, and more preferably below 350°C. 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. 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.).

[0130] To increase the Tg of resin A (preferably setting Tg above 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 include the following methods (a) to (e). (a) Introducing large substituents into the main chain (b) Introducing multiple substituents into the main chain (c) Introducing substituents near the main chain to induce interactions between resin A groups. (d) Forming a main chain with a ring structure (e) Connection between the ring structure and the main chain Furthermore, resin A is preferably a repeating unit with a Tg of 130°C or higher, which is a homopolymer. 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.

[0131] (The repeating unit represented by equation (A)) As an example of a specific method of achieving (a), a method of introducing the repeating unit represented by formula (A) into resin A can be cited.

[0132] [Chemistry 30]

[0133] 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. 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. 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%.

[0134] (The repeating unit represented by equation (B)) As an example of a specific method of achieving (b), the method of introducing the repeating unit represented by formula (B) into resin A can be cited.

[0135] [Chemistry 31]

[0136] 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. 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. 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. 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. 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%.

[0137] (The repeating unit represented by equation (C)) As an example of a specific method of achieving (c), the method of introducing the repeating unit represented by formula (C) into resin A can be cited.

[0138] [Chemistry 32]

[0139] 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 within a number of atoms up to 3 originates from a carbon atom in the main chain. Preferably, the hydrogen atom with hydrogen bonding within a number of atoms up to 2 (closer to the main chain) is used to induce the interaction between the main chains of resin A. 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. 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%.

[0140] (The repeating unit represented by equation (D)) As an example of a specific method of achieving (d), the method of introducing the repeating unit represented by formula (D) into resin A can be cited.

[0141] [Chemistry 33]

[0142] 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. 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. 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%.

[0143] (The repeating unit represented by equation (E)) As an example of a specific method of achieving (e), the method of introducing the repeating unit represented by formula (E) into resin A can be cited.

[0144] [Chemistry 34]

[0145] 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. 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. 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. 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%.

[0146] <Repeating units with hydroxyl or cyano groups> Resin A may contain repeating units with hydroxyl or cyano groups. This improves substrate adhesion and developer affinity. 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. 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. The content of repeating units with 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%.

[0147] <Repeating unit with an alicyclic hydrocarbon structure that does not exhibit acid decomposition properties> Resin A may contain repeating units with an alicyclic hydrocarbon structure that do not exhibit acid decomposition properties. This reduces the dissolution 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. The content of repeating units having an alicyclic hydrocarbon structure and not exhibiting acid decomposition ability relative to all repeating units in resin A is preferably 1 mol% to 65 mol%, more preferably 5 mol% to 45 mol.

[0148] <The repeating unit represented by formula (III) that does not contain either a hydroxyl or a cyano group> Resin A may contain repeating units represented by formula (III) that do not have either hydroxyl or cyano groups.

[0149] [Chemistry 35]

[0150] In formula (III), R5 represents a hydrocarbon group having at least one cyclic structure and not having either a hydroxyl or a cyano group. Ra represents a hydrogen atom, an alkyl group, or a -CH2-O-Ra2 group. In the formula, Ra2 represents a hydrogen atom, an alkyl group, or a acetyl group.

[0151] 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. 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. 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.

[0152] <Other repeating units> Furthermore, resin A may have repeating units other than the repeating units mentioned above. 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. 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%. Other repeating units are shown below.

[0153] [Chemistry 36]

[0154] 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.

[0155] Resin A preferably has a specified SP value for all repeating units constituting resin A. The specified value for the repeating unit is 18.0 MPa0.5 or more, preferably 18.0 MPa0.5 to 30.0 MPa0.5. The so-called SP value of all repeating units constituting resin A is actually just a matter of the SP value of all repeating units being specified. The content of repeating units with SP values ​​specified relative to all repeating units is 98% to 100% by mass, preferably 99% to 100% by mass, and even more preferably 99.8% to 100% by mass.

[0156] In this specification, the SP value (unit: MPa0.5) of the repeating unit constituting resin A is calculated based on the following formula. SP value = (δD² + δP² + δH²) × 0.5 δD: Dispersion term of repeating unit (unit: MPa0.5) δP: Interpole term of repeating unit (unit: MPa0.5) δH: Hydrogen bond term of repeating unit (unit: MPa0.5) In addition, the dispersion term, inter-dipole term, and hydrogen bond term in the repeating unit are each calculated using HSPiP (software "Hansen Solubility Parameters in Practice (HSPiP) ver.5.1.08"). Specifically, the dispersion term, inter-dipole term, and hydrogen bond term of the repeating unit being calculated are calculated based on the structure of the polymerizable monomer corresponding to the repeating unit. That is, the dispersion term, inter-dipole term, and hydrogen bond term obtained by using the software (HSPiP) to determine the structure of the polymerizable monomer corresponding to a certain repeating unit are set as the dispersion term, inter-dipole term, and hydrogen bond term of the repeating unit. The term "structure of polymeric monomers corresponding to repeating units" refers to a structure that assumes the main chain of the repeating unit, which is the object of calculation, extends relative to other repeating units, and becomes a polymeric double bond, thus becoming a monomer that does not have a bond relative to other repeating units. For example, if the repeating unit to be calculated is a repeating unit P0 represented by the following structural formula, then the compound P0x represented by the following structural formula corresponds to the structure of the polymerizable monomer corresponding to the repeating unit P0. Similarly, compounds P1x and P2x represented by the following structural formulas correspond to the structures of the polymerizable monomers corresponding to the repeating units P1 and P2, respectively.

[0157] [Chemistry 37]

[0158] [Chemistry 38]

[0159] Resin A can be synthesized using conventional methods (such as free radical polymerization). Using the GPC method, the weight-average molecular weight of resin A, converted to polystyrene, is preferably 1,000~200,000, more preferably 3,000~20,000, and even more preferably 5,000~15,000. By setting the weight-average molecular weight of resin A to 1,000~200,000, the degradation of heat resistance and dry etching resistance can be further suppressed. In addition, the degradation of developability and the degradation of film-forming properties due to increased viscosity can also be further suppressed. The dispersion (molecular weight distribution) of resin A is typically 1 to 5, preferably 1 to 3, 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.

[0160] In the resist composition, the content of resin A relative to the total solid content of the composition is preferably 10% to 99% by mass, more preferably 20% to 98% by mass, and even more preferably 25% to 95% by mass. Furthermore, resin A can be used alone or in combination with two or more other resins. When using two or more resins, it is preferable that their total content falls within the range of the preferred content. 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.

[0161] [Additive B] The resist composition includes additive B. Additive B is at least one of an acid having an acid group with a pKa of -3.60 or higher (hereinafter also referred to as "specific acid") and a salt having a structure in which a hydrogen atom of an acid group with a pKa of -3.60 or higher is cation-substituted (hereinafter also referred to as "specific salt").

[0162] <Specific Acids> A specific acid has an acid group with a specified pKa value. The specified value in the specific acid is -3.60 or higher, preferably -3.60 to 12.00, more preferably 0.00 to 11.00, and even more preferably 5.00 to 10.00. The number of acid groups in a particular acid is, for example, 1 to 10. When a particular acid has multiple acid groups, it is sufficient that the pKa of at least one acid group is a specified value, preferably that the pKa of more than half of the acid groups is a specified value, and more preferably that the pKa of all acid groups is a specified value. In addition, when a particular acid has multiple acid groups, it is preferable to use the pKa of the acid group that exhibits the lowest pKa as the specified value.

[0163] Examples of acid groups that a particular acid may possess include: carboxyl, hydroxyl, phenolic hydroxyl, fluorinated alcohol (preferably hexafluoroisopropanol), sulfonic acid, sulfonamide, and isopropanol, with phenolic hydroxyl being the most preferred.

[0164] A specific acid can be in the form of a low molecular weight compound or in a form incorporated into a polymer. Alternatively, both the low molecular weight compound form and the form incorporated into a polymer can be used together. When a specific acid is incorporated into a part of the polymer, it can be incorporated into a part of resin A, or into a resin different from resin A. In this invention, the specific acid is preferably in the form of a low molecular weight compound. The molecular weight (weight average molecular weight in the case of molecular weight distribution) of a particular acid is preferably 100 to 1000, more preferably 150 to 800.

[0165] Specific acids may be listed, for example, as compounds represented by the general formula (RA1) or general formula (RA2) below, and compounds having repeating units represented by the general formula (RA3). ArA -(OH)ax (RA1) Q[-ArA -(OH)ax ]bx (RA2) -[ALA -ArA (OH)ax ]- (RA3)

[0166] In the general formula (RA1), ax represents an integer greater than or equal to 1, preferably an integer between 1 and 3. In the general formula (RA1), ArA represents an aromatic cyclic group. The aromatic cyclic group can be monocyclic or polycyclic, and the number of ring member atoms is preferably 5 to 15. The aromatic cyclic group may have one or more (e.g., one to five) heteroatoms (oxygen, sulfur, and / or nitrogen, etc.) as ring member atoms, but preferably none. Examples of the aromatic cyclic group include: benzene cyclic group, naphthyl cyclic group, and anthracene cyclic group. The aromatic cyclic group may also have substituents other than hydroxyl groups. Examples of such substituents include alkyl, alkoxy, and alkoxycarbonyl groups. The alkyl portion of the alkyl group, alkoxy group, and alkoxycarbonyl group may be linear or branched, and the number of carbon atoms is preferably 1 to 15.

[0167] In the general formula (RA2), ax represents an integer greater than or equal to 1. The ax in the general formula (RA2) is the same as the ax in the general formula (RA1). In general formula (RA2), ArA represents an aromatic ring group. The ArA in general formula (RA2) is the same as the ArA in general formula (RA1). In the general formula (RA2), bx represents an integer greater than 2, preferably an integer between 2 and 10. In the general formula (RA2), Q represents a linking group with a bx valence. Preferably, the linking group with a bx valence is -CO-, -O-, -S-, -SO-, -SO2-, -NH-, -N<, cyclic groups, chain hydrocarbon cyclic groups, and groups formed by combining these. The cyclic group can be a hydrocarbon cyclic group or a heterocyclic group, an aromatic cyclic group or a non-aromatic cyclic group, a monocyclic group or a polycyclic group, and preferably has 3 to 12 ring members, and preferably has a divalent to pentavalent oxidation state. The chain-like hydrocarbon cyclic group can be straight-chain or branched-chain, preferably has 2 to 10 carbon atoms, and preferably has a divalent to pentavalent oxidation state.

[0168] In the general formula (RA3), ax represents an integer greater than or equal to 1. The ax in the general formula (RA3) is the same as the ax in the general formula (RA1). In general formula (RA3), ArA represents an aromatic ring group. The ArA in general formula (RA3) is the same as the ArA in general formula (RA1). In the general formula (RA3), ALA represents an enyl group. The enyl group can be linear or branched, and preferably has 1 to 5 carbon atoms. A compound having a repeating unit represented by the general formula (RA3) is sufficient to have only the repeating unit represented by the general formula (RA3). The content of the repeating unit represented by the general formula (RA3) is preferably 60% to 100% by mass, more preferably 80% to 100% by mass, and even more preferably 98% to 100% by mass, relative to the total mass of the compound. The compound can be a polymer or an oligomer. Additionally, the compound can be a cyclic compound having all or part of the repeating unit represented by the general formula (RA3) as a cyclic structure. For example, a cyclic compound is one in which the compound is represented by "-[ALA-ArA(OH)ax]-[ALA-ArA(OH)ax]AZ-[ALA-ArA(OH)ax]- (AZ is an integer greater than or equal to 1, preferably an integer from 1 to 10. Other notations have the same meaning as described above)," and the ALA at the left end and the ArA at the right end are bonded together.

[0169] The following examples illustrate specific acids. The values ​​listed near each specific acid are the pKa values ​​of the acid groups possessed by that specific acid. Furthermore, in the case where a specific acid has multiple acid groups, only the pKa of the acid group that exhibits the lowest pKa among the multiple acid groups is shown.

[0170] [Chemistry 39]

[0171] <Specific Salts> A specific salt is a salt with a structure in which the hydrogen atom of an acid group with a specified pKa value is replaced by a cation. The specified value in the specific salt is -3.60 or higher, preferably -3.60 to 12.00, more preferably -3.60 to 7.00, and even more preferably -3.60 to 5.00. The number of acid groups in a particular salt where hydrogen atoms are substituted by cations is, for example, 1 to 10. In the case where a particular salt has multiple said acid groups, it is permissible as long as the pKa of at least one said acid group is a predetermined value. In a specific salt, the cation that substitutes the hydrogen atom of the acid group may also be separated from the acid group by more than one atom and linked by a covalent bond. That is, the specific salt may be an intramolecular salt (zwitterion, betaine compound). Furthermore, the cation that substitutes the hydrogen atom of the acid group may not be covalently linked to the acid group. That is, a particular salt may be an onium salt. A specific salt can be a compound that produces acid through exposure to photochemical rays or radiation (photoacid generator), or it can be something else. A specific salt can be in the form of a low-molecular-weight compound or in a form incorporated into a polymer. Alternatively, both the low-molecular-weight compound form and the form incorporated into a polymer can be used together. When the salt is in the form of a low molecular weight compound, the molecular weight is preferably 3000 or less, more preferably 2000 or less, and even more preferably 1000 or less. When the specific salt is compound (I) or compound (II) described later, its molecular weight is preferably 100 to 10,000, more preferably 100 to 2,500, and even more preferably 100 to 1,500. When a specific salt is incorporated into a part of the polymer, it can be incorporated into a part of resin A, or into a resin different from resin A. In this invention, the specific salt is preferably in the form of a low molecular weight compound.

