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

Abstract

A first problem to be addressed by the present invention is to provide an actinic-ray-sensitive or radiation-sensitive resin composition having a characteristic property that a space width where bridge defects begin to occur in the formation of an L / S pattern is narrow.　A second problem to be addressed by the present invention is to provide a resist film, a pattern formation method, and an electronic device manufacturing method, in all of which the actinic-ray-sensitive or radiation-sensitive resin composition is involved.　The actinic-ray-sensitive or radiation-sensitive resin composition according to the present invention comprises a resin having a group that is decomposed by the action of an acid to generate a polar group, a photoacid generator, and a boron-containing compound, and satisfies requirement 1.　Requirement 1: The A value obtained by formula (1) is 0.120 or more.

Description

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

[0001] The present invention relates to an actinic ray-sensitive or radiation-sensitive resin composition, a resist film, a pattern forming method, and a method for producing 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 actinic ray-sensitive or radiation-sensitive 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 studied. Under these circumstances, various configurations have been proposed as actinic ray-sensitive or radiation-sensitive resin compositions.

[0003] For example, Patent Document 1 discloses a radiation-sensitive resin composition containing a polymer having predetermined properties and a radiation-sensitive acid generator (photoacid generator) having predetermined properties.

[0004] JP 2016-85382 A

[0005] The present inventors have studied the composition described in Patent Document 1 and found that, when forming a line and space pattern (L / S pattern), bridge defects may occur even when the space width is relatively wide. Recently, there has been a demand for even finer patterns, and there is a demand for preventing bridge defects even when the space width is narrow (in other words, for the space distance required to prevent bridge defects from occurring to be narrow). In other words, it has become clear that there is room for further improvement in terms of narrowing the space width at which bridge defects begin to occur when forming an L / S pattern.

[0006] Therefore, an object of the present invention is to provide an actinic ray-sensitive or radiation-sensitive resin composition that narrows the space width at which bridge defects begin to occur when forming an L / S pattern. Another object of the present invention is to provide a resist film, a pattern formation method, and a method for manufacturing an electronic device, which relate to the actinic ray-sensitive or radiation-sensitive resin composition.

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

[0008] [1] An actinic ray-sensitive or radiation-sensitive resin composition comprising a resin having a group that decomposes under the action of an acid to generate a polar group, a photoacid generator, and a boron-containing compound, the actinic ray-sensitive or radiation-sensitive resin composition satisfying Requirement 1. Requirement 1: The A value calculated by the formula (1) described below is 0.120 or more. [2] The actinic ray-sensitive or radiation-sensitive resin composition according to [1], further comprising an acid diffusion controller. [3] The actinic ray-sensitive or radiation-sensitive resin composition according to [1] or [2], wherein the photoacid generator is an onium salt compound, the boron-containing compound is a salt compound, and the composition satisfies Requirement 4 when the composition contains an acid diffusion controller that is a salt compound, and satisfies Requirement 5 when the composition does not contain an acid diffusion controller that is a salt compound. Requirement 4: The C1 value calculated by the formula (4) described below is 0.115 or more. Requirement 5: The C2 value calculated by the formula (5) described below is 0.115 or more. [4] The actinic ray-sensitive or radiation-sensitive resin composition according to [3], wherein the composition contains an acid diffusion controller, and the acid diffusion controller is not a salt compound. [5] The actinic ray-sensitive or radiation-sensitive resin composition according to [3], wherein the composition contains an acid diffusion controller, and the acid diffusion controller is a salt compound. [6] The actinic ray-sensitive or radiation-sensitive resin composition according to [5], wherein the acid diffusion controller is an onium salt compound. [7] The actinic ray-sensitive or radiation-sensitive resin composition according to any one of [1] to [6], wherein the photoacid generator contains a cation containing a fluorine atom. [8] A resist film formed using the actinic ray-sensitive or radiation-sensitive resin composition according to any one of [1] to [7]. [9] A pattern forming method comprising the steps of forming a resist film on a substrate using the actinic ray-sensitive or radiation-sensitive resin composition according to any one of [1] to [7], exposing the resist film to light, and developing the exposed resist film with a developer to form a pattern.

[10] The pattern forming method according to [9], wherein the developer contains an organic solvent.

[11] The pattern forming method according to

[10] , wherein the developer contains an ester-based solvent having 6 or less carbon atoms and a hydrocarbon-based solvent.

[12] A method for producing an electronic device, comprising the pattern forming method according to [9].

[13] The actinic ray-sensitive or radiation-sensitive resin composition according to claim 1, wherein the photoacid generator is an onium salt compound, the boron-containing compound is a salt compound, and the composition satisfies Requirement 2 when it contains an acid diffusion controller that is an onium salt compound, and satisfies Requirement 3 when it does not contain an acid diffusion controller that is an onium salt compound. Requirement 2: The B1 value calculated by the formula (2) described below is 0.115 or more. Requirement 3: The B2 value calculated by the formula (3) described below is 0.115 or more.

[14] The actinic ray-sensitive or radiation-sensitive resin composition according to [1] or

[13] , wherein the photoacid generator contains a cation containing a fluorine atom.

[15] The actinic ray-sensitive or radiation-sensitive resin composition according to any one of [1],

[13] , or

[14] , further containing an acid diffusion controller.

[16] The actinic ray-sensitive or radiation-sensitive resin composition according to

[15] , wherein the acid diffusion controller is an onium salt compound.

[17] A resist film formed using the actinic ray-sensitive or radiation-sensitive resin composition according to any one of [1] and

[13] to

[16] .

[18] A pattern formation method comprising the steps of: forming a resist film on a substrate using the actinic ray-sensitive or radiation-sensitive resin composition according to any one of [1] and

[13] to

[16] ; exposing the resist film; and developing the exposed resist film using a developer to form a pattern.

[19] The pattern formation method according to

[18] , wherein the developer contains an organic solvent.

[20] The pattern formation method according to

[18] or

[19] , wherein the developer contains an ester-based solvent having 6 or less carbon atoms and a hydrocarbon-based solvent.

[21] A method for producing an electronic device, comprising the pattern formation method according to any one of

[18] to

[20] .

[0009] According to the present invention, there is provided an actinic ray-sensitive or radiation-sensitive resin composition that narrows the space width at which bridge defects begin to occur when forming an L / S pattern. Furthermore, according to the present invention, there are provided a resist film, a pattern formation method, and a method for manufacturing an electronic device, which relate to the actinic ray-sensitive or radiation-sensitive resin composition.

[0010] 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 referred to 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), X-rays, and electron beams (EB). In this specification, "light" refers to actinic rays or radiation. Unless otherwise specified, "exposure" in this specification includes not only exposure using the bright line spectrum of a mercury lamp, far ultraviolet light typified by an excimer laser, extreme ultraviolet light, X-rays, and EUV light, but also drawing using particle beams such as electron beams and ion beams. In this specification, the word "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 above compound may be "X-CO-O-Z" or "X-O-CO-Z".

[0011] 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).

[0012] 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.

[0013] Software package 1: Advanced Chemistry Development (ACD / Labs) Software V8.14 for Solaris (1994-2007 ACD / Labs).

[0014] 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.

[0015] 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.

[0016] In this specification, examples of halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms.

[0017] 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.

[0018] [Actinic ray-sensitive or radiation-sensitive resin composition] The actinic ray-sensitive or radiation-sensitive resin composition of the present invention (hereinafter also referred to as "resist composition") is a resist composition that contains a resin (hereinafter also referred to as "acid-decomposable resin") having a group that decomposes under the action of acid to generate a polar group (hereinafter also referred to as "acid-decomposable group"), a photoacid generator, and a boron-containing compound, and satisfies the following requirement 1. Requirement 1: The value A calculated by formula (1) is 0.12 or more. Formula (1): A=([H Ａ ]×0.04+[C Ａ ]×1.0+[N Ａ ]×2.1+[O Ａ ]×3.6+[F Ａ ]×5.6+[S Ａ ]×1.5+[B Ａ ]×0.5+[I Ａ ]×39.5) / ([H Ａ ]×1+[C Ａ ]×12+[N Ａ ]×14+[O Ａ ]×16+[F Ａ ]×19+[S Ａ ]×32+[B Ａ ]×11+[I Ａ]×127) In formula (1), [H Ａ ] represents the molar ratio of hydrogen atoms derived from the total solid content to all atoms in the total solid content in the composition, and [C Ａ ] represents the molar ratio of carbon atoms originating from the total solid content to all atoms in the total solid content in the composition, and [N Ａ ] represents the molar ratio of nitrogen atoms derived from the total solid content to all atoms in the total solid content in the composition, and [O Ａ ] represents the molar ratio of oxygen atoms derived from the total solid content to all atoms in the total solid content in the composition, and [F Ａ ] represents the molar ratio of fluorine atoms derived from the total solid content to all atoms in the total solid content in the composition, and [S Ａ ] represents the molar ratio of sulfur atoms derived from the total solid content to all atoms in the total solid content in the composition, and [B Ａ ] represents the molar ratio of boron atoms derived from the total solid content to all atoms in the total solid content in the composition, and [I Ａ ] represents the molar ratio of iodine atoms derived from the total solid content to all atoms in the total solid content in the composition.

[0019] The resist composition of the present invention having the above-described configuration has a narrow space width at which bridge defects begin to occur when forming an L / S pattern. In other words, the resist composition of the present invention has a narrow space distance required to prevent bridge defects when forming an L / S pattern. Below, the characteristics of the resist composition of the present invention will be described together with its presumed mechanism of action.

[0020] First, one of the characteristics of the resist composition of the present invention is that the A value calculated by equation (1) is 0.120 or greater (requirement 1). For example, among actinic rays and radiation, light with a relatively short wavelength (e.g., EUV light (wavelength 13.5 nm)) has a small number of incident photons when exposed at the same sensitivity. Therefore, the impact of "photon shot noise," which is the stochastic variation in the number of photons, is significant, making bridge defects more likely to occur. One way to reduce photon shot noise is to increase the exposure dose to increase the number of incident photons, but this involves a trade-off with the need for higher sensitivity. In contrast, the present invention increases light absorptance by a method that does not rely on increasing the exposure dose. In other words, by increasing the A value as defined in requirement 1, the light absorption per film thickness of the film (resist film) formed from the resist composition is increased, thereby suppressing bridge defects and the like caused by photon shot noise.

[0021] For example, when a resist composition contains an acid-decomposable resin, a photoacid generator, a boron-containing compound, an acid diffusion controller, and a solvent, the acid-decomposable resin, the photoacid generator, the boron-containing compound, and the acid diffusion controller correspond to the solid content. In other words, the total atoms of the total solid content correspond to the sum of all atoms derived from the acid-decomposable resin, all atoms derived from the photoacid generator, all atoms derived from the boron-containing compound, and all atoms derived from the acid diffusion controller. For example, [H Ａ ] represents the molar ratio of hydrogen atoms derived from the total solid content to all atoms in the total solid content, and based on the above example, [H Ａ ] represents the molar ratio of the sum of hydrogen atoms derived from the acid-decomposable resin, the photoacid generator, the boron-containing compound, and the acid diffusion controller to the sum of all atoms derived from the acid-decomposable resin, the photoacid generator, the boron-containing compound, and the acid diffusion controller.

[0022] The A value can be calculated by calculating the atomic ratio of the components contained in the resist composition when the structures and contents of the components of the total solid content of the resist composition are known. Even when the components are unknown, the atomic ratio of the components can be calculated by analytical techniques such as elemental analysis of a resist film obtained by evaporating the solvent component of the resist composition.

[0023] Another characteristic feature of the resist composition of the present invention is that it contains a boron-containing compound. When a film (resist film) formed from the resist composition of the present invention is irradiated with actinic rays and radiation (preferably EUV light), a large amount of radical cations and electrons of the acid-decomposable resin, which is present in a relatively large amount, are generated within the film, and electrons may transfer from the orbital of the highly electron-donating boron-containing compound to the radical cation of the acid-decomposable resin. As a result, the radical cation of the acid-decomposable resin becomes a neutral radical, and electrons generated in the system upon irradiation with actinic rays or radiation are transferred to this neutral radical of the acid-decomposable resin, generating a radical anion of the acid-decomposable resin. In other words, the presence of the boron-containing compound in the resist film formed from the resist composition results in excellent generation efficiency of the radical anion of the acid-decomposable resin. It is believed that the boron-containing compound improves the efficiency of generating radical anions of the acid-decomposable resin, and the greater the amount of radical anions generated by the acid-decomposable resin, the more easily electrons are transferred from the radical anions of the acid-decomposable resin to the photoacid generator in the film, promoting the decomposition of the photoacid generator and the generation of the generated acid. As a result, the deprotection reaction of the acid-decomposable resin by the generated acid is more likely to proceed appropriately, and the space width at which bridge defects begin to occur when forming an L / S pattern is narrowed (i.e., the space distance required to prevent bridge defects when forming an L / S pattern is narrow). Note that if the boron-containing compound is not present in the resist film, the radical cations of the acid-decomposable resin generated in the film are more likely to recombine with electrons, so the above-mentioned mechanism does not occur, and the desired effect is less likely to be achieved.

[0024] As described above, the A value is 0.120 or more, but is preferably 0.130 or more, and more preferably 0.135 or more, from the viewpoints of narrowing the space width at which bridge defects begin to occur when forming an L / S pattern, enabling the formation of a pattern with smaller LER (Line Edge Roughness), enabling the formation of a pattern with superior resolution, and / or further improving sensitivity. There is no particular upper limit, but if the A value is too large, the light transmittance of the resist film decreases and the optical image profile in the resist film deteriorates, making it difficult to obtain a good pattern shape, so the A value is preferably 0.240 or less, and more preferably 0.220 or less.

[0025] Hereinafter, the narrower the space width at which bridge defects begin to occur when forming an L / S pattern may also be referred to as "the effect of the present invention is better."

[0026] The various components contained in the resist composition will now be described.

[0027] [Acid-Decomposable Resin (Resin (A))] The resist composition contains an acid-decomposable resin (hereinafter also referred to as "resin (A)"). The acid-decomposable resin is a resin that decomposes under the action of an acid to generate a polar group (acid-decomposable group), and is preferably a resin that contains a repeating unit having an acid-decomposable group. The acid-decomposable resin is typically a resin that decomposes under the action of an acid to increase its polarity. The polarity of the acid-decomposable resin increases under the action of an acid, increasing its solubility in an alkaline developer and decreasing its solubility in an organic solvent. In other words, when pattern formation is carried out using an acid-decomposable resin, typically, a positive pattern is preferably formed when an alkaline developer is used as the developer, and a negative pattern is preferably formed when an organic solvent-based developer is used as the developer.

[0028] <Repeating unit having acid-decomposable group> The acid-decomposable group preferably has a structure in which a polar group is protected with a leaving group that is eliminated by the action of an acid. Hereinafter, the acid-decomposable group will be described, and then the repeating unit having the acid-decomposable group will be described.

[0029] (Acid-decomposable group) The acid-decomposable group refers to a group that decomposes under the action of an acid to generate a polar group. The acid-decomposable group preferably has a structure in which the polar group is protected by a leaving group that is released under the action of an acid. The acid-decomposable group can decompose under the action of an acid to generate a polar group. The polar group is preferably an alkali-soluble group, and examples thereof include acidic groups such as a carboxyl group, a phenolic hydroxyl group, a fluorinated alcohol group, a sulfonic acid group, a phosphate group, a sulfonamide group, a sulfonylimide group, a (alkylsulfonyl) (alkylcarbonyl) methylene group, a (alkylsulfonyl) (alkylcarbonyl) imide group, a bis(alkylcarbonyl) methylene group, a bis(alkylcarbonyl) imide group, a bis(alkylsulfonyl) methylene group, a bis(alkylsulfonyl) imide group, a tris(alkylcarbonyl) methylene group, and a tris(alkylsulfonyl) methylene group, as well as an alcoholic hydroxyl group. Of these, the polar group is preferably a carboxyl group, a phenolic hydroxyl group, a fluorinated alcohol group (preferably a hexafluoroisopropanol group), or a sulfonic acid group.

