Photosensitive resin composition, resist film, pattern forming method, and electronic device manufacturing method

Abstract

The present invention provides: a photosensitive resin composition containing a solvent and a resin that has repeating units represented by general formula (1) described in the specification and repeating units represented by general formula (2) described in the specification, the photosensitive resin composition having a water content of 10 ppm or more relative to the total mass of the photosensitive resin composition; a resist film; a pattern forming method; and an electronic device manufacturing method including said pattern forming method.

Description

Photosensitive resin composition, resist film, pattern forming method, and method for manufacturing electronic device

[0001] The present invention relates to a photosensitive resin composition, a resist film, a pattern forming method, and a method for manufacturing an electronic device.

[0002] Since the development of resists for KrF excimer lasers (248 nm), pattern formation methods utilizing chemical amplification have been used to compensate for the loss of sensitivity due to light absorption. For example, in positive-tone chemical amplification methods, a photoacid generator contained in the exposed area decomposes upon light irradiation to generate acid. Then, during a post-exposure bake (PEB) process, the catalytic action of the generated acid changes the alkali-insoluble groups of the resin contained in the photosensitive resin composition to alkali-soluble groups, thereby changing the solubility in the developer. Development is then performed, for example, using a basic aqueous solution. This removes the exposed areas to obtain the desired pattern. To achieve miniaturization of semiconductor elements, the wavelength of exposure light sources has become shorter and the numerical aperture (NA) of projection lenses has become higher. Currently, exposure machines using an ArF excimer laser with a wavelength of 193 nm as a light source have been developed. Recently, pattern formation methods using extreme ultraviolet (EUV) light and electron beam (EB) light sources have also been investigated. Under these circumstances, various photosensitive resin compositions have been proposed, and recently, resin compositions containing a resin whose main chain decomposes or cleaves upon exposure have become known as those capable of achieving ultra-fine patterns. Pattern formation methods using such resin compositions do not utilize the chemical amplification described above and are non-chemically amplified.

[0003] Patent Document 1 describes a positive resist composition containing a main chain scission type polymer that includes a predetermined monomer unit in which the α-position is halogenated and a predetermined monomer unit having an aromatic hydrocarbon group.

[0004] Japanese Patent Application Publication No. 2021-33293

[0005] The present inventors have prepared and studied actinic ray- or radiation-sensitive resin compositions containing a specific polymer with reference to Patent Document 1, and have found that there is room for further improvement in sensitivity. Furthermore, it has also been found that there is room for further improvement in LWR (line width roughness) performance of patterns formed using the compositions, particularly in the formation of ultrafine patterns.

[0006] Therefore, an object of the present invention is to provide a photosensitive resin composition capable of forming a pattern that can improve sensitivity and LWR performance in the formation of an ultrafine pattern (for example, a line-and-space pattern with a line width of 20 nm or less, a hole pattern with a hole diameter of 20 nm or less, etc.) Another object of the present invention is to provide a resist film, a pattern formation method, and a method for manufacturing an electronic device using the photosensitive resin composition.

[0007] The present inventors have found that the above problems can be solved by the following configuration.

[0008] [1] A photosensitive resin composition comprising a resin having a repeating unit represented by the following general formula (1) and a repeating unit represented by the following general formula (2), and a solvent, wherein the photosensitive resin composition has a water content of 10 ppm or more relative to the total mass of the photosensitive resin composition:

[0009]

[0010] In the general formula (1), X represents a halogen atom, a cyano group, an alkylsulfonyl group, an alkoxy group, a nitro group, an acyl group, an alkyl ester group, or a halogenated alkyl group. ０ represents a hydrogen atom or a substituent. １ represents a substituent. ０ and R １ may be bonded to each other to form a ring.

[0011]

[0012] In general formula (2), A １ represents an organic group. ２ represents a hydrogen atom or a substituent.１ represents an aromatic ring group. ３ represents a substituent. k represents an integer of 0 to 7. When k represents an integer of 2 to 7, a plurality of R ３ may be the same or different. When k is an integer of 2 to 7, a plurality of R ３ Adjacent R ３ They may be bonded to each other to form a ring.

[0013] [2] The photosensitive resin composition according to [1], wherein the water content is 100 ppm or more and 1000 ppm or less. [3] The photosensitive resin composition according to [1] or [2], wherein the total content of at least one metal element selected from the group consisting of Li, Na, Mg, Al, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Ag, Cd, Sn, Ba, W, Au, and Pb is 2.0 ppb or less, based on the total mass of the photosensitive resin composition.

[0014] [4] The photosensitive resin composition according to any one of [1] to [3], wherein the solvent contains a compound having at least one structure selected from the group consisting of a phenol ether structure, a ketone structure, and an ester structure. [5] The photosensitive resin composition according to any one of [1] to [4], wherein the resin has a weight average molecular weight of 20,000 or more.

[0015] [6] A resist film formed from the photosensitive resin composition according to any one of [1] to [5]. [7] A pattern forming method comprising the steps of: forming a resist film on a substrate using the photosensitive resin composition according to any one of [1] to [5]; exposing the resist film; and developing the exposed resist film using a developer. [8] A method for manufacturing an electronic device, comprising the pattern forming method according to [7].

[0016] According to the present invention, a photosensitive resin composition can be provided that can form a pattern that can improve sensitivity and LWR performance in the formation of an ultrafine pattern (for example, a line-and-space pattern with a line width of 20 nm or less, a hole pattern with a hole diameter of 20 nm or less, etc.) Furthermore, according to the present invention, a resist film, a pattern formation method, and a method for manufacturing an electronic device can be provided that use the photosensitive resin composition.

[0017] The present invention will be described in detail below. The following description of the constituent elements may be based on a representative embodiment of the present invention, but the present invention is not limited to such an embodiment. In the present specification, when a group (atomic group) is designated without specifying whether it is substituted or unsubstituted, it encompasses both unsubstituted and substituted groups, unless it is contrary to the spirit of the present invention. For example, the term "alkyl group" encompasses not only unsubstituted alkyl groups (unsubstituted alkyl groups) but also substituted alkyl groups (substituted alkyl groups). Furthermore, the term "organic group" in this specification refers to a group containing at least one carbon atom. Unless otherwise specified, the substituent is preferably a monovalent substituent. In this specification, "actinic rays" or "radiation" refers to, for example, the emission line spectrum of a mercury lamp, far ultraviolet light typified by excimer lasers, extreme ultraviolet light (EUV: Extreme Ultraviolet), X-rays, and electron beams (EB: Electron Beam). In this specification, "light" refers to actinic rays or radiation. Unless otherwise specified, the term "exposure" used herein includes not only exposure using the bright line spectrum of a mercury lamp, far ultraviolet light typified by an excimer laser, extreme ultraviolet light (EUV light: Extreme Ultraviolet), and X-rays, but also drawing using particle beams such as electron beams (EB) and ion beams. In this specification, the term "to" is used to mean that the numerical values ​​before and after it are included as the lower and upper limits. The bonding direction of divalent groups expressed in this specification is not limited unless otherwise specified. For example, when Y is -COO- in a compound represented by the formula "X-Y-Z", Y may be -CO-O- or -O-CO-. Furthermore, the compound may be "X-CO-O-Z" or "X-O-CO-Z".

[0018] In this specification, the weight average molecular weight (Mw), number average molecular weight (Mn), and dispersity (also referred to as molecular weight distribution) (Mw / Mn) of a resin are defined as polystyrene-equivalent values ​​measured by gel permeation chromatography (GPC) using a GPC apparatus (HLC-8120GPC manufactured by Tosoh Corporation) (solvent: tetrahydrofuran, flow rate (sample injection amount): 10 μL, column: TSK gel Multipore HXL-M manufactured by Tosoh Corporation, column temperature: 40° C., flow rate: 1.0 mL / min, detector: differential refractive index detector).

[0019] In this specification, the acid dissociation constant (pKa) refers to the pKa in an aqueous solution, and specifically, is a value determined by calculation based on a database of Hammett's substituent constants and known literature values ​​using the following software package 1. All pKa values ​​described in this specification are values ​​determined by calculation using this software package.

[0020] Software package 1: Advanced Chemistry Development (ACD / Labs) Software V8.14 for Solaris (1994-2007 ACD / Labs).

[0021] On the other hand, pKa can also be determined by molecular orbital calculation. A specific method for this is to calculate the pKa of H in an aqueous solution based on the thermodynamic cycle. ＋ One method is to calculate the dissociation free energy. ＋ The dissociation free energy can be calculated by, for example, DFT (density functional theory), but various other methods have been reported in the literature, and the method is not limited to these. There are several software programs that can perform DFT, and Gaussian 16 is an example.

[0022] As described above, the pKa in this specification refers to a value calculated using software package 1 based on a database of Hammett's substituent constants and publicly known literature values, but if the pKa cannot be calculated by this method, a value obtained by Gaussian 16 based on DFT (density functional theory) will be used. Furthermore, as described above, the pKa in this specification refers to "pKa in aqueous solution," but if the pKa in aqueous solution cannot be calculated, "pKa in dimethyl sulfoxide (DMSO) solution" will be used.

[0023] In this specification, the term "substituent T" refers to a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom; an alkoxy group such as a methoxy group, an ethoxy group, or a tert-butoxy group; a cycloalkyloxy group; an aryloxy group such as a phenoxy group or a p-tolyloxy group; an alkoxycarbonyl group such as a methoxycarbonyl group, a butoxycarbonyl group, or a phenoxycarbonyl group; an acyloxy group such as an acetoxy group, a propionyloxy group, or a benzoyloxy group; or an acyl group such as an acetyl group, a benzoyl group, an isobutyryl group, an acryloyl group, a methacryloyl group, or a methoxalyl group. Examples of such groups include alkylsulfanyl groups such as methylsulfanyl and tert-butylsulfanyl; arylsulfanyl groups such as phenylsulfanyl and p-tolylsulfanyl; alkyl groups; cycloalkyl groups; aryl groups; heteroaryl groups; hydroxyl groups; carboxy groups; formyl groups; sulfo groups; cyano groups; alkylaminocarbonyl groups; arylaminocarbonyl groups; sulfonamide groups; silyl groups; amino groups; imino groups; monoalkylamino groups; dialkylamino groups; arylamino groups, nitro groups; formyl groups; thiol groups; thioether groups; and combinations thereof. The alkyl groups may be either linear or branched. Furthermore, when the alkyl group contains a fluorine atom, it may be a perfluoroalkyl group. Furthermore, the aryl group and heteroaryl group may be either monocyclic or polycyclic.

[0024] In this specification, examples of halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms.

[0025] In this specification, the term "solid content" refers to components that form a resist film and does not include solvents. Furthermore, any component that forms a resist film is considered to be a solid content even if it is in a liquid state.

[0026] [Photosensitive Resin Composition] The photosensitive resin composition of the present invention is a photosensitive resin composition containing a resin having a repeating unit represented by the following general formula (1) and a repeating unit represented by the following general formula (2), and a solvent, wherein the photosensitive resin composition has a water content of 10 ppm or more relative to the total mass of the photosensitive resin composition:

[0027]

[0028] In the general formula (1), X represents a halogen atom, a cyano group, an alkylsulfonyl group, an alkoxy group, a nitro group, an acyl group, an alkyl ester group, or a halogenated alkyl group. ０ represents a hydrogen atom or a substituent. １ represents a substituent. ０ and R １ may be bonded to each other to form a ring.

[0029]

[0030] In general formula (2), A １ represents an organic group. ２ represents a hydrogen atom or a substituent. １ represents an aromatic ring group. ３ represents a substituent. k represents an integer of 0 to 7. When k represents an integer of 2 to 7, a plurality of R ３ may be the same or different. When k is an integer of 2 to 7, a plurality of R ３ Adjacent R ３ They may be bonded to each other to form a ring.