[0172] Examples of acid groups in specific salts include: phenolic hydroxyl groups, sulfonic acid groups (aliphatic sulfonic acid groups, aromatic sulfonic acid groups, and camphor sulfonic acid groups, etc.), carboxylic acid groups (aliphatic carboxylic acid groups, aromatic carboxylic acid groups, and aralkyl carboxylic acid groups, etc.), carbonylsulfonyl imino groups, bis(sulfonyl)imino groups (bis(alkylsulfonyl)imino groups, etc.), bis(carbonyl)imino groups, and tri(alkylsulfonyl)methyl groups.

[0173] The following sections will first describe in detail the specific salts that are onium salts, and then explain the specific salts that are intramolecular salts.

[0174] (A specific salt as an onium salt) A specific salt that is an onium salt typically has both a cationic and anionic sites. A cation is a cation that substitutes for a hydrogen atom of an acid group in a specific salt. The anionic site is an acid group or part thereof in which a hydrogen atom is substituted by a cation. Specific salts that are onium salts can be listed, for example, compounds represented by "Mp+ m Xq- n". In “Mp+ m Xq- n ”, p, q, m, and n each independently represent an integer greater than or equal to 1 (preferably 1 to 8). Mp+ represents an organic cation with charge p. 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. Xq- represents an organic anion with charge 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. When multiple Mp+ and Xq- exist, they can be the same or different from each other. The value obtained by multiplying the average of p in the possible multiple Mp+ by m is the same as the value obtained by multiplying the average of q in the possible multiple Xq- by n. Among them, p is preferably 1. For example, it is preferable that p, q, m, and n are all 1. In addition, it is also preferable to have p = 1, q = 2~8, m and q = the same value, and n = 1.

[0175] Organic cations The cation site is a structural site containing positively charged atoms or groups of atoms, preferably, for example, a monovalent organic cation (Mp+ with p=1). The organic cations are preferably organic cations represented by formula (ZaI) (cation (ZaI)) or organic cations represented by formula (ZaII) (cation (ZaII)).

[0176] [Chemistry 40]

[0177] In the formula (ZaI), R201, R202, and R203 each independently represent an organic group. 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-.

[0178] 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).

[0179] First, the cation (ZaI-1) will be explained. The cation (ZaI-1) is an aryl strontium cation of formula (ZaI) in which at least one of R201 to R203 is aryl. The aryl strontium cation can be entirely aryl in R201 to R203, or it can be partially aryl in R201 to R203 and the remainder alkyl or cycloalkyl. Alternatively, one of R201 to R203 may be an aryl group, and the other two bonds in R201 to R203 may form a ring structure. The ring may also contain an oxygen atom, a sulfur atom, an ester group, a amide group, or a carbonyl group. Examples of groups formed by the two bonds in R201 to R203 include one or more methylene groups that may be substituted with an oxygen atom, a sulfur atom, an ester group, an amide group, and / or a carbonyl group (e.g., butyl, pentyl, or -CH2-CH2-O-CH2-CH2-). Examples of aryl strontium cations include: triaryl strontium cations, diarylalkyl strontium cations, aryldialkyl strontium cations, diarylcycloalkyl strontium cations, and aryldicycloalkyl strontium cations.

[0180] 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. 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 methyl, ethyl, propyl, n-butyl, dibutyl, tributyl, cyclopropyl, cyclobutyl, or cyclohexyl.

[0181] 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), halogen atoms (e.g., fluorine, iodine), hydroxyl, carboxyl, ester, sulfinyl, sulfonyl, alkylthio, and phenylthio, etc. 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. In addition, the substituents are preferably formed by any combination to create acid-degradable groups. 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 a structure in which the polar group is detached by a release group protected by the action of an acid. The polar group and the release group are as described above.

[0182] Next, the cation (ZaI-2) will be explained. 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. 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. 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.

[0183] The 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). R201 to R203 can also be further substituted by halogen atoms, alkoxy groups (e.g., carbon 1 to 5), hydroxyl groups, cyano groups, or nitro groups. In addition, the substituents of R201 to R203 are preferably formed independently by any combination of substituents to form acid-degradable groups.

[0184] Next, the cation (ZaI-3b) will be explained. The cation (ZaI-3b) is the cation represented by the following formula (ZaI-3b).

[0185] [Chemistry 41]

[0186] In formula (ZaI-3b), R1c ~ R5c each independently represent a hydrogen atom, alkyl, cycloalkyl, aryl, alkoxy, aryloxy, alkoxycarbonyl, alkylcarbonyloxy, cycloalkylcarbonyloxy, halogen atom, hydroxyl, nitro, alkylthio, or arylthio. 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. Rx and Ry each independently represent alkyl, cycloalkyl, 2-oxoalkyl, 2-oxocycloalkyl, alkoxycarbonylalkyl, allyl, or vinyl. In addition, the substituents of R1c to R7c, as well as Rx and Ry, are preferably formed independently by any combination of substituents to create acid-degrading groups.

[0187] 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, which can independently contain an oxygen atom, a sulfur atom, a ketone group, an ester bond, or a amide bond. 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 the alkyl group may be substituted with heteroatoms such as oxygen atoms. The group formed by the bond between R5c and R6c, and between R5c and Rx, is preferably a single bond or an alkyl group. Examples of alkyl groups include methylene and ethyl groups.

[0189] Rings formed by the mutual bonding of R1c ~ R5c, R6c, R7c, Rx, Ry, and any two or more of R1c ~ R5c, R5c and R6c, R6c and R7c, R5c and Rx, and Rx and Ry may have substituents.

[0190] Next, the cation (ZaI-4b) will be explained. The cation (ZaI-4b) is the cation represented by the following formula (ZaI-4b).

[0191] [Chemistry 42]

[0192] In formula (ZaI-4b), l represents an integer from 0 to 2. r represents an integer from 0 to 8. 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. 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 case of multiple R14 groups, each independently represents the hydroxyl group, etc. 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 one state, it is preferred that the two R15 groups are alkyl groups and bond together to form a ring structure. Furthermore, the alkyl group, the cycloalkyl group, the naphthyl group, and the ring formed by the two R15 groups may have substituents.

[0193] 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. In addition, the substituents of R13 to R15, as well as Rx and Ry, are preferably formed independently by any combination of substituents to form acid-degrading groups.

[0194] Next, we will explain equation (ZaII). In formula (ZaII), R204 and R205 each independently represent aryl, alkyl, or cycloalkyl. 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, nitrogen atom, or sulfur atom. Examples of heterocyclic aryl groups include: pyrrole, furan, thiophene, indole, benzofuran, and benzothiophene. 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).

[0195] The aryl, alkyl, and cycloalkyl groups in R204 and R205 can each independently have substituents. Examples of substituents that can 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.

[0196] Organic cations can also include quaternary ammonium cations. As quaternary ammonium compounds, cations represented by the following formula (ZaIII) can be listed. (RCA)⁴ N⁺ (ZaIII) In the formula, RCA represents an alkyl group. The alkyl group may preferably have hydroxyl or phenyl substituents. The four RCA groups may be the same or different.

[0197] As represented by RCA, the alkyl group is preferably an alkyl group having 1 to 6 carbon atoms. 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.

[0198] Examples of quaternary ammonium compounds include: tetramethylammonium cation, trimethylethylammonium cation, dimethyldiethylammonium cation, methyltriethylammonium cation, tetraethylammonium cation, tetrapropylammonium cation, tetrabutylammonium cation, 2-hydroxyethyltrimethylammonium cation, bis(2-hydroxyethyl)dimethylammonium cation, tris(2-hydroxyethyl)methylammonium cation, tetra(2-hydroxyethyl)ammonium cation, benzyltrimethylammonium cation, and cetyltrimethylammonium cation.

[0199] Organic anions An organic anion is any organic anion that combines with a hydrogen atom to form an acid that has one or more (e.g., one to ten) acid groups with a specified pKa value (above -3.60). 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.

[0200] 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. 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). 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.

[0201] 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.

[0202] 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.

[0203] 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.

[0204] Examples of sulfonylimid anions include, for instance, saccharin anion.

[0205] 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. In addition, the alkyl groups in the bis(alkylsulfonyl)imidin anion can bond with each other to form a ring structure.

[0206] 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.

[0207] In addition, the organic anion is preferably the anion represented by the following formula (AN).

[0208] [Chemistry 43]

[0209] 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.

[0210] In formula (AN), AX represents -SO3- or -COO-.

[0211] 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. 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.

[0212] 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, R4 and R5 may be the same or different. The alkyl groups represented by R4 and R5 may have substituents other than fluorine atoms, preferably having 1 to 4 carbon atoms. Specific examples and preferred states of alkyl groups substituted with at least one fluorine atom are the same as those of Xf. R4 and R5 are preferably hydrogen atoms. 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 a fluorine atom).

[0213] In equation (AN), L represents a divalent linkage base. When there are multiple Ls, they can be the same or different. 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-.

[0214] In formula (AN), W represents an organic group containing a cyclic structure. Preferably, the organic group is cyclic. Examples of cyclic organic groups include alicyclic groups, aryl groups, and heterocyclic groups. 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.

[0215] The aryl group can be monocyclic or polycyclic. Examples of aryl groups include phenyl, naphthyl, phenanthryl, and anthracene. 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.

[0216] 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.

[0217] The preferred anions represented by formula (AN) are 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.

[0218] In addition, the compounds represented by formulas (Ia-1) to (Ia-5) described below, as well as the portions other than the organic cations in the compounds represented by formula (IIa-1) and formula (IIa-2) described below, may also be used as organic anions.

[0219] Compound (I) and Compound (II) The specific salt that is an onium salt may be one or more selected from the group consisting of compounds (I) and (II) described below. Compounds (I) and (II) are also compounds that produce acids by exposure to photochemical rays or radiation (photoacid generators).

[0220] Compound (I) 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. 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. 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. Among them, compound (I) satisfies the following condition I.

[0221] 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, formed by replacing the cation M1+ in the structural site X with H+, and the acid dissociation constant a2 originates from the acidic site represented by HA2, formed by replacing the cation M2+ in the structural site Y with H+. Furthermore, the acid dissociation constant a2 is greater than the acid dissociation constant a1.

[0222] The following is a more detailed explanation of condition I. 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". 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.

[0223] 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". When the acid dissociation constant of this compound PI is determined, the acid dissociation constant when compound PI is a "compound having one A1-, one HA1, and one HA2", and the acid dissociation constant when "a compound having one A1-, one HA1, and one HA2" is a "compound having two A1- and one HA2", are equivalent to the acid dissociation constant a1. Furthermore, the acid dissociation constant when "a compound having two A1- and one HA2" is a "compound having two A1- and A2-" are equivalent to the acid dissociation constant a2. That is, in the case of this 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 "a compound having one A1-, one HA1, and one HA2", and the acid dissociation constant of "a compound having one A1-, one HA1, and one HA2" is defined as "a compound having two A1- and one HA2", the relationship between aa and ab satisfies aa <ab。

[0224] The acid dissociation constants a1 and a2 are determined by the method for determining the acid dissociation constant. The compound PI is equivalent to the acid produced when compound (I) is irradiated with photochemical rays or radiation. 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. In addition, the A1- and A2-, as well as the M1+ and M2+ in compound (I) may be the same or different, and the A1- and A2- are preferably different.

[0225] Regarding the superior LWR performance 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.

[0226] Furthermore, regarding the superior LWR performance 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 greater.

[0227] Furthermore, regarding the superior LWR performance 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 for the acid dissociation constant a1, it is preferably -20.0 or more.

[0228] 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 preferably an acidic site capable of forming a small acid dissociation constant, preferably any one of formulas (AA-1) to (AA-3). Furthermore, as anionic site A2-, it is preferably an acidic site capable of forming a larger acid dissociation constant than anionic site A1-, and preferably selected from any one of formulas (BB-1) to (BB-6). Moreover, in formulas (AA-1) to (AA-3) and (BB-1) to (BB-6) below, * indicates a bonding position. In formula (AA-2), RA represents a monovalent organic group. Examples of monovalent organic groups represented by RA include cyano, trifluoromethyl, and methanesulfonyl.