[0030] Examples of the leaving group that is eliminated by the action of an acid include groups represented by formulae (Y1) to (Y4). Formula (Y1): —C(Rx １ ) (Rx ２ ) (Rx ３ ) Formula (Y2): -C(=O)OC(Rx １ ) (Rx ２ ) (Rx ３ ) Formula (Y3): -C(R ３６ ) (R ３７ ) (OR ３８ ) Formula (Y4): -C(Rn)(H)(Ar)

[0031] In formula (Y1) and formula (Y2), Rx １ ~Rx ３ Each of Rx independently represents a linear or branched alkyl group, a cycloalkyl group, an alkenyl group, or an aryl group. １ ~Rx ３ may be bonded to form a ring.

[0032] In addition, Rx １ ~Rx ３When all of Rx are linear or branched alkyl groups, １ ~Rx ３ At least two of Rx are preferably methyl groups. １ ~Rx ３ As the alkyl group, a linear or branched alkyl group is preferred, and a linear alkyl group is more preferred.

[0033] Rx １ ~Rx ３ The linear or branched alkyl group represented by Rx is preferably a linear alkyl group. １ ~Rx ３ The number of carbon atoms in the linear or branched alkyl group represented by the formula (I) is preferably 1 to 10, more preferably 1 to 5, and even more preferably 1 to 3. １ ~Rx ３ Specific examples of the linear or branched alkyl group represented by the formula (I) include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, and a t-butyl group.

[0034] Rx １ ~Rx ３ The cycloalkyl group represented by the formula (I) may be either a monocyclic or polycyclic group. １ ~Rx ３ The number of carbon atoms in the cycloalkyl group represented by Rx is preferably 6 to 15, and more preferably 6 to 10. １ ~Rx ３ Specific examples of the cycloalkyl group represented by the formula (I) 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.

[0035] Rx １ ~Rx ３ The alkenyl group is preferably a vinyl group.

[0036] Rx １ ~Rx ３ The aryl group is preferably an aryl group having 6 to 10 carbon atoms, and examples thereof include a phenyl group, a naphthyl group, and an anthryl group.

[0037] Also, Rx １ ~Rx ３ may be bonded to form a ring. The ring may be either a monocyclic or polycyclic ring. The ring is preferably a cycloalkyl group, more preferably a 5- or 6-membered monocyclic cycloalkyl group. Specific examples of the ring 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. Rx １ ~Rx ３ In the cycloalkyl group formed by bonding these two, for example, one of the methylene groups constituting the ring may be replaced with a heteroatom such as an oxygen atom, a group having a heteroatom such as a carbonyl group, or a vinylidene group. Furthermore, in these cycloalkyl groups, one or more of the ethylene groups constituting the cycloalkane ring may be replaced with a vinylene group. The group represented by formula (Y1) or formula (Y2) can be, for example, Rx １ is a methyl group or an ethyl group, and Rx ２ and Rx ３ and Rx are preferably bonded to form the above-described cycloalkyl group. When the resist composition is, for example, a resist composition for EUV exposure, １ ~Rx ３ and Rx １ ~Rx ３ The ring formed by combining these two groups preferably further has a fluorine atom or an iodine atom as a substituent.

[0038] In formula (Y3), R ３６ ~R ３８ R each independently represents a hydrogen atom or a monovalent organic group. ３７ and R ３８ may be bonded to each other to form a ring. ３６is also preferably a hydrogen atom. Examples of the monovalent organic group include a linear or branched alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, and an alkenyl group. One or more methylene groups in the linear or branched alkyl group, cycloalkyl group, aryl group, and aralkyl group may be substituted with a group selected from the group consisting of heteroatoms such as oxygen atoms and atomic groups having heteroatoms such as carbonyl groups. In other words, the linear or branched alkyl group, cycloalkyl group, aryl group, and aralkyl group may contain atomic groups having heteroatoms such as oxygen atoms and atomic groups having heteroatoms such as carbonyl groups. In addition, in the repeating unit having an acid-decomposable group described later, R ３８ may bond with another substituent on the main chain of the repeating unit to form a ring. ３８ The group formed by bonding together R and another substituent on the main chain of the repeating unit is preferably an alkylene group such as a methylene group. ３６ ~R ３８ and a monovalent organic group represented by R ３７ and R ３８ The ring formed by bonding these groups together preferably further has a fluorine atom or an iodine atom as a substituent.

[0039] Formula (Y3) is preferably a group represented by the following formula (Y3-1).

[0040]

[0041] Here, L １ and L ２Each independently represents a hydrogen atom, a linear or branched alkyl group, a cycloalkyl group, an aryl group, or a group combining these (for example, a group combining a linear or branched alkyl group and an aryl group). M represents a single bond or a divalent linking group. Q represents a linear or branched alkyl group that may contain heteroatoms, a cycloalkyl group that may contain heteroatoms, an aryl group that may contain heteroatoms, an amino group, an ammonium group, a mercapto group, a cyano group, an aldehyde group, or a group combining these (for example, a group combining a linear or branched alkyl group and a cycloalkyl group). In the linear or branched alkyl group and cycloalkyl group, for example, one of the methylene groups may be replaced with a group selected from heteroatoms such as oxygen atoms and atomic groups having heteroatoms such as carbonyl groups. It should be noted that L １ and L ２ It is preferred that one of Q, M, and L is a hydrogen atom, and the other is a linear or branched alkyl group, a cycloalkyl group, an aryl group, or a group in which an alkylene group and an aryl group are combined. １ At least two of the groups may be bonded to form a ring (preferably a 5- or 6-membered ring). ２ is preferably a secondary or tertiary alkyl group, and more preferably a tertiary alkyl group. Examples of secondary alkyl groups include an isopropyl group, a cyclohexyl group, and a norbornyl group, and examples of tertiary alkyl groups include a tert-butyl group and an adamantane group. In these embodiments, the Tg (glass transition temperature) and activation energy of the resin (A) are increased in the repeating unit having an acid-decomposable group, which will be described later, and therefore, in addition to ensuring film strength, fogging can be suppressed.

[0042] When the resist composition is, for example, a resist composition for EUV exposure, L １ and L ２It is also preferred that the linear or branched alkyl group, cycloalkyl group, aryl group, and combinations thereof represented by the formula (I) further have a fluorine atom or an iodine atom as a substituent. Furthermore, it is also preferred that the linear or branched alkyl group, cycloalkyl group, aryl group, and aralkyl group have one methylene group replaced with a group selected from heteroatoms such as oxygen atoms and atomic groups containing heteroatoms such as carbonyl groups. Furthermore, when the resist composition is, for example, a resist composition for EUV exposure, it is also preferred that the heteroatom in the linear or branched alkyl group which may contain a heteroatom, cycloalkyl group which may contain a heteroatom, aryl group which may contain a heteroatom, amino group, ammonium group, mercapto group, cyano group, aldehyde group, and combinations thereof represented by Q be a heteroatom selected from the group consisting of fluorine atom, iodine atom, and oxygen atom.

[0043] In formula (Y4), Ar represents an aromatic ring group. Rn represents a linear or branched alkyl group, a cycloalkyl group, or an aryl group. Rn and Ar may be bonded to each other to form a non-aromatic ring. Ar is more preferably an aryl group. When the resist composition is, for example, a resist composition for EUV exposure, the aromatic ring group represented by Ar and the linear or branched alkyl group, cycloalkyl group, and aryl group represented by Rn preferably have a fluorine atom and an iodine atom as a substituent.

[0044] In terms of further improving acid decomposability, when a non-aromatic ring is directly bonded to the polar group (or a residue thereof) in the leaving group protecting the polar group, it is also preferable that the ring atom in the non-aromatic ring adjacent to the ring atom directly bonded to the polar group (or a residue thereof) does not have a halogen atom such as a fluorine atom as a substituent.

[0045] The leaving group that is eliminated by the action of an acid may also be a 2-cyclopentenyl group having a substituent (such as an alkyl group), such as a 3-methyl-2-cyclopentenyl group, or a cyclohexyl group having a substituent (such as an alkyl group), such as a 1,1,4,4-tetramethylcyclohexyl group.

[0046] (Repeating unit containing an acid-decomposable group) Next, a repeating unit containing an acid-decomposable group that may be contained in the resin (A) will be described. As the repeating unit containing an acid-decomposable group, in addition to the repeating units containing an acid-decomposable group described above, a repeating unit represented by the following formula (A) is also preferred.

[0047]

[0048] L １ represents a divalent linking group which may have a fluorine atom or an iodine atom. １ represents a hydrogen atom, a fluorine atom, an iodine atom, an alkyl group which may have a fluorine atom or an iodine atom, or an aryl group which may have a fluorine atom or an iodine atom. ２ represents a leaving group which is eliminated by the action of an acid and which may have a fluorine atom or an iodine atom. １ , R １ , and R ２ At least one of L preferably has a fluorine atom or an iodine atom. １ represents a divalent linking group which may have a fluorine atom or an iodine atom. Examples of the divalent linking group which may have a fluorine atom or an iodine atom include -CO-, -O-, -S-, -SO-, and -SO ２ -, hydrocarbon groups which may have a fluorine atom or an iodine atom (for example, linear or branched alkylene groups, cycloalkylene groups, alkenylene groups, arylene groups, etc.), and linking groups in which a plurality of these groups are linked together. １As the arylene group, -CO-, an arylene group, or -arylene group-straight-chain or branched-chain alkylene group having a fluorine atom or an iodine atom- is preferred, and -CO- or -arylene group-straight-chain or branched-chain alkylene group having a fluorine atom or an iodine atom- is more preferred. As the arylene group, a phenylene group is preferred. The number of carbon atoms in the straight-chain or branched-chain alkylene group is not particularly limited, but is preferably 1 to 10, more preferably 1 to 3. The total number of fluorine atoms and iodine atoms contained in the straight-chain or branched-chain alkylene group having a fluorine atom or an iodine atom is not particularly limited, but is preferably 2 or more, more preferably 2 to 10, and even more preferably 3 to 6.

[0049] R １ represents a hydrogen atom, a fluorine atom, an iodine atom, a straight-chain or branched-chain alkyl group which may have a fluorine atom or an iodine atom, or an aryl group which may have a fluorine atom or an iodine atom. The number of carbon atoms in the straight-chain or branched-chain alkyl group is not particularly limited, but is preferably 1 to 10, and more preferably 1 to 3. The total number of fluorine atoms and iodine atoms contained in the straight-chain or branched-chain alkyl group which has a fluorine atom or an iodine atom is not particularly limited, but is preferably 1 or more, more preferably 1 to 5, and even more preferably 1 to 3. The straight-chain or branched-chain alkyl group which has a fluorine atom or an iodine atom may contain a heteroatom other than a halogen atom, such as an oxygen atom.

[0050] R ２ represents a leaving group which is eliminated by the action of an acid and which may have a fluorine atom or an iodine atom. Examples of the leaving group which may have a fluorine atom or an iodine atom include the leaving groups represented by the above formulae (Y1) to (Y4) and leaving groups which are represented by the above formulae (Y1) to (Y4) and which have a fluorine atom or an iodine atom, and preferred embodiments are also the same.

[0051] Furthermore, the repeating unit having an acid-decomposable group is preferably a repeating unit represented by formula (AI).

[0052]

[0053] In formula (AI), Xa １ represents a hydrogen atom or an alkyl group which may have a substituent. T represents a single bond or a divalent linking group. Rx １ ~Rx ３ Each of Rx independently represents a linear or branched alkyl group, a cycloalkyl group, an alkenyl group, or an aryl group. １ ~Rx ３ may be bonded to form a ring.

[0054] In addition, Rx １ ~Rx ３ When all of Rx are linear or branched alkyl groups, １ ~Rx ３ At least two of Rx are preferably methyl groups. １ ~Rx ３ As the alkyl group, a linear or branched alkyl group is preferred, and a linear alkyl group is more preferred.

[0055] Xa １ Examples of the alkyl group represented by the formula (I) which may have a substituent include a methyl group or a —CH ２ -R １１ Examples of the group include a group represented by R １１ represents a halogen atom (such as a fluorine atom), a hydroxyl group, or a monovalent organic group, and examples thereof include an alkyl group having 5 or less carbon atoms which may be substituted with a halogen atom, an acyl group having 5 or less carbon atoms which may be substituted with a halogen atom, and an alkoxy group having 5 or less carbon atoms which may be substituted with a halogen atom, and an alkyl group having 3 or less carbon atoms is preferred, and a methyl group is more preferred. １ is preferably a hydrogen atom, a methyl group, a trifluoromethyl group, or a hydroxymethyl group.

[0056] Examples of the divalent linking group represented by T include an alkylene group, an aromatic ring group, a -COO-Rt- group, and a -O-Rt- group. In the formula, Rt represents a linear or branched alkylene group or a cycloalkylene group. T is preferably a single bond or a -COO-Rt- group. When T represents a -COO-Rt- group, Rt is preferably an alkylene group having 1 to 5 carbon atoms, and is preferably a -CH２ -, -(CH ２ ) ２ - or -(CH ２ ) ３ - is more preferable.

[0057] Rx １ ~Rx ３ The linear or branched alkyl group represented by Rx is preferably a linear alkyl group. １ ~Rx ３ The number of carbon atoms in the linear or branched alkyl group represented by the formula (I) is preferably 1 to 10, more preferably 1 to 5, and even more preferably 1 to 3. １ ~Rx ３ Specific examples of the linear or branched alkyl group represented by the formula (I) include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, and a t-butyl group.

[0058] Rx １ ~Rx ３ The cycloalkyl group represented by the formula (I) may be either a monocyclic or polycyclic group. １ ~Rx ３ The number of carbon atoms in the cycloalkyl group represented by Rx is preferably 6 to 15, and more preferably 6 to 10. １ ~Rx ３ Specific examples of the cycloalkyl group represented by the formula (I) 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.

[0059] Rx １ ~Rx ３ The alkenyl group is preferably a vinyl group.

[0060] Rx １ ~Rx ３ The aryl group is preferably an aryl group having 6 to 10 carbon atoms, and examples thereof include a phenyl group, a naphthyl group, and an anthryl group.

[0061] Also, Rx １ ~Rx ３may be bonded to form a ring. The ring may be either a monocyclic or polycyclic ring. The ring is preferably a cycloalkyl group, more preferably a 5- or 6-membered monocyclic cycloalkyl group. Specific examples of the ring 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. Rx １ ~Rx ３ In the cycloalkyl group formed by bonding these two, for example, one of the methylene groups constituting the ring may be replaced with a heteroatom such as an oxygen atom, a group having a heteroatom such as a carbonyl group, or a vinylidene group. Furthermore, in these cycloalkyl groups, one or more of the ethylene groups constituting the cycloalkane ring may be replaced with a vinylene group.

[0062] The repeating unit represented by formula (AI) is, for example, Rx １ is a methyl group or an ethyl group, and Rx ２ and Rx ３ and are preferably bonded to form the above-mentioned cycloalkyl group.