[0031] The photosensitive resin composition of the present invention, as described above, is capable of forming patterns that can improve sensitivity and LWR performance in the formation of ultrafine patterns (e.g., line-and-space patterns with line widths of 20 nm or less and hole patterns with hole diameters of 20 nm or less). While the reason for this is not clear in detail, the present inventors speculate as follows: There is a need for improved sensitivity and LWR in pattern formation using a photosensitive resin composition containing a resin whose main chain decomposes or cleaves upon exposure. To improve sensitivity and LWR, the present inventors focused on using a trace amount of water, which has traditionally been difficult to use in photosensitive resin compositions, and surprisingly found that this improves sensitivity and LWR. The photosensitive resin composition of the present invention has a water content of 10 ppm or more relative to the total mass of the photosensitive resin composition. Although the reason why the sensitivity and LWR are improved by including 10 ppm or more of water in the composition relative to the total mass of the photosensitive resin composition is unclear, it is thought that, for example, protons derived from water may promote the elimination of X at the α-position in the repeating unit represented by general formula (1) in the resin contained in the photosensitive resin composition of the present invention, thereby accelerating main chain decomposition during exposure. It is presumed that the sensitivity and LWR can be improved by accelerating the decomposition and scission of the main chain of the resin during exposure.

[0032] [Resin] First, the resin (hereinafter also referred to as resin (A)) contained in the photosensitive resin composition of the present invention will be described. The resin has a repeating unit represented by the above general formula (1).

[0033] In the above general formula (1), X represents a halogen atom, a cyano group, an alkylsulfonyl group, an alkoxy group, a nitro group, an acyl group, an alkyl ester group, or a halogenated alkyl group.

[0034] Examples of the halogen atom represented by X include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, with a chlorine atom, a bromine atom, or an iodine atom being preferred, and a chlorine atom being more preferred.

[0035] The alkyl group in the alkylsulfonyl group represented by X includes linear or branched alkyl groups having 1 to 6 carbon atoms, and methyl and ethyl groups are preferred.

[0036] Examples of the alkyl group in the alkoxy group represented by X include the alkyl groups in the alkylsulfonyl group described above, and preferred examples are also the same.

[0037] Examples of the alkyl group in the alkyl ester group (alkylcarbonyloxy group) represented by X include the alkyl groups in the alkylsulfonyl group described above, and preferred examples are also the same.

[0038] Examples of the alkyl group in the halogenated alkyl group represented by X include the alkyl group in the alkylsulfonyl group described above, and preferred examples are also the same. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom and a chlorine atom are more preferred.

[0039] Examples of the alkyl group in the acyl group (alkylcarbonyl group or arylcarbonyl group) represented by X include the alkyl groups in the alkylsulfonyl group described above, and preferred examples are also the same. Examples of the aryl group include aryl groups having 6 to 12 carbon atoms, and a phenyl group is preferred.

[0040] The above group represented by X may further have a substituent, if possible. Examples of the substituent include the substituent T described below.

[0041] X preferably represents a halogen atom, a cyano group, or a halogenated alkyl group, more preferably a halogen atom, more preferably a chlorine atom, a bromine atom, or an iodine atom, and even more preferably a chlorine atom.

[0042] R ０ The substituent of R is not particularly limited, but may be, for example, an alkyl group. The alkyl group may be either linear or branched, and may be, for example, an alkyl group having 1 to 20 carbon atoms, preferably an alkyl group having 1 to 10 carbon atoms, and more preferably an alkyl group having 1 to 6 carbon atoms. ０preferably represents a hydrogen atom.

[0043] R １ The substituent of R is not particularly limited, but examples thereof include a hydroxy group, an amino group, a halogen atom, and an organic group. The organic group may have a heteroatom (e.g., a nitrogen atom, an oxygen atom, a sulfur atom, etc.). Examples of the organic group include the groups exemplified in the organic group W below. In one preferred embodiment, R １ Is, L １ -R １Ａ It is preferable that L is a group represented by the following formula: １ is —O— or —NR Ｘ - represents. Ｘ represents a hydrogen atom or an organic group. １Ａ represents a hydrogen atom or a substituent. １Ａ or Rx is R ０ may be bonded to each other to form a ring. １Ａ or Rx is R ０ The ring formed by bonding with each other is R １ and R ０ are bonded to each other to form a ring, and the preferred range is also the same.

[0044] R Ｘ The organic group is not particularly limited, but examples thereof include organic groups having 1 to 20 carbon atoms. As the organic group, an alkyl group or a cycloalkyl group is preferred. The alkyl group may be either linear or branched, and examples thereof include alkyl groups having 1 to 20 carbon atoms, preferably alkyl groups having 1 to 10 carbon atoms, and more preferably alkyl groups having 1 to 6 carbon atoms. The cycloalkyl group may be monocyclic or polycyclic, and is preferably a cycloalkyl group having 5 to 20 carbon atoms, and more preferably a cycloalkyl group having 5 to 15 carbon atoms. R Ｘ preferably represents a hydrogen atom.

[0045] R １Ａ The substituent of is not particularly limited, but may be, for example, an organic group. Examples of the organic group include the groups exemplified as the organic group W below.

[0046] (Organic Group W) Examples of the organic group W include alkyl groups, cycloalkyl groups, alkenyl groups, cycloalkenyl groups, alkynyl groups, cycloalkynyl groups, aryl groups, heteroaryl groups, aralkyl groups, cyano groups, alkoxy groups, cycloalkoxy groups, aryloxy groups, heterocyclic oxy groups, acyl groups (alkylcarbonyl groups or arylcarbonyl groups), acyloxy groups (alkylcarbonyloxy groups or arylcarbonyloxy groups), carbamoyloxy groups, alkoxycarbonyloxy groups, aryloxycarbonyloxy groups, alkylthio groups, arylthio groups, heterocyclic thio groups, alkyl or arylsulfinyl groups, alkyl or arylsulfonyl groups, aryloxycarbonyl groups, alkoxycarbonyl groups, aryl or heterocyclic azo groups, sulfonamide groups, imide groups, acylamino groups, carbamoyl groups, and lactone groups.In addition, each of the above groups may further have a substituent, if possible.For example, an alkyl group that may have a substituent is also included as one form of the organic group W. The substituent is not particularly limited, and examples thereof include one or more of the groups exemplified above as the organic group W, a halogen atom, a nitro group, a primary to tertiary amino group, a phosphino group, a phosphinyl group, a phosphinyloxy group, a phosphinylamino group, a phosphono group, a silyl group, a hydroxy group, a carboxy group, a sulfonic acid group, and a phosphate group (hereinafter, these are referred to as "substituents T1"). The number of carbon atoms contained in the organic group W is, for example, 1 to 20. The number of atoms other than hydrogen atoms contained in the organic group W is, for example, 1 to 30.

[0047] The number of carbon atoms in the alkyl group exemplified by the organic group W is preferably 1 to 20, more preferably 1 to 10, and even more preferably 1 to 6. The alkyl group may be either linear or branched. Examples of the alkyl group include linear or branched alkyl groups such as methyl, ethyl, n-propyl, i-propyl, n-butyl, t-butyl, and n-hexyl. In the alkyl group that may have a substituent, the substituent that the alkyl group may have is not particularly limited, and examples include the groups exemplified by the above-mentioned substituent T1. In addition, in order to further improve the interactivity with ionic compounds (e.g., photodegradable onium salt compounds) that the photosensitive resin composition may contain, which will be described later, and to further enhance the effects of the present invention, it is also preferable for the substituent to have a group that interacts with ionic compounds (hereinafter referred to as an "interactive group"), such as a hydroxy group (such as an alcoholic hydroxyl group and a phenolic hydroxyl group), a carboxyl group, a sulfonic acid group, an amide group, or a sulfonamide group, as a substituent. The phenolic hydroxyl group refers to a hydroxyl group substituted on a ring atom of an aromatic ring (aromatic hydrocarbon ring or aromatic heterocyclic ring). The amide group is not particularly limited, but examples thereof include -C(=O)-NHR Ｐ (R Ｐ represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms.

[0048] The alkyl group moiety in the alkoxy group (including the alkoxy group moiety in a substituent containing an alkoxy group (for example, an alkoxycarbonyloxy group)) exemplified in the organic group W, the alkyl group moiety in the aralkyl group, the alkyl group moiety in the alkylcarbonyl group, the alkyl group moiety in the alkylcarbonyloxy group, the alkyl group moiety in the alkylthio group, the alkyl group moiety in the alkylsulfinyl group, and the alkyl group moiety in the alkylsulfonyl group are preferably the above-mentioned alkyl groups. Furthermore, in the alkoxy group which may have a substituent, the aralkyl group which may have a substituent, the alkylcarbonyloxy group which may have a substituent, the alkylthio group which may have a substituent, the alkylsulfinyl group which may have a substituent, and the alkylsulfonyl group which may have a substituent, examples of the substituent that the alkoxy group, aralkyl group, alkylcarbonyloxy group, alkylthio group, alkylsulfinyl group, and alkylsulfonyl group may have include the same examples as the substituent in the alkyl group which may have a substituent.

[0049] Examples of the cycloalkyl group exemplified in the organic group W include monocyclic cycloalkyl groups such as a cyclopentyl group and a cyclohexyl group, and polycyclic cycloalkyl groups such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, and an adamantyl group. The number of carbon atoms in the cycloalkyl group is preferably 5 to 20, and more preferably 5 to 15. In the cycloalkyl group which may have a substituent, examples of the substituent which the cycloalkyl group may have include the same as the substituent in the alkyl group which may have a substituent. In addition, at least one -CH ２ - may be replaced by -C(=O)-. As the cycloalkyl group moiety in the cycloalkoxy group exemplified as the organic group W, the above-mentioned cycloalkyl groups are preferable. Furthermore, in the cycloalkoxy group which may have a substituent, examples of the substituent which the cycloalkoxy group may have are the same as those of the substituent in the alkyl group which may have a substituent.

[0050] The alkenyl group exemplified in the organic group W may be either linear or branched. The number of carbon atoms in the alkenyl group is preferably 2 to 20. In the optionally substituted alkenyl group, examples of the substituent that the alkenyl group may have include the same examples as the substituents in the optionally substituted alkyl group. The number of carbon atoms in the cycloalkenyl group exemplified in the organic group W is preferably 5 to 20. In the optionally substituted cycloalkenyl group, examples of the substituent that the cycloalkenyl group may have include the same examples as the substituents in the optionally substituted alkyl group.

[0051] The alkynyl group exemplified in the organic group W may be either linear or branched. The number of carbon atoms in the alkynyl group is preferably 2 to 20. In the alkynyl group which may have a substituent, examples of the substituent that the alkynyl group may have include the same as the substituents in the alkyl group which may have a substituent. The number of carbon atoms in the cycloalkynyl group exemplified in the organic group W is preferably 5 to 20. In the cycloalkynyl group which may have a substituent, examples of the substituent that the cycloalkynyl group may have include the same as the substituents in the alkyl group which may have a substituent.

[0052] The aryl group exemplified in the organic group W may be either a monocyclic or polycyclic (e.g., 2 to 6 rings, etc.) unless otherwise specified. The number of ring atoms in the aryl group is preferably 6 to 15, more preferably 6 to 10. The aryl group is preferably a phenyl group, a naphthyl group, or an anthryl group, and more preferably a phenyl group. In the aryl group which may have a substituent, examples of the substituent which the aryl group may have include the same examples as the substituent in the alkyl group which may have a substituent. Furthermore, among the groups exemplified in the organic group W, examples of the aryl group moiety in the substituent containing an aryl group (e.g., an aryloxy group) include the same examples as the aryl group exemplified in the organic group W.