[0229] [Chemistry 44]

[0230] 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)).

[0231] 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. The compounds represented by formula (Ia-1) will be described below. The compounds represented by formula (Ia-1) are as follows.

[0232] M11 + A11 - -L1 -A12 - M12 + (Ia-1)

[0233] The compound (Ia-1) produces an acid represented by HA11-L1-A12 H by exposure to photochemical rays or radiation.

[0234] In formula (Ia-1), M11+ and M12+ each independently represent organic cations. A11- and A12- each independently represent monovalent anionic functional groups. L1 represents a binary linkage base. M11+ and M12+ can be the same or different. A11 and A12 can be the same or different, but it is better if they are different from each other. 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. In addition, at least one of M11+, M12+, A11-, A12-, and L1 may have an acid-degradable group as a substituent.

[0235] 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.

[0236] 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-. 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 of formulas (AA-1) to (AA-3) and (BB-1) to (BB-6), 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 of formulas (AX-1) to (AX-3). Furthermore, as a 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).

[0237] [Chemistry 45]

[0238] In equations (AX-1) to (AX-3), RA1 and RA2 each independently represent a monovalent organic group. * indicates the bond position.

[0239] Examples of monovalent organic groups represented by RA1 include cyano, trifluoromethyl, and methanesulfonyl.

[0240] The monovalent organic group represented by RA2 is preferably a straight-chain, branched-chain, or cyclic alkyl group or an aryl group. The alkyl group preferably has 1 to 15 carbon atoms, more preferably 1 to 10, and even more preferably 1 to 6. 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.

[0241] The aryl group is preferably phenyl or naphthyl, and more preferably phenyl. 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.

[0242] In equations (BX-1) to (BX-4) and (BX-6), RB represents a monovalent organic group. * indicates the bond position. The monovalent organic group represented by RB is preferably a straight-chain, branched-chain, or cyclic alkyl group or an aryl group. The alkyl group preferably has 1 to 15 carbon atoms, more preferably 1 to 10, and even more preferably 1 to 6. 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. 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. In addition, the carbon atoms in the alkyl group may be substituted with carbonyl carbons.

[0243] The aryl group is preferably phenyl or naphthyl, and more preferably phenyl. 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.

[0244] In equation (Ia-1), there are no particular restrictions on the divalent linker represented by L1, and examples include: -CO-, -NR-, -CO-, -O-, -S-, -SO-, -SO2. - Alkyl groups (preferably having 1 to 6 carbon atoms; may be straight-chain or branched-chain), cycloalkyl groups (preferably having 3 to 15 carbon atoms), alkenyl groups (preferably having 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 cycloalkyl groups (preferably 6- to 10-membered rings, and even more preferably 6-membered rings), and divalent linking groups formed by multiple combinations of these. The R may include hydrogen atoms or monovalent organic groups. There are no particular restrictions on the monovalent organic group; for example, it is preferably an alkyl group (preferably with 1 to 6 carbon atoms). 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).

[0245] As a binary linking base represented by L1, the binary linking base represented by equation (L1) is preferred.

[0246] [Chemistry 46]

[0247] In equation (L1), L111 represents a single bond or a divalent linker. 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. p represents an integer from 0 to 3, preferably an integer from 1 to 3. v represents an integer of 0 or 1. 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. 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. 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. * indicates the location of the bond. In the case where L1 in equation (Ia-1) represents the divalent linker represented by equation (L1), it is preferred that the bonding bond (*) on the L111 side of equation (L1) is bonded to the A12-bond in equation (Ia-1).

[0248] Next, equations (Ia-2) to (Ia-4) will be explained.

[0249] [Chemistry 47]

[0250] 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 is no particular limitation on the monovalent anionic functional group 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. 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.

[0251] [Chemistry 48]

[0252] 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 same in the preferred state. L21 and L22 each independently represent a divalent organic group.

[0253] 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. Furthermore, A21a- and A21b- can be the same or different. In addition, M21a+, M21b+, and M22+ can be the same or different. In addition, at least one of M21a+, M21b+, M22+, A21a-, A21b-, L21, and L22 may have an acid-degradable group as a substituent.

[0254] 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. 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. 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 the following formula (AX-4).

[0255] [Chemistry 49]

[0256] 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. L31 and L32 each independently represent a divalent organic group.

[0257] 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, acid dissociation constants a1-3 and a1-4 are equivalent to the acid dissociation constant a1. Furthermore, A31a- and A32- can be the same or different. In addition, M31a+, M31b+, and M32+ can be the same or different. In addition, at least one of M31a+, M31b+, M32+, A31a-, A32-, L31, and L32 may have an acid-degradable group as a substituent.

[0258] 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 of A21a- and A21b- in equation (Ia-2). Additionally, the definition of the monovalent anionic functional group represented by A42- is the same as that of A32- in equation (Ia-3), and the preferred state is also the same. M41a+, M41b+, and M42+ each independently represent an organic cation. L41 represents a trivalent organic group.

[0259] 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. Furthermore, A41a-, A41b-, and A42- can be the same or different. Additionally, M41a+, M41b+, and M42+ can be the same or different. In addition, at least one of M41a+, M41b+, M42+, A41a-, A41b-, A42-, and L41 may have an acid-degradable group as a substituent.

[0260] 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 having 1 to 6 carbon atoms; may be straight-chain or branched-chain), cycloalkyl groups (preferably having 3 to 15 carbon atoms), alkenyl groups (preferably having 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 cycloalkyl groups (preferably 6- to 10-membered rings, and even more preferably 6-membered rings), and divalent organogroups formed by combinations of multiple of these. R may include hydrogen atoms or monovalent organogroups. There are no particular restrictions on the monovalent organic group; for example, it is preferably an alkyl group (preferably with 1 to 6 carbon atoms). 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).

[0261] 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, formula (L2) below.

[0262] [Transformation 50]

[0263] In equation (L2), q represents an integer from 1 to 3. * indicates the bond position. 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. 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.

[0264] LA represents a single bond or a divalent linker. 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 cycloalloys (preferably 6-membered to 10-membered rings, and more preferably 6-membered rings), and divalent linkers formed by combining multiple of these. 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).

[0265] 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 extensiphenyl group that may have substituents, preferably 1,4-extensiphenyl. 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). When L21 and L22 in formula (Ia-2) 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 A21a- and A21b- in formula (Ia-2). 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).

[0266] 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.

[0267] [Chemistry 51]

[0268] In formula (L3), LB represents a trivalent hydrocarbon cyclic group or a trivalent heterocyclic group. * indicates the bond position.

[0269] 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. As 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.

[0270] Furthermore, in equation (L3), LB1 to LB3 each independently represent a single bond or a divalent linker. There are no particular restrictions on the divalent linkers represented by LB1 to LB3; for example, -CO-, -NR-, -O-, -S-, -SO-, and -SO2 can be listed. - Alkyl groups (preferably having 1 to 6 carbon atoms; may be straight-chain or branched-chain), cycloalkyl groups (preferably having 3 to 15 carbon atoms), alkenyl groups (preferably having 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 cycloalkyl groups (preferably 6- to 10-membered rings, and even more preferably 6-membered rings), and divalent linking groups formed by multiple combinations of these. The R may include hydrogen atoms or monovalent organic groups. There are no particular restrictions on the monovalent organic group; for example, it is preferably an alkyl group (preferably with 1 to 6 carbon atoms). 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). 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.

[0271] As the divalent linking bases represented by LB1 ~LB3, the divalent linking base represented by equation (L3-1) is more preferably the one represented by the equation (L3-1).

[0272] [Chemistry 52]

[0273] In equation (L3-1), LB11 represents a single bond or a divalent linker. 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. r represents an integer from 1 to 3. Xf has the same meaning as Xf in the above formula (L2), and the better state sample is also the same. * indicates the location of the bond.

[0274] Examples of divalent linkages represented by LB1 to LB3 include: *-O-*, *-O-SO2-CF2-*, *-O-SO2-CF2-CF2-*, *-O-SO2-CF2-CF2-*, and *-COO-CH2-CH2-*. 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).

[0275] Next, the compounds represented by formula (Ia-5) will be explained.

[0276] [Chemistry 53]

[0277] 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. 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 A22- include those selected from the group consisting of formulas (BX-8) to (BX-11).

[0278] 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. 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. 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.

[0279] Furthermore, in formula (Ia-5), in the 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. Furthermore, A51a-, A51b-, and A51c- can be the same or different. Additionally, A52a- and A52b- can be the same or different. Furthermore, M51a+, M51b+, M51c+, M52a+, and M52b+ can be the same or different. 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.

[0280] ･･Compound (II) 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. Structural site Z: The site capable of neutralizing the nonionic nature of acids.

[0281] 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.

[0282] In compound (II), in compound PII formed by replacing the cation M1+ in the 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 the structural site X with H+, is the same as the acid dissociation constant a1 in compound PI. Furthermore, in the case where compound (II) is, for example, a compound having two acids originating from the first acidic site of structural site X and the acid of 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 A1- and one HA1", and the acid dissociation constant when "a compound having one A1- and one HA1" is "a compound having two A1-s", are equivalent to the acid dissociation constant a1.

[0283] The acid dissociation constant a1 is determined by the method for determining the acid dissociation constant. The compound PII is equivalent to the acid produced when compound (II) is irradiated with photochemical rays or radiation. 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.

[0284] 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. 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.

[0285] [Chemistry 54]

[0286] 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.

[0287] 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.

[0288] [Chemistry 55]

[0289] In equation (IIa-1), A61a- and A61b- each have the same meaning as A11- in equation (Ia-1), and the preferred state is also the same. Furthermore, M61a+ and M61b+ each have the same meaning as M11+ in equation (Ia-1), and the preferred state is also the same. In equation (IIa-1), L61 and L62 each have the same meaning as L1 in equation (Ia-1), and the preferred state is also the same.

[0290] 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), which may be substituted with one or more of the group consisting of -CO-, -NH-, -O-, -S-, -SO-, and -SO2-. 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.

[0291] 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 and a1-8 derived from the acidic site represented by A61aH are equivalent to the acid dissociation constant a1. 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. In addition, at least one of M61a+, M61b+, A61a-, A61b-, L61, L62, and R2X may have an acid-degradable group as a substituent.

[0292] 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. 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.

[0293] Furthermore, in the compound PIIa-2 formed by replacing the organic cations represented by M71a+, M71b+, and M71c+ with H+ in formula (IIa-2), the acid dissociation constants a1-9 derived from the acidic site represented by A71aH, a1-10 derived from the acidic site represented by A71bH, and a1-11 derived from the acidic site represented by A71cH are equivalent to the acid dissociation constant a1. 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. 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.

[0294] 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. Structural site X: A structural site containing anionic site A1- and cationic site M1+, which forms the acidic site represented by HA1 through irradiation by photochemical rays or radiation. The two or more structural parts X may be the same or different. In addition, the two or more A1- and the two or more M1+ may be the same or different. The definitions of structural site X, and A1- and M1+, are the same as those in compound (I), and are also the same in the preferred form.

[0295] The organic cations shown below, along with other sites, can be suitably combined to serve as specific salts of onium salts.

[0296] First, let's take an example of an organic cation.

[0297] [Chemistry 56]

[0298] [Chemistry 57]

[0299] [Chem.58]

[0300] Secondly, examples are given for sites other than organic cations (organic anions). 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.

[0301] [Chemistry 59]

[0302] [Transformation 60]

[0303] [Chemistry 61]

[0304] [Chemistry 62]

[0305] (A specific salt as an intramolecular salt) The specific salt that is 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 a monium cation. Regarding specific salts that are intramolecular salts, examples include compounds (ZbI) and (ZbII). 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-. 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-. 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-").

[0306] Examples of specific salts that are intramolecular salts. The values ​​shown near the sites where the hydrogen atoms of the acid group in the following specific salts are cation-substituted (anionic functional groups) represent the pKa of the acid group assuming that the hydrogen atoms are not cation-substituted. In other words, the pKa shown below is the pKa of the acid group (an anionic functional group bonded to a hydrogen atom) in a compound (acid) assuming that the anionic functional group of the salt in the molecule is bonded to a hydrogen atom.

[0307] [Chemistry 63]

[0308] In the resist composition, the content of additive B is preferably 1% to 99% by mass, more preferably 3% to 90% by mass, and even more preferably 5% to 80% by mass, relative to the total solid content of the composition. Furthermore, additive B can be used alone or in combination with two or more additives. When using two or more additives, it is preferable that their total content falls within the range of the preferred content.

[0309] [Hydrophobic resin] The resist composition may additionally include a hydrophobic resin different from resin A. Hydrophobic resins are preferably designed to exist on the surface of the resist film, but unlike surfactants, they do not necessarily need to have hydrophilic groups in their molecules, and may not contribute to the uniform mixing of polar and non-polar substances. The effects of adding hydrophobic resins include controlling the static and dynamic contact angle of the resist film surface relative to water, and suppressing gas escape.