[0063] When each of the above groups has a substituent, examples of the substituent include an alkyl group (having 1 to 4 carbon atoms), a halogen atom, a hydroxyl group, an alkoxy group (having 1 to 4 carbon atoms), a carboxyl group, and an alkoxycarbonyl group (having 2 to 6 carbon atoms).

[0064] The repeating unit represented by formula (AI) is preferably an acid-decomposable (meth)acrylic acid tertiary alkyl ester repeating unit (Xa １ represents a hydrogen atom or a methyl group, and T represents a single bond).

[0065] Specific examples of repeating units having an acid-decomposable group are shown below, but the present invention is not limited thereto. １ is H, CH ３ , C.F. ３ , and C.H. ２ Either of OH, Rxa and Rxb each represents a linear or branched alkyl group having 1 to 5 carbon atoms.

[0066]

[0067] (Repeating unit having an acid-decomposable group containing an unsaturated bond) The resin (A) preferably has a repeating unit having an acid-decomposable group containing an unsaturated bond as a repeating unit having an acid-decomposable group. As the repeating unit having an acid-decomposable group containing an unsaturated bond, a repeating unit represented by formula (B) is preferred.

[0068]

[0069] In formula (B), Xb represents a hydrogen atom, a halogen atom, or an alkyl group which may have a substituent. L represents a single bond or a divalent linking group which may have a substituent. Ry １ ~Ry ３ each independently represents a hydrogen atom, a linear or branched alkyl group, a monocyclic or polycyclic cycloalkyl group, an alkenyl group, an alkynyl group, or a monocyclic or polycyclic aryl group. １ ~Ry ３ Any two of Ry may be bonded to form a monocyclic or polycyclic ring (for example, a monocyclic or polycyclic cycloalkyl group or cycloalkenyl group). １ ~Ry ３ At least one of R represents an alkenyl group, an alkynyl group, a monocyclic or polycyclic cycloalkenyl group, or a monocyclic or polycyclic aryl group, or R １ ~Ry ３ Any two of Ry bond to each other to form a monocyclic or polycyclic alicyclic ring (for example, a monocyclic or polycyclic cycloalkyl group or cycloalkenyl group). １ ~Ry ３ Two or more of Ry are not hydrogen atoms. １ ~Ry ３ When any one of R represents a hydrogen atom, R １ ~Ry ３ two other groups bond to each other to form a ring having one or more vinylene groups in the ring structure, and at least one of the vinylene groups is １ ~Ry ３A hydrogen atom represented by any one of the following is present adjacent to the carbon atom to which it is bonded.

[0070] Ry １ ~Ry ３ The alkyl group of Ry is preferably an alkyl group having 1 to 4 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, or a t-butyl group. １ ~Ry ３ The cycloalkyl group of Ry is preferably a monocyclic cycloalkyl group such as a cyclopentyl group or a cyclohexyl group, or a polycyclic cycloalkyl group such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, or an adamantyl group. １ ~Ry ３ The aryl group in Ry is preferably an aryl group having 6 to 15 carbon atoms, more preferably an aryl group having 6 to 10 carbon atoms, and examples thereof include a phenyl group, a naphthyl group, and an anthryl group. １ ~Ry ３ The alkenyl group in Ry is preferably a vinyl group. １ ~Ry ３ The alkynyl group in Ry is preferably an ethynyl group. １ ~Ry ３ The cycloalkenyl group of Ry is preferably a structure containing a double bond in a part of a monocyclic cycloalkyl group such as a cyclopentyl group or a cyclohexyl group. １ ~Ry ３ The cycloalkyl group formed by combining the above two is preferably a monocyclic cycloalkyl group such as a cyclopentyl group or a cyclohexyl group, and is also preferably a polycyclic cycloalkyl group such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, or an adamantyl group. Of these, a monocyclic cycloalkyl group having 5 to 6 carbon atoms is preferred. １ ~Ry ３ The cycloalkyl group and cycloalkenyl group formed by bonding two of the above are, for example, those in which one of the methylene groups constituting the ring is substituted with a heteroatom such as an oxygen atom, a carbonyl group, or —SO ２ - group, and -SO ３These cycloalkyl groups and cycloalkenyl groups may have one or more ethylene groups constituting the cycloalkane ring and cycloalkene ring replaced with a vinylene group. １ ~Ry ３ A preferred embodiment of the combination is, for example, Ry １ is a methyl group, an ethyl group, a vinyl group, an allyl group, or an aryl group, and Ry ２ and Rx ３ and R are bonded to form the above-mentioned cycloalkyl group or cycloalkenyl group, and １ is a hydrogen atom, and Ry ２ and Ry ３ are bonded to each other to form a ring having one or more vinylene groups in the ring structure, and at least one of the vinylene groups is Ry １ and a hydrogen atom represented by the formula (I) is present adjacent to the carbon atom to which the hydrogen atom is bonded.

[0071] Ry １ ~Ry ３ When further having a substituent, examples of the substituent include an alkyl group (having 1 to 4 carbon atoms), a halogen atom, a hydroxyl group, an alkoxy group (having 1 to 4 carbon atoms), a carboxyl group, and an alkoxycarbonyl group (having 2 to 6 carbon atoms).

[0072] The alkyl group represented by Xb, which may have a substituent, is, for example, a methyl group or —CH ２ -R １１ Examples of the group include a group represented by R １１ represents a halogen atom (such as a fluorine atom), a hydroxyl group, or a monovalent organic group, and examples thereof include an alkyl group having 5 or less carbon atoms which may be substituted with a halogen atom, an acyl group having 5 or less carbon atoms which may be substituted with a halogen atom, and an alkoxy group having 5 or less carbon atoms which may be substituted with a halogen atom, and an alkyl group having 3 or less carbon atoms is preferred, and a methyl group is more preferred. Xb is preferably a hydrogen atom, a fluorine atom, a methyl group, a trifluoromethyl group, or a hydroxymethyl group.

[0073] Examples of the divalent linking group represented by L include a -Rt- group, a -CO- group, a -COO-Rt- group, a -COO-Rt-CO- group, a -Rt-CO- group, and a -O-Rt- group, with a -Rt- group, a -CO- group, a -COO-Rt-CO- group, or a -Rt-CO- group being preferred. Rt represents a linear or branched alkylene group, a cycloalkylene group, or an aromatic ring group, with an aromatic ring group being preferred. The aromatic ring group may have a substituent such as a halogen atom, a hydroxyl group, or an alkoxy group.

[0074] When each of the groups in formula (B) has a substituent, examples of the substituent include an alkyl group (having 1 to 4 carbon atoms), a halogen atom, a hydroxyl group, an alkoxy group (having 1 to 4 carbon atoms), a carboxyl group, and an alkoxycarbonyl group (having 2 to 6 carbon atoms).

[0075] The repeating unit represented by formula (B) is preferably an acid-decomposable (meth)acrylic acid tertiary ester repeating unit (a repeating unit in which Xb represents a hydrogen atom or a methyl group and L represents a —CO— group), an acid-decomposable hydroxystyrene tertiary alkyl ether repeating unit (a repeating unit in which Xb represents a hydrogen atom or a methyl group and L represents a phenyl group), or an acid-decomposable styrene carboxylic acid tertiary ester repeating unit (a repeating unit in which Xb represents a hydrogen atom or a methyl group and L represents a —Rt—CO— group (Rt is an aromatic group)).

[0076] Specific examples of repeating units having an acid-decomposable group containing an unsaturated bond include the repeating units described in paragraphs

[0067] to

[0071] of WO 2022 / 024928.

[0077] The content of the repeating units having an acid-decomposable group in the resin (A) is preferably 15 mol% or more, more preferably 20 mol% or more, and even more preferably 30 mol% or more, based on the total repeating units in the resin (A), and the upper limit is preferably 90 mol% or less, more preferably 80 mol% or less, particularly preferably 70 mol% or less, and most preferably 60 mol% or less.

[0078] The resin (A) may contain repeating units other than the repeating units described above. Examples of the other repeating units include at least one repeating unit selected from the group consisting of Group A below. Group A: A group consisting of the repeating units (20) to (26) below. (20) A repeating unit having an acid group, as described below. (21) A repeating unit having a fluorine atom or an iodine atom and having neither an acid-decomposable group nor an acid group, as described below. (22) A repeating unit having a lactone group, a sultone group, or a carbonate group, as described below. (23) A repeating unit having a photoacid-generating group, as described below. (24) A repeating unit represented by formula (V-1) or the following formula (V-2), as described below. (25) A repeating unit for reducing the mobility of the main chain. The repeating units represented by formulas (A) to (E), as described below, correspond to (25) a repeating unit for reducing the mobility of the main chain. (26) A repeating unit having an alicyclic hydrocarbon structure and not exhibiting acid decomposability, as described below.

[0079] The resin (A) preferably has an acid group, and preferably contains a repeating unit having an acid group, as described below. The definition of the acid group will be explained later together with preferred embodiments of the repeating unit having an acid group.

[0080] When the resist composition is used as a resist composition for EUV exposure, it is preferable that the resin (A) has at least one repeating unit selected from the group consisting of Group A. Furthermore, when the resist composition is used as a resist composition for EUV exposure, it is preferable that the resin (A) has at least one of a fluorine atom and an iodine atom. When the resin (A) contains both a fluorine atom and an iodine atom, the resin (A) may have one repeating unit containing both a fluorine atom and an iodine atom, or the resin (A) may have two repeating units: a repeating unit containing a fluorine atom and a repeating unit containing an iodine atom. Furthermore, when the resist composition is used as a resist composition for EUV exposure, it is also preferable that the resin (A) has a repeating unit containing an aromatic group.

[0081] <Repeating Unit Having an Acid Group> The resin (A) preferably has a repeating unit having an acid group. The acid group preferably has a pKa of 13 or less. As described above, the acid dissociation constant of the acid group is preferably 13 or less, more preferably 3 to 13, and even more preferably 5 to 10. When the resin (A) has an acid group with a pKa of 13 or less, the content of the acid group in the resin (A) is not particularly limited, but is often 0.2 to 6.0 mmol / g. Of these, 0.8 to 6.0 mmol / g is preferred, 1.2 to 5.0 mmol / g is more preferred, and 1.6 to 4.0 mmol / g is even more preferred. When the content of the acid group is within the above range, development proceeds well, and the formed pattern shape is excellent, and resolution is also excellent. Preferred examples of the acid group include a carboxyl group, a hydroxyl group, a phenolic hydroxyl group, a fluorinated alcohol group (preferably a hexafluoroisopropanol group), a sulfonic acid group, a sulfonamide group, or an isopropanol group, with a phenolic hydroxyl group being more preferred. The phenolic hydroxyl group refers to a hydroxyl group substituted on a ring atom of an aromatic ring. In addition, one or more fluorine atoms (preferably one to two) of the hexafluoroisopropanol group may be substituted with a group other than a fluorine atom (such as an alkoxycarbonyl group). The -C(CF) thus formed may be ３ )(OH)—CF ２ - is also preferred as an acid group. In addition, one or more fluorine atoms may be substituted with a group other than a fluorine atom to form -C(CF ３ )(OH)—CF ２ The repeating unit having an acid group is preferably a repeating unit different from the repeating unit having a structure in which a polar group is protected with a leaving group that is eliminated by the action of an acid, and a repeating unit having a lactone group, a sultone group, or a carbonate group, which will be described later. The repeating unit having an acid group may have a fluorine atom or an iodine atom.

[0082] As the repeating unit having an acid group, a repeating unit having a phenolic hydroxyl group is preferable in terms of achieving the effects of the present invention more excellently. Examples of the repeating unit having a phenolic hydroxyl group include a repeating unit represented by the following formula (1):

[0083]

[0084] In formula (1), A represents a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, or a cyano group. R represents a halogen atom, an alkyl group, a cycloalkyl group, an aryl group, an alkenyl group, an aralkyl group, an alkoxy group, an alkylcarbonyloxy group, an alkylsulfonyloxy group, an alkyloxycarbonyl group, or an aryloxycarbonyl group, and when there are multiple Rs, they may be the same or different. When there are multiple Rs, they may combine with each other to form a ring. R is preferably a hydrogen atom. a represents an integer of 1 to 3. b represents an integer of 0 to (5-a).

[0085] Specific examples of repeating units having a phenolic hydroxyl group include the following repeating units: wherein a represents 1 or 2.

[0086]

[0087] Other specific examples of repeating units having an acid group can be found in, for example, paragraphs

[0088] to

[0089] and

[0103] to

[0110] of WO 2022 / 024928.

[0088] The content of the repeating units having an acid group is preferably 10 mol% or more, more preferably 15 mol% or more, based on the total repeating units in the resin (A), and the upper limit thereof is preferably 70 mol% or less, more preferably 65 mol% or less, and even more preferably 60 mol% or less, based on the total repeating units in the resin (A).

[0089] <Repeating units having neither an acid-decomposable group nor an acid group, but having a fluorine atom or an iodine atom> In addition to the above-mentioned <repeating units having an acid-decomposable group> and <repeating units having an acid group>, the resin (A) may have a repeating unit having a fluorine atom or an iodine atom (hereinafter also referred to as unit X). Furthermore, the <repeating units having a fluorine atom or an iodine atom> referred to here is preferably different from other types of repeating units belonging to Group A, such as the below-described <repeating units having a lactone group, a sultone group, or a carbonate group> and <repeating units having a photoacid-generating group>.

[0090] The unit X is preferably a repeating unit represented by formula (C).

[0091]

[0092] L ５ represents a single bond or an ester group. ９ represents a hydrogen atom or an alkyl group which may have a fluorine atom or an iodine atom. １０ represents a hydrogen atom, an alkyl group which may have a fluorine atom or an iodine atom, a cycloalkyl group which may have a fluorine atom or an iodine atom, an aryl group which may have a fluorine atom or an iodine atom, or a group which is a combination of these.

[0093] Specific examples of the unit X are shown below.

[0094]

[0095] The content of the units X is preferably 0 mol% or more, more preferably 5 mol% or more, and even more preferably 10 mol% or more, relative to all repeating units in the resin (A), and the upper limit is preferably 50 mol% or less, more preferably 45 mol% or less, and even more preferably 40 mol% or less.

[0096] Among the repeating units of the resin (A), the total content of repeating units containing at least one of a fluorine atom and an iodine atom is preferably 10 mol% or more, more preferably 20 mol% or more, even more preferably 30 mol% or more, and particularly preferably 40 mol% or more, based on the total repeating units of the resin (A). The upper limit is not particularly limited, but is, for example, 100 mol% or less. Examples of repeating units containing at least one of a fluorine atom and an iodine atom include repeating units having a fluorine atom or an iodine atom and an acid-decomposable group, repeating units having a fluorine atom or an iodine atom and an acid group, and repeating units having a fluorine atom or an iodine atom.

[0097] <Repeating unit having a lactone group, a sultone group, or a carbonate group> The resin (A) may have a repeating unit (hereinafter also referred to as "unit Y") having at least one selected from the group consisting of a lactone group, a sultone group, and a carbonate group. It is also preferable that the unit Y does not have a hydroxyl group or an acid group such as a hexafluoropropanol group.

[0098] The lactone group or sultone group may have a lactone structure or a sultone structure. The lactone structure or sultone structure is preferably a 5- to 7-membered lactone structure or a 5- to 7-membered sultone structure. Among these, a 5- to 7-membered lactone structure to which another ring structure is fused, forming a bicyclo or spiro structure, or a 5- to 7-membered sultone structure to which another ring structure is fused, forming a bicyclo or spiro structure, is more preferred. Resin (A) preferably has a repeating unit having a lactone group or sultone group formed by abstracting one or more hydrogen atoms from a ring atom of a lactone structure represented by any one of formulas (LC1-1) to (LC1-21) below, or a sultone structure represented by any one of formulas (SL1-1) to (SL1-3) below. Furthermore, the lactone group or sultone group may be directly bonded to the main chain. For example, the ring atom of the lactone group or sultone group may constitute the main chain of resin (A).