[0053] The heteroaryl group exemplified as the organic group W may be either a monocyclic or polycyclic (e.g., 2 to 6 rings, etc.) unless otherwise specified. The number of heteroatoms contained in the heteroaryl group as ring atoms is, for example, 1 to 10. Examples of the heteroatom include a nitrogen atom, a sulfur atom, an oxygen atom, a selenium atom, a tellurium atom, a phosphorus atom, a silicon atom, and a boron atom. The number of ring atoms in the heteroaryl group is preferably 5 to 15. In the heteroaryl group which may have a substituent, examples of the substituent which the heteroaryl group may have include the same as the substituents in the alkyl group which may have a substituent.

[0054] The heterocycle exemplified in the organic group W intends a ring containing a heteroatom as a ring member atom, and unless otherwise specified, may be either an aromatic heterocycle or an aliphatic heterocycle, and may be either a monocycle or a polycycle (e.g., 2-6 rings, etc.). The number of heteroatoms contained in the heterocycle as ring member atoms is, for example, 1 to 10. Examples of the heteroatom include a nitrogen atom, a sulfur atom, an oxygen atom, a selenium atom, a tellurium atom, a phosphorus atom, a silicon atom, and a boron atom. The number of ring member atoms in the heterocycle is preferably 5 to 15. In the heterocycle which may have a substituent, examples of the substituent which the heterocycle may have include the same as the substituents in the alkyl group which may have a substituent.

[0055] The lactone group exemplified as the organic group W is preferably a 5- to 7-membered lactone group, and more preferably a 5- to 7-membered lactone ring to which another ring structure is condensed so as to form a bicyclo structure or a spiro structure. In the lactone group which may have a substituent, examples of the substituent which the lactone group may have are the same as those of the substituent in the alkyl group which may have a substituent.

[0056] R ０ and R １ may be bonded to each other to form a ring. ０ and R １The ring formed by bonding together is not particularly limited and may be either a monocyclic ring or a polycyclic ring. The ring may contain heteroatoms such as oxygen atoms, nitrogen atoms, and sulfur atoms, and / or carbonyl carbon atoms as ring member atoms. Among these, the ring is preferably a 5- or 6-membered ring.

[0057] The resin is a so-called main chain scission polymer, in which the main chain decomposes (the main chain is scissioned) upon exposure. Resin (A) is preferably a resin whose main chain decomposes upon irradiation with X-rays, electron beams (EB), or extreme ultraviolet rays (EUV), and more preferably a resin whose main chain decomposes upon irradiation with electron beams or extreme ultraviolet rays. The exposure light source is not particularly limited, but examples include the bright line spectrum of a mercury lamp, far ultraviolet rays typified by excimer lasers, extreme ultraviolet rays, X-rays, and electron beams (EB). Among these, X-rays, electron beams, or EUV light are preferred, electron beams or EUV light are more preferred, and EUV light is even more preferred.

[0058] Resin (A) contains a repeating unit represented by the general formula (1) above, and can function as a main chain scission polymer. Resin (A) is preferably a copolymer containing a repeating unit represented by the general formula (1) above and a repeating unit (preferably a repeating unit represented by the general formula (2) described below) that functions better as a main chain scission polymer. Resin (A) may be a random copolymer, a block copolymer, or an alternating copolymer, and is more preferably an alternating copolymer.

[0059] Specific examples of the monomers constituting the repeating unit represented by formula (1) are listed below, but the present invention is not limited to these.

[0060]

[0061] Specific examples of the repeating unit represented by formula (1) are listed below, but the invention is not limited thereto.

[0062]

[0063]

[0064]

[0065] In the resin, the content of the repeating unit represented by general formula (1) is preferably 10 mol% or more, more preferably 20 mol% or more, and even more preferably 40 mol% or more, based on the total repeating units. The upper limit is, for example, preferably 95 mol% or less, more preferably 90 mol% or less, even more preferably 80 mol% or less, and particularly preferably 60 mol% or less, based on the total repeating units. The repeating unit represented by general formula (1) may be contained in one type alone, or in two or more types. When two or more types are contained, the total content is preferably within the above-mentioned preferred content range.

[0066] The resin further has a repeating unit represented by the following general formula (2).

[0067]

[0068] In general formula (2), A １ represents an organic group. ２ represents a hydrogen atom or a substituent. １ represents an aromatic ring group. ３ represents a substituent. k represents an integer of 0 to 7. When k represents an integer of 2 to 7, a plurality of R ３ may be the same or different. When k is an integer of 2 to 7, a plurality of R ３ Adjacent R ３ They may be bonded to each other to form a ring.

[0069] A １ The organic group in A is not particularly limited, but examples thereof include an alkyl group and a cycloalkyl group. １ The alkyl group may be either linear or branched, and examples thereof include alkyl groups having 1 to 20 carbon atoms, preferably alkyl groups having 1 to 10 carbon atoms, and more preferably alkyl groups having 1 to 6 carbon atoms. １The cycloalkyl group may be monocyclic or polycyclic, and is preferably a cycloalkyl group having 5 to 20 carbon atoms, more preferably a cycloalkyl group having 5 to 15 carbon atoms.

[0070] R ２ The substituent of R is not particularly limited, but may be, for example, an alkyl group. The alkyl group may be either linear or branched, and may be, for example, an alkyl group having 1 to 20 carbon atoms, preferably an alkyl group having 1 to 10 carbon atoms, and more preferably an alkyl group having 1 to 6 carbon atoms. ２ preferably represents a hydrogen atom.

[0071] Ar １ Examples of the aromatic ring in the aromatic ring group include an aromatic hydrocarbon ring and an aromatic heterocycle. The aromatic hydrocarbon ring may be a monocycle or a polycycle. The number of ring atoms is preferably 6 to 15, and more preferably 6 to 10. Examples of the aromatic hydrocarbon ring include a benzene ring, a naphthalene ring, and an anthracene ring. Of these, a benzene ring or a naphthalene ring is preferred, and a benzene ring is more preferred.

[0072] The aromatic heterocycle may be a monocycle or a polycycle. The number of ring atoms is preferably 5 to 15. Examples of the heterocycle having aromaticity include a furan ring, a thiophene ring, a benzofuran ring, a benzothiophene ring, a dibenzofuran ring, a dibenzothiophene ring, a pyridine ring, an indole ring, a benzodiazole ring, and a carbazole ring.

[0073] R ３ The substituent of R is not particularly limited, but examples thereof include the above-mentioned organic group W, a halogen atom, a hydroxy group, and a nitro group. ３ represents preferably an alkyl group, an alkoxy group, a halogen atom, or a hydroxy group. The alkyl group and alkoxy group may further have a substituent. The substituent is not particularly limited, but a halogen atom is preferred.

[0074] k represents an integer of 0 to 7. When k represents an integer of 2 to 7, a plurality of R ３ Adjacent R ３may be bonded to each other to form a ring. ３ Adjacent R ３ The ring formed by bonding together is not particularly limited and may be either a monocyclic ring or a polycyclic ring. The ring may contain heteroatoms such as oxygen atoms, nitrogen atoms, and sulfur atoms, and / or carbonyl carbon atoms as ring member atoms. Among these, the ring is preferably a 5- or 6-membered ring.

[0075] Specific examples of the monomer that constitutes the repeating unit represented by formula (2) are listed below, but the present invention is not limited to these.

[0076]

[0077] Specific examples of the repeating unit represented by formula (2) are listed below, but the invention is not limited thereto.

[0078]

[0079]

[0080] In the resin, the content of the repeating unit represented by general formula (2) is preferably 10 mol% or more, more preferably 20 mol% or more, and even more preferably 40 mol% or more, based on the total repeating units. The upper limit is preferably 90 mol% or less, more preferably 80 mol% or less, even more preferably 70 mol% or less, and particularly preferably 60 mol% or less, based on the total repeating units. The repeating unit represented by general formula (2) may be contained in one type alone or in two or more types. When two or more types are contained, the total content is preferably within the above-mentioned preferred content range.

[0081] The resin is preferably a copolymer containing a repeating unit represented by the general formula (1) and a repeating unit represented by the general formula (2). The resin may be a random copolymer, a block copolymer, or an alternating copolymer, and is more preferably an alternating copolymer.

[0082] In the resin, the total content of the repeating units represented by the general formula (1) and the repeating units represented by the general formula (2) is preferably 90 mol % or more, more preferably 95 mol % or more, based on the total repeating units, and the upper limit is preferably 100 mol % or less.

[0083] <Other Repeating Units> The resin may contain repeating units other than the repeating units described above, as long as the effects of the present invention are not impaired.

[0084] When the resin contains other repeating units, the content of such units is preferably 30 mol % or less, more preferably 15 mol % or less, based on the total repeating units.

[0085] The number-average molecular weight of the resin is preferably 2,500 or more, more preferably 5,000 or more, and even more preferably 10,000 or more. The weight-average molecular weight of the resin is preferably 5,000 or more, more preferably 10,000 or more, and even more preferably 20,000 or more. The weight-average molecular weight of the resin is preferably 200,000 or less, more preferably 150,000 or less, even more preferably 100,000 or less, and particularly preferably 85,000 or less. The number-average molecular weight and weight-average molecular weight values ​​are values ​​determined as polystyrene equivalent values ​​by GPC. The dispersity (molecular weight distribution) of the resin is usually 1.0 to 3.0, preferably 1.0 to 2.0, more preferably 1.0 to 1.9, and even more preferably 1.0 to 1.8. When the dispersity is within the above range, the resolution and resist shape are more likely to be excellent. The resin can be synthesized according to a conventional method (e.g., radical polymerization).

[0086] In the photosensitive resin composition of the present invention, the content of the resin is preferably 50.0% by mass or more, more preferably 60.0% by mass or more, and even more preferably 70.0% by mass or more, based on the total solid content of the composition. The upper limit is 100% by mass or less, preferably 99.9% by mass or less. The resins may be used alone or in combination. When two or more types are used, the total content is preferably within the preferred range.

[0087] The water content is 10 ppm or more relative to the total mass of the photosensitive resin composition. If the water content is too high, resolution tends to become difficult. The water content is preferably, for example, 50,000 ppm or less relative to the total mass of the photosensitive resin composition. The water content is 10 ppm or more, preferably 50 ppm or more, and more preferably 100 ppm or more, relative to the total mass of the photosensitive resin composition. The water content is preferably 50,000 ppm or less, more preferably 10,000 ppm or less, more preferably 5,000 ppm or less, and even more preferably 1,000 ppm or less, relative to the total mass of the photosensitive resin composition. The water content is preferably 10 ppm or more and 50,000 ppm or less, more preferably 100 ppm or more and 10,000 ppm or less, more preferably 100 ppm or more and 5,000 ppm or less, and even more preferably 100 ppm or more and 1,000 ppm or less, based on the total mass of the photosensitive resin composition.

[0088] In a preferred embodiment, the water content is preferably 1,000 ppm or more and 50,000 ppm or less, more preferably 1,000 ppm or more and 40,000 ppm or less, more preferably 5,000 ppm or more and 40,000 ppm or less, and even more preferably 10,000 ppm or more and 40,000 ppm or less, relative to the total mass of the photosensitive resin composition. The water is not particularly limited, but examples thereof include pure water and ultrapure water.

[0089] [Solvent] The photosensitive resin composition of the present invention contains a solvent. The solvent preferably contains (M1) propylene glycol monoalkyl ether carboxylate and (M2) at least one selected from the group consisting of propylene glycol monoalkyl ether, lactate ester, acetate ester, alkoxypropionate ester, linear ketone, cyclic ketone, lactone, and alkylene carbonate. The solvent may further contain components other than components (M1) and (M2).

[0090] When such a solvent is used in combination with the resin whose main chain decomposes upon exposure, the coatability of the photosensitive resin composition is improved and a pattern with fewer development defects is easily formed. This is presumably because these solvents have an excellent balance of solubility, boiling point, and viscosity for the resin whose main chain decomposes upon exposure, thereby suppressing unevenness in the film thickness of the resist film, which is a composition film of the photosensitive resin composition, and the occurrence of precipitates during spin coating.