[0310] Regarding the presence of the hydrophobic resin on the film surface, it is preferable that the hydrophobic resin has one or more of "fluorine atoms", "silicon atoms", and "CH3 moiety contained in the side chain portion of the resin", more preferably two or more. Furthermore, the hydrophobic resin preferably has hydrocarbon groups with 5 or more carbon atoms. These groups may be present in the main chain of the resin or may be substituted in the side chain. As hydrophobic resins, the compounds described in paragraphs

[0275] to

[0279] of International Publication No. 2020 / 004306 can be cited.

[0311] When the resist composition contains a hydrophobic resin, its content relative to the total solid content of the resist composition is preferably 0.01% to 20% by mass, more preferably 0.1% to 15% by mass, even more preferably 0.1% to 10% by mass, and particularly preferably 0.1% to 8.0% by mass. Hydrophobic resins can be used alone or in combination. When using two or more resins, it is preferable that their total content be within the range of the preferred content.

[0312] [Surfactants] The resist composition may include surfactants. If surfactants are included, patterns with better adhesion and fewer development defects can be formed. Fluorine-based and / or silicone-based surfactants are preferred. 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. 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. 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.

[0313] [Other additives] The resist composition may also contain other additives as components different from the stated components. Other additives include, for example, basic compounds (CA) and low molecular weight compounds (CD) that have nitrogen atoms and groups that are released due to the action of acids.

[0314] As specific examples of basic compounds (CA), those described in paragraphs

[0132] to

[0136] of International Publication No. 2020 / 066824 can be cited. Specific examples of low molecular weight compounds (CD) having nitrogen atoms and having a group that is removed by the action of an acid can be cited from paragraphs

[0156] to

[0163] of International Publication No. 2020 / 066824.

[0315] When the resist composition contains other additives, the content of the additives is preferably 0.1% to 40% by mass, more preferably 0.1% to 30% by mass, and even more preferably 0.4% to 25% by mass, relative to the total solid content of the composition. Other additives may be used alone or in combination. When using two or more additives, it is preferable that their total content be within the range of the preferred content.

[0316] [Solvent] The composition of the resist may contain solvent. 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).

[0317] 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. Details of ingredients (M1) and (M2) are set out in paragraphs

[0218] to

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

[0318] 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.

[0319] 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. This can further improve the coatability of the resist composition. In other words, relative to the total mass of the composition, 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. The solvent may be used alone or in combination with two or more solvents. When using two or more solvents, it is preferable that their total content be within the range of the preferred content. Furthermore, the term "solid component" refers to all components other than the solvent.

[0320] [Other additives] The resist composition may further include a dissolution-inhibiting compound, dye, plasticizer, photosensitizer, light absorber, and / or a compound that promotes solubility relative to the developer (including alicyclic or aliphatic compounds containing carboxylic acid groups).

[0321] 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.

[0322] The resist composition of the present invention can also be preferably used as a photosensitive composition for EUV light. EUV light has a wavelength of 13.5 nm, which is shorter than ArF light (193 nm). Therefore, the number of incident photons is lower when exposed at the same sensitivity. Consequently, the effect of "photon shot noise," caused by the random dispersion of photons, is significant, leading to deterioration of the LWR 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 a trade-off with the requirement for high sensitivity.

[0323] When the A value obtained using the following formula (1) is high, the absorption efficiency of EUV light and electron beam of the resist film formed from the resist composition is higher, which is effective in reducing photon shot noise. The A value represents the absorption efficiency of EUV light and electron beam of the resist film by mass ratio. 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) The A value is preferably 0.120 or higher. There is no particular upper limit. However, if the A value is too high, the transmittance of EUV light and electron beam in the resist film will decrease, the optical image contour 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.

[0324] 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. For example, when the resist composition comprises resin A, additive B, and solvent, resin A and additive B are equivalent to solid components. That is, all atoms of the total solid component are equivalent to the sum of all atoms originating from resin A and all atoms originating from additive B. For example, [H] represents the molar ratio of hydrogen atoms originating from the total solid component to all atoms of the total solid component. If explained based on the above example, then [H] represents the molar ratio of the sum of hydrogen atoms originating from resin A and hydrogen atoms originating from additive B to the sum of all atoms originating from resin A and all atoms originating from additive B.

[0325] 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.

[0326] [Resist film and pattern formation method] The procedure for patterning using the resist composition is not particularly limited, but it is preferred to include the following steps. Step 1: Forming a resist film on the substrate using a resist composition. Step 2: Exposure of the resist film Step 3: Developing the exposed resist film using a developer. The procedures for each step are described in detail below.

[0327] <Step 1: Resist Film Formation Steps> Step 1 is the step of forming a resist film on the substrate using a resist composition. The composition of the resist is defined as described above.

[0328] 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. 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.

[0329] 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 coating machine. 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. 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.

[0330] 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.

[0331] 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 finer patterns with higher precision. Among these, when EUV 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.

[0332] Furthermore, a topcoat can be formed by applying a topcoat composition over the resist film. 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. 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. 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.

[0333] <Step 2: Exposure Step> Step 2 is the step of exposing the resist film. As a method of exposure, one example is irradiating the formed resist film with photochemical rays or radiation through a prescribed mask. 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 of less than 250 nm, more preferably less than 220 nm, and especially preferably 1 nm to 200 nm can be listed. Specifically, KrF excimer laser (248 nm), ArF excimer laser (193 nm), F2 excimer laser (157 nm), EUV light (13 nm), X-rays, and electron beams can be listed.

[0334] 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. The preferred heating temperature is 80℃~150℃, more preferably 80℃~140℃, and even more preferably 80℃~130℃. 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. Heating can be performed using mechanisms included in conventional exposure and / or developing machines, or using heating plates, etc. This step is also known as Post Exposure Bake (PEB).

[0335] <Step 3: Development Step> Step 3 is the step of developing the exposed resist film with a developer to form a pattern. The developer can be an alkaline developer or a developer containing organic solvents (hereinafter also referred to as an organic developer).

[0336] 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). Alternatively, after the developing step, a step can be performed where the solvent is replaced with another solvent while the developing process is stopped. 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. The optimal temperature for the developer is 0℃~50℃, and more preferably 15℃~35℃.

[0337] Alkaline developers preferably use 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, aqueous solutions containing quaternary ammonium salts, represented by tetramethylammonium hydroxide (TMAH), are preferred. Appropriate amounts of alcohols and surfactants may also be added to the alkaline developer. The alkali concentration of the alkaline developer is typically 0.1% to 20% by mass. Furthermore, the pH of the alkaline developer is typically 10.0 to 15.0. The water content of the alkaline developer is preferably 51% to 99.95% by mass.

[0338] 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.

[0339] 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. 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, even more preferably 90% to 100% by mass, and especially preferably 95% to 100% by mass.

[0340] <Other Steps> The pattern forming method preferably includes a cleaning step using a rinsing solution after step 3.

[0341] For example, pure water can be used as the rinsing solution in the rinsing step following the development step with an alkaline developer. Alternatively, an appropriate amount of surfactant can be added to the pure water. An appropriate amount of surfactant can also be added to the rinsing solution.

[0342] 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.

[0343] 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). 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).

[0344] 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. 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.

[0345] 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.

[0346] 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.

[0347] 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.

[0348] 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.

[0349] 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. 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.).

[0350] Manufacturing methods for electronic devices In addition, the present invention also relates to a method for manufacturing an electronic device including the pattern forming method, and an electronic device manufactured by the manufacturing method. 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]

[0351] 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.

[0352] [Various components of photosensitive or radiosensitive linear resin compositions (resist compositions)] The following describes the components contained in the resist composition used in the experiments provided for the examples.

[0353] [Resin] The mole ratio, weight-average molecular weight (Mw), and dispersibility (Mw / Mn) of the repeating units of the resins (A-1~A-67, A'-1~A'-4) used in the preparation of the resist composition are shown in the table below. The resins shown in the table below were synthesized according to the synthesis method of resin A-1 described later (synthesis example 1). In the table, the "Type" column indicates the types of repeating units that make up the resin. The "Morby" column indicates the content (in moles) of each repeating unit relative to all repeating units. The "SP Value" column indicates the SP value of each repeating unit. Hereinafter, resins A-1 to A-67 and A'-1 are equivalent to resin A.

[0354] [Table 1] Table 1 Repeating Unit 1 Repeating Unit 2 Repeating Unit 3 Repeating Unit 4 Repeating Unit 5 Mw Mw / Mn type Mörby SP value type Mörby SP value type Mörby SP value type Mörby SP value type Molar ratio SP value A-1 M-1 40 20.2 M-12 10 19.8 M-71 20 21.7 M-34 30 16.3 - - - 10000 1.60 A-2 M-2 30 20.5 - - - M-72 35 19.5 M-37 10 16.7 M-33 25 16.8 8000 1.54 A-3 M-3 30 18.7 M-20 20 24.5 M-73 30 19.8 M-31 20 17.4 - - - 9000 1.67 A-4 M-4 15 20.2 M-14 15 15.9 M-74 40 19.0 M-31 30 17.4 - - - 7500 1.55 A-5 M-5 35 18.9 M-13 5 21.9 M-75 20 21.3 M-35 40 17.3 - - - 8500 1.59 A-6 M-6 15 20.0 M-2 25 20.5 M-76 50 22.2 M-32 5 17.2 M-37 5 16.7 5500 1.68 A-7 M-7 15 18.8 M-1 25 20.2 M-77 45 19.5 M-32 5 17.2 M-38 10 17.3 4500 1.77 A-8 M-8 25 23.7 M-19 15 21.9 M-78 50 20.6 M-31 10 17.4 - - - 12000 1.84 A-9 M-9 25 23.5 M-19 30 21.9 M-79 25 20.9 M-49 20 17.4 - - - 14000 1.65 A-10 M-10 20 20.7 M-28 35 17.5 M-80 35 20.7 M-42 10 16.7 - - - 8800 1.55 A-11 M-11 40 20.9 - - - M-81 30 19.0 M-39 20 17.1 M-32 10 17.2 22000 1.56 A-12 M-19 30 21.9 M-15 30 16.9 M-82 35 23.6 M-36 5 17.0 - - - 14000 1.65 A-13 M-16 25 17.2 M-19 25 21.9 M-83 35 21.6 M-47 15 18.2 - - - 6500 1.40 A-14 M-17 30 19.6 M-14 20 15.9 M-84 40 20.8 M-33 10 16.8 - - - 6700 1.50 A-15 M-18 10 21.9 M-8 10 23.7 M-85 60 24.9 M-66 10 18.9 M-41 10 17.3 7200 1.54 A-16 M-21 20 25.4 M-3 15 18.7 M-86 55 22.6 M-43 5 16.1 M-46 5 17.3 8000 1.29 A-17 M-22 25 23.6 - - - M-87 70 22.0 M-45 5 16.2 - - - 4500 1.35 A-18 M-23 15 19.4 M-4 20 20.2 M-88 55 21.4 M-31 10 17.4 - - - 5000 1.25 A-19 M-24 35 20.8 M-68 10 22.6 M-89 40 22.7 M-44 5 16.1 M-40 10 17.0 5500 1.50 A-20 M-25 20 21.7 M-19 25 21.9 M-90 45 19.9 M-31 10 17.4 - - - 5600 1.60 A-21 M-26 40 17.7 M-61 10 27.0 M-91 25 22.4 M-55 10 17.5 M-58 15 19.2 7800 1.56 A-22 M-27 10 20.3 M-20 5 24.5 M-92 80 19.1 M-50 5 18.6 - - - 9000 1.54 A-23 M-30 20 23.2 M-6 30 20.0 M-93 25 20.4 M-48 25 16.9 - - - 8000 1.74 A-24 M-62 20 19.9 M-8 20 23.7 M-94 35 18.0 M-51 10 17.8 M-54 15 18.3 7500 1.55 A-25 - - - - - - M-95 50 20.7 M-65 50 17.3 - - - 8600 1.72 A-26 M-63 20 20.4 - - - M-96 40 19.4 M-59 40 18.6 - - - 12500 1.80 A-27 M-64 20 19.2 M-4 30 20.2 M-77 45 19.5 M-52 5 19.1 - - - 5500 1.33 A-28 M-4 20 20.2 M-19 20 21.9 M-84 50 20.8 M-69 10 17.6 - - - 4500 1.40 A-29 M-19 30 21.9 - - - M-72 60 19.5 M-70 10 17.6 - - - 6500 1.55 A-30 M-102 25 21.0 - - - M-71 25 21.7 M-43 50 16.1 - - - 6000 1.65 A-31 M-1 15 20.2 M-23 15 19.4 M-82 30 23.6 M-32 20 17.2 M-53 20 16.4 5900 1.56 A-32 M-4 20 20.2 M-20 20 24.5 M-81 50 19.0 M-55 5 17.5 M-33 5 16.8 8900 1.55 A-33 M-8 35 23.7 M-14 15 15.9 M-87 40 22.0 M-56 5 16.8 M-32 5 17.2 12000 1.65 A-34 M-6 40 20.0 - M-97 35 23.6 M-60 15 20.1 M-67 10 19.7 8000 1.55 A-35 M-11 35 20.9 M-15 15 16.9 M-89 35 22.7 M-57 10 16.7 M-37 5 16.7 14000 1.56