[0099]

[0100] The lactone structure or sultone structure portion may have a substituent (Rb ２ ) may have a preferable substituent (Rb ２ ) includes an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 4 to 7 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an alkoxycarbonyl group having 1 to 8 carbon atoms, a carboxyl group, a halogen atom, a cyano group, and an acid-decomposable group. n2 represents an integer of 0 to 4. When n2 is 2 or more, a plurality of Rb ２ may be different, and multiple Rb ２ They may be bonded to each other to form a ring.

[0101] Examples of repeating units having a group having a lactone structure represented by any one of formulas (LC1-1) to (LC1-21) or a sultone structure represented by any one of formulas (SL1-1) to (SL1-3) include repeating units represented by the following formula (AI):

[0102]

[0103] In formula (AI), Rb ０ represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms. ０ Preferred substituents that the alkyl group of Rb may have include a hydroxyl group and a halogen atom. ０ Examples of the halogen atom in Rb include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. ０ is preferably a hydrogen atom or a methyl group. Ab represents a single bond, an alkylene group, a divalent linking group having a monocyclic or polycyclic alicyclic hydrocarbon structure, an ether group, an ester group, a carbonyl group, a carboxyl group, or a divalent group formed by combining these. Among these, a single bond or -Ab １ -CO ２ A linking group represented by - is preferred. １is a linear or branched alkylene group, or a monocyclic or polycyclic cycloalkylene group, and is preferably a methylene group, an ethylene group, a cyclohexylene group, an adamantylene group, or a norbornylene group. V is a group obtained by removing one hydrogen atom from a ring member atom of a lactone structure represented by any of formulas (LC1-1) to (LC1-21), or a group obtained by removing one hydrogen atom from a ring member atom of a sultone structure represented by any of formulas (SL1-1) to (SL1-3).

[0104] When optical isomers exist in the repeating unit having a lactone group or a sultone group, any optical isomer may be used. One optical isomer may be used alone, or multiple optical isomers may be used in combination. When one optical isomer is primarily used, its optical purity (ee) is preferably 90 or more, more preferably 95 or more.

[0105] The carbonate group is preferably a cyclic carbonate ester group. Examples of repeating units having a cyclic carbonate ester group include the repeating units described in paragraphs

[0127] to

[0133] of WO 2022 / 024928.

[0106] The content of the unit Y is preferably 1 mol% or more, more preferably 5 mol% or more, and even more preferably 10 mol% or more, based on all repeating units in the resin (A), and the upper limit thereof is preferably 85 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 all repeating units in the resin (A).

[0107] <Repeating unit having a photoacid generating group> As described below, the resin (A) may be integrated with a photoacid generator. That is, the resin (A) may have a structure in which the photoacid generator is integrated with the resin (A). When the photoacid generator is integrated with the resin (A), the resin (A) contains a repeating unit having a photoacid generating group. Examples of such repeating units include repeating units represented by the following formula (4):

[0108]

[0109] R ４１represents a hydrogen atom or a methyl group. ４１ represents a single bond or a divalent linking group. ４２ represents a divalent linking group. ４０ represents a photoacid generating group. ４０ The photoacid generating group represented by the formula (I) is preferably a group obtained by removing one hydrogen atom from a photoacid generator described later, and more preferably a group obtained by removing one hydrogen atom from the anion moiety of a photoacid generator having an onium salt structure described later. Examples of repeating units having a photoacid generating group include the following repeating units.

[0110]

[0111] Other examples of the repeating unit represented by formula (4) include the repeating units described in paragraphs

[0094] to

[0105] of JP 2014-041327 A and the repeating unit described in paragraph

[0094] of WO 2018 / 193954 A.

[0112] The content of the repeating unit having a photoacid generating group is preferably 1 mol% or more, more preferably 5 mol% or more, based on the total repeating units in the resin (A), and the upper limit is preferably 40 mol% or less, more preferably 35 mol% or less, and even more preferably 30 mol% or less.

[0113] <Repeating unit represented by formula (V-1) or the following formula (V-2)> The resin (A) may have a repeating unit represented by the following formula (V-1) or the following formula (V-2). The repeating units represented by the following formula (V-1) and the following formula (V-2) are preferably repeating units different from the above-mentioned repeating units.

[0114]

[0115] In the formula, R ６ and R ７Each of n independently represents a hydrogen atom, a hydroxyl group, an alkyl group, an alkoxy group, an acyloxy group, a cyano group, a nitro group, an amino group, a halogen atom, an ester group (-OCOR or -COOR: R is an alkyl group or a fluorinated alkyl group having 1 to 6 carbon atoms), or a carboxyl group. As the alkyl group, a linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms is preferred. ３ represents an integer of 0 to 6. ４ represents an integer of 0 to 4. ４ is a methylene group, an oxygen atom, or a sulfur atom. Examples of repeating units represented by formula (V-1) or (V-2) are shown below. Examples of repeating units represented by formula (V-1) or (V-2) include the repeating units described in paragraph

[0100] of WO 2018 / 193954.

[0116] <Repeating Unit for Reducing Mobility of Main Chain> The resin (A) preferably has a high glass transition temperature (Tg) in order to suppress excessive diffusion of generated acid or pattern collapse during development. The Tg is preferably higher than 90°C, more preferably higher than 100°C, even more preferably higher than 110°C, and particularly preferably higher than 125°C. In order to achieve an excellent dissolution rate in a developer, the Tg is preferably 400°C or lower, more preferably 350°C or lower. In this specification, the glass transition temperature (Tg) of a polymer such as resin (A) (hereinafter also referred to as "Tg of repeating unit") is calculated by the following method. First, the Tg of a homopolymer consisting of only each repeating unit contained in the polymer is calculated using the Bicerano method. Next, the mass proportion (%) of each repeating unit relative to all repeating units in the polymer is calculated. Next, the Tg at each mass ratio is calculated using the Fox formula (described in Materials Letters 62 (2008) 3152, etc.), and the sum of these values ​​is used to determine the Tg (°C) of the polymer. The Bicerano method is described in, for example, "Prediction of Polymer Properties," Marcel Dekker Inc., New York (1993). Calculation of Tg by the Bicerano method can be performed using polymer property estimation software MDL Polymer (MDL Information Systems, Inc.).

[0117] In order to increase the Tg of resin (A) (preferably to make the Tg greater than 90°C), it is preferable to reduce the mobility of the main chain of resin (A). Methods for reducing the mobility of the main chain of resin (A) include the following methods (a) to (e): (a) Introduction of a bulky substituent into the main chain; (b) Introduction of multiple substituents into the main chain; (c) Introduction of a substituent that induces interactions between resins (A) near the main chain; (d) Formation of a main chain with a cyclic structure; (e) Linking of a cyclic structure to the main chain. It is preferable that resin (A) has a repeating unit that exhibits a homopolymer Tg of 130°C or higher. The type of repeating unit that exhibits a homopolymer Tg of 130°C or higher is not particularly limited, and it is sufficient that the repeating unit exhibits a homopolymer Tg of 130°C or higher as calculated by the Bicerano method. It is to be noted that depending on the type of functional group in the repeating units represented by formulas (A) to (E) described below, it may be considered a repeating unit that exhibits a homopolymer Tg of 130°C or higher.

[0118] (Repeating Unit Represented by Formula (A)) One example of a specific means for achieving the above (a) is a method of introducing a repeating unit represented by formula (A) into resin (A).

[0119]

[0120] Formula (A), R Ａ represents a group having a polycyclic structure. ｘ represents a hydrogen atom, a methyl group, or an ethyl group. A group having a polycyclic structure is a group having multiple ring structures, and the multiple ring structures may be condensed or not condensed. Specific examples of the repeating unit represented by formula (A) include those described in paragraphs

[0107] to

[0119] of WO 2018 / 193954.

[0121] (Repeating Unit Represented by Formula (B)) One example of a specific means for achieving the above (b) is a method of introducing a repeating unit represented by formula (B) into resin (A).

[0122]

[0123] In formula (B), R ｂ１ ~R ｂ４each independently represents a hydrogen atom or an organic group; R ｂ１ ~R ｂ４ At least two of these represent organic groups. Furthermore, when at least one of the organic groups is a group in which a ring structure is directly linked to the main chain in the repeating unit, the type of the other organic group is not particularly limited. Furthermore, when none of the organic groups is a group in which a ring structure is directly linked to the main chain in the repeating unit, at least two of the organic groups are substituents having three or more constituent atoms excluding hydrogen atoms. Specific examples of the repeating unit represented by formula (B) include those described in paragraphs

[0113] to

[0115] of WO 2018 / 193954.

[0124] (Repeating Unit Represented by Formula (C)) One example of a specific means for achieving the above (c) is a method of introducing a repeating unit represented by formula (C) into resin (A).

[0125]

[0126] In formula (C), R ｃ１ ~R ｃ４ each independently represents a hydrogen atom or an organic group; R ｃ１ ~R ｃ４ At least one of the repeating units represented by formula (C) is a group having a hydrogen-bonding hydrogen atom within three atoms from the main chain carbon. In particular, in order to induce interactions between the main chains of resin (A), it is preferable to have a hydrogen-bonding hydrogen atom within two atoms (closer to the main chain). Specific examples of the repeating unit represented by formula (C) include those described in paragraphs

[0119] to

[0121] of WO 2018 / 193954.

[0127] (Repeating Unit Represented by Formula (D)) One example of a specific means for achieving the above (d) is a method of introducing a repeating unit represented by formula (D) into the resin (A).

[0128]

[0129] In formula (D), "Cyclic" represents a group that forms a main chain with a cyclic structure. The number of constituent atoms of the ring is not particularly limited. Specific examples of the repeating unit represented by formula (D) include those described in paragraphs

[0126] to

[0127] of WO 2018 / 193954.

[0130] (Repeating Unit Represented by Formula (E)) One example of a specific means for achieving the above (e) is a method of introducing a repeating unit represented by formula (E) into the resin (A).

[0131]

[0132] In formula (E), each Re independently represents a hydrogen atom or an organic group. Examples of the organic group include an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, and an alkenyl group, each of which may have a substituent. "Cyclic" refers to a cyclic group containing carbon atoms in the main chain. The number of atoms contained in the cyclic group is not particularly limited. Specific examples of the repeating unit represented by formula (E) include those described in paragraphs

[0131] to

[0133] of WO 2018 / 193954.

[0133] <Repeating Unit Having Alicyclic Hydrocarbon Structure and Not Exhibiting Acid Decomposability> The resin (A) may have a repeating unit having an alicyclic hydrocarbon structure and not exhibiting acid decomposability. Examples of such repeating units include repeating units derived from 1-adamantyl (meth)acrylate, diamantyl (meth)acrylate, tricyclodecanyl (meth)acrylate, or cyclohexyl (meth)acrylate.

[0134] In addition, the alicyclic hydrocarbon structure is preferably substituted with a hydroxyl group or a cyano group, in order to improve substrate adhesion and developer affinity. Specific examples of repeating units having an alicyclic hydrocarbon structure having a hydroxyl group or a cyano group include those described in paragraphs

[0081] to

[0084] of JP 2014-098921 A.

[0135] <Other Repeating Units> Furthermore, the resin (A) may have a repeating unit other than the repeating units described above. For example, the resin (A) may have a repeating unit selected from the group consisting of a repeating unit having an oxathiane ring group, a repeating unit having an oxazolone ring group, a repeating unit having a dioxane ring group, and a repeating unit having a hydantoin ring group. Examples of such repeating units are shown below.

[0136]

[0137] In addition to the repeating structural units described above, the resin (A) may have various repeating structural units for the purpose of adjusting dry etching resistance, suitability for a standard developer, substrate adhesion, resist profile, resolution, heat resistance, sensitivity, and the like.

[0138] Resin (A) can be synthesized according to a conventional method (e.g., radical polymerization). The weight average molecular weight of resin (A), as measured by GPC in terms of polystyrene, is preferably 30,000 or less, more preferably 1,000 to 30,000, even more preferably 3,000 to 30,000, and particularly preferably 5,000 to 15,000. The dispersity (molecular weight distribution) of resin (A) is preferably 1 to 5, more preferably 1 to 3, even more preferably 1.2 to 3.0, and particularly preferably 1.2 to 2.0. The smaller the dispersity, the better the resolution and resist shape, and furthermore, the smoother the sidewalls of the resist pattern and the better the roughness.

[0139] In the resist composition, the lower limit of the content of resin (A) is preferably 35.0 mass% or more, more preferably 40.0 mass% or more, and even more preferably 45.0 mass% or more, based on the total solid content of the resist composition. The upper limit of the content of resin (A) is preferably 99.9 mass% or less, more preferably 90.0 mass% or less, and even more preferably 80.0 mass% or less, based on the total solid content of the resist composition. Resin (A) may be used alone, or two or more types may be used in combination. Resin (A) may be used alone, or two or more types may be used. When two or more types are used, it is preferable that the total content is within the above-mentioned suitable content range.

[0140] [Boron-Containing Compound] The resist composition contains a boron-containing compound. The boron-containing compound is not particularly limited as long as it contains a boron atom. However, compounds (salt compounds) having a borate anion are more preferred because they provide superior effects of the present invention. Among compounds having a borate anion, onium salt compounds are preferred, with sulfonium salt compounds, iodonium salt compounds, quaternary ammonium salt compounds, and quaternary phosphonium salt compounds being more preferred. The compound having a borate anion may be either a low-molecular-weight compound or a high-molecular-weight compound, but a low-molecular-weight compound is preferred. 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. While the lower limit is not particularly limited, a molecular weight of 400 or more is preferred. Among compounds having a borate anion, compounds represented by the following formula (3) are more preferred:

[0141] <Compound represented by the following formula (3)>

[0142]

[0143] In formula (3), R ４ ~R ７ R each independently represents a substituent. ４ ~R ７ The substituent represented by the formula (I) is not particularly limited, and examples thereof include the groups exemplified as the substituent T.

[0144] (Substituent T) The substituent T is 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; 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; an acyl group such as an acetyl group, a benzoyl group, an isobutyryl group, an acryloyl group, a methacryloyl group, or a methoxalyl group; a methylsulfonyl group; Examples of the alkyl group include alkylsulfanyl groups such as phenylsulfanyl and tert-butylsulfanyl groups; arylsulfanyl groups such as phenylsulfanyl and p-tolylsulfanyl groups; alkyl 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 linear, branched, or cyclic. Furthermore, when the alkyl group contains a fluorine atom, it may be a perfluoroalkyl group. Furthermore, the aryl group and heteroaryl group may be monocyclic or polycyclic.

[0145] R ４ ~R ７Examples of the substituent represented by the formula (I) include an aryl group which may have a substituent, a heteroaryl group which may have a substituent, 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 are preferably 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, an indole ring, a benzofuran ring, and a benzothiophene ring.