[0091] As the component (M1), at least one selected from the group consisting of propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether propionate, and propylene glycol monoethyl ether acetate is preferred, and propylene glycol monomethyl ether acetate (PGMEA) is more preferred.

[0092] The following are preferred as component (M2). As the propylene glycol monoalkyl ether, propylene glycol monomethyl ether (PGME) and propylene glycol monoethyl ether (PGEE) are preferred. As the lactate ester, ethyl lactate, butyl lactate, or propyl lactate is preferred. As the acetate ester, methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, propyl acetate, isoamyl acetate, methyl formate, ethyl formate, butyl formate, propyl formate, or 3-methoxybutyl acetate is preferred. Butyl butyrate is also preferred. The alkoxypropionic acid ester is preferably methyl 3-methoxypropionate (MMP) or ethyl 3-ethoxypropionate (EEP). The chain ketone is preferably 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, acetone, 2-heptanone, 4-heptanone, 1-hexanone, 2-hexanone, diisobutyl ketone, phenylacetone, methyl ethyl ketone, methyl isobutyl ketone, acetylacetone, acetonylacetone, ionone, diacetonyl alcohol, acetylcarbinol, acetophenone, methyl naphthyl ketone, or methyl amyl ketone. The cyclic ketone is preferably methylcyclohexanone, isophorone, cyclopentanone, or cyclohexanone. The lactone is preferably γ-butyrolactone, and the alkylene carbonate is preferably propylene carbonate.

[0093] As the component (M2), propylene glycol monomethyl ether (PGME), ethyl lactate, ethyl 3-ethoxypropionate, methyl amyl ketone, cyclohexanone, butyl acetate, pentyl acetate, γ-butyrolactone, or propylene carbonate is more preferred.

[0094] In addition to the above-mentioned components, the solvent preferably contains an ester-based solvent having 7 or more carbon atoms (preferably 7 to 14, more preferably 7 to 12, and even more preferably 7 to 10) and 2 or less heteroatoms. Preferred ester-based solvents having 7 or more carbon atoms and 2 or less heteroatoms include amyl acetate, 2-methylbutyl acetate, 1-methylbutyl acetate, hexyl acetate, pentyl propionate, hexyl propionate, butyl propionate, isobutyl isobutyrate, heptyl propionate, and butyl butanoate, and isoamyl acetate is more preferred.

[0095] Component (M2) preferably has a flash point (hereinafter also referred to as fp) of 37°C or higher. Examples of such component (M2) include propylene glycol monomethyl ether (fp: 47°C), ethyl lactate (fp: 53°C), ethyl 3-ethoxypropionate (fp: 49°C), methyl amyl ketone (fp: 42°C), cyclohexanone (fp: 44°C), pentyl acetate (fp: 45°C), methyl 2-hydroxyisobutyrate (fp: 45°C), γ-butyrolactone (fp: 101°C), and propylene carbonate (fp: 132°C). Among these, propylene glycol monoethyl ether, ethyl lactate, pentyl acetate, and cyclohexanone are more preferred, and propylene glycol monoethyl ether and ethyl lactate are even more preferred. The term "flash point" used herein refers to the value listed in the reagent catalogs of Tokyo Chemical Industry Co., Ltd. or Sigma-Aldrich Corporation.

[0096] The solvent preferably contains component (M1). It is more preferable that the solvent consists essentially of component (M1) alone, or is a mixed solvent of component (M1) with other components. In the latter case, it is even more preferable that the solvent contains both component (M1) and component (M2). The mass ratio (M1 / M2) of component (M1) to component (M2) is preferably within the range of 100 / 0 to 15 / 85, more preferably within the range of 100 / 0 to 40 / 60, and even more preferably within the range of 100 / 0 to 60 / 40. In other words, it is preferable that the solvent consists solely of component (M1) or contains both component (M1) and component (M2), and that the mass ratio between them is as follows: That is, in the latter case, the mass ratio of component (M1) to component (M2) is preferably 15 / 85 or more, more preferably 40 / 60 or more, and even more preferably 60 / 40 or more. By adopting such a configuration, it is possible to further reduce the number of development defects.

[0097] When the solvent contains both the component (M1) and the component (M2), the mass ratio of the component (M1) to the component (M2) is, for example, 99 / 1 or less.

[0098] When the solvent further contains components other than the components (M1) and (M2), the content of the components other than the components (M1) and (M2) is preferably 5 to 30 mass % based on the total amount of the solvent.

[0099] In a preferred embodiment, the photosensitive resin composition of the present invention preferably contains, as a solvent, a compound having one or more structures selected from the group consisting of a phenol ether structure, a ketone structure, and an ester structure. Examples of compounds having a phenol ether structure include, but are not limited to, anisole. Examples of compounds having a ketone structure include, but are not limited to, the above-mentioned solvents having a ketone structure. Examples of compounds having an ester structure include, but are not limited to, the above-mentioned solvents having an ester structure.

[0100] The content of the solvent in the photosensitive resin composition of the present invention is preferably determined so that the solid content concentration is 0.5 to 30 mass %, more preferably 1 to 20 mass %, in terms of better coatability.

[0101] In the photosensitive resin composition of the present invention, the total content of at least one metal element selected from the group consisting of Li, Na, Mg, Al, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Ag, Cd, Sn, Ba, W, Au, and Pb (also referred to as the "total content of metal elements") is preferably 2.0 ppb or less relative to the total mass of the photosensitive resin composition. A total content of the metal elements within the above range is preferred because it can further improve sensitivity and LWR performance in the formation of ultrafine patterns. The total content of the metal elements (mass ppb) can be measured using an inductively coupled plasma mass spectrometer (ICP-MS 8900, manufactured by Agilent). The content of the metal element can be determined as the total content of at least one metal element selected from the group consisting of Li, Na, Mg, Al, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Ag, Cd, Sn, Ba, W, Au, and Pb.

[0102] The total content of metal elements is preferably 0.1 ppt or more and 1 ppm or less, more preferably 2.0 ppb or less, more preferably 1.8 ppb or less, more preferably 1.5 ppb or less, and even more preferably 1.0 ppb or less, relative to the total mass of the photosensitive resin composition. The total content of metal elements can be appropriately adjusted by known methods such as those described in paragraphs

[0517] to

[0519] of WO 2020 / 235608.

[0103] <Ionic Compound> The photosensitive resin composition preferably contains an ionic compound. The ionic compound is more preferably a compound with an onium salt structure that generates acid upon exposure (photodegradable onium salt compound). When the photosensitive resin composition contains an ionic compound such as a photodegradable onium salt compound, the resin whose main chain decomposes upon exposure in the unexposed areas is likely to aggregate with the ionic compound via an interactive group that may be contained in the resin. On the other hand, upon exposure, dissociation between the ionic compound and the interactive group or cleavage of the photodegradable onium salt compound occurs, which can release the aggregated structure. In other words, this action further enhances the dissolution contrast between the unexposed and exposed areas of the resist film, making the effects of the present invention more effective. When the photosensitive resin composition contains an ionic compound such as a photodegradable onium salt compound, the resin whose main chain decomposes upon exposure contained in the photosensitive resin composition preferably has an interactive group. Examples of the interactive group include the above-mentioned hydroxyl group (such as an alcoholic hydroxyl group and a phenolic hydroxyl group), carboxyl group, sulfonic acid group, amide group, and sulfonamide group.

[0104] The photodegradable onium salt compound will now be described. The photodegradable onium salt compound preferably has at least one salt structural moiety composed of an anion structural moiety and a cation structural moiety, and decomposes upon exposure to generate an acid (preferably an organic acid). The salt structural moiety of the photodegradable onium salt compound is preferably composed of an organic cation structural moiety and an organic anion structural moiety with significantly low nucleophilicity, because it is easily decomposable upon exposure and has excellent organic acid generation properties. The salt structural moiety may be a portion or the entirety of the photodegradable onium salt compound. An example of a case where the salt structural moiety is a portion of the photodegradable onium salt compound is a structure in which two or more salt structural moieties are linked, such as the photodegradable onium salt PG2 described below. The number of salt structural moieties in the photodegradable onium salt is not particularly limited, but is preferably 1 to 10, more preferably 1 to 6, and even more preferably 1 to 3.

[0105] Examples of organic acids generated from the photodegradable onium salt compound by the action of exposure include sulfonic acids (aliphatic sulfonic acids, aromatic sulfonic acids, camphorsulfonic acids, etc.), carboxylic acids (aliphatic carboxylic acids, aromatic carboxylic acids, aralkyl carboxylic acids, etc.), carbonylsulfonylimido acids, bis(alkylsulfonyl)imido acids, and tris(alkylsulfonyl)methide acids. Furthermore, the organic acid generated from the photodegradable onium salt compound by the action of exposure may be a polyvalent acid having two or more acid groups. For example, when the photodegradable onium salt compound is the photodegradable onium salt compound PG2 described below, the organic acid generated by decomposition of the photodegradable onium salt compound by exposure is a polyvalent acid having two or more acid groups.

[0106] In the photodecomposable onium salt compound, the cationic moiety constituting the salt structure moiety is preferably an organic cationic moiety, and among these, an organic cation represented by formula (ZaI) (cation (ZaI)) or an organic cation represented by formula (ZaII) (cation (ZaII)) described later is preferred.

[0107] (Photodecomposable Onium Salt Compound PG1) One example of a preferred embodiment of the photodecomposable onium salt compound is "M ＋ X － " which generates an organic acid upon exposure to light (hereinafter also referred to as "photodecomposable onium salt compound PG1"). ＋ X － In the compound represented by the formula ", M ＋ represents an organic cation, and X － represents an organic anion. The photodecomposable onium salt compound PG1 will be described below.

[0108] M in the photodecomposable onium salt compound PG1 ＋ The organic cation represented by formula (ZaI) (cation (ZaI)), the organic cation represented by formula (ZaII) (cation (ZaII)), or an ammonium cation is preferred.

[0109]

[0110] In the above formula (ZaI), R ２０１ , R ２０２ , and R ２０３ R each independently represents an organic group. ２０１ , R ２０２ , and R ２０３ The number of carbon atoms in the organic group represented by R is usually 1 to 30, and preferably 1 to 20. ２０１ ~R ２０３ Two of these may be bonded to form a ring structure, and the ring may contain an oxygen atom, a sulfur atom, an ester group, an amide group, or a carbonyl group. ２０１ ~R ２０３ Examples of groups formed by combining two of these include alkylene groups (e.g., butylene and pentylene groups) and —CH ２ -CH ２ -O-CH ２ -CH ２ - are listed.

[0111] Suitable embodiments of the organic cation in formula (ZaI) include cation (ZaI-1), cation (ZaI-2), an organic cation represented by formula (ZaI-3b) (cation (ZaI-3b)), and an organic cation represented by formula (ZaI-4b) (cation (ZaI-4b)), which will be described later.

[0112] First, the cation (ZaI-1) will be described. The cation (ZaI-1) is R in the above formula (ZaI). ２０１ ~R ２０３ is an arylsulfonium cation, in which at least one of R is an aryl group. ２０１ ~R ２０３ may all be aryl groups, or R ２０１ ~R ２０３ A part of R may be an aryl group, and the rest may be an alkyl group or a cycloalkyl group. ２０１ ~R ２０３ is an aryl group, and R ２０１ ~R ２０３ The remaining two of R may be bonded to form a ring structure, and the ring may contain an oxygen atom, a sulfur atom, an ester group, an amide group, or a carbonyl group.２０１ ~R ２０３ Examples of the group formed by combining two of the above include an alkylene group in which one or more methylene groups may be substituted with an oxygen atom, a sulfur atom, an ester group, an amide group, and / or a carbonyl group (e.g., a butylene group, a pentylene group, or a -CH ２ -CH ２ -O-CH ２ -CH ２ Examples of the arylsulfonium cation include triarylsulfonium cation, diarylalkylsulfonium cation, aryldialkylsulfonium cation, diarylcycloalkylsulfonium cation, and aryldicycloalkylsulfonium cation.