[0355] [Table 2] Table 1 (Continued) Repeat Unit 1 Repeat Unit 2 Repeat Unit 3 Repeat Unit 4 Repeat Unit 5 Mw Mw / Mn Kind Mörby SP value type Mörby SP value type Mörby SP value type Mörby SP value type Mörby SP value A-36 M-4 60 20.2 - - - M-88 40 21.4 - - - - - - 12000 1.65 A-37 M-2 50 20.5 - - - M-72 50 19.5 - - - - - - 8000 1.40 A-38 M-1 40 20.2 M-12 15 19.8 M-77 45 19.5 - - - - - - 6500 1.54 A-39 M-9 30 23.5 M-14 15 15.9 M-81 55 19.0 - - - - - - 5500 1.29 A-40 M-5 20 18.9 M-10 20 20.7 M-90 60 19.9 - - - - - - 4000 1.35 A-41 M-8 20 23.7 M-28 10 17.5 M-89 70 22.7 - - - - - - 8800 1.25 A-42 M-15 45 16.9 - - - M-82 55 23.6 - - - - - - 10000 1.50 A-43 M-3 45 18.7 - - - M-83 55 21.6 - - - - - - 7100 1.67 A-44 M-19 30 21.9 - - - M-77 70 19.5 - - - - - - 6600 1.65 A-45 M-23 20 19.4 - - - M-86 80 22.6 - - - - - - 12200 1.55 A-46 M-13 25 21.9 M-1 40 20.2 M-77 35 19.5 - - - - - - 7700 1.56 A-47 M-18 20 21.9 M-64 35 19.2 M-95 45 20.7 - - - - - - 6700 1.65 A-48 M-6 40 20.0 M-14 10 15.9 M-72 50 19.5 - - - - - - 5400 1.40 A-49 M-1 30 20.2 M-19 20 21.9 M-79 50 20.9 - - - - - - 4300 1.54 A-50 M-8 15 23.7 M-10 15 20.7 M-88 70 21.4 - - - - - - 5400 1.29 A-51 M-5 20 18.9 M-27 20 20.3 M-85 60 24.9 - - - - - - 6800 1.35 A-52 M-24 25 20.8 M-30 20 23.2 M-97 55 23.6 - - - - - - 7100 1.25 A-53 M-16 30 17.2 - - - M-77 70 19.5 - - - - - - 7400 1.50 A-54 M-25 10 21.7 - - - M-87 90 22.0 - - - - - - 6900 1.60 A-55 M-26 25 17.7 M-29 20 19.0 M-96 55 19.4 - - - - - - 8500 1.55 A-56 M-19 20 21.9 - - - M-83 80 21.6 - - - - - - 6500 1.55 A-57 M-6 25 20.0 - - - M-81 75 19.0 - - - - - - 5500 1.55 A-58 M-2 30 20.5 - - - M-88 70 21.4 - - - - - - 4000 1.55 A-59 M-20 20 24.5 - - - M-97 80 23.6 - - - - - - 8800 1.55 A-60 M-4 25 20.2 - - - M-83 75 21.6 - - - - - - 10000 1.55 A-61 - - - - - - M-95 100 20.7 - - - - - - 7100 1.55 A-62 - - - - - - M-76 100 22.2 - - - - - - 6600 1.55 A-63 - - - - - - M-87 100 22.0 - - - - - - 12200 1.55 A-64 - - - - - - M-86 100 22.6 - - - - - - 7700 1.55 A-65 - - - - - - M-84 100 20.8 - - - - - - 6700 1.55 A-66 - - - - - - M-88 100 21.4 - - - - - - 8500 1.55 A-67 - - - - - - M-77 100 19.5 - - - - - - 20000 1.55 A'-1 M-19 60 21.9 M-99 10 18.3 M-98 30 22.2 - - - - - - 10000 1.60 A'-2 M-19 63 21.9 - - - M-100 10 24.1 M-101 27 18.2 - - - 10000 1.60 A'-3 M-19 50 21.9 - - - - - - M-31 50 17.4 - - - 10000 1.60 A'-4 M-19 50 21.9 - - - M-103 50 21.8 - - - - - - 10000 1.60

[0356] The following shows the structure of the unit corresponding to each repeating unit in the resin. Furthermore, in the following, M-71~M-98 and M-100 are the units that become the source of the repeating unit a1.

[0357] [Chemistry 64]

[0358] [Chemistry 65]

[0359] [Chemistry 66]

[0360] [Chemistry 67]

[0361] [Chemistry 68]

[0362] [Chemistry 69]

[0363] <Synthesis Example 1: Synthesis of Resin A-1> Cyclohexanone (62 g) was heated to 85°C under a nitrogen atmosphere. While stirring the liquid, a mixture of monomers represented by formula M-1 (34 g), M-12 (13.5 g), M-71 (29 g), M-34 (31 g), cyclohexanone (246 g), and a cyclohexanone solution (10% by mass) of dimethyl 2,2'-azobisisobutyrate (V-601, manufactured by Wako Pure Chemical Industries, Ltd.) (100.7 g) was added dropwise over 6 hours to obtain a reaction solution. After the addition was complete, the reaction solution was stirred at 85°C for another 2 hours. The obtained reaction solution was cooled, reprecipitated using a large amount of methanol / water (7:3 by mass), filtered, and the obtained solid was vacuum dried to obtain resin A-1 (83 g). All operations were performed under yellow light.

[0364] [Chemistry 70]

[0365] [Additive B] The following shows the structure of additive B (a specific acid or a specific salt) used in the preparation of the resist composition. The values ​​shown near the cation-substituted hydrogen atom of the acid group in the following specific salts represent the pKa of the acid group in an acid assuming that the hydrogen atom is not cation-substituted. Furthermore, B-1 to B-29 are specific salts corresponding to compounds (I) or (II) described in the specification. The values ​​shown near a specific acid represent the pKa of the acid group possessed by that specific acid. Furthermore, in the case where a specific acid has multiple acid groups, only the pKa of the acid group exhibiting the lowest pKa is shown.

[0366] [Chemistry 71]

[0367] [Chemistry 72]

[0368] [Chemistry 73]

[0369] [Chemistry 74]

[0370] [Chemistry 75]

[0371] [Chemistry 76]

[0372] [Chemistry 77]

[0373] [Chemistry 78]

[0374] [Chemistry 79]

[0375] [Chemistry 80]

[0376] [Other additives] The following shows the structures of other additives used in the preparation of the resist composition.

[0377] [Chemistry 81]

[0378] [Hydrophobic resin] The structure of the hydrophobic resin used in the preparation of the resist composition is shown below.

[0379] [Chemistry 82]

[0380] The following shows the composition ratio (mass ratio, corresponding from left to right), weight average molecular weight (Mw), and dispersity (Mw / Mn) of each repeating unit of the hydrophobic resin. Furthermore, the hydrophobic resin is synthesized according to the synthesis method of resin A-1 (synthesis example 1).

[0381] [Table 3] Table 2 mass ratio of repeating units Mw Mw / Mn D-1 50 45 5 - 6500 1.52 D-2 50 50 - - 25000 1.65 D-3 30 65 5 - 22000 1.55 D-4 40 40 20 - 12000 1.68 D-5 40 50 5 5 5500 1.49 D-6 90 8 2 - 12000 1.63 D-7 20 30 40 10 13000 1.55

[0382] [Surfactants] The following shows the surfactants used in the preparation of the anti-corrosion composition. H-1: Megafac F176 (manufactured by DIC Corporation, a fluorinated surfactant) H-2: Megafac R08 (manufactured by DIC (stock), a fluorine and silicon-based surfactant) H-3: PF656 (manufactured by OMNOVA, a fluorinated surfactant)

[0383] [Solvent] The following shows the solvents used in the preparation of the resist composition. G-1: Propylene glycol monomethyl ether acetate (PGMEA) G-2: Propylene glycol monomethyl ether (PGME) G-3: Propylene glycol monoethyl ether (PGEE) G-4: Cyclohexanone G-5: Cyclopentanone G-6:2-Heptanone G-7: Ethyl lactate G-8: γ-Butyrolactone G-9: Propylene carbonate

[0384] [Preparation of the resist composition] The components shown in the table below were mixed to a solid content concentration of 1.4% by mass. The resulting mixture was then passed through and filtered in the following order: first through a polyethylene filter with a pore size of 50 nm, then through a nylon filter with a pore size of 10 nm, and finally through a polyethylene filter with a pore size of 5 nm, thereby preparing the resist compositions (Re-1 to Re-67, Re'-1 to Re'-5). Furthermore, "solid components" refers to all components other than the solvent. The obtained resist compositions were used in the examples and comparative examples. In the table, the "Quantity" column indicates the content (mass %) of each solid component relative to the total solid component. In the table, the "Mixing Ratio" column for solvents indicates the mixing ratio (mass ratio) of each solvent.

[0385] [Table 4] Table 3 solid components solvent resin Additive B Other additives Hydrophobic resin surfactants type quantity type quantity type quantity type quantity type quantity type Mixing ratio (mass ratio) Re-1 A-1 85.0 B-1 15.0 - - - - - - G-1 / G-2 80 / 20 Re-2 A-2 56.5 B-2 40.2 - - D-1 3.3 - - G-1 / G-5 85 / 15 Re-3 A-3 77.7 B-3 22.3 - - - - - - G-1 / G-2 80 / 20 Re-4 A-4 95.0 B-4 5.0 - - - - - - G-1 / G-2 / G-8 40 / 20 / 40 Re-5 A-5 88.0 B-5 12.0 - - - - - - G-1 / G-2 80 / 20 Re-6 A-6 63.7 B-6 28.0 C-1 4.3 D-2 4 - - G-1 / G-9 85 / 15 Re-7 A-7 84.9 B-7 15.0 - - - - H-1 0.1 G-1 / G-7 90 / 10 Re-8 A-8 90.0 B-8 10.0 - - - - - - G-1 / G-2 80 / 20 Re-9 A-9 34.5 B-9 65.5 - - - - - - G-1 / G-2 80 / 2 Re-10 A-10 87.2 B-10 10.0 C-2 2.8 - - - - G-1 / G-2 / G-6 70 / 20 / 1 Re-11 A-11 85.5 B-11 14.5 - - - - - - G-1 / G-2 80 / 2 Re-12 A-12 47.6 B-12 45.8 - - D-3 6.6 - - G-1 / G-4 80 / 2 Re-13 A-13 94.0 B-13 6.0 - - - - - - G-1 / G-2 80 / 2 Re-14 A-14 75.7 B-14 12.0 C-3 12.2 - - H-2 0.1 G-4 100 Re-15 A-15 66.1 B-15 33.9 - - - - - - G-1 / G-5 85 / 15 Re-16 A-16 88.0 B-16 12.0 - - - - - - G-1 / G-2 80 / 20 Re-17 A-17 63.5 B-17 26.0 C-4 10.5 - - - - G-1 / G-3 75 / 25 Re-18 A-18 92.0 B-18 8.0 - - - - - - G-1 / G-2 / G-8 34 / 33 / 33 Re-19 A-19 67.5 B-19 11.3 C-5 21.2 - - - - G-1 / G-2 80 / 20 Re-20 A-20 93.5 B-20 6.5 - - - - - - G-1 / G-2 80 / 20 Re-21 A-21 62.0 B-21 22.0 C-1 C-2 10.5 5.5 - - - - G-1 / G-6 80 / 20 Re-22 A-22 93.9 B-22 6.0 - - - - H-3 0.1 G-1 / G-8 85 / 15 Re-23 A-2 85.9 B-23 12.0 - - D-4 2.1 - - G-1 / G-2 / G-8 80 / 15 / 5 Re-24 A-2 89.5 B-24 8.0 - - D-5 2.5 - - G-1 / G-2 80 / 2 Re-25 A-2 84.9 B-25 15.1 - - - - - - G-1 / G-7 90 / 1 Re-26 A-2 82.0 B-26 18.0 - - - - - - G-1 / G-4 80 / 2 Re-27 A-27 44.8 B-27 55.2 - - - - - - G-1 / G-2 80 / 20 Re-28 A-28 35.4 B-28 64.5 - - - - H-3 0.1 G-4 100 Re-29 A-29 27.9 B-29 72.1 - - - - - - G-1 / G-5 85 / 15 Re-30 A-30 75.0 B-30 B-63 20.0 5.0 - - - - - - G-1 / G-2 80 / 20 Re-31 A-31 79.9 B-31 B-65 15.0 5.0 - - - - H-1 0.1 G-1 / G-3 75 / 2 Re-32 A-32 85.0 B-32 15.0 - - - - - - G-1 / G-2 / G-8 40 / 20 / 4 Re-33 A-33 79.8 B-33 15.0 - - D-6 5.2 - - G-1 / G-2 80 / 2 Re-34 A-34 85.0 B-34 15.0 - - - - - - G-1 / G-2 80 / 2 Re-35 A-35 77.9 B-35 22.1 - - - - - - G-1 / G-2 80 / 2