[0146] The substituents that the aryl group and heteroaryl group may have are not particularly limited, and examples thereof include the groups exemplified above as the substituent T. Examples of the substituents include alkyl groups (e.g., linear alkyl groups having 1 to 15 carbon atoms, branched alkyl groups having 3 to 15 carbon atoms, and cyclic alkyl groups having 3 to 15 carbon atoms), aryl groups (which may be either monocyclic or polycyclic, preferably having 6 to 20 carbon atoms, more preferably having 6 to 10 carbon atoms), heteroaryl groups (which may be either monocyclic or polycyclic, preferably having 3 to 15 carbon atoms, more preferably having 3 to 10 carbon atoms), alkoxy groups (e.g., linear alkoxy groups having 1 to 15 carbon atoms, branched alkoxy groups having 1 to 15 carbon atoms, and cyclic alkoxy groups having 3 to 15 carbon atoms), halogen atoms (e.g., fluorine atoms, chlorine atoms, iodine atoms, etc.), hydroxyl groups, cyano groups, and nitro groups. The substituents may further have other substituents. For example, the alkyl groups may have halogen atoms as substituents, resulting in halogenated alkyl groups such as trifluoromethyl groups.

[0147] In addition, R ４ ~R ７Among 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.

[0148] Y ｍ＋ represents an organic cation or inorganic 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.

[0149] Y ｍ＋ The organic cation represented by the formula (ZaI) is not particularly limited, and examples thereof include quaternary ammonium cations and quaternary phosphonium cations such as an organic cation represented by the formula (ZaI) below (cation (ZaI)), an organic cation represented by the formula (ZaII) below (cation (ZaII)), an organic cation represented by the formula (ZaIII) below (cation (ZaIII)), and an organic cation represented by the formula (ZaIV) below (cation (ZaIV)).

[0150]

[0151] In the formula (ZaI), R ２０１ ~R ２０３ R each independently represents an organic group. ２０１ ~R ２０３ The number of carbon atoms in the organic group represented by R is preferably 1 to 30, and more preferably 1 to 20. ２０１ ~R ２０３ Two of the organic groups represented by the formula (I) 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 bonding two of the organic groups represented by the formula (I) include an alkylene group (e.g., a butylene group and a pentylene group), and —CH ２ -CH ２ -O-CH２ -CH ２ - are listed.

[0152] Of the above-mentioned cations (ZaI), cations (ZaI-1), (ZaI-2), organic cations represented by formula (ZaI-3b) (cations (ZaI-3b)), or organic cations represented by formula (ZaI-4b) (cations (ZaI-4b)) are preferred.

[0153] First, the cation (ZaI-1) will be described. In the cation (ZaI-1), R ２０１ ~R ２０３ At least one of R represents a monovalent aromatic ring group which may have a substituent. ２０１ ~R ２０３ may all be monovalent aromatic ring groups, or R ２０１ ~R ２０３ A part of R may be a monovalent aromatic ring group, and the rest may be an alkyl group which may have a substituent. ２０１ ~R ２０３ one of which is a monovalent aromatic ring group, and R ２０１ ~R ２０３ The remaining two of R may be bonded to form a ring structure, and the formed 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 -) are listed.

[0154] In the cation (ZaI-1), examples of the monovalent aromatic ring group include an aryl group and a heteroaryl 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, more preferably 6 to 10. Specific examples of the aryl group are preferably a phenyl group or a naphthyl group, 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, more preferably 3 to 10. Specific examples of the ring constituting the heteroaryl group include a pyrrole ring, a furan ring, a thiophene ring, an indole ring, a benzofuran ring, and a benzothiophene ring. In the cation (ZaI-1), R ２０１ ~R ２０３ When two or more of the above are monovalent aromatic ring groups, the two or more monovalent aromatic ring groups may be the same or different.

[0155] In the cation (ZaI-1), the alkyl group is preferably a linear alkyl group having 1 to 15 carbon atoms, a branched alkyl group having 3 to 15 carbon atoms, or a cyclic alkyl group having 3 to 15 carbon atoms, and examples thereof include 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, and a cyclohexyl group.

[0156] R ２０１ ~R ２０３The monovalent aromatic ring group and the substituent that the alkyl group may have each independently include alkyl groups (e.g., linear alkyl groups having 1 to 15 carbon atoms, branched alkyl groups having 3 to 15 carbon atoms, and cyclic alkyl groups having 3 to 15 carbon atoms), aryl groups (which may be either monocyclic or polycyclic. The carbon number is preferably 6 to 20, and more preferably 6 to 10), heteroaryl groups (which may be either monocyclic or polycyclic. The carbon number is preferably 3 to 15, and more preferably 3 to 10), alkoxy groups (e.g., linear alkoxy groups having 1 to 15 carbon atoms, branched alkoxy groups having 1 to 15 carbon atoms, and cyclic alkoxy groups having 3 to 15 carbon atoms), halogen atoms (e.g., fluorine atoms, chlorine atoms, and iodine atoms), hydroxyl groups, cyano groups, and nitro groups. The substituents may further have other substituents. For example, the alkyl groups may have halogen atoms as substituents, forming halogenated alkyl groups such as trifluoromethyl groups.

[0157] Examples of the cation (ZaI-1) include an optionally substituted triarylsulfonium cation, an optionally substituted diarylalkylsulfonium cation, and an optionally substituted aryldialkylsulfonium cation. Among these, an optionally substituted triarylsulfonium cation is preferred in terms of achieving the effects of the present invention more excellently.

[0158] Next, the cation (ZaI-2) will be described. In the cation (ZaI-2), R ２０１ ~R ２０３ Each of R independently represents an organic group that does not have an aromatic ring. ２０１ ~R ２０３ The organic group having no aromatic ring represented by the formula (I) generally has 1 to 30 carbon atoms, preferably 1 to 20 carbon atoms. ２０１ ~R ２０３ The organic group having no aromatic ring represented by the formula (I) is preferably an alkyl group, an allyl group, a vinyl group, a linear or branched 2-oxoalkyl group, a 2-oxocycloalkyl group, or an alkoxycarbonylmethyl group, and more preferably a linear or branched 2-oxoalkyl group.

[0159] In cation (ZaI-2), examples of the alkyl group include a linear alkyl group having 1 to 15 carbon atoms (preferably 1 to 10 carbon atoms), a branched alkyl group having 3 to 15 carbon atoms (preferably 3 to 10 carbon atoms), and a cyclic alkyl group (which may be either monocyclic or polycyclic) having 3 to 15 carbon atoms (preferably 3 to 10 carbon atoms). In cation (ZaI-2), the number of carbon atoms in the linear or branched 2-oxoalkyl group is preferably 2 to 15, more preferably 2 to 10. In cation (ZaI-2), the number of carbon atoms in the 2-oxocycloalkyl group is preferably 4 to 15, more preferably 4 to 10. In cation (ZaI-2), the number of carbon atoms in the alkoxycarbonylmethyl group is preferably 3 to 15, more preferably 3 to 10. In addition, R ２０１ ~R ２０３ Each of the above groups represented by the formula (I) may further have a substituent, such as a halogen atom, an alkoxy group (e.g., having 1 to 5 carbon atoms), a hydroxyl group, a cyano group, or a nitro group.

[0160] Next, the cation (ZaI-3b) will be described.

[0161]

[0162] In formula (ZaI-3b), R １ｃ ~R ５ｃ each independently represents a hydrogen atom, an alkyl group, a monovalent aromatic ring group, an alkoxy group, an aryloxy group, an alkoxycarbonyl group, an alkylcarbonyloxy group, a halogen atom, a hydroxyl group, a nitro group, an alkylthio group, or an arylthio group.

[0163] R １ｃ ~R ５ｃ The alkyl group represented by the formula (I) is preferably a linear alkyl group having 1 to 15 carbon atoms, a branched alkyl group having 3 to 15 carbon atoms, or a cyclic alkyl group having 3 to 15 carbon atoms. The alkyl group may further have a substituent. Examples of the substituent include a halogen atom, an alkoxy group (e.g., having 1 to 5 carbon atoms), a hydroxyl group, a cyano group, and a nitro group.

[0164] R １ｃ~R ５ｃ The alkyl group moiety in the alkoxy group, alkoxycarbonyloxy group, and alkylthio group represented by the formula (I) is preferably a linear alkyl group having 1 to 15 carbon atoms, a branched alkyl group having 3 to 15 carbon atoms, or a cyclic alkyl group having 3 to 15 carbon atoms. １ｃ ~R ５ｃ The alkyl group moiety in the alkoxy group, alkoxycarbonyloxy group, and alkylthio group represented by the formula (I) may further have a substituent, such as a halogen atom, an alkoxy group (e.g., having 1 to 5 carbon atoms), a hydroxyl group, a cyano group, or a nitro group.

[0165] R １ｃ ~R ５ｃExamples of the monovalent aromatic ring group represented by the formula (I) include an aryl group and a heteroaryl 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, an indole ring, a benzofuran ring, and a benzothiophene ring. 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 alkyl groups (e.g., linear alkyl groups having 1 to 15 carbon atoms, branched alkyl groups having 3 to 15 carbon atoms, and cyclic alkyl groups having 3 to 15 carbon atoms), aryl groups (which may be either monocyclic or polycyclic, preferably having 6 to 20 carbon atoms, and more preferably having 6 to 10 carbon atoms), heteroaryl groups (which may be either monocyclic or polycyclic, preferably having 3 to 15 carbon atoms, and more preferably having 3 to 10 carbon atoms), alkoxy groups (e.g., linear alkoxy groups having 1 to 15 carbon atoms, branched alkoxy groups having 1 to 15 carbon atoms, and cyclic alkoxy groups having 3 to 15 carbon atoms), halogen atoms (e.g., fluorine atoms, chlorine atoms, and iodine atoms), hydroxyl groups, cyano groups, and nitro groups. The substituents may further have other substituents. For example, the alkyl groups may have halogen atoms as substituents to form halogenated alkyl groups such as trifluoromethyl groups.

[0166] R １ｃ ~R ５ｃEach aryl group moiety in the aryloxy group and arylthio group represented by the formula (I) may be either a monocyclic or polycyclic ring. The number of carbon atoms in the aryl group moiety is, for example, preferably 6 to 20, more preferably 6 to 10. Specific examples of the aryl group moiety include a phenyl group or a naphthyl group, and more preferably a phenyl group. R １ｃ ~R ５ｃ The aryl group moiety of the aryloxy group and arylthio group represented by the following formula may further have a substituent. １ｃ ~R ５ｃ The same substituents as those which the monovalent aromatic ring group represented by the following formula (I) may have are listed, and the preferred embodiments are also the same.

[0167] In formula (ZaI-3b), R ６ｃ and R ７ｃ R each independently represents a hydrogen atom, an alkyl group, a halogen atom, a cyano group, or an aryl group. ６ｃ and R ７ｃ Examples of the alkyl group represented by the formula (ZaI-3b) include R １ｃ ~R ５ｃ The meaning and preferred embodiments are the same as those of the alkyl group represented by the formula R ６ｃ and R ７ｃ The aryl group represented by the formula (ZaI-3b) includes R １ｃ ~R ５ｃ The meaning and preferred embodiments are also the same as those of the aryl group represented by the following formula:

[0168] In formula (ZaI-3b), R ｘ and R ｙ R each independently represents an alkyl group, a linear or branched 2-oxoalkyl group, a 2-oxocycloalkyl group, an alkoxycarbonylalkyl group, an allyl group, or a vinyl group. ｘ and R ｙ Examples of the alkyl group represented by the formula (ZaI-3b) include R １ｃ ~R ５ｃ The meaning and preferred embodiments are the same as those of the alkyl group represented by the formula R ｘ and R ｙThe number of carbon atoms in the linear or branched 2-oxoalkyl group represented by R is, for example, preferably 2 to 15, and more preferably 2 to 10. ｘ and R ｙ The number of carbon atoms in the 2-oxocycloalkyl group represented by R is preferably 4 to 15, and more preferably 4 to 10. ｘ and R ｙ The number of carbon atoms in the alkoxycarbonylmethyl group represented by the formula (I) is preferably 3 to 15, more preferably 3 to 10. ｘ and R ｙ Each of the above groups represented by the formula (I) may further have a substituent, such as a halogen atom, an alkoxy group (e.g., having 1 to 5 carbon atoms), a hydroxyl group, a cyano group, or a nitro group.

[0169] In formula (ZaI-3b), 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 the formed rings may each independently contain an oxygen atom, a sulfur atom, a ketone group, an ester group, or an amide bond. Examples of the ring include an aromatic or non-aromatic monocyclic (preferably a 3- to 10-membered ring, more preferably a 4- to 8-membered ring, and even more preferably a 5- or 6-membered ring) hydrocarbon ring, an aromatic or non-aromatic monocyclic (preferably a 3- to 10-membered ring, more preferably a 4- to 8-membered ring, and even more preferably a 5- or 6-membered ring) heterocycle, and a polycyclic fused ring formed by combining two or more of these monocyclic rings.

[0170] 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.

[0171] Next, the cation (ZaI-4b) will be described.

[0172]

[0173] In formula (ZaI-4b), l represents an integer of 0 to 2, and r represents an integer of 0 to 8. １３ represents a hydrogen atom, a fluorine atom, a hydroxyl group, an alkyl group, an alkoxy group, or an alkoxycarbonyl group. １３ The alkyl group represented by the formula (I) is preferably a linear alkyl group having 1 to 15 carbon atoms, a branched alkyl group having 3 to 15 carbon atoms, or a cyclic alkyl group having 3 to 15 carbon atoms. The alkyl group may further have a substituent. Examples of the substituent include a halogen atom, an alkoxy group (e.g., having 1 to 5 carbon atoms), a hydroxyl group, a cyano group, and a nitro group.

[0174] R １３ The alkyl group moiety in the alkoxy group and alkoxycarbonyl group represented by the formula (I) is preferably a linear alkyl group having 1 to 15 carbon atoms, a branched alkyl group having 3 to 15 carbon atoms, or a cyclic alkyl group having 3 to 15 carbon atoms. １３ Each alkyl group in the alkoxy group and alkoxycarbonyl group represented by the formula (I) may further have a substituent, which may include a halogen atom, an alkoxy group (e.g., having 1 to 5 carbon atoms), a hydroxyl group, a cyano group, and a nitro group.

[0175] R １４ represents a hydroxyl group, an alkyl group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, or an alkylsulfonyl group. １４The alkyl group represented by R is preferably a linear alkyl group having 1 to 10 carbon atoms, a branched alkyl group having 3 to 10 carbon atoms, or a cyclic alkyl group having 3 to 10 carbon atoms. The alkyl group may further have a substituent. Examples of the substituent include a halogen atom, an alkoxy group (e.g., having 1 to 5 carbon atoms), a hydroxyl group, a cyano group, and a nitro group. １４ The alkyl group moiety in the alkoxy group, alkoxycarbonyl group, alkylcarbonyl group, and alkylsulfonyl group represented by the formula (I) is preferably a linear alkyl group having 1 to 10 carbon atoms, a branched alkyl group having 3 to 10 carbon atoms, or a cyclic alkyl group having 3 to 10 carbon atoms. １４ Each alkyl group moiety in the alkoxy group, alkoxycarbonyl group, alkylcarbonyl group, and alkylsulfonyl group represented by the formula (I) may further have a substituent, such as a halogen atom, an alkoxy group (e.g., having 1 to 5 carbon atoms), a hydroxyl group, a cyano group, or a nitro group.

[0176] R １５ R each independently represents an alkyl group or a naphthyl group. １５ The alkyl group represented by R may be linear, branched, or cyclic. The number of carbon atoms in the alkyl group is preferably 1 to 10. The alkyl group is preferably a methyl group, an ethyl group, an n-butyl group, or a t-butyl group. １５ The alkyl group and naphthyl group represented by the following formula may further have a substituent. The substituent is not particularly limited, and examples thereof include the groups exemplified above as the substituent T. 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 are bonded to each other to form an aliphatic hydrocarbon ring structure.