[0113] The aryl group contained in the arylsulfonium cation is preferably a phenyl group or a naphthyl group, and more preferably a phenyl group. The aryl group may be an aryl group having a heterocyclic structure containing an oxygen atom, a nitrogen atom, or a sulfur atom. Examples of heterocyclic structures include pyrrole residues, furan residues, thiophene residues, indole residues, benzofuran residues, and benzothiophene residues. When the arylsulfonium cation has two or more aryl groups, the two or more aryl groups may be the same or different. The alkyl group or cycloalkyl group optionally contained in the arylsulfonium cation is preferably a linear alkyl group having 1 to 15 carbon atoms, a branched alkyl group having 3 to 15 carbon atoms, or a cycloalkyl group having 3 to 15 carbon atoms, and more preferably, for example, a methyl group, an ethyl group, a propyl group, an n-butyl group, a sec-butyl group, a t-butyl group, a cyclopropyl group, a cyclobutyl group, or a cyclohexyl group.

[0114] R ２０１ ~R ２０３Preferred substituents that the aryl group, alkyl group, and cycloalkyl group may have are each independently an alkyl group (e.g., having 1 to 15 carbon atoms), a cycloalkyl group (e.g., having 3 to 15 carbon atoms), an aryl group (e.g., having 6 to 14 carbon atoms), an alkoxy group (e.g., having 1 to 15 carbon atoms), a cycloalkylalkoxy group (e.g., having 1 to 15 carbon atoms), a halogen atom (e.g., fluorine, iodine), a hydroxyl group, a carboxyl group, an ester group, a sulfinyl group, a sulfonyl group, an alkylthio group, and a phenylthio group. The above substituents may further have a substituent if possible; for example, it is also preferred that the above alkyl group has a halogen atom as a substituent to form a halogenated alkyl group such as a trifluoromethyl group.

[0115] Next, the cation (ZaI-2) will be described. The cation (ZaI-2) is a cation represented by the formula (ZaI) R ２０１ ~R ２０３ are each independently a cation representing an organic group that does not have an aromatic ring. Here, the aromatic ring also includes an aromatic ring containing a heteroatom. ２０１ ~R ２０３ The organic group having no aromatic ring as R generally has 1 to 30 carbon atoms, preferably 1 to 20 carbon atoms. ２０１ ~R ２０３ are each independently preferably an alkyl group, a cycloalkyl group, an allyl group, or a vinyl group, more preferably a linear or branched 2-oxoalkyl group, a 2-oxocycloalkyl group, or an alkoxycarbonylmethyl group, and still more preferably a linear or branched 2-oxoalkyl group.

[0116] R ２０１ ~R ２０３ Examples of the alkyl and cycloalkyl groups include linear alkyl groups having 1 to 10 carbon atoms or branched alkyl groups having 3 to 10 carbon atoms (e.g., methyl, ethyl, propyl, butyl, and pentyl groups), and cycloalkyl groups having 3 to 10 carbon atoms (e.g., cyclopentyl, cyclohexyl, and norbornyl groups). ２０１ ~R ２０３may be further substituted with a halogen atom, an alkoxy group (eg, having 1 to 5 carbon atoms), a hydroxyl group, a cyano group, or a nitro group.

[0117] Next, the cation (ZaI-3b) will be described. The cation (ZaI-3b) is a cation represented by the following formula (ZaI-3b).

[0118]

[0119] In formula (ZaI-3b), R １ｃ ~R ５ｃ R each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an alkoxy group, an aryloxy group, an alkoxycarbonyl group, an alkylcarbonyloxy group, a cycloalkylcarbonyloxy group, a halogen atom, a hydroxyl group, a nitro group, an alkylthio group, or an arylthio group. ６ｃ and R ７ｃ R each independently represents a hydrogen atom, an alkyl group (such as a t-butyl group), a cycloalkyl group, a halogen atom, a cyano group, or an aryl group. ｘ and R ｙ each independently represents an alkyl group, a cycloalkyl group, a 2-oxoalkyl group, a 2-oxocycloalkyl group, an alkoxycarbonylalkyl group, an allyl group, or a vinyl group.

[0120] R １ｃ ~R ５ｃ Two or more of the following, R ５ｃ and R ６ｃ , R ６ｃ and R ７ｃ , R ５ｃ and R ｘ , and R ｘ and R ｙ may be bonded to each other to form a ring, and each of these rings may independently contain an oxygen atom, a sulfur atom, a ketone group, an ester bond, or an amide bond. Examples of the ring 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 the ring include 3- to 10-membered rings, preferably 4- to 8-membered rings, and more preferably 5- or 6-membered rings.

[0121] R １ｃ ~R ５ｃ Two or more of the following, R ６ｃ and R ７ｃ , and R ｘ and R ｙ Examples of the group formed by bonding of R include alkylene groups such as butylene and pentylene. A methylene group in this alkylene group may be substituted with a heteroatom such as an oxygen atom. ５ｃ and R ６ｃ , and R ５ｃ and R ｘ The group formed by bonding is preferably a single bond or an alkylene group. Examples of the alkylene group include a methylene group and an ethylene group.

[0122] R １ｃ ~R ５ｃ , R ６ｃ , R ７ｃ , R ｘ , R ｙ , and R １ｃ ~R ５ｃ Two or more of the following, R ５ｃ and R ６ｃ , R ６ｃ and R ７ｃ , R ５ｃ and R ｘ , and R ｘ and R ｙ The ring formed by bonding together may have a substituent.

[0123] Next, the cation (ZaI-4b) will be described. The cation (ZaI-4b) is a cation represented by the following formula (ZaI-4b).

[0124]

[0125] In formula (ZaI-4b), l represents an integer of 0 to 2. r represents an integer of 0 to 8. １３represents a hydrogen atom, a halogen atom (e.g., a fluorine atom, an iodine atom, etc.), a hydroxyl group, an alkyl group, a halogenated alkyl group, an alkoxy group, a carboxyl group, an alkoxycarbonyl group, or a group having a cycloalkyl group (which may be a cycloalkyl group itself or a group containing a cycloalkyl group as a part). These groups may have a substituent. R １４ represents a hydroxyl group, a halogen atom (e.g., a fluorine atom, an iodine atom, etc.), an alkyl group, a halogenated alkyl 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 a cycloalkyl group itself or a group containing a cycloalkyl group as a part). These groups may have a substituent. R １４ When a plurality of R are present, each independently represents the above group such as a hydroxyl group. １５ each independently represents an alkyl group, a cycloalkyl group, or a naphthyl group. １５ may be bonded to each other to form a ring. １５ When two R are bonded to each other to form a ring, the ring skeleton may contain a heteroatom such as an oxygen atom or a nitrogen atom. １５ are preferably alkylene groups and bonded to each other to form a ring structure. １５ The ring formed by bonding together may have a substituent.

[0126] In formula (ZaI-4b), R １３ , R １４ , and R １５ The alkyl group is preferably linear or branched, and the number of carbon atoms in the alkyl group is preferably 1 to 10. The alkyl group is more preferably a methyl group, an ethyl group, an n-butyl group, a t-butyl group, or the like.

[0127] Next, formula (ZaII) will be described. In formula (ZaII), R ２０４ and R ２０５ R each independently represents an aryl group, an alkyl group, or a cycloalkyl group.２０４ and R ２０５ The aryl group in R is preferably a phenyl group or a naphthyl group, and more preferably a phenyl group. ２０４ and R ２０５ The aryl group in R may be an aryl group having a heterocycle containing an oxygen atom, a nitrogen atom, a sulfur atom, or the like. Examples of the skeleton of the aryl group having a heterocycle include pyrrole, furan, thiophene, indole, benzofuran, and benzothiophene. ２０４ and R ２０５ The alkyl group and cycloalkyl group are preferably a linear alkyl group having 1 to 10 carbon atoms or a branched alkyl group having 3 to 10 carbon atoms (e.g., methyl, ethyl, propyl, butyl, or pentyl), or a cycloalkyl group having 3 to 10 carbon atoms (e.g., cyclopentyl, cyclohexyl, or norbornyl).

[0128] R ２０４ and R ２０５ The aryl group, alkyl group, and cycloalkyl group in R may each independently have a substituent. ２０４ and R ２０５ Examples of the substituent that the aryl group, alkyl group, and cycloalkyl group may have include an alkyl group (e.g., having 1 to 15 carbon atoms), a cycloalkyl group (e.g., having 3 to 15 carbon atoms), an aryl group (e.g., having 6 to 15 carbon atoms), an alkoxy group (e.g., having 1 to 15 carbon atoms), a halogen atom, a hydroxyl group, and a phenylthio group.

[0129] The ammonium cation is not particularly limited, but examples thereof include N ＋ (R ３０１ ) ４ Examples of the ammonium cation include those represented by the formula: R ３０１ each independently represents an alkyl group (for example, having 1 to 15 carbon atoms). The alkyl group may have a substituent.

[0130] X in the photodecomposable onium salt compound PG1 －The organic anion represented by the formula (I) is preferably a non-nucleophilic anion (an anion with extremely low ability to cause a nucleophilic reaction). Examples of the non-nucleophilic anion include sulfonate anions (aliphatic sulfonate anions, aromatic sulfonate anions, camphorsulfonate anions, etc.), carboxylate anions (aliphatic carboxylate anions, aromatic carboxylate anions, aralkyl carboxylate anions, etc.), sulfonylimide anions, bis(alkylsulfonyl)imide anions, and tris(alkylsulfonyl)methide anions.

[0131] The organic anion is preferably, for example, an organic anion represented by the following formula (DA).

[0132]

[0133] In formula (DA), A ３１ － represents an anionic group. ａ１ represents a hydrogen atom or a monovalent organic group. ａ１ represents a single bond or a divalent linking group.

[0134] A ３１ － represents an anionic group. ３１ － The anionic group represented by the formula (B-1) is not particularly limited, but is preferably a group selected from the group consisting of groups represented by formulas (B-1) to (B-14), and among these, formula (B-1), formula (B-2), formula (B-3), formula (B-4), formula (B-5), formula (B-6), formula (B-10), formula (B-12), formula (B-13), or formula (B-14) is more preferred.

[0135]

[0136] *-O － Formula (B-14)

[0137] In formulas (B-1) to (B-14), * represents a bonding position. Ｘ１ Each independently represents a monovalent organic group. Ｘ２Each of the two R in formula (B-7) independently represents a hydrogen atom or a substituent other than a fluorine atom or a perfluoroalkyl group. Ｘ２ may be the same or different. ＸＦ１ represents a hydrogen atom, a fluorine atom, or a perfluoroalkyl group, provided that two R ＸＦ１ At least one of the two R in formula (B-8) represents a fluorine atom or a perfluoroalkyl group. ＸＦ１ may be the same or different. Ｘ３ represents a hydrogen atom, a halogen atom, or a monovalent organic group. n1 represents an integer of 0 to 4. When n1 represents an integer of 2 to 4, a plurality of R Ｘ３ may be the same or different. ＸＦ２ represents a fluorine atom or a perfluoroalkyl group. The bond to the bonding position represented by * in formula (B-14) is preferably a phenylene group which may have a substituent. Examples of the substituent which the phenylene group may have include a halogen atom.

[0138] In formulas (B-1) to (B-5) and (B-12), R Ｘ１ R each independently represents a monovalent organic group. Ｘ１ As the R, an alkyl group (which may be linear or branched, and preferably has 1 to 15 carbon atoms), a cycloalkyl group (which may be monocyclic or polycyclic, and preferably has 3 to 20 carbon atoms), or an aryl group (which may be monocyclic or polycyclic, and preferably has 6 to 20 carbon atoms) is preferred. Ｘ１ The above group represented by the formula (B-5) may have a substituent. Ｘ１ Inside, N － The atoms directly bonded to are the carbon atoms in —CO— and —SO ２ It is also preferred that neither of the sulfur atoms in - is present.