[0386] [Table 5] Table 3 (continued) solid components solvent resin Additive B Other additives Hydrophobic resin surfactants type quantity type quantity type quantity type quantity type quantity type Mixing ratio (mass ratio) Re-36 A-36 76.1 B-36 17.8 - - D-7 6.1 - - G-1 / G-9 85 / 15 Re-37 A-37 80.5 B-37 19.5 - - - - - - G-1 / G-7 90 / 10 Re-38 A-38 85.7 B-38 14.3 - - - - - - G-1 / G-2 80 / 2 Re-39 A-39 80.5 B-39 19.5 - - - - - - G-1 / G-7 90 / 1 Re-40 A-40 79.7 B-40 20.3 - - - - - - G-1 / G-4 80 / 2 Re-41 A-41 90.1 B-41 9.9 - - - - - - G-1 / G-2 80 / 2 Re-42 A-42 81.5 B-42 18.5 - - - - - - G-1 / G-2 80 / 2 Re-43 A-43 82.4 B-43 17.6 - - - - - - G-1 / G-2 / G-8 34 / 33 / 3 Re-4 A-4 85.5 B-44 14.5 - - - - - - G-1 / G-2 80 / 2 Re-45 A-45 54.8 B-45 45.2 - - - - - - G-1 / G-9 85 / 1 Re-46 A-4 66.7 B-46 33.3 - - - - - - G-1 / G-7 90 / 1 Re-47 A-47 80.0 B-47 B-64 15.0 5.0 - - - - - - G-1 / G-2 80 / 2 Re-48 A-48 80.6 B-48 19.4 - - - - - - G-1 / G-2 80 / 2 Re-49 A-4 76.9 B-49 22.5 C-1 0.6 - - - - G-1 / G-2 / G-8 34 / 33 / 3 Re-50 A-50 47.9 B-50 52.1 - - - - - - G-1 / G-7 90 / 1 Re-51 A-51 69.5 B-51 30.5 - - - - - - G-1 / G-4 80 / 2 Re-52 A-52 82.5 B-52 17.5 - - - - - - G-1 / G-2 80 / 2 Re-53 A-53 85.5 B-53 14.5 - - - - - - G-1 / G-2 80 / 2 Re-54 A-54 89.5 B-54 10.5 - - - - - - G-1 / G-2 80 / 2 Re-55 A-55 82.4 B-55 17.6 - - - - - - G-1 / G-2 / G-8 40 / 20 / 4 Re-56 A-56 84.4 B-56 15.6 - - - - - - G-1 / G-7 90 / 1 Re-57 A-57 82.5 B-57 17.5 - - - - - - G-1 / G-4 80 / 2 Re-58 A-58 85.1 B-58 14.9 - - - - - - G-1 / G-2 80 / 2 Re-59 A-59 77.3 B-59 22.7 - - - - - - G-1 / G-2 80 / 2 Re-60 A-60 68.8 B-60 31.2 - - - - - - G-1 / G-2 / G-8 34 / 33 / 3 Re-61 A-61 80.5 B-61 19.5 - - - - - - G-1 / G-2 80 / 2 Re-62 A-62 75.9 B-62 24.1 - - - - - - G-1 / G-9 85 / 1 Re-63 A-63 79.8 B-63 20.2 - - - - - - G-1 / G-7 90 / 1 Re-64 A-64 78.6 B-64 21.4 - - - - - - G-1 / G-2 80 / 2 Re-65 A-65 77.5 B-65 22.5 - - - - - - G-1 / G-2 / G-8 40 / 20 / 4 Re-66 A-66 78.5 B-66 21.5 - - - - - - G-1 / G-2 80 / 2 Re-67 A-67 66.7 B-46 33.3 - - - - - - G-1 / G-2 80 / 2 Re'-1 A'-1 66.7 B-67 33.3 - - - - - - G-1 / G-2 80 / 2 Re'-2 A'-2 66.7 B-46 33.3 - - - - - - G-1 / G-2 80 / 2 Re'-3 A'-3 66.7 B-46 33.3 - - - - - - G-1 / G-2 80 / 20 Re'-4 A'-4 66.7 B-46 33.3 - - - - - - G-1 / G-2 80 / 20 Re'-5 A-1 100.0 - - - - - - - - G-1 / G-2 80 / 20

[0387] [Experiment] [Pattern formation (1): EUV exposure, organic solvent development] <Pattern Formation> A substrate film with a thickness of 20 nm was formed by coating an AL412 substrate (manufactured by Brewer Science) onto a 12-inch diameter silicon wafer and baking it at 205°C for 60 seconds. An anti-corrosion film with a thickness of 20 nm was then formed by coating an anti-corrosion film prepared as described above onto the substrate and baking it at 100°C for 60 seconds. Exposure was performed using an EUV exposure machine (ASML NXE3350, NA 0.33, Dipole 45°, Outer Sigma 0.87, Inner Sigma 0.60) with a reflective mask having a septum size of 20 nm and a line-to-space ratio of 1:1. Subsequently, for Examples 1-1 to 1-67 and Comparative Examples 1-1 to 1-5, heating (PEB) was performed at 100°C for 60 seconds. This step was omitted for Examples 1-68 to 1-134 and Comparative Examples 1-6 to 1-10. Subsequently, the wafer was developed with n-butyl acetate for 30 seconds and then rotated at 2000 rpm for 40 seconds to form a negative pattern with a line size of 20 nm and a line-to-space ratio of 1:1.

[0388] <Evaluation of Defect Suppression> For the patterns obtained using the method described above, the number of defects per silicon wafer was counted using a UVision5 (manufactured by AMAT) and a SEMVisionG4 (manufactured by AMAT), and the defect suppression performance of the resist composition was evaluated according to the following evaluation criteria. The fewer the number of defects, the better the defect suppression performance.

[0389] "A": Number of defects is less than 50 "B": Number of defects exceeds 50 but is less than 100 "C": Number of defects exceeds 100 but is less than 200 "D": Number of defects exceeds 200 but is less than 300 "E": Number of defects exceeds 300 but is less than 400 "F": Number of defects exceeds 400 but is less than 500 "G": Number of defects exceeds 500 but is less than 600 "H": More than 600 defects

[0390] <Analytical evaluation (limit of analytical performance, nm)> In the pattern forming method described above, exposure is performed at the optimal exposure level Eop (μC / cm2) (the exposure level when the pattern formed using the resist composition reproduces the pattern of the mask used in the exposure). Next, experiments were conducted to form line and spatial patterns by gradually and slightly changing the exposure starting from the optimal exposure level (Eop). At this time, the minimum size of the pattern that could be resolved without collapse was determined using a length-measuring scanning electron microscope (SEM, Hitachi, Ltd. S-9380II). This was taken as the "limiting resolution (nm)". The smaller the limiting resolution value, the better the resolution. In addition, the preferred limiting resolution (nm) is in the order of 18.0 nm or less, 17.0 nm or less, 16.0 nm or less, 15.0 nm or less, 14.0 nm or less, 13.0 nm or less, and 12.0 nm or less. <Results>

[0391] The evaluation results are shown in the table below. In the table, the "Resist Composition" column indicates the types of resist compositions used. The "Amount of Repeating Unit a1" column indicates the content (in moles) of repeating unit a1 of resin A in the resist composition used relative to the total number of repeating units of resin A. The "Amount of Acid-Degradable Repeating Units" column indicates the content (in moles%) of repeating units with acid-degradable groups in resin A contained in the resist composition used, relative to all repeating units of resin A. Furthermore, the repeating units with acid-degradable groups are those other than repeating unit a1. The "SP value of 18.0 or higher" column indicates whether the SP value of substantially all repeating units of resin A contained in the resist composition used is 18.0 MPa 0.5 or higher. If this requirement is met, it is recorded as A; otherwise, it is recorded as B. The "Repeating Units Containing Lactones" column indicates whether resin A in the resist composition used contains repeating units with lactone groups. If this requirement is met, it is recorded as A; otherwise, it is recorded as B. The "PEB" column indicates whether post-exposure baking (PEB) was performed during pattern formation. It is recorded as A if this requirement is met, and as B if it is not.

[0392] [Table 6] Table 4 Anti-corrosion composition Characteristics of resist composition PEB result Repeating unit a1 quantity Acid decomposition repeating unit quantity SP value of 18.0 or above Repeating units containing lactones Defect suppression Limiting analysis (nm) Example 1-1 Re-1 20 30 B A A D 14.4 Examples 1-2 Re-2 35 35 B A A D 14.5 Examples 1-3 Re-3 30 20 B A A C 13.4 Examples 1-4 Re-4 40 30 B A A C 13.5 Examples 1-5 Re-5 20 40 B A A D 14.2 Examples 1-6 Re-6 50 10 B A A B 12.5 Examples 1-7 Re-7 45 15 B A A B 12.4 Examples 1-8 Re-8 50 10 B B A C 13.5 Examples 1-9 Re-9 25 20 B B A D 14.7 Examples 1-10 Re-10 35 10 B B A D 14.8 Examples 1-11 Re-11 30 30 B B A E 15.4 Examples 1-12 Re-12 35 5 B B A D 14.5 Examples 1-13 Re-13 35 15 B A A C 13.6 Examples 1-14 Re-14 40 10 B B A C 13.4 Examples 1-15 Re-15 60 20 B B A C 13.3 Examples 1-16 Re-16 55 10 B A A B 12.3 Examples 1-17 Re-17 70 5 B B A C 13.8 Examples 1-18 Re-18 55 10 B A A B 12.8 Examples 1-19 Re-19 40 15 B B A C 13.7 Examples 1-20 Re-20 45 10 B B A C 13.5 Examples 1-21 Re-21 25 25 B B A E 15.7 Examples 1-22 Re-22 80 5 A B A B 12.5 Examples 1-23 Re-23 25 25 B A A D 14.4 Examples 1-24 Re-24 35 25 B A A D 14.2 Examples 1-25 Re-25 50 50 B B A D 14.5 Examples 1-26 Re-26 40 40 A A A B 12.4 Examples 1-27 Re-27 45 5 A A A A 11.5 Examples 1-28 Re-28 50 10 B A A B 12.5 Examples 1-29 Re-29 60 10 B B A C 13.4 Examples 1-30 Re-30 25 50 B B A E 15.8 Examples 1-31 Re-31 30 40 B A A D 14.8 Examples 1-32 Re-32 50 10 B A A B 12.4 Examples 1-33 Re-33 40 10 B B A C 13.3 Examples 1-34 Re-34 35 25 A A A C 13.9 Examples 1-35 Re-35 35 15 B B A D 14.3

[0393] [Table 7] Table 4 (continued) Anti-corrosion composition Characteristics of resist composition PEB result Repeating unit a1 quantity Acid decomposition repeating unit quantity SP value of 18.0 or above Repeating units containing lactones Defect suppression Limiting analysis (nm) Examples 1-36 Re-36 40 0 A A A A 11.8 Examples 1-37 Re-37 50 0 A A A A 11.3 Examples 1-38 Re-38 45 0 A A A A 11.2 Examples 1-39 Re-39 55 0 B B A C 13.7 Examples 1-40 Re-40 60 0 A A A A 11.5 Examples 1-41 Re-41 70 0 B B A C 13.6 Examples 1-42 Re-42 55 0 B B A C 13.4 Examples 1-43 Re-43 55 0 A A A A 11.6 Examples 1-44 Re-44 70 0 A B A B 12.2 Examples 1-45 Re-45 80 0 A B A B 12.7 Examples 1-46 Re-46 35 0 A A A B 12.6 Actual example 1-47 Re-47 45 0 A A A A 11.5 Actual example 1-48 Re-48 50 0 B A A B 12.4 Actual example 1-49 Re-49 50 0 A A A A 11.3 Actual example 1-50 Re-50 70 0 A B A B 12.8 Actual example 1-51 Re-51 60 0 A A A A 11.7 Actual example 1-52 Re-52 55 0 A B A B 12.4 Examples 1-53 Re-53 70 0 B A A B 12.9 Examples 1-54 Re-54 90 0 A B A B 12.5 Examples 1-55 Re-55 55 0 B A A B 12.6 Examples 1-56 Re-56 80 0 A B A B 12.4 Examples 1-57 Re-57 75 0 A A A A 11.4 Examples 1-58 Re-58 70 0 A A A A 11.5 Examples 1-59 Re-59 80 0 A B A B 12.2 Examples 1-60 Re-60 75 0 A A A A 11.5 Examples 1-61 Re-61 100 0 A B A B 12.4 Examples 1-62 Re-62 100 0 A B A B 12.6 Examples 1-63 Re-63 100 0 A B A B 12.5 Examples 1-64 Re-64 100 0 A B A B 12.7 Examples 1-65 Re-65 100 0 A B A B 12.3 Examples 1-66 Re-66 100 0 A B A B 12.4 Examples 1-67 Re-67 100 0 A B A B 12.3 Comparative Example 1-1 Re'-1 30 0 A B A H 19.2 Comparative Examples 1-2 Re'-2 10 27 A B A H 18.8 Comparative Examples 1-3 Re'-3 - 50 B B A H 18.9 Comparative Examples 1-4 Re'-4 - 0 A B A Non-analyzed Non-analyzed Comparative Examples 1-5 Re'-5 20 30 B A A H 19.1