[0177] Next, the cation (ZaII) will be described. In formula (ZaII), R ２０４ and R ２０５each independently represents an optionally substituted monovalent aromatic ring group or an optionally substituted alkyl group, and a monovalent aromatic ring group is preferred in that the effects of the present invention are more excellent.

[0178] R ２０４ and R ２０５ Examples of the monovalent aromatic ring group include an aryl group and a heteroaryl group. The aryl group is preferably a phenyl group or a naphthyl group, and more preferably a phenyl group. The heteroaryl group has a heteroatom such as an oxygen atom, a nitrogen atom, or a sulfur atom. Examples of the ring constituting the heteroaryl group include a pyrrole ring, a furan ring, a thiophene ring, an indole ring, a benzofuran ring, and a benzothiophene ring. R ２０４ and R ２０５ The alkyl group is preferably a linear alkyl group having 1 to 10 carbon atoms or a branched alkyl group having 3 to 10 carbon atoms (e.g., methyl, ethyl, propyl, butyl, and pentyl), or a cyclic alkyl group having 3 to 10 carbon atoms (e.g., cyclopentyl, cyclohexyl, and norbornyl).

[0179] R ２０４ and R ２０５ The monovalent aromatic ring group and alkyl group may further have another substituent, and examples of the other substituent include an alkyl group (e.g., having 1 to 15 carbon atoms), a monovalent aromatic ring 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.

[0180] In formula (ZaII), R ２０４ and R ２０５ each independently represents an optionally substituted monovalent aromatic ring group or an optionally substituted alkyl group, and a monovalent aromatic ring group is preferred in that the effects of the present invention are more excellent.

[0181] Next, the cation (ZaIII) will be described. The cation (ZaIII) corresponds to a quaternary ammonium cation or a quaternary phosphonium cation.

[0182]

[0183] In formula (ZaIII), X ３０１ represents a nitrogen atom or a phosphorus atom. ３０１ ~R ３０４ Each independently represents a monovalent aromatic ring group which may have a substituent or an alkyl group which may have a substituent. ３０１ The nitrogen atom or phosphorus atom represented by the formula: is cationized.

[0184] R ３０１ ~R ３０４ The alkyl group represented by the formula (I) may be linear, branched, or cyclic, but is preferably linear or branched, and more preferably linear. The number of carbon atoms in the alkyl group is preferably 1 to 20, more preferably 4 to 18, and even more preferably 6 to 12. The substituent that the alkyl group may have is not particularly limited, and examples thereof include the groups exemplified for the substituent T above.

[0185] R ３０１ ~R ３０４Examples of the monovalent aromatic ring group represented by the formula (I) include an aryl group and a heteroaryl 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, an indole ring, a benzofuran ring, and a benzothiophene ring. 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 alkyl groups (e.g., linear alkyl groups having 1 to 15 carbon atoms, branched alkyl groups having 3 to 15 carbon atoms, and cyclic alkyl groups having 3 to 15 carbon atoms), aryl groups (which may be either monocyclic or polycyclic, preferably having 6 to 20 carbon atoms, and more preferably having 6 to 10 carbon atoms), heteroaryl groups (which may be either monocyclic or polycyclic, preferably having 3 to 15 carbon atoms, and more preferably having 3 to 10 carbon atoms), alkoxy groups (e.g., linear alkoxy groups having 1 to 15 carbon atoms, branched alkoxy groups having 1 to 15 carbon atoms, and cyclic alkoxy groups having 3 to 15 carbon atoms), halogen atoms (e.g., fluorine atoms, chlorine atoms, and iodine atoms), hydroxyl groups, cyano groups, and nitro groups. The substituents may further have other substituents. For example, the alkyl groups may have halogen atoms as substituents to form halogenated alkyl groups such as trifluoromethyl groups.

[0186] In formula (ZaIII), R ３０１ ~R ３０４ may be bonded to each other to form an alicyclic ring. The alicyclic ring may have X as a ring member atom, as shown in the formula. ３０１The alicyclic ring may contain a heteroatom other than the nitrogen atom or phosphorus atom (for example, an oxygen atom, a nitrogen atom, an oxygen atom, etc.). Furthermore, a ring member atom may be substituted with a carbonyl carbon (>C=O). The alicyclic ring may be monocyclic or polycyclic. The number of ring member atoms of the alicyclic ring is preferably 5 to 15, more preferably 5 to 10, and even more preferably 5 or 6. The alicyclic ring may further have a substituent. Examples of the substituent include the groups exemplified as the substituent T above.

[0187] Next, the cation (ZaIV) will be described. The cation (ZaIV) corresponds to a quaternary ammonium cation or a quaternary phosphonium cation.

[0188]

[0189] In formula (ZaIV), X ３０２ represents a nitrogen atom or a phosphorus atom. ３０５ represents an alkyl group which may have a substituent; W ３０１ has X as a ring member atom ３０２ The cation (ZaIV) represents an aromatic ring containing a nitrogen atom or a phosphorus atom represented by the formula: ３０２ The nitrogen atom or phosphorus atom represented by the formula: is cationized.

[0190] R ３０５ Examples of the alkyl group which may have a substituent represented by the formula (ZaIII) include R ３０１ ~R ３０４ The meaning and preferred embodiments are the same as those of the alkyl group optionally having a substituent represented by the following formula: ３０１ The aromatic ring represented by the formula (I) may be either a monocyclic ring or a polycyclic ring. ３０１ The aromatic ring represented by the formula may contain, as a ring member atom, a heteroatom other than the nitrogen atom or phosphorus atom specified in the formula (for example, an oxygen atom, a nitrogen atom, an oxygen atom, etc.). ３０１ The number of ring atoms in the aromatic ring represented by the formula (I) is preferably 5 to 15, more preferably 5 to 10, and even more preferably 5 or 6. ３０１The aromatic ring represented by the formula (I) may further have a substituent. Examples of the substituent include the groups exemplified as the substituent T above. Examples of the substituent include alkyl groups (e.g., linear alkyl groups having 1 to 15 carbon atoms, branched alkyl groups having 3 to 15 carbon atoms, and cyclic alkyl groups having 3 to 15 carbon atoms), aryl groups (which may be either monocyclic or polycyclic, preferably having 6 to 20 carbon atoms, more preferably having 6 to 10 carbon atoms), heteroaryl groups (which may be either monocyclic or polycyclic, preferably having 3 to 15 carbon atoms, more preferably having 3 to 10 carbon atoms), alkoxy groups (e.g., linear alkoxy groups having 1 to 15 carbon atoms, branched alkoxy groups having 1 to 15 carbon atoms, and cyclic alkoxy groups having 3 to 15 carbon atoms), halogen atoms (e.g., fluorine atoms, chlorine atoms, and iodine atoms), hydroxyl groups, cyano groups, and nitro groups. Specific examples of the aromatic ring include pyridinium cations.

[0191] In formula (3), Y ｍ＋ The inorganic cation represented by the formula (I) is not particularly limited, and examples thereof include alkali metal ions such as lithium ion, potassium ion, sodium ion, rubidium ion, and cesium ion, and alkaline earth metal ions such as magnesium ion and calcium ion.

[0192] In formula (3), Y ｍ＋ As the cation, an organic cation is preferred, a sulfonium cation or an iodonium cation is more preferred, and the above-mentioned cation (ZaI) or cation (ZaII) is even more preferred.

[0193] In terms of the effects of the present invention being more excellent, the boron-containing compound is also preferably a compound in which the atom at the bonding position to the boron atom in the atomic group bonding to the boron atom is selected from a carbon atom, an oxygen atom, or a nitrogen atom.

[0194] The boron-containing compound preferably contains at least one of a fluorine atom and an iodine atom, in that the effects of the present invention are more excellent.

[0195] A preferred embodiment of the boron-containing compound is a compound having a borate anion, in which the atom at the bonding position to the boron atom in the atomic group bonding to the boron atom is any one of a carbon atom, an oxygen atom, and a nitrogen atom, and also includes a fluorine atom or an iodine atom. In this embodiment, the boron atom is anionized. Furthermore, the counter cation of the borate anion is preferably an organic cation, more preferably a sulfonium cation or an iodonium cation, and even more preferably the above-mentioned cation (ZaI) or cation (ZaII).

[0196] The content of the boron-containing compound in the resist composition is preferably 1.0 mass% or more, more preferably 2.0 mass% or more, and even more preferably 4.0 mass% or more, based on the total solid content of the resist composition. The upper limit is preferably 30.0 mass% or less, more preferably 25.0 mass% or less, even more preferably 20.0 mass% or less, and particularly preferably 10.0 mass% or less. The boron-containing compound may be used alone or in combination. When two or more types are used, the total content thereof is preferably within the above-mentioned preferred content range.

[0197] [Photoacid Generator] The resist composition contains a photoacid generator. The photoacid generator is a compound that generates an acid when irradiated with actinic rays or radiation. The photoacid generator may be in the form of a low molecular weight compound or a polymer. Examples of polymeric photoacid generators include those in which the photoacid generator is incorporated into a portion of the resin (A) (acid-decomposable resin) described above. More specifically, examples include those in which the photoacid generator is covalently linked to the resin (A) (acid-decomposable resin). Note that a photoacid generator in the form of a low molecular weight compound may be used in combination with a photoacid generator in the form of a polymer (for example, incorporated into a portion of the resin (A) (acid-decomposable resin) described above). When the photoacid generator is in the form of a low molecular weight compound, the molecular weight of the photoacid generator is preferably 3,000 or less, more preferably 2,000 or less, and even more preferably 1,000 or less. There is no particular lower limit, but a molecular weight of 100 or more is preferred. When the photoacid generator is in a form incorporated into a part of a polymer, it may be incorporated into a part of the resin (A) or into a resin different from the resin (A). In this specification, the photoacid generator is preferably in the form of a low molecular weight compound. The photoacid generator is preferably an onium salt compound, and as described below, a sulfonium salt compound or an iodonium salt compound is preferred.

[0198] <Photoacid Generator PG1> An example of a preferred embodiment of the photoacid generator is "M ＋ X － " which generates an organic acid upon exposure to light (hereinafter also referred to as "photoacid generator PG1"). ＋ X － In the compound represented by the formula ", M ＋ represents an organic cation, and X －represents an organic anion. Examples of the organic acid 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. The pKa of the organic acid is preferably 2.0 or less, more preferably less than 0. The lower limit of the acid dissociation constant a1 is preferably -20.0 or more. The photoacid generator PG1 will be described below.

[0199] "M ＋ X － In the compound represented by the formula ", M ＋ represents an organic cation. The organic cation is not particularly limited. The valence of the organic cation may be monovalent or divalent or higher. Specific examples of the organic cation include the cation (ZaI) and cation (ZaII) that may be contained in the above-mentioned boron-containing compound, and the preferred embodiments are also the same. The organic cation preferably contains a fluorine atom, as this provides a more excellent effect of the present invention.

[0200] "M ＋ X － In the compound represented by the formula "X － represents an organic anion. The organic anion is not particularly limited, and examples thereof include monovalent or divalent or higher organic anions. As the organic anion, an anion having a significantly low ability to cause a nucleophilic reaction is preferred, and a non-nucleophilic anion is more preferred.

[0201] Examples of non-nucleophilic anions 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.

[0202] The organic anion is preferably, for example, an organic anion represented by the following formula (DA).

[0203]

[0204] 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.

[0205] 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 the formulas (B-1) to (B-14).

[0206]

[0207] *-O － Formula (B-14)

[0208] In formulas (B-1) to (B-14), * represents a bonding position. Ｘ１ Each independently represents a monovalent organic group. Ｘ２ Each 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. ＸＦ２represents 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.

[0209] 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 The atom directly bonded to N- in -CO- and -SO ２ It is also preferred that neither of the sulfur atoms in - is present.

[0210] 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.

[0211] 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.

[0212] 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 Ｘ１The 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.

[0213] 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.

[0214] 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.

[0215] 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.

[0216] 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.

[0217] 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.

[0218] 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.

[0219] 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.

[0220] 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 and an oxygen atom. 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.

[0221] L ａ１The divalent linking group as is not particularly limited, and may be an alkylene group, a cycloalkylene group, an aromatic group, —O—, —CO—, —SO—, —SO ２ -, and groups formed by combining two or more of these. The alkylene group may be linear or branched, and preferably has 1 to 20 carbon atoms, 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, and preferably has 6 to 20 carbon atoms, and more preferably has 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, and specific examples include 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, and 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. In addition, A ３１－ and R ａ１ may be bonded to each other to form a ring.

[0222] As the photoacid generator 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.

[0223] The molecular weight of the photoacid generator PG1 is preferably 3,000 or less, more preferably 2,000 or less, and even more preferably 1,000 or less.

[0224] <Photoacid generator PG2> Another suitable example of the photoacid generator is the following compound (I) (hereinafter also referred to as "photoacid generator PG2"). Photoacid generator PG2 is a compound that has two or more of the above-mentioned salt structure moieties and generates a polyvalent organic acid upon exposure to light. Photoacid generator PG2 will be described below.

[0225] (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 the first acidic moiety derived from the structural moiety X and the 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):

[0226] 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.

[0227] One embodiment of compound (I) is an embodiment having two structural moieties X and one structural moiety Y.

[0228] For example, when compound (I) is a compound having two structural moieties X and one structural moiety Y (i.e., an acid-generating compound having two of the first acidic moieties derived from the structural moiety X and one of the second acidic moieties derived from the structural moiety Y), compound PI is a compound having "two HAs" １ and one HA ２ When the acid dissociation constant of compound PI is calculated, compound PI corresponds to "a compound having one A １ － and one HA １ and one HA ２ and the acid dissociation constant when "a compound having one A １ － and one HA １ and one HA ２ "Compound having two A １ － and one HA ２ The acid dissociation constant when the compound is a compound having two A's corresponds to the acid dissociation constant a1 described above. １ － and one HA ２ "Compound having two A １ － and A ２ － In other words, in the case of compound PI, the acid dissociation constant when the compound becomes a compound having the cation moiety M in the structural moiety X corresponds to the acid dissociation constant a2. １ ＋ H ＋ HA is replaced by １ When the compound PI has a plurality of acid dissociation constants derived from the acidic moiety represented by the formula (I), the value of the acid dissociation constant a2 is larger than the largest value of the plurality of acid dissociation constants a1. １ － and one HA １ and one HA ２ The acid dissociation constant when the compound is aa is defined as "a compound having one A １ － and one HA １ and one HA ２ "Compound having two A １ － and one HA２ When the acid dissociation constant when the compound becomes "a compound having the formula (I)" is ab, the relationship between aa and ab satisfies aa<ab.

[0229] The acid dissociation constants a1 and a2 can be determined by the above-mentioned method for measuring an acid dissociation constant. The compound PI corresponds to the acid generated when compound (I) is irradiated with actinic rays or radiation.

[0230] In the compound PI, the difference (absolute value) between the acid dissociation constant a1 (the maximum value when there are multiple acid dissociation constants a1) and the acid dissociation constant a2 is preferably 0.1 or more, more preferably 0.5 or more, and even more preferably 1.0 or more. The upper limit of the difference (absolute value) between the acid dissociation constant a1 (the maximum value when there are multiple acid dissociation constants a1) and the acid dissociation constant a2 is not particularly limited, but is, for example, 16 or less.

[0231] In the compound PI, the acid dissociation constant a2 is preferably 20 or less, and more preferably 15 or less. The lower limit of the acid dissociation constant a2 is preferably −4.0 or more, more preferably −1.0 or more, even more preferably 0 or more, and most preferably 0.5 or more.