[0139] R Ｘ１ The cycloalkyl group in R may be monocyclic or polycyclic. Ｘ１ Examples of the cycloalkyl group in the formula include a norbornyl group and an adamantyl group.

[0140] R Ｘ１ The substituent that the cycloalkyl group in R may have is not particularly limited, but is preferably an alkyl group (which may be linear or branched, and preferably has 1 to 5 carbon atoms). Ｘ１ One or more of the carbon atoms which are ring members of the cycloalkyl group in the formula (I) may be replaced by a carbonyl carbon atom.

[0141] R Ｘ１ The alkyl group in R preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms. Ｘ１ The substituent that the alkyl group in R may have is not particularly limited, but is preferably, for example, a cycloalkyl group, a fluorine atom, or a cyano group. Examples of the cycloalkyl group as the substituent include R Ｘ１ The same cycloalkyl groups as those described above when R is a cycloalkyl group are exemplified. Ｘ１ When the alkyl group in R has a fluorine atom as the substituent, the alkyl group may be a perfluoroalkyl group. Ｘ１ The alkyl group in ２ - may be substituted with a carbonyl group.

[0142] R Ｘ１ The aryl group in R is preferably a benzene ring group. Ｘ１ The substituent that the aryl group in R may have is not particularly limited, but is preferably an alkyl group, a fluorine atom, or a cyano group. Ｘ１ The alkyl groups described above when is an alkyl group are also included.

[0143] In formulas (B-7) and (B-11), R Ｘ２ each independently represents a hydrogen atom or a substituent other than a fluorine atom or a perfluoroalkyl group (for example, an alkyl group not containing a fluorine atom and a cycloalkyl group not containing a fluorine atom). Ｘ２ may be the same or different.

[0144] In formula (B-8), R ＸＦ１ represents a hydrogen atom, a fluorine atom, or a perfluoroalkyl group. ＸＦ１ At least one of the two R in formula (B-8) represents a fluorine atom or a perfluoroalkyl group. ＸＦ１ may be the same or different. ＸＦ１ The perfluoroalkyl group represented by the formula (I) preferably has 1 to 15 carbon atoms, more preferably 1 to 10 carbon atoms, and even more preferably 1 to 6 carbon atoms.

[0145] In formula (B-9), R Ｘ３ represents a hydrogen atom, a halogen atom, or a monovalent organic group. Ｘ３ Examples of the halogen atom as R include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and among these, a fluorine atom is preferred. Ｘ３ The monovalent organic group as R Ｘ１ n1 represents an integer of 0 to 4. n1 is preferably an integer of 0 to 2, and more preferably 0 or 1. When n1 represents an integer of 2 to 4, a plurality of R Ｘ３ may be the same or different.

[0146] In formula (B-10), R ＸＦ２ represents a fluorine atom or a perfluoroalkyl group. ＸＦ２ The perfluoroalkyl group represented by the formula (I) preferably has 1 to 15 carbon atoms, more preferably 1 to 10 carbon atoms, and even more preferably 1 to 6 carbon atoms.

[0147] In formula (DA), R ａ１ The monovalent organic group R is not particularly limited, but generally has 1 to 30 carbon atoms, preferably 1 to 20 carbon atoms. ａ１ is preferably an alkyl group, a cycloalkyl group, or an aryl group.

[0148] The alkyl group may be linear or branched, and is preferably an alkyl group having 1 to 20 carbon atoms, more preferably an alkyl group having 1 to 15 carbon atoms, and even more preferably an alkyl group having 1 to 10 carbon atoms. The cycloalkyl group may be monocyclic or polycyclic, and is preferably a cycloalkyl group having 3 to 20 carbon atoms, more preferably a cycloalkyl group having 3 to 15 carbon atoms, and even more preferably a cycloalkyl group having 3 to 10 carbon atoms. The aryl group may be monocyclic or polycyclic, and is preferably an aryl group having 6 to 20 carbon atoms, more preferably an aryl group having 6 to 15 carbon atoms, and even more preferably an aryl group having 6 to 10 carbon atoms.

[0149] The cycloalkyl group may contain a heteroatom as a ring member atom. Examples of the heteroatom include, but are not limited to, a nitrogen atom, an oxygen atom, etc. The cycloalkyl group may also contain a carbonyl bond (>C=O) as a ring member atom. The alkyl group, cycloalkyl group, and aryl group may further have a substituent. In addition, A ３１ － and R ａ１ may be bonded to each other to form a ring.

[0150] L ａ１The divalent linking group represented by is not particularly limited, but represents an alkylene group, a cycloalkylene group, an aromatic group, -O-, -CO-, -COO-, or a group formed by combining two or more of these. The alkylene group may be linear or branched and preferably has 1 to 20 carbon atoms, more preferably 1 to 10 carbon atoms. The cycloalkylene group may be monocyclic or polycyclic and preferably has 3 to 20 carbon atoms, more preferably 3 to 10 carbon atoms. The aromatic group is a divalent aromatic group, preferably an aromatic group having 6 to 20 carbon atoms, more preferably an aromatic group having 6 to 15 carbon atoms. The aromatic ring constituting the aromatic group is not particularly limited, but examples include aromatic rings having 6 to 20 carbon atoms, specifically, a benzene ring, a naphthalene ring, an anthracene ring, and a thiophene ring. The aromatic ring constituting the aromatic group is preferably a benzene ring or a naphthalene ring, more preferably a benzene ring. The alkylene group, cycloalkylene group, and aromatic group may further have a substituent, and the substituent is preferably a halogen atom. ａ１ Preferably, represents a single bond.

[0151] A preferred embodiment of the photodecomposable onium salt compound PG1 is a compound having a borate anion. The compound having a borate anion may be a low molecular weight compound or a high molecular weight compound, but is preferably a low molecular weight compound. The molecular weight of the compound having a borate anion is preferably 1,200 or less, more preferably 1,000 or less, and even more preferably 800 or less. There is no particular lower limit, but 400 or more is preferred. Among these, compounds having a borate anion are more preferably compounds represented by the following formula (3):

[0152] <Compound represented by the following formula (3)>

[0153]

[0154] In formula (3), R ４ ~R ７ R each independently represents a substituent. ４ ~R ７The substituent represented by R is not particularly limited, and examples thereof include the groups exemplified as the substituent T above. ４ ~R ７ Examples of the substituent represented by the formula (I) include an aryl group, a heteroaryl group, a halogen atom (preferably a fluorine atom), and a cyano group. The aryl group and the heteroaryl group may be either monocyclic or polycyclic. The number of carbon atoms in the aryl group is, for example, preferably 6 to 20, and more preferably 6 to 10. Specific examples of the aryl group include a phenyl group or a naphthyl group, and more preferably a phenyl group. The type of heteroatom contained in the heteroaryl group is not particularly limited, and examples include an oxygen atom, a nitrogen atom, and a sulfur atom. The number of carbon atoms in the heteroaryl group is, for example, preferably 3 to 15, and more preferably 3 to 10. Specific examples of the ring constituting the heteroaryl group include a pyrrole ring, a furan ring, a thiophene ring, a pyridine ring, an imidazolyl ring, an indole ring, a benzofuran ring, a benzothiazole ring, and a benzothiophene ring.

[0155] The substituent that the aryl group and the heteroaryl group may have is not particularly limited, and examples thereof include the groups exemplified above as the substituent T. Examples of the substituent include an alkyl group (for example, a linear alkyl group having 1 to 15 carbon atoms, a branched alkyl group having 3 to 15 carbon atoms, etc.), a cycloalkyl group (a cycloalkyl group having 3 to 15 carbon atoms), an aryl group (which may be either a monocyclic or polycyclic group, preferably having 6 to 20 carbon atoms, more preferably having 6 to 10 carbon atoms), a heteroaryl group (which may be either a monocyclic or polycyclic group, preferably having 3 to 15 carbon atoms, more preferably having 3 to 10 carbon atoms), an alkoxy group (for example, a linear alkoxy group having 1 to 15 carbon atoms, Examples of the alkyl group include a branched alkoxy group having 1 to 15 carbon atoms, a cycloalkyloxy group (having 3 to 15 carbon atoms), a halogen atom (for example, a fluorine atom, a chlorine atom, an iodine atom, etc.), a hydroxyl group, a cyano group, a nitro group, and an amino group (specifically, an amino group, a monoalkylamino group, and a dialkylamino group. Examples of the alkyl group moiety in a monoalkylamino group and a dialkylamino group include a linear alkyl group having 1 to 15 carbon atoms, and a branched alkyl group having 3 to 15 carbon atoms). The above substituents may further have another substituent; for example, the alkyl group may have a halogen atom as a substituent to form a halogenated alkyl group such as a trifluoromethyl group.

[0156] In addition, R ４ ~R ７ Among these, adjacent ones may be bonded to each other to form a ring. The ring formed by bonding adjacent ones to each other is not particularly limited and may be either a monocycle or a polycycle. The ring may contain heteroatoms such as oxygen atoms, nitrogen atoms, and sulfur atoms, and / or carbonyl carbon as ring member atoms. In addition, the ring may be either an aromatic ring or an alicyclic ring.

[0157] R ４ ~R ７ The substituents represented by R may all be the same or different. ４ ~R ７ When the substituents represented by R ４ ~R６ The substituents represented by R ７ is a substituent represented by R ４ ~R ６ or an embodiment in which the substituent is different from the substituent represented by R ４ ~R ５ The substituents represented by R ６ ~R ７ is a substituent represented by R ４ ~R ５ It is also preferable that the substituent is different from the substituent represented by the following formula:

[0158] Also, R ４ ~R ７ When the substituents represented by R ４ ~R ６ and R ７ is a substituent represented by R ４ ~R ６ and is a heteroaryl group (preferably a heteroaryl group containing a nitrogen atom) which may have a substituent, and which is different from the substituent represented by R ４ ~R ６ and R ７ is a substituent represented by R ４ ~R ６ and is an aryl group having an unsubstituted or substituted amino group as a substituent.

[0159] Also, R ４ ~R ７ When the substituents represented by R ４ ~R ５ and R ６ ~R ７ is a substituent represented by R ４ ~R ５and is a heteroaryl group which may have a substituent (preferably a heteroaryl group containing a nitrogen atom which may have a substituent).

[0160] Y ｍ＋ represents an organic cation having a positive charge with a valence of m. m represents an integer of 1 or more. m is not particularly limited as long as it is an integer of 1 or more, and is, for example, preferably 1 to 3, more preferably 1 or 2, and even more preferably 1. Y ｍ＋ The organic cation represented by the formula (ZaI) is not particularly limited, but examples thereof include an organic cation represented by the formula (ZaI) (cation (ZaI)), an organic cation represented by the formula (ZaII) (cation (ZaII)), or an ammonium cation. ｍ＋ The organic cation represented by the formula (I) preferably has m monovalent organic cations.

[0161] As the photodecomposable onium salt compound PG1, it is also preferable to use, for example, the photoacid generators disclosed in paragraphs

[0135] to

[0171] of WO 2018 / 193954, paragraphs

[0077] to

[0116] of WO 2020 / 066824, and paragraphs

[0018] to

[0075] and

[0334] to

[0335] of WO 2017 / 154345.

[0162] The molecular weight of the photodegradable onium salt compound PG1 is preferably 3,000 or less, more preferably 2,000 or less, and even more preferably 1,000 or less.

[0163] (Photodecomposable onium salt compound PG2) Another example of a suitable embodiment of the photodecomposable onium salt compound includes the following compound (I) and compound (II) (hereinafter, "compound (I) and compound (II)" will also be referred to as "photodecomposable onium salt compound PG2"). The photodecomposable onium salt compound PG2 has two or more of the above-mentioned salt structural moieties and generates a polyvalent organic acid upon exposure to light. The photodecomposable onium salt compound PG2 will be described below.