[0394] [Table 8] Table 4 (continued) Anti-corrosion composition Characteristics of resist composition PEB result Repeating unit a1 quantity Acid decomposition repeating unit quantity SP value of 18.0 or above Repeating units containing lactones Defect suppression Limiting analysis (nm) Examples 1-68 Re-1 20 30 B A B F 16.2 Examples 1-69 Re-2 35 35 B A B F 16.4 Examples 1-70 Re-3 30 20 B A B D 14.4 Examples 1-71 Re-4 40 30 B A B D 14.6 Examples 1-72 Re-5 20 40 B A B F 16.5 Examples 1-73 Re-6 50 10 B A B B 12.5 Examples 1-74 Re-7 45 15 B A B B 12.4 Examples 1-75 Re-8 50 10 B B B C 13.5 Examples 1-76 Re-9 25 20 B B B E 15.5 Examples 1-77 Re-10 35 10 B B B E 15.4 Examples 1-78 Re-11 30 30 B B B G 17.5 Examples 1-79 Re-12 35 5 B B B E 15.3 Examples 1-80 Re-13 35 15 B A B D 14.8 Examples 1-81 Re-14 40 10 B B B C 13.2 Examples 1-82 Re-15 60 20 B B B C 13.6 Examples 1-83 Re-16 55 10 B A B B 12.6 Examples 1-84 Re-17 70 5 B B B C 13.7 Examples 1-85 Re-18 55 10 B A B B 12.3 Examples 1-86 Re-19 40 15 B B B C 13.5 Examples 1-87 Re-20 45 10 B B B C 13.4 Examples 1-88 Re-21 25 25 B B B G 17.4 Examples 1-89 Re-22 80 5 A B B B 12.4 Examples 1-90 Re-23 25 25 B A B F 16.2 Examples 1-91 Re-24 35 25 B A B F 16.7 Examples 1-92 Re-25 50 50 B B B E 15.5 Examples 1-93 Re-26 40 40 A A B B 12.7 Examples 1-94 Re-27 45 5 A A B A 11.5 Examples 1-95 Re-28 50 10 B A B B 12.6 Examples 1-96 Re-29 60 10 B B B C 13.6 Examples 1-97 Re-30 25 50 B B B G 17.2 Examples 1-98 Re-31 30 40 B A B F 16.8 Examples 1-99 Re-32 50 10 B A B B 12.2 Example 1-100 Re-33 40 10 B B B C 13.5 Example 1-101 Re-34 35 25 A A B E 15.4 Example 1-102 Re-35 35 15 B B B E 15.8

[0395] [Table 9] Table 4 (continued) Anti-corrosion composition Characteristics of resist composition PEB result Repeating unit a1 quantity Acid decomposition repeating unit quantity SP value of 18.0 or above Repeating units containing lactones Defect suppression Limiting analysis (nm) Example 1-103 Re-36 40 0 A A B A 11.1 Example 1-104 Re-37 50 0 A A B A 11.2 Example 1-105 Re-38 45 0 A A B A 11.2 Example 1-106 Re-39 55 0 B B B C 13.7 Example 1-107 Re-40 60 0 A A B A 11.4 Example 1-108 Re-41 70 0 B B B C 13.2 Example 1-109 Re-42 55 0 B B B C 13.6 Example 1-110 Re-43 55 0 A A B A 11.3 Example 1-111 Re-44 70 0 A B B B 12.1 Example 1-112 Re-45 80 0 A B B B 12.4 Example 1-113 Re-46 35 0 A A B C 13.4 Example 1-114 Re-47 45 0 A A B A 11.3 Example 1-115 Re-48 50 0 B A B B 12.2 Example 1-116 Re-49 50 0 A A B A 11.4 Example 1-117 Re-50 70 0 A B B B 12.5 Example 1-118 Re-51 60 0 A A B A 11.6 Example 1-119 Re-52 55 0 A B B B 12.2 Example 1-120 Re-53 70 0 B A B B 12.4 Example 1-121 Re-54 90 0 A B B B 12.3 Example 1-122 Re-55 55 0 B A B B 12.3 Examples 1-123 Re-56 80 0 A B B B 12.4 Examples 1-124 Re-57 75 0 A A B A 11.2 Example 1-125 Re-58 70 0 A A B A 11.4 Examples 1-126 Re-59 80 0 A B B B 12.5 Example 1-127 Re-60 75 0 A A B A 11.1 Example 1-128 Re-61 100 0 A B B B 12.5 Example 1-129 Re-62 100 0 A B B B 12.4 Example 1-130 Re-63 100 0 A B B B 12.3 Example 1-131 Re-64 100 0 A B B B 12.6 Example 1-132 Re-65 100 0 A B B B 12.4 Example 1-133 Re-66 100 0 A B B B 12.7 Example 1-134 Re-67 100 0 A B B B 12.4 Comparative Examples 1-6 Re'-1 30 0 A B B Non-analyzed Non-analyzed Comparative Examples 1-7 Re'-2 10 27 A B B Non-analyzed Non-analyzed Comparative Examples 1-8 Re'-3 - 50 B B B Non-analyzed Non-analyzed Comparative Examples 1-9 Re'-4 - 0 A B B Non-analyzed Non-analyzed Comparative Examples 1-10 Re'-5 20 30 B A B H 19.8

[0396] Based on the results shown in the table, it was confirmed that when using the resist composition of the present invention and forming patterns by developing with an organic solvent, the defect performance (defect suppression) and resolution are excellent. On the other hand, in the resist compositions of comparative examples that are not equivalent to the resist composition of the present invention, these properties are insufficient.

[0397] Furthermore, it has been confirmed that the more of the following conditions are met: the content of repeating unit a1 in resin A is 40 mol% or more; the content of repeating units with acid-degradable groups in resin A is 20 mol% or less; the SP value of substantially all repeating units constituting the repeating units of resin A is 18.0 MPa0.5 or more; and the resin A contains a greater number of repeating units with lactone groups, the better the effect of the present invention (refer to the comparison between examples with PEB or examples without PEB, etc.).

[0398] [Pattern formation (2): EUV exposure, alkaline development] <Pattern Formation> A substrate film with a thickness of 20 nm was formed by coating an AL412 composition (manufactured by Brewer Science) onto a 12-inch diameter silicon wafer and baking it at 205°C for 60 seconds. A resist composition prepared as described above was then coated onto the substrate and baked at 100°C for 60 seconds to form a resist film with a thickness of 20 nm. Exposure was performed using an EUV exposure machine (ASML NXE3350, NA 0.33, Dipole 45°, outer sigma 0.87, inner sigma 0.60) with a reflective mask having a septum dimension of 20 nm and a line-to-space ratio of 1:1. Subsequently, for Examples 2-1 to 2-67 and Comparative Examples 2-1 to 2-5, heating was performed at 100°C for 60 seconds (PEB). This step was omitted for Examples 2-68 to 2-134 and Comparative Examples 2-6 to 2-10. Next, the wafer was developed with a 2.38% (w / w) tetramethylammonium hydroxide (TMAH) aqueous solution for 30 seconds, followed by rinsing with water for 20 seconds. Then, the wafer was rotated at 2000 rpm for 40 seconds to form a positive pattern with a line size of 20 nm and a line-to-space ratio of 1:1. Using the obtained positive pattern, the defect suppression and resolution were evaluated in the same manner as described above.

[0399] The evaluation results are shown in the table below. The meanings of each column in the table are as described above.

[0400] [Table 10] Table 5 Anti-corrosion composition Characteristics of resist composition PEB result Repeating unit a1 quantity Acid decomposition repeating unit quantity SP value of 18.0 or above Repeating units containing lactones Defect suppression Limiting analysis (nm) Example 2-1 Re-1 20 30 B A A D 14.5 Example 2-2 Re-2 35 35 B A A D 14.4 Example 2-3 Re-3 30 20 B A A C 13.3 Examples 2-4 Re-4 40 30 B A A C 13.5 Examples 2-5 Re-5 20 40 B A A D 14.6 Examples 2-6 Re-6 50 10 B A A B 12.6 Examples 2-7 Re-7 45 15 B A A B 12.5 Examples 2-8 Re-8 50 10 B B A C 13.6 Examples 2-9 Re-9 25 20 B B A D 14.7 Example 2-10 Re-10 35 10 B B A D 14.4 Example 2-11 Re-11 30 30 B B A E 15.2 Example 2-12 Re-12 35 5 B B A D 14.2 Example 2-13 Re-13 35 15 B A A C 13.3 Example 2-14 Re-14 40 10 B B A C 13.4 Example 2-15 Re-15 60 20 B B A C 13.2 Example 2-16 Re-16 55 10 B A A B 12.4 Example 2-17 Re-17 70 5 B B A C 13.5 Example 2-18 Re-18 55 10 B A A B 12.6 Example 2-19 Re-19 40 15 B B A C 13.3 Example 2-20 Re-20 45 10 B B A C 13.7 Example 2-21 Re-21 25 25 B B A E 15.3 Example 2-22 Re-22 80 5 A B A B 12.4 Example 2-23 Re-23 25 25 B A A D 14.4 Example 2-24 Re-24 35 25 B A A D 14.8 Example 2-25 Re-25 50 50 B B A D 14.7 Example 2-26 Re-26 40 40 A A A B 12.4 Example 2-27 Re-27 45 5 A A A A 11.4 Example 2-28 Re-28 50 10 B A A B 12.5 Example 2-29 Re-29 60 10 B B A C 13.9 Examples 2-30 Re-30 25 50 B B A E 15.3 Example 2-31 Re-31 30 40 B A A D 14.7 Example 2-32 Re-32 50 10 B A A B 12.6 Example 2-33 Re-33 40 10 B B A C 13.3 Examples 2-34 Re-34 35 25 A A A C 13.7 Example 2-35 Re-35 35 15 B B A D 14.4

[0401] [Table 11] Table 5 (continued) Anti-corrosion composition Characteristics of resist composition PEB result Repeating unit a1 quantity Acid decomposition repeating unit quantity SP value of 18.0 or above Repeating units containing lactones Defect suppression Limiting analysis (nm) Examples 2-36 Re-36 40 0 A A A A 11.7 Example 2-37 Re-37 50 0 A A A A 11.6 Example 2-38 Re-38 45 0 A A A A 11.1 Example 2-39 Re-39 55 0 B B A C 13.2 Example 2-40 Re-40 60 0 A A A A 11.5 Example 2-41 Re-41 70 0 B B A C 13.1 Actual example 2-42 Re-42 55 0 B B A C 13.3 Actual example 2-43 Re-43 55 0 A A A A 11.8 Actual example 2-44 Re-44 70 0 A B A B 12.3 Actual example 2-45 Re-45 80 0 A B A B 12.4 Actual example 2-46 Re-46 35 0 A A A B 12.3 Actual example 2-47 Re-47 45 0 A A A A 11.3 Actual example 2-48 Re-48 50 0 B A A B 12.4 Actual example 2-49 Re-49 50 0 A A A A 11.3 Actual example 2-50 Re-50 70 0 A B A B 12.5 Actual example 2-51 Re-51 60 0 A A A A 11.5 Actual example 2-52 Re-52 55 0 A B A B 12.3 Actual example 2-53 Re-53 70 0 B A A B 12.5 Actual example 2-54 Re-54 90 0 A B A B 12.6 Actual example 2-55 Re-55 55 0 B A A B 12.3 Actual example 2-56 Re-56 80 0 A B A B 12.4 Actual example 2-57 Re-57 75 0 A A A A 11.3 Actual example 2-58 Re-58 70 0 A A A A 11.6 Actual example 2-59 Re-59 80 0 A B A B 12.3 Actual example 2-60 Re-60 75 0 A A A A 11.4 Actual example 2-61 Re-61 100 0 A B A B 12.3 Example 2-62 Re-62 100 0 A B A B 12.6 Example 2-63 Re-63 100 0 A B A B 12.4 Example 2-64 Re-64 100 0 A B A B 12.7 Example 2-65 Re-65 100 0 A B A B 12.4 Example 2-66 Re-66 100 0 A B A B 12.4 Example 2-67 Re-67 100 0 A B A B 12.2 Comparative Example 2-1 Re'-1 30 0 A B A H 19.2 Comparative Example 2-2 Re'-2 10 27 A B A H 18.9 Comparative Examples 2-3 Re'-3 - 50 B B A H 19.4 Comparative Examples 2-4 Re'-4 - 0 A B A Non-analyzed Non-analyzed Comparative Examples 2-5 Re'-5 20 30 B A A H 18.9