[0232] In the compound PI, the acid dissociation constant a1 is preferably 2.0 or less, and more preferably less than 0. The lower limit of the acid dissociation constant a1 is preferably −20.0 or more.

[0233] 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 A２ － are preferably different from each other.

[0234] 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 formulae (AA-1) to (AA-3) and formulae (BB-1) to (BB-6) shown below. １ － As the anionic moiety A, those capable of forming an acidic moiety with a small acid dissociation constant are preferred, and among these, any of formulas (AA-1) to (AA-3) is more preferred, and any of formulas (AA-1) and (AA-3) is even more preferred. ２ － As the anion moiety A １ － Preferably, it is one that can form an acidic site with a larger acid dissociation constant than the above, more preferably any of formulas (BB-1) to (BB-6), and even more preferably any of formulas (BB-1) and (BB-4). In the following formulas (AA-1) to (AA-3) and formulas (BB-1) to (BB-6), * represents a bonding position. In formula (AA-2), R Ａ represents a monovalent organic group. Ａ The monovalent organic group represented by the formula (I) is not particularly limited, but examples thereof include a cyano group, a trifluoromethyl group, and a methanesulfonyl group.

[0235]

[0236] 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. Specific examples of the organic cation include the cation (ZaI) and the cation (ZaII) that may be contained in the boron-containing compound described above, and the preferred embodiments are also the same. The organic cation preferably contains a fluorine atom, as this provides a more excellent effect of the present invention.

[0237] The molecular weight of the photoacid generator PG2 is preferably 100 to 10,000, more preferably 100 to 2,500, and even more preferably 100 to 1,500.

[0238] Examples of the photoacid generator PG2 include the compounds exemplified in paragraphs

[0023] to

[0078] of WO 2020 / 158313.

[0239] The photoacid generator is preferably a compound containing a cation containing a fluorine atom, and more preferably an onium salt compound in which an organic cation containing a fluorine atom and a nucleophilic organic anion are paired, in terms of achieving better effects of the present invention, being able to form a pattern with a smaller LER, being able to form a pattern with better resolution, and / or being more excellent in sensitivity.

[0240] The content of the photoacid generator in the resist composition is not particularly limited, but in order to form a more rectangular cross-sectional shape of the pattern, it is preferably 0.5% by mass or more, more preferably 5.0% by mass or more, even more preferably 10.0% by mass or more, and particularly preferably 20.0% by mass or more, relative to the total solid content of the resist composition. The content is preferably 50.0% by mass or less, more preferably 45.0% by mass or less, and even more preferably 40.0% by mass or less, relative to the total solid content of the resist composition. The photoacid generator may be used alone, or two or more types may be used. When two or more types are used, the total content thereof is preferably within the above-mentioned preferred content range.

[0241] [Acid Diffusion Controller] The resist composition preferably contains an acid diffusion controller. The acid diffusion controller traps the acid generated from the photoacid generator or the like during exposure, and acts as a quencher that suppresses the reaction of the acid-decomposable resin in unexposed areas due to excess generated acid. The type of acid diffusion controller is not particularly limited, and examples include basic compounds (DA), compounds (DB) whose basicity is reduced or eliminated by irradiation with actinic rays or radiation, low-molecular-weight compounds (DC) having a group that is cleaved by the action of an acid, and onium salt compounds (DD) that generate an acid that is weaker than the photoacid generator. Specific examples of the basic compound (DA) include those described in paragraphs

[0132] to

[0136] of WO 2020 / 066824. Specific examples of the basic compound (DB) whose basicity is reduced or eliminated by irradiation with actinic rays or radiation include those described in paragraphs

[0137] to

[0155] of WO 2020 / 066824. Specific examples of the low molecular weight compound (DC) having a group that leaves under the action of an acid include those described in paragraphs

[0156] to

[0163] of WO 2020 / 066824. Specific examples of the onium salt compound (DD) that generates an acid that is relatively weakly acidic to the photoacid generator include those described in paragraph

[0164] of WO 2020 / 066824. Specific examples of the onium salt compound (DD) that generates an acid that is weaker than the photoacid generator include those described in paragraphs

[0305] to

[0314] of WO 2020 / 158337.

[0242] In addition to the above, for example, known compounds disclosed in paragraphs

[0627] to

[0664] of U.S. Patent Application Publication No. 2016 / 0070167A1, paragraphs

[0095] to

[0187] of U.S. Patent Application Publication No. 2015 / 0004544A1, paragraphs

[0403] to

[0423] of U.S. Patent Application Publication No. 2016 / 0237190A1, and paragraphs

[0259] to

[0328] of U.S. Patent Application Publication No. 2016 / 0274458A1 can be suitably used as the acid diffusion controller.

[0243] When the acid diffusion controller is an onium salt compound (DD) that generates an acid that is weaker than the photoacid generator, the acid dissociation constant of the generated acid is preferably 20 or less, more preferably 15 or less. The lower limit of the acid dissociation constant is preferably −4.0 or more, more preferably −1.0 or more, even more preferably 0 or more, and most preferably 0.5 or more. The onium salt compound is preferably a sulfonium salt compound or an iodonium salt compound.

[0244] When the resist composition contains an acid diffusion controller, the content of the acid diffusion controller (or the total content if multiple types are present) is preferably 0.1 to 20.0 mass%, more preferably 0.1 to 15.0 mass%, and even more preferably 1.0 to 15.0 mass%, relative to the total solids content of the resist composition. In the resist composition, one type of acid diffusion controller may be used alone, or two or more types may be used in combination. When two or more types are used, the total content thereof preferably falls within the above-mentioned preferred content range.

[0245] [Surfactant] The resist composition may contain a surfactant. When the resist composition contains a surfactant, it is possible to form a pattern with better adhesion and fewer development defects. 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.

[0246] These surfactants may be used alone or in combination of two or more.

[0247] When the resist composition contains a surfactant, the content of the surfactant is preferably from 0.0001 to 2.0 mass%, more preferably from 0.0005 to 1.0 mass%, and even more preferably from 0.1 to 1.0 mass%, relative to the total solids content of the resist composition. When two or more surfactants are used, the total content thereof preferably falls within the above-mentioned preferred content range.

[0248] [Hydrophobic Resin] The resist composition may further contain a hydrophobic resin different from the resin (A). The hydrophobic resin is preferably designed so as to be unevenly distributed on the surface of the resist film, but unlike surfactants, it does not necessarily have to have a hydrophilic group in its molecule, and it does not necessarily have to contribute to uniform mixing of polar and non-polar substances. The effects of adding a hydrophobic resin include controlling the static and dynamic contact angles of the resist film surface with water, and suppressing outgassing.

[0249] The hydrophobic resin contains fluorine atoms, silicon atoms, and CH atoms contained in the side chain portion of the resin in order to be unevenly distributed on the surface layer of the film. ３ It is preferable to have one or more of the partial structures, and more preferably two or more. The hydrophobic resin preferably has a hydrocarbon group having 5 or more carbon atoms. These groups may be present in the main chain of the resin or may be substituted on a side chain. Examples of hydrophobic resins include the compounds described in paragraphs

[0275] to

[0279] of WO 2020 / 004306.

[0250] When the resist composition contains a hydrophobic resin, the content of the hydrophobic resin is preferably 0.01 to 20.0 mass%, and more preferably 0.1 to 15.0 mass%, relative to the total solids content of the resist composition. In the resist composition, one hydrophobic resin may be used alone, or two or more hydrophobic resins may be used in combination. When two or more hydrophobic resins are used, the total content thereof preferably falls within the above-mentioned preferred content range.

[0251] [Solvent] The resist composition preferably contains a solvent. The solvent preferably contains (M1) propylene glycol monoalkyl ether carboxylate and (M2) at least one selected from the group consisting of propylene glycol monoalkyl ether, lactate ester, acetate ester, alkoxypropionate ester, chain ketone, cyclic ketone, lactone (e.g., γ-butyrolactone), and alkylene carbonate. The solvent may further contain components other than components (M1) and (M2).

[0252] Combining the above-mentioned solvent with the above-mentioned resin is preferable in terms of improving the coatability of the resist composition and reducing the number of development defects in the pattern. The above-mentioned solvent has a good balance of the solubility, boiling point, and viscosity of the above-mentioned resin, and can therefore suppress unevenness in the film thickness of the resist film and the occurrence of precipitates during spin coating. Details of component (M1) and component (M2) are described in paragraphs

[0218] to

[0226] of WO 2020 / 004306, the contents of which are incorporated herein by reference.

[0253] 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.

[0254] The content of the solvent in the resist composition is preferably determined so that the solids concentration is 0.5 to 30 mass %, and more preferably 1 to 20 mass %, which further improves the coatability of the resist composition.

[0255] [Other Additives] The resist composition may further contain a dissolution inhibiting compound, a dye, a plasticizer, a photosensitizer, a light absorber, and / or a compound that promotes solubility in a developer (for example, a phenol compound having a molecular weight of 1,000 or less, or an alicyclic or aliphatic compound containing a carboxyl group).

[0256] The "dissolution inhibiting compound" is a compound having a molecular weight of 3,000 or less that is decomposed by the action of an acid and has a reduced solubility in an organic solvent-based developer.

[0257] [Preferred Embodiments of Resist Composition] The resist composition is also preferably embodiment E1 or E2 below, in that the effects of the present invention are more excellent, a pattern with a smaller LER can be formed, and / or sensitivity is even more excellent.

[0258] <<Resist Composition Aspect E1>> In a resist composition, if the photoacid generator is an onium salt compound, the boron-containing compound is a salt compound, and the resist composition contains an acid diffusion controller that is a salt compound, then Requirement 4 is satisfied; and if the resist composition does not contain an acid diffusion controller that is a salt compound, then Requirement 5 is satisfied.

[0259] Requirement 4: The C1 value calculated by formula (4) is 0.115 or more. Formula (4): C1 = ([H Ｃ１ ]×0.04+[C Ｃ１ ]×1.0+[N Ｃ１ ]×2.1+[O Ｃ１ ]×3.6+[F Ｃ１ ]×5.6+[S Ｃ１ ]×1.5+[B Ｃ１ ]×0.5+[I Ｃ１ ]×39.5) / ([H Ｃ１ ]×1+[C Ｃ１ ]×12+[N Ｃ１ ]×14+[O Ｃ１ ]×16+[F Ｃ１ ]×19+[S Ｃ１ ]×32+[B Ｃ１ ]×11+[I Ｃ１ ]×127)

[0260] In formula (4), [H Ｃ１ [C] represents the molar ratio of the sum of hydrogen atoms derived from cations of the photoacid generator, the boron-containing compound, and the acid diffusion controller to the sum of all atoms derived from cations of the photoacid generator, the boron-containing compound, and the acid diffusion controller. Ｃ１ ] represents the molar ratio of the total of carbon atoms derived from cations of the photoacid generator, the total of carbon atoms derived from cations of the boron-containing compound, and the total of carbon atoms derived from cations of the acid diffusion controller to the total of all atoms derived from cations of the photoacid generator, the total of all atoms derived from cations of the boron-containing compound, and the total of all atoms derived from cations of the acid diffusion controller. Ｃ１[O] represents the molar ratio of the sum of nitrogen atoms derived from cations of the photoacid generator, the sum of nitrogen atoms derived from cations of the boron-containing compound, and the acid diffusion controller to the sum of all atoms derived from cations of the photoacid generator, the sum of all atoms derived from cations of the boron-containing compound, and the acid diffusion controller. Ｃ１ [F] represents the molar ratio of the sum of oxygen atoms derived from cations of the photoacid generator, oxygen atoms derived from cations of the boron-containing compound, and oxygen atoms derived from cations of the acid diffusion controller to the sum of all atoms derived from cations of the photoacid generator, oxygen atoms derived from cations of the boron-containing compound, and oxygen atoms derived from cations of the acid diffusion controller. Ｃ１ [S] represents the molar ratio of the sum of fluorine atoms derived from cations of the photoacid generator, cations of the boron-containing compound, and cations of the acid diffusion controller to the sum of all atoms derived from cations of the photoacid generator, cations of the boron-containing compound, and cations of the acid diffusion controller. Ｃ１ [B] represents the molar ratio of the sum of sulfur atoms derived from cations of the photoacid generator, sulfur atoms derived from cations of the boron-containing compound, and sulfur atoms derived from cations of the acid diffusion controller to the sum of all atoms derived from cations of the photoacid generator, all atoms derived from cations of the boron-containing compound, and all atoms derived from cations of the acid diffusion controller. Ｃ１ [I] represents the molar ratio of the sum of boron atoms derived from cations of the photoacid generator, boron atoms derived from cations of the boron-containing compound, and boron atoms derived from cations of the acid diffusion controller to the sum of all atoms derived from cations of the photoacid generator, all atoms derived from cations of the boron-containing compound, and all atoms derived from cations of the acid diffusion controller. Ｃ１ ] represents the molar ratio of the sum of iodine atoms derived from cations of the photoacid generator, iodine atoms derived from cations of the boron-containing compound, and iodine atoms derived from cations of the acid diffusion controller to the sum of all atoms derived from cations of the photoacid generator, all atoms derived from cations of the boron-containing compound, and all atoms derived from cations of the acid diffusion controller.

[0261] Requirement 5: The C2 value calculated by formula (5) is 0.115 or more. Formula (5): C2 = ([H Ｃ２]×0.04+[C Ｃ２ ]×1.0+[N Ｃ２ ]×2.1+[O Ｃ２ ]×3.6+[F Ｃ２ ]×5.6+[S Ｃ２ ]×1.5+[B Ｃ２ ]×0.5+[I Ｃ２ ]×39.5) / ([H Ｃ２ ]×1+[C Ｃ２ ]×12+[N Ｃ２ ]×14+[O Ｃ２ ]×16+[F Ｃ２ ]×19+[S Ｃ２ ]×32+[B Ｃ２ ]×11+[I Ｃ２ ]×127)

[0262] In formula (5), [H Ｃ２ [C] represents the molar ratio of the sum of hydrogen atoms derived from the cation of the photoacid generator and the cation of the boron-containing compound to the sum of all atoms derived from the cation of the photoacid generator and the cation of the boron-containing compound. Ｃ２ ] represents the molar ratio of the sum of carbon atoms derived from the cation of the photoacid generator and the carbon atoms derived from the cation of the boron-containing compound to the sum of all atoms derived from the cation of the photoacid generator and the boron-containing compound. Ｃ２ [O] represents the molar ratio of the sum of nitrogen atoms derived from the cation of the photoacid generator and the nitrogen atoms derived from the cation of the boron-containing compound to the sum of all atoms derived from the cation of the photoacid generator and the boron-containing compound. Ｃ２ ] represents the molar ratio of the sum of oxygen atoms derived from the cation of the photoacid generator and the oxygen atoms derived from the cation of the boron-containing compound to the sum of all atoms derived from the cation of the photoacid generator and the oxygen atoms derived from the cation of the boron-containing compound. Ｃ２ ] represents the molar ratio of the sum of fluorine atoms derived from the cation of the photoacid generator and the cation of the boron-containing compound to the sum of all atoms derived from the cation of the photoacid generator and the cation of the boron-containing compound. Ｃ２[B] represents the molar ratio of the sum of sulfur atoms derived from the cation of the photoacid generator and the sulfur atoms derived from the cation of the boron-containing compound to the sum of all atoms derived from the cation of the photoacid generator and the boron-containing compound. Ｃ２ [I] represents the molar ratio of the sum of the boron atoms derived from the cations of the photoacid generator and the boron atoms derived from the cations of the boron-containing compound to the sum of all atoms derived from the cations of the photoacid generator and the boron-containing compound. Ｃ２ ] represents the molar ratio of the sum of iodine atoms derived from the cation of the photoacid generator and the cation of the boron-containing compound to the sum of all atoms derived from the cation of the photoacid generator and the cation of the boron-containing compound.