[0164] <<Compound (I)>> Compound (I) is a compound having one or more structural moieties X and one or more structural moieties Y, which generates an acid containing a first acidic moiety derived from the structural moiety X and a second acidic moiety derived from the structural moiety Y when irradiated with actinic rays or radiation: Structural moiety X: Anionic moiety A １ － and the cationic moiety M １ ＋ and HA is produced by irradiation with actinic rays or radiation. １ Structural moiety Y: anionic moiety A, which forms a first acidic moiety represented by the formula: ２ － and the cationic moiety M ２ ＋ and HA is produced by irradiation with actinic rays or radiation. ２ A structural moiety forming a second acidic moiety represented by the following formula (I):

[0165] Condition I: In the compound (I), the cationic moiety M in the structural moiety X １ ＋ and the cationic moiety M in the structural moiety Y ２ ＋ H ＋ The compound PI in which the cation moiety M in the structural moiety X is replaced by １ ＋ H ＋ HA is replaced by １ and the cationic moiety M in the structural moiety Y. ２ ＋ H ＋ HA is replaced by ２ and the acid dissociation constant a2 is greater than the acid dissociation constant a1. The compound PI corresponds to an acid generated when compound (I) is irradiated with actinic rays or radiation.

[0166] When compound (I) has two or more structural moieties X, the structural moieties X may be the same or different from each other. １ －, and two or more of the above M １ ＋ may be the same or different. １ － and the above A ２ － , and the above M １ ＋ and the above M ２ ＋ may be the same or different, but １ － and the above A ２ － are preferably different from each other.

[0167] Anion site A １ － and anionic moiety A ２ － is a structural moiety containing a negatively charged atom or atomic group, and examples thereof include structural moieties selected from the group consisting of formulas (AA-1) to (AA-3) and formulas (BB-1) to (BB-6) shown below. In the following formulas (AA-1) to (AA-3) and formulas (BB-1) to (BB-6), * represents a bonding position. Ａ represents a monovalent organic group. Ａ Examples of the monovalent organic group represented by the formula (I) include a cyano group, a trifluoromethyl group, and a methanesulfonyl group.

[0168]

[0169] In addition, the cationic moiety M １ ＋ and cationic moiety M ２ ＋ is a structural moiety containing a positively charged atom or atomic group, and examples thereof include monovalent organic cations. The organic cation is not particularly limited, but is preferably an organic cation represented by the above formula (ZaI) (cation (ZaI)) or an organic cation represented by the above formula (ZaII) (cation (ZaII)).

[0170] <<Compound (II)>> Compound (II) is a compound having two or more of the structural moieties X described above and one or more of the structural moieties Z described below, and is a compound that generates an acid containing two or more of the first acidic moieties derived from the structural moiety X and the structural moiety Z upon irradiation with actinic rays or radiation. Structural moiety Z: a ​​nonionic moiety capable of neutralizing an acid

[0171] The compound (II) can be converted into the cation moiety M in the structural moiety X by irradiation with actinic rays or radiation. １ ＋ H ＋ HA is replaced by １ In other words, the compound PII can generate a compound PII (acid) having an acidic site represented by the above HA. １ and a structural moiety Z, which is a nonionic moiety capable of neutralizing the acid. In compound (II), the definition of the structural moiety X and A １ － and M １ ＋ The definition of the structural moiety X in the compound (I) and the definition of A １ － and M １ ＋ The definition and preferred embodiments are the same as those of the above. In addition, the two or more structural moieties X may be the same or different. In addition, the two or more structural moieties A １ － , and two or more of the above M １ ＋ may be the same or different.

[0172] The nonionic moiety capable of neutralizing an acid in the structural moiety Z is not particularly limited, and is preferably, for example, a moiety containing a functional group having an electron or a group capable of electrostatically interacting with a proton. Examples of the functional group having an electron or a group capable of electrostatically interacting with a proton include functional groups having a macrocyclic structure such as cyclic polyethers, and functional groups having a nitrogen atom with an unshared electron pair that does not contribute to π-conjugation. The nitrogen atom with an unshared electron pair that does not contribute to π-conjugation is, for example, a nitrogen atom having a partial structure shown in the following formula:

[0173]

[0174] Examples of the partial structure of the functional group having a group or electron capable of electrostatically interacting with a proton include a crown ether structure, an azacrown ether structure, a primary amine structure, a secondary amine structure, a tertiary amine structure, a pyridine structure, an imidazole structure, and a pyrazine structure. Of these, a primary amine structure, a secondary amine structure, a tertiary amine structure, and a tertiary amine structure are preferred.

[0175] The molecular weight of the photodegradable onium salt compound PG2 is preferably 100 to 10,000, more preferably 100 to 2,500, and even more preferably 100 to 1,500.

[0176] Examples of the photodecomposable onium salt compound PG2 include the compounds exemplified in paragraphs

[0023] to

[0095] of WO 2020 / 158313.

[0177] Examples of moieties other than cations that the photodecomposable onium salt compound PG2 may have are shown below.

[0178]

[0179]

[0180] In the photosensitive resin composition of the present invention, the content of the ionic compound is not particularly limited, but is preferably 0.1 to 20% by mass relative to the total solid content of the photosensitive resin composition. The lower limit of the content is more preferably 0.5% by mass or more, even more preferably 1.0% by mass or more, and particularly preferably 2.0% by mass or more. The upper limit of the content is more preferably 10.0% by mass or less, even more preferably 5.0% by mass or less. The ionic compound may be used alone, or two or more types may be used. When two or more types are used, the total content is preferably within the above-mentioned preferred content range.

[0181] [Surfactant] The photosensitive resin composition of the present invention may contain a surfactant. When a surfactant is contained, a pattern with better adhesion and fewer development defects can be formed. The surfactant is preferably a fluorine-based and / or silicon-based surfactant. Examples of the fluorine-based and / or silicon-based surfactant include the surfactants disclosed in paragraphs

[0218] and

[0219] of WO 2018 / 193954.

[0182] These surfactants may be used alone or in combination of two or more.

[0183] When the photosensitive resin composition of the present invention contains a surfactant, the content of the surfactant is preferably from 0.0001 to 2 mass %, more preferably from 0.0005 to 1 mass %, based on the total solid content of the composition.

[0184] [Resist Film and Pattern Forming Method] The present invention also relates to a resist film formed using the photosensitive resin composition. The present invention also relates to a pattern forming method including the steps of forming a resist film on a substrate using the photosensitive resin composition, exposing the resist film to light, and developing the exposed resist film using a developer.

[0185] The procedure of the pattern formation method using the photosensitive resin composition is not particularly limited, but preferably includes the following steps: Step 1: forming a resist film on a substrate using the photosensitive resin composition, Step 2: exposing the resist film to light, and Step 3: developing the exposed resist film using a developer. The procedure of each of the above steps will be described in detail below.

[0186] <Step 1: Resist Film Forming Step> Step 1 is a step of forming a resist film on a substrate using a photosensitive resin composition.

[0187] A method for forming a resist film on a substrate using a photosensitive resin composition includes, for example, applying the photosensitive resin composition to a substrate. It is preferable to filter the photosensitive resin composition as needed before application. The pore size of the filter is preferably 0.1 μm or less, more preferably 0.05 μm or less, and even more preferably 0.03 μm or less. The filter is preferably made of polytetrafluoroethylene, polyethylene, or nylon.

[0188] The photosensitive resin composition can be applied onto a substrate (e.g., silicon, silicon coated with silicon dioxide) such as those used in the manufacture of integrated circuit elements by an appropriate application method such as a spinner or coater. Spin application using a spinner is preferred. The rotation speed when spin application using a spinner is preferably 1000 to 3000 rpm. After application of the photosensitive resin composition, the substrate may be dried to form a resist film. If necessary, various undercoating films (inorganic film, organic film, anti-reflective film) may be formed below the resist film.

[0189] An example of a drying method is a method of drying by heating. Heating can be performed by means provided in a normal exposure machine and / or developing machine, and may also be performed using a hot plate or the like. The heating temperature is preferably 80 to 150°C, more preferably 80 to 140°C, and even more preferably 80 to 130°C. The heating time is preferably 30 to 1,000 seconds, more preferably 60 to 800 seconds, and even more preferably 60 to 600 seconds.

[0190] The thickness of the resist film is not particularly limited, but is preferably 10 to 120 nm from the viewpoint of forming a finer pattern with higher precision. In particular, when EUV exposure and EB exposure are used, the thickness of the resist film is more preferably 10 to 65 nm, and even more preferably 15 to 50 nm. Furthermore, when ArF immersion exposure is used, the thickness of the resist film is more preferably 10 to 120 nm, and even more preferably 15 to 90 nm.

[0191] A top coat may be formed on the resist film using a top coat composition. It is preferable that the top coat composition does not mix with the resist film and can be uniformly applied to the resist film. The top coat is not particularly limited, and a conventionally known top coat can be formed by a conventionally known method. For example, a top coat can be formed based on the description in paragraphs

[0072] to

[0082] of JP 2014-059543 A. For example, a top coat containing a basic compound such as that described in JP 2013-061648 A is preferably formed on the resist film. Specific examples of basic compounds that may be contained in the top coat include basic compounds that may be contained in the photosensitive resin composition. It is also preferable that the top coat contain a compound containing at least one group or bond selected from the group consisting of an ether bond, a thioether bond, a hydroxyl group, a thiol group, a carbonyl bond, and an ester bond.

[0192] <Step 2: Exposure Step> Step 2 is a step of exposing the resist film. Examples of exposure methods include irradiating the formed resist film with actinic rays or radiation through a predetermined mask. Examples of actinic rays or radiation include infrared light, visible light, ultraviolet light, far ultraviolet light, extreme ultraviolet light, X-rays, and electron beams, and preferably far ultraviolet light with a wavelength of 250 nm or less, more preferably 220 nm or less, and particularly preferably 1 to 200 nm, specifically KrF excimer laser (248 nm), ArF excimer laser (193 nm), F ２ These include excimer laser (157 nm), EUV (13 nm), X-ray, and electron beam.

[0193] After exposure, it is preferable to perform post-exposure heat treatment (also referred to as post-exposure baking) before development. Post-exposure heat treatment promotes the reaction of the exposed area, resulting in better sensitivity and pattern shape. The heating temperature is preferably 80 to 150°C, more preferably 80 to 140°C, and even more preferably 80 to 130°C. The heating time is preferably 10 to 1,000 seconds, more preferably 10 to 180 seconds, and even more preferably 30 to 120 seconds. Heating can be performed using means provided in a typical exposure machine and / or development machine, and may also be performed using a hot plate or the like.

[0194] <Step 3: Development Step> Step 3 is a step of developing the exposed resist film using a developer to form a pattern. The developer is preferably a developer containing an organic solvent (hereinafter also referred to as an organic developer).

[0195] Examples of development methods include a method in which a substrate is immersed in a tank filled with a developer for a certain period of time (dip method), a method in which a developer is piled up on the surface of a substrate by surface tension and then left stationary for a certain period of time for development (puddle method), a method in which a developer is sprayed onto the surface of the substrate (spray method), and a method in which a developer is continuously dispensed onto a substrate rotating at a constant speed while a developer dispense nozzle is scanned at a constant speed (dynamic dispense method). After the development step, a step of stopping development while replacing the solvent with another solvent may be carried out. The development time is not particularly limited as long as it is long enough to sufficiently dissolve the resin in the unexposed areas, and is preferably 10 to 300 seconds, more preferably 20 to 120 seconds. The temperature of the developer is preferably 0 to 50°C, more preferably 15 to 35°C.

[0196] The organic developer is preferably a developer containing at least one organic solvent selected from the group consisting of ketone-based solvents, ester-based solvents, alcohol-based solvents, amide-based solvents, ether-based solvents, and hydrocarbon-based solvents.