[0402] [Table 12] Table 5 (continued) Anti-corrosion composition Characteristics of resist composition PEB result Repeating unit a1 quantity Acid decomposition repeating unit quantity SP value of 18.0 or above Repeating units containing lactones Defect suppression Limiting analysis (nm) Example 2-68 Re-1 20 30 B A B F 16.4 Example 2-69 Re-2 35 35 B A B F 16.4 Example 2-70 Re-3 30 20 B A B D 14.4 Example 2-71 Re-4 40 30 B A B D 14.5 Example 2-72 Re-5 20 40 B A B F 16.5 Example 2-73 Re-6 50 10 B A B B 12.5 Example 2-74 Re-7 45 15 B A B B 12.4 Example 2-75 Re-8 50 10 B B B C 13.5 Example 2-76 Re-9 25 20 B B B E 15.2 Example 2-77 Re-10 35 10 B B B E 15.4 Example 2-78 Re-11 30 30 B B B G 17.5 Example 2-79 Re-12 35 5 B B B E 15.3 Example 2-80 Re-13 35 15 B A B D 14.7 Example 2-81 Re-14 40 10 B B B C 13.2 Example 2-82 Re-15 60 20 B B B C 13.6 Example 2-83 Re-16 55 10 B A B B 12.3 Example 2-84 Re-17 70 5 B B B C 13.5 Example 2-85 Re-18 55 10 B A B B 12.3 Example 2-86 Re-19 40 15 B B B C 13.5 Example 2-87 Re-20 45 10 B B B C 13.4 Example 2-88 Re-21 25 25 B B B G 17.4 Example 2-89 Re-22 80 5 A B B B 12.4 Example 2-90 Re-23 25 25 B A B F 16.2 Example 2-91 Re-24 35 25 B A B F 16.4 Example 2-92 Re-25 50 50 B B B E 15.5 Example 2-93 Re-26 40 40 A A B B 12.7 Example 2-94 Re-27 45 5 A A B A 11.3 Example 2-95 Re-28 50 10 B A B B 12.5 Example 2-96 Re-29 60 10 B B B C 13.6 Example 2-97 Re-30 25 50 B B B G 17.2 Example 2-98 Re-31 30 40 B A B F 16.8 Example 2-99 Re-32 50 10 B A B B 12.2 Example 2-100 Re-33 40 10 B B B C 13.5 Example 2-101 Re-34 35 25 A A B E 15.4 Example 2-102 Re-35 35 15 B B B E 15.8

[0403] [Table 13] Table 5 (continued) Anti-corrosion composition Characteristics of resist composition PEB result Repeating unit a1 quantity Acid decomposition repeating unit quantity SP value of 18.0 or above Repeating units containing lactones Defect suppression Limiting analysis (nm) Example 2-103 Re-36 40 0 A A B A 11.1 Example 2-104 Re-37 50 0 A A B A 11.2 Example 2-105 Re-38 45 0 A A B A 11.2 Example 2-106 Re-39 55 0 B B B C 13.7 Example 2-107 Re-40 60 0 A A B A 11.4 Example 2-108 Re-41 70 0 B B B C 13.2 Example 2-109 Re-42 55 0 B B B C 13.6 Example 2-110 Re-43 55 0 A A B A 11.3 Example 2-111 Re-44 70 0 A B B B 12.1 Example 2-112 Re-45 80 0 A B B B 12.4 Example 2-113 Re-46 35 0 A A B C 13.4 Example 2-114 Re-47 45 0 A A B A 11.3 Example 2-115 Re-48 50 0 B A B B 12.3 Example 2-116 Re-49 50 0 A A B A 11.4 Example 2-117 Re-50 70 0 A B B B 12.5 Example 2-118 Re-51 60 0 A A B A 11.8 Example 2-119 Re-52 55 0 A B B B 12.2 Example 2-120 Re-53 70 0 B A B B 12.4 Example 2-121 Re-54 90 0 A B B B 12.4 Example 2-122 Re-55 55 0 B A B B 12.3 Example 2-123 Re-56 80 0 A B B B 12.4 Example 2-124 Re-57 75 0 A A B A 11.2 Example 2-125 Re-58 70 0 A A B A 11.4 Example 2-126 Re-59 80 0 A B B B 12.3 Example 2-127 Re-60 75 0 A A B A 11.1 Example 2-128 Re-61 100 0 A B B B 12.5 Example 2-129 Re-62 100 0 A B B B 12.4 Example 2-130 Re-63 100 0 A B B B 12.4 Example 2-131 Re-64 100 0 A B B B 12.6 Example 2-132 Re-65 100 0 A B B B 12.4 Example 2-133 Re-66 100 0 A B B B 12.5 Example 2-134 Re-67 100 0 A B B B 12.4 Comparative Examples 2-6 Re'-1 30 0 A B B Non-analyzed Non-analyzed Comparative Examples 2-7 Re'-2 10 27 A B B Non-analyzed Non-analyzed Comparative Examples 2-8 Re'-3 - 50 B B B Non-analyzed Non-analyzed Comparative Examples 2-9 Re'-4 - 0 A B B Non-analyzed Non-analyzed Comparative Example 2-10 Re'-5 20 30 B A B H 20.9

[0404] Based on the results shown in the table, it was confirmed that when using the resist composition of the present invention and forming patterns by alkaline development, the defect performance (defect suppression) and resolution are also excellent. On the other hand, in the resist compositions of comparative examples that are not equivalent to the resist composition of the present invention, these properties are insufficient.

[0405] Furthermore, it has been confirmed that the more of the following conditions are met: the content of repeating unit a1 in resin A is 40 mol% or more; the content of repeating units with acid-degradable groups in resin A is 20 mol% or less; the SP value of substantially all repeating units constituting the repeating units of resin A is 18.0 MPa0.5 or more; and the resin A contains a greater number of repeating units with lactone groups, the better the effect of the present invention (refer to the comparison between examples with PEB or examples without PEB, etc.).

[0406] none

Claims

1. A photosensitive or radiosensitive linear resin composition comprising: resin A, having at least 20 moles of repeating unit a1 relative to all repeating units, said repeating unit a1 having a base represented by any one of general formulas (1) to (6) as a nonionic base that decomposes upon irradiation by photosensitive rays or radiation; and additive B, being at least one of an acid having an acid group having a pKa of -3.60 to 12.00, and a salt having a structure in which the hydrogen atom of the acid group having a pKa of -3.60 to 12.00 is cationically substituted.

1. In general formulas (1) to (6), * indicates the bonding position; in general formula (1), R1 and R2 each independently represent an organic group; R1 and R2 can bond with each other to form a ring; in general formula (2), R3 and R4 each independently represent an organic group; R3 and R4 can bond with each other to form a ring; in general formula (3), R5 and R6 each independently represent a hydrogen atom or an organic group; R5 and R6 can bond with each other to form a ring; n represents 0 or 1; Ar represents an aromatic ring group that can have substituents; in general formula (4), R7 represents an organic group; X represents -CO- or -SO2-; in general formula (5), R8 and R9 each independently represent an organic group; R8 and R9 can bond with each other to form a ring; in general formula (6), R10 and R11 each independently represent an organic group; R10 and R11 can bond with each other to form a ring.

2. The photosensitive radioactive or radiosensitive linear resin composition as claimed in claim 1, wherein the resin A comprises the content of the repeating unit a1 being 40 mol% or more relative to all repeating units.

3. The photosensitive radioactive or radiosensitive linear resin composition as claimed in claim 1 or claim 2, wherein the content of repeating units having acid-degradable groups that are not equivalent to any of the groups represented by general formulas (1) to (6) is 20 mol% or less relative to all repeating units.

4. The photosensitive radioactive or radiosensitive linear resin composition as described in claim 1 or claim 2, wherein the solubility parameter value of all repeating units constituting the resin A is 18.0 MPa 0.5 or higher.

5. The photosensitive radioactive or radiosensitive linear resin composition as claimed in claim 1 or claim 2, wherein the resin A contains repeating units having lactone groups.

6. The photosensitive radioactive or radiosensitive linear resin composition as described in claim 1 or claim 2, wherein the concentration of the solid component is less than 2% by mass.

7. A photosensitive radioactive or radiosensitive linear resin composition as claimed in claim 1 or claim 2, wherein the acid is a compound represented by general formula (RA1) or general formula (RA2) or a compound having a repeating unit represented by general formula (RA3), the salt is selected from onium salts and intramolecular salts, the onium salt having an organic cation and an organic anion, the organic cation being selected from the group consisting of organic cations represented by formula (ZaI), organic cations represented by formula (ZaII), and organic cations represented by formula (ZaIII). One less, wherein the organic anion is an aliphatic sulfonate anion in which at least α-position of a sulfonic acid is substituted with a fluorine atom, an aliphatic sulfonate anion in which α-position of a sulfonic acid is not substituted with a fluorine atom, an aromatic sulfonate anion substituted with a fluorine atom or a group having a fluorine atom, an alkyl bis(alkylsulfonyl)imidin anion substituted with a fluorine atom, or an alkyl tri(alkylsulfonyl)methyl anion substituted with a fluorine atom, wherein the intramolecular salt is at least one selected from the group consisting of compounds represented by formula (ZbI) and compounds represented by formula (ZbII), ArA-(OH)ax (RA1) Q[-ArA-(OH)ax]bx (RA2) -[ALA-ArA(OH)ax]- (RA3) In general formula (RA1), ax represents an integer of 1 or more, ArA represents an aromatic cyclic group, which may have one or more heteroatoms as ring members, and may also have substituents other than hydroxyl groups; In general formula (RA2), ax represents an integer of 1 or more, ArA represents an aromatic cyclic group, which may have one or more heteroatoms as ring members, and may also have substituents other than hydroxyl groups, bx represents an integer of 2 or more, and Q represents a linking group with a bx valence; In general formula (RA3), ax represents an integer of 1 or more, ArA represents an aromatic cyclic group, which may have one or more heteroatoms as ring members, and may also have substituents other than hydroxyl groups, and ALA represents an alkyl group; 7. R204-|+-R205 (ZaII) (RCA)4N+ (ZaIII) In formula (ZaI), R201, R202, and R203 each independently represent an organogroup (wherein, Except for aryl groups having -SO3- or -COO- as substituents, two of R201 to R203 can be bonded to form a ring structure, and the ring structure may also contain an oxygen atom, a sulfur atom, an ester group, an amino group or a carbonyl group; in formula (ZaII), R204 and R205 each independently represent an aryl group (except for aryl groups having -SO3- or -COO- as substituents), an alkyl group or a cycloalkyl group; in formula (ZaIII), RCA each independently represent an alkyl group; 7. R204-|+-R205 (ZbII) In formula (ZbI), one of R201 to R203 represents an aryl group having a substituent containing -SO3- or -COO-, and the other two of R201 to R203 each independently represent an organic group. The two of R201 to R203 can be bonded to form a ring structure, and the ring structure may contain an oxygen atom, a sulfur atom, an ester group, an amino group, or a carbonyl group; In formula (ZbII), one of R204 and R205 represents an aryl group having a substituent containing -SO3- or -COO-, and the other of R204 and R205 represents an aryl, alkyl, or cycloalkyl group.

8. The photosensitive radioactive or radiosensitive linear resin composition as claimed in claim 1 or claim 2, wherein the additive B is at least one of an acid having an acid group having a pKa of 0.00 to 11.00, and a salt having a structure in which the hydrogen atom of an acid group having a pKa of 0.00 to 11.00 is cationically substituted.

9. The photosensitive radioactive or radiosensitive linear resin composition as claimed in claim 1 or claim 2, wherein the additive B is at least one of an acid having an acid group having a pKa of 5.00 to 10.00, and a salt having a structure in which the hydrogen atom of an acid group having a pKa of 5.00 to 10.00 is cationically substituted.

10. A resist film formed using a photosensitive radioactive or radiosensitive linear resin composition as described in any one of claims 1 to 9.

11. 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 9; exposing the resist film; and developing the exposed resist film using a developer.

12. A method for manufacturing an electronic device, comprising the pattern forming method as described in claim 11.