[0263] <Resist Composition Satisfying Requirement 4> As described above, when the resist composition contains an onium salt compound as the photoacid generator, a salt compound as the boron-containing compound, and an acid diffusion controller that is a salt compound, it preferably satisfies Requirement 4. Requirement 4 has been described above. In addition, when the resist composition contains an onium salt compound as the photoacid generator, a salt compound as the boron-containing compound, and an acid diffusion controller that is a salt compound, and satisfies Requirement 4, the resist composition may further contain an acid diffusion controller other than a salt compound.

[0264] In formula (4), for example, [H Ｃ１ ] represents the molar ratio of the sum of hydrogen atoms derived from cations of the photoacid generator, the boron-containing compound, and the acid diffusion controller to the sum of all atoms derived from cations of the photoacid generator, the boron-containing compound, and the acid diffusion controller. More specifically, [H Ｃ１] represents the molar ratio of the sum of hydrogen atoms derived from the cation moiety of the photoacid generator which is an onium salt compound, the hydrogen atoms derived from the cation moiety of the boron-containing compound which is a salt compound, and the hydrogen atoms derived from the cation moiety of the acid diffusion controller which is a salt compound to the sum of all atoms derived from the cation moiety of the photoacid generator which is an onium salt compound, the hydrogen atoms derived from the cation moiety of the boron-containing compound which is a salt compound, and the hydrogen atoms derived from the cation moiety of the acid diffusion controller which is a salt compound.

[0265] In addition, when the resist composition contains two or more photoacid generators that are onium salt compounds, for example, [H Ｃ１ [H] is an example of the boron-containing compound, and the total atoms derived from the cations of the photoacid generator are the sum of all atoms derived from the cations of each photoacid generator, and the molar ratio of hydrogen atoms derived from the cations of the photoacid generator is the molar ratio of the total hydrogen atoms derived from the cations of each photoacid generator. Ｃ１ [H] is an example of the acid diffusion controller, and the molar ratio of hydrogen atoms derived from the cations of the boron-containing compound refers to the total molar ratio of hydrogen atoms derived from the cations of the boron-containing compound. Ｃ１

[0049] is taken as an example to explain this, the total atoms derived from the cations of the acid diffusion controller is the sum of all atoms derived from the cations of each acid diffusion controller, and the molar ratio of hydrogen atoms derived from the cations of the acid diffusion controller means the molar ratio of the sum of hydrogen atoms derived from the cations of each acid diffusion controller.

[0266] <Resist Composition Satisfying Requirement 5> As described above, a resist composition preferably satisfies Requirement 5 when the photoacid generator is an onium salt compound, the boron-containing compound is a salt compound, and the resist composition does not contain an acid diffusion controller that is a salt compound. Here, "not containing an acid diffusion controller that is a salt compound" corresponds to a resist composition that does not contain an acid diffusion controller, or a resist composition that contains only an acid diffusion controller other than a salt compound as the acid diffusion controller. Requirement 5 is as described above.

[0267] In formula (5), for example, [H Ｃ２ ] represents the molar ratio of the sum of hydrogen atoms derived from the cation of the photoacid generator and the cation of the boron-containing compound to the sum of all atoms derived from the cation of the photoacid generator and the cation of the boron-containing compound. More specifically, [H Ｃ２ ] represents the molar ratio of the sum of hydrogen atoms derived from the cation moiety of the photoacid generator which is an onium salt compound and the hydrogen atoms derived from the cation moiety of the boron-containing compound which is a salt compound to the sum of all atoms derived from the cation moiety of the photoacid generator which is an onium salt compound and the boron-containing compound which is a salt compound.

[0268] In addition, when the resist composition contains two or more photoacid generators that are onium salt compounds, for example, [H Ｃ２ [H] is an example of the boron-containing compound, and the total atoms derived from the cations of the photoacid generator are the sum of all atoms derived from the cations of each photoacid generator, and the molar ratio of hydrogen atoms derived from the cations of the photoacid generator is the molar ratio of the total hydrogen atoms derived from the cations of each photoacid generator. Ｃ２

[0049] is taken as an example to explain this, the total atoms derived from the cations of the boron-containing compound is the sum of all atoms derived from the cations of each boron-containing compound, and the molar ratio of hydrogen atoms derived from the cations of the boron-containing compound is intended to be the molar ratio of the sum of hydrogen atoms derived from the cations of each boron-containing compound.

[0269] The C1 and C2 values ​​can be calculated by calculating the atomic ratios of the photoacid generator, boron-containing compound, and acid diffusion controller contained in the resist composition when their structures and contents are known. Even when the components are unknown, the atomic ratios of the resist film obtained by evaporating the solvent component of the resist composition can be calculated by analytical techniques such as elemental analysis.

[0270] As described above, the C1 value and C2 value are 0.115 or more, but are preferably 0.130 or more in terms of achieving better effects of the present invention, being able to form a pattern with smaller LER, being able to form a pattern with better resolution, and / or being even more excellent in sensitivity. There is no particular upper limit, but if the C1 value and C2 value are too large, the light transmittance of the resist film decreases, the optical image profile in the resist film deteriorates, and as a result, it becomes difficult to obtain a good pattern shape. Therefore, the upper limit is preferably 0.240 or less, and more preferably 0.220 or less.

[0271] <<Resist Composition Aspect E2>> In a resist composition, if the photoacid generator is an onium salt compound, the boron-containing compound is a salt compound, and the resist composition contains an acid diffusion controller that is an onium salt compound, then Requirement 2 is satisfied; and if the resist composition does not contain an acid diffusion controller that is an onium salt compound, then Requirement 3 is satisfied.

[0272] Requirement 2: The B1 value calculated by formula (2) is 0.115 or more. Formula (2): B1 = ([H Ｂ１ ]×0.04+[C Ｂ１ ]×1.0+[N Ｂ１ ]×2.1+[O Ｂ１ ]×3.6+[F Ｂ１ ]×5.6+[S Ｂ１ ]×1.5+[B Ｂ１ ]×0.5+[I Ｂ１ ]×39.5) / ([H Ｂ１ ]×1+[C Ｂ１ ]×12+[N Ｂ１ ]×14+[O Ｂ１ ]×16+[F Ｂ１ ]×19+[S Ｂ１ ]×32+[B Ｂ１ ]×11+[I Ｂ１ ]×127)

[0273] In formula (2), [H Ｂ１[C] represents the molar ratio of the sum of hydrogen atoms derived from cations of the photoacid generator, the boron-containing compound, and the acid diffusion controller to the sum of all atoms derived from cations of the photoacid generator, the boron-containing compound, and the acid diffusion controller. Ｂ１ ] represents the molar ratio of the total of carbon atoms derived from cations of the photoacid generator, the total of carbon atoms derived from cations of the boron-containing compound, and the total of carbon atoms derived from cations of the acid diffusion controller to the total of all atoms derived from cations of the photoacid generator, the total of all atoms derived from cations of the boron-containing compound, and the total of all atoms derived from cations of the acid diffusion controller. Ｂ１ [O] represents the molar ratio of the sum of nitrogen atoms derived from cations of the photoacid generator, the sum of nitrogen atoms derived from cations of the boron-containing compound, and the acid diffusion controller to the sum of all atoms derived from cations of the photoacid generator, the sum of all atoms derived from cations of the boron-containing compound, and the acid diffusion controller. Ｂ１ [F] represents the molar ratio of the sum of oxygen atoms derived from cations of the photoacid generator, oxygen atoms derived from cations of the boron-containing compound, and oxygen atoms derived from cations of the acid diffusion controller to the sum of all atoms derived from cations of the photoacid generator, oxygen atoms derived from cations of the boron-containing compound, and oxygen atoms derived from cations of the acid diffusion controller. Ｂ１ [S] represents the molar ratio of the sum of fluorine atoms derived from cations of the photoacid generator, cations of the boron-containing compound, and cations of the acid diffusion controller to the sum of all atoms derived from cations of the photoacid generator, cations of the boron-containing compound, and cations of the acid diffusion controller. Ｂ１ [B] represents the molar ratio of the sum of sulfur atoms derived from cations of the photoacid generator, sulfur atoms derived from cations of the boron-containing compound, and sulfur atoms derived from cations of the acid diffusion controller to the sum of all atoms derived from cations of the photoacid generator, all atoms derived from cations of the boron-containing compound, and all atoms derived from cations of the acid diffusion controller. Ｂ１[I] represents the molar ratio of the sum of boron atoms derived from cations of the photoacid generator, boron atoms derived from cations of the boron-containing compound, and boron atoms derived from cations of the acid diffusion controller to the sum of all atoms derived from cations of the photoacid generator, all atoms derived from cations of the boron-containing compound, and all atoms derived from cations of the acid diffusion controller. Ｂ１ ] represents the molar ratio of the sum of iodine atoms derived from cations of the photoacid generator, iodine atoms derived from cations of the boron-containing compound, and iodine atoms derived from cations of the acid diffusion controller to the sum of all atoms derived from cations of the photoacid generator, all atoms derived from cations of the boron-containing compound, and all atoms derived from cations of the acid diffusion controller.

[0274] Requirement 3: The B2 value calculated by formula (3) is 0.115 or more. Formula (3): B2 = ([H Ｂ２ ]×0.04+[C Ｂ２ ]×1.0+[N Ｂ２ ]×2.1+[O Ｂ２ ]×3.6+[F Ｂ２ ]×5.6+[S Ｂ２ ]×1.5+[B Ｂ２ ]×0.5+[I Ｂ２ ]×39.5) / ([H Ｂ２ ]×1+[C Ｂ２ ]×12+[N Ｂ２ ]×14+[O Ｂ２ ]×16+[F Ｂ２ ]×19+[S Ｂ２ ]×32+[B Ｂ２ ]×11+[I Ｂ２ ]×127) In formula (3), [H Ｂ２ [C] represents the molar ratio of the sum of hydrogen atoms derived from the cation of the photoacid generator and the cation of the boron-containing compound to the sum of all atoms derived from the cation of the photoacid generator and the cation of the boron-containing compound. Ｂ２ ] represents the molar ratio of the sum of carbon atoms derived from the cation of the photoacid generator and the carbon atoms derived from the cation of the boron-containing compound to the sum of all atoms derived from the cation of the photoacid generator and the boron-containing compound. Ｂ２[O] represents the molar ratio of the sum of nitrogen atoms derived from the cation of the photoacid generator and the nitrogen atoms derived from the cation of the boron-containing compound to the sum of all atoms derived from the cation of the photoacid generator and the boron-containing compound. Ｂ２ ] represents the molar ratio of the sum of oxygen atoms derived from the cation of the photoacid generator and the oxygen atoms derived from the cation of the boron-containing compound to the sum of all atoms derived from the cation of the photoacid generator and the oxygen atoms derived from the cation of the boron-containing compound. Ｂ２ ] represents the molar ratio of the sum of fluorine atoms derived from the cation of the photoacid generator and the cation of the boron-containing compound to the sum of all atoms derived from the cation of the photoacid generator and the cation of the boron-containing compound. Ｂ２ [B] represents the molar ratio of the sum of sulfur atoms derived from the cation of the photoacid generator and the sulfur atoms derived from the cation of the boron-containing compound to the sum of all atoms derived from the cation of the photoacid generator and the boron-containing compound. Ｂ２ [I] represents the molar ratio of the sum of the boron atoms derived from the cations of the photoacid generator and the boron atoms derived from the cations of the boron-containing compound to the sum of all atoms derived from the cations of the photoacid generator and the boron-containing compound. Ｂ２ ] represents the molar ratio of the sum of iodine atoms derived from the cation of the photoacid generator and the cation of the boron-containing compound to the sum of all atoms derived from the cation of the photoacid generator and the cation of the boron-containing compound.

[0275] <Resist Composition Satisfying Requirement 2> As described above, when the resist composition contains an onium salt compound as the photoacid generator, a salt compound as the boron-containing compound, and an onium salt compound as the acid diffusion controller, it is preferable that the resist composition satisfies Requirement 2. Requirement 2 has been described above. In addition, when the resist composition contains an onium salt compound as the photoacid generator, a salt compound as the boron-containing compound, and an onium salt compound as the acid diffusion controller, and satisfies Requirement 2, the resist composition may further contain an acid diffusion controller other than an onium salt compound.

[0276] In formula (2), for example, [H Ｂ１ ] represents the molar ratio of the sum of hydrogen atoms derived from cations of the photoacid generator, the boron-containing compound, and the acid diffusion controller to the sum of all atoms derived from cations of the photoacid generator, the boron-containing compound, and the acid diffusion controller. More specifically, [H Ｂ１ ] represents the molar ratio of the sum of hydrogen atoms derived from the cation moiety of the photoacid generator which is an onium salt compound, the hydrogen atoms derived from the cation moiety of the boron-containing compound which is a salt compound, and the hydrogen atoms derived from the cation moiety of the acid diffusion controller which is an onium salt compound to the sum of all atoms derived from the cation moiety of the photoacid generator which is an onium salt compound, the hydrogen atoms derived from the cation moiety of the boron-containing compound which is a salt compound, and the hydrogen atoms derived from the cation moiety of the acid diffusion controller which is an onium salt compound.

[0277] In addition, when the resist composition contains two or more photoacid generators that are onium salt compounds, for example, [H Ｂ１ [H] is an example of the boron-containing compound, and the total atoms derived from the cations of the photoacid generator are the sum of all atoms derived from the cations of each photoacid generator, and the molar ratio of hydrogen atoms derived from the cations of the photoacid generator is the molar ratio of the total hydrogen atoms derived from the cations of each photoacid generator. Ｂ１ [H] is an example of the acid diffusion controller that can be used in a resist composition containing two or more onium salt compounds. Ｂ１

[0049] is taken as an example to explain this, the total atoms derived from the cations of the acid diffusion controller is the sum of all atoms derived from the cations of each acid diffusion controller, and the molar ratio of hydrogen atoms derived from the cations of the acid diffusion controller means the molar ratio of the sum of hydrogen atoms derived from the cations of each acid diffusion controller.

[0278] <Resist Composition Satisfying Requirement 3> As described above, a resist composition preferably satisfies Requirement 3 when the photoacid generator is an onium salt compound, the boron-containing compound is a salt compound, and the resist composition does not contain an acid diffusion controller that is an onium salt compound. Here, "not containing an acid diffusion controller that is an onium salt compound" corresponds to a resist composition that does not contain an acid diffusion controller, or a resist composition that contains only an acid diffusion controller other than an onium salt compound as the acid diffusion controller. Requirement 3 has been described above.

[0279] In formula (3), for example, [H Ｂ２ ] represents the molar ratio of the sum of hydrogen atoms derived from the cation of the photoacid generator and the cation of the boron-containing compound to the sum of all atoms derived from the cation of the photoacid generator and the cation of the boron-containing compound. More specifically, [H Ｂ２ ] represents the molar ratio of the sum of hydrogen atoms derived from the cation moiety of the photoacid generator which is an onium salt compound and the hydrogen atoms derived from the cation moiety of the boron-containing compound which is a salt compound to the sum of all atoms derived from the cation moiety of the photoacid generator which is an onium salt compound and the boron-containing compound which is a salt compound.

[0280] In addition, when the resist composition contains two or more photoacid generators that are onium salt compounds, for example, [H Ｂ２