[0197] The above-mentioned solvents may be mixed in plural, or may be mixed with a solvent other than the above or water. The water content of the developer as a whole is preferably less than 50% by mass, more preferably less than 20% by mass, even more preferably less than 10% by mass, and particularly preferably substantially free of water. The content of the organic solvent in the organic developer is preferably 50% by mass or more and 100% by mass or less, more preferably 80% by mass or more and 100% by mass or less, even more preferably 90% by mass or more and 100% by mass or less, and particularly preferably 95% by mass or more and 100% by mass or less, based on the total amount of the developer.

[0198] <Other Steps> The pattern formation method preferably includes, after step 3, a step of cleaning with a rinse liquid.

[0199] The rinse liquid used in the rinse step after the development step using an organic developer is not particularly limited as long as it does not dissolve the pattern, and a solution containing a general organic solvent can be used. The rinse liquid is preferably a rinse liquid 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.

[0200] The method for the rinsing step is not particularly limited, and examples include a method in which a rinsing solution is continuously discharged onto a substrate rotating at a constant speed (spin coating method), a method in which a substrate is immersed in a tank filled with the rinsing solution for a certain period of time (dipping method), and a method in which the rinsing solution is sprayed onto the surface of the substrate (spray method). The pattern formation method of the present invention may also include a heating step (post-bake) after the rinsing step. This step removes the developer and rinsing solution remaining between and within the pattern by baking. This step also has the effect of annealing the resist pattern and improving the surface roughness of the pattern. The heating step after the rinsing step is typically performed at 40 to 250°C (preferably 90 to 200°C) for typically 10 seconds to 3 minutes (preferably 30 to 120 seconds).

[0201] Alternatively, the substrate may be etched using the formed pattern as a mask. That is, the substrate (or the underlayer film and the substrate) may be processed using the pattern formed in step 3 as a mask to form a pattern on the substrate. The method for processing the substrate (or the underlayer film and the substrate) is not particularly limited, but a method of forming a pattern on the substrate by dry etching the substrate (or the underlayer film and the substrate) using the pattern formed in step 3 as a mask is preferred. The dry etching is preferably oxygen plasma etching.

[0202] A conductive compound may be added to an organic processing liquid such as a rinse solution to prevent breakdown of the chemical solution piping and various parts (filters, O-rings, tubes, etc.) due to static charging and subsequent electrostatic discharge. The conductive compound is not particularly limited, but examples include methanol. The amount added is not particularly limited, but in order to maintain favorable development or rinsing characteristics, it is preferably 10% by mass or less, and more preferably 5% by mass or less. For the chemical solution piping, for example, stainless steel (SUS), or various piping coated with antistatically treated polyethylene, polypropylene, or fluororesin (such as polytetrafluoroethylene or perfluoroalkoxy resin), can be used. Similarly, for the filters and O-rings, polyethylene, polypropylene, or fluororesin (such as polytetrafluoroethylene or perfluoroalkoxy resin) that have been antistatically treated can be used.

[0203] [Method for Manufacturing Electronic Device] The present invention also relates to a method for manufacturing an electronic device, including the above-mentioned pattern formation method, and an electronic device manufactured by this manufacturing method. The electronic device of the present invention is suitable for installation in electrical and electronic equipment (such as home appliances, office automation (OA), media-related equipment, optical equipment, and communication equipment).

[0204] The present invention will be described in more detail below with reference to examples. The materials, amounts used, ratios, treatment contents, treatment procedures, etc. shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the examples shown below.

[0205] [Various Components of Photosensitive Resin Composition] [Resins] The resins (E-1, E-1A, E-3, E-3A, E-4 to E-17) shown in Tables 2 to 4 are shown below. E-1 was synthesized by the synthesis method (Synthesis Example 1) described below. E-1A, E-3, E-3A, E-4 to E-17 were synthesized according to Synthesis Example 1 or by known methods. Table 1 shows the compositions of resins E-1, E-1A, E-3, E-3A, E-4 to E-17 (type of repeating unit, composition ratio of repeating units (mol % ratio, listed from left to right), weight average molecular weight (Mw), and dispersity (Mw / Mn)). The weight average molecular weight (Mw) and dispersity (Mw / Mn) of Resins E-1, E-1A, E-3, E-3A, and E-4 to E-17 were measured by GPC (carrier: tetrahydrofuran (THF)) (in terms of polystyrene). The composition ratios (mol %) of the resins were as follows: １３ Measurement was performed by C-NMR (Nuclear Magnetic Resonance).

[0206]

[0207]

[0208]

[0209]

[0210] In Table 1, "k" represents "×1000."

[0211] Synthesis Example 1: Synthesis of Resin E-1 A monomer composition containing 3.000 g of methyl α-chloroacrylate as a monomer, 6.510 g of α-methylstyrene as a monomer, and 0.009183 g of azobisisobutyronitrile as a polymerization initiator was placed in a glass container, the glass container was sealed and purged with nitrogen, and a polymerization reaction was carried out by stirring for 8 hours in a constant temperature bath at 78°C under a nitrogen atmosphere. The temperature was then returned to room temperature, and the glass container was opened to the atmosphere. 10 g of THF (tetrahydrofuran) was then added to the resulting solution. The solution to which THF had been added was then added dropwise to 300 g of MeOH (methanol) to precipitate a polymer. The precipitated polymer was then recovered by filtration. The resulting polymer was Resin E-1 containing 50 mol% each of repeating units derived from methyl α-chloroacrylate and repeating units derived from α-methylstyrene.

[0212] [Ionic Compounds] The structures of the ionic compounds (B-1 to B-2) shown in Tables 2 to 4 are shown below. Note that the onium salt compounds (B-1 to B-2) all fall under the category of photodecomposable onium salt compounds.

[0213]

[0214] [Solvents] The solvents shown in Tables 2 to 4 are as follows: G-1: Anisole G-2: Toluene G-3: Propylene glycol monomethyl ether acetate (PGMEA) G-4: γ-butyrolactone G-5: Cyclohexanone G-6: Isoamyl acetate

[0215] [Preparation of Resist Compositions] The components other than the solvent shown in Tables 2 to 4 were mixed to a solids concentration of 1.3% by mass. The resulting mixture was then filtered through a polyethylene filter with a pore size of 0.03 μm to prepare resist compositions (A-1a to A-7, A-9 to A-25, A-1R, A-9R to A-25R). Here, "solids" refers to all components other than the solvent. The resulting resist compositions were used in the Examples and Comparative Examples. The resin and ionic compound contents (% by mass) in Tables 2 to 4 indicate the content relative to the total solids content of the composition.

[0216] Pure water was used as the water, and the water content (water content) is based on the total mass of the resist composition.

[0217] The total content of at least one metal element selected from the group consisting of Li, Na, Mg, Al, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Ag, Cd, Sn, Ba, W, Au, and Pb relative to the total mass of the resist composition is also shown as "Amount of Metal Element" in Tables 2 to 4. The total content (mass ppb) of the above metal elements was measured using an inductively coupled plasma mass spectrometer (ICP-MS 8900, manufactured by Agilent Technologies).

[0218] [Pattern Formation and Evaluation] An underlayer film-forming composition AL412 (manufactured by Brewer Science) was applied to a silicon wafer and baked at 205°C for 60 seconds to form an underlayer film with a thickness of 20 nm. A composition (resist composition) shown in Tables 2 to 4 was applied to the underlayer film and baked at 100°C for 60 seconds to form a resist film with a thickness of 30 nm. Using an EUV exposure device (manufactured by Exitech, Micro Exposure Tool, NA 0.3, Quadrupol, outer sigma 0.68, inner sigma 0.36), the silicon wafer having the resulting resist film was subjected to pattern irradiation. A mask with a line size of 20 nm and a line:space ratio of 1:1 was used as the reticle. The exposed resist film was baked at 100°C for 60 seconds, and then developed by puddling with a developer shown in Tables 2 to 4 for 30 seconds. The wafer was then rotated at 4000 rpm for 30 seconds to obtain a line and space pattern (line:space=1:1) with a pitch of 40 nm.

[0219] <Sensitivity> The cross-sectional shape of the obtained pattern was observed using a scanning electron microscope (S-9380II manufactured by Hitachi, Ltd.). The optimum exposure dose when resolving a 1:1 line and space resist pattern with a line width of 20 nm was determined as the sensitivity (Eopt) (mJ / cm ２ )

[0220] <LWR (Line Width Roughness) Performance> A 20 nm (1:1) line and space pattern resolved at an exposure dose showing the above sensitivity (Eopt) was observed from above using a critical dimension scanning electron microscope (SEM (S-9380II manufactured by Hitachi, Ltd.)). The line width of the pattern was observed at 100 random points, and the standard deviation (σ) was determined, and the measurement variation in line width was evaluated using 3σ (nm). A smaller value indicates better performance.

[0221]

[0222]

[0223]

[0224] The developers in Tables 2 to 4 are described below: F-1: Isopropyl alcohol F-2: Isoamyl acetate F-3: Hexyl acetate F-4: Butyl acetate:n-undecane=90:10 (mass ratio)

[0225] From the results shown in Tables 2 to 4, it is clear that the photosensitive resin compositions according to the examples can improve sensitivity and LWR performance in the formation of ultrafine patterns (for example, line and space patterns with line widths of 20 nm or less, hole patterns with hole diameters of 20 nm or less, etc.).

[0226] According to the present invention, a photosensitive resin composition can be provided that can form a pattern that can improve sensitivity and LWR performance in the formation of an ultrafine pattern (for example, a line-and-space pattern with a line width of 20 nm or less, a hole pattern with a hole diameter of 20 nm or less, etc.) Furthermore, according to the present invention, a resist film, a pattern formation method, and a method for manufacturing an electronic device can be provided that use the photosensitive resin composition.

[0227] Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the present invention. This application is based on a Japanese patent application (Patent Application No. 2023-148830) filed on September 13, 2023, the contents of which are incorporated herein by reference.

Claims

1. A photosensitive resin composition comprising a resin having a repeating unit represented by the following general formula (1) and a repeating unit represented by the following general formula (2), and a solvent, the photosensitive resin composition having a water content of 10 ppm or more based on the total mass of the photosensitive resin composition. In the general formula (1), X represents a halogen atom, a cyano group, an alkylsulfonyl group, an alkoxy group, a nitro group, an acyl group, an alkyl ester group, or a halogenated alkyl group. ０ represents a hydrogen atom or a substituent. １ represents a substituent. ０ and R １ may be bonded to each other to form a ring. In general formula (2), A １ represents an organic group. ２ represents a hydrogen atom or a substituent. １ represents an aromatic ring group. ３ represents a substituent. k represents an integer of 0 to 7. When k represents an integer of 2 to 7, a plurality of R ３ may be the same or different. When k is an integer of 2 to 7, a plurality of R ３ Among the adjacent R ３ They may be bonded to each other to form a ring.

2. The photosensitive resin composition according to claim 1, wherein the water content is from 100 ppm to 1000 ppm.

3. The photosensitive resin composition according to claim 1, wherein the total content of at least one metal element selected from the group consisting of Li, Na, Mg, Al, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Ag, Cd, Sn, Ba, W, Au, and Pb is 2.0 ppb or less based on the total mass of the photosensitive resin composition.

4. The photosensitive resin composition according to claim 1, which contains as the solvent a compound containing at least one structure selected from the group consisting of a phenol ether structure, a ketone structure and an ester structure.

5. The photosensitive resin composition according to claim 1, wherein the resin has a weight average molecular weight of 20,000 or more.

6. A resist film formed from the photosensitive resin composition according to any one of claims 1 to 5.

7. A pattern forming method comprising the steps of: forming a resist film on a substrate using the photosensitive resin composition according to any one of claims 1 to 5; exposing the resist film to light; and developing the exposed resist film using a developer.

8. A method for manufacturing an electronic device, comprising the pattern formation method according to claim 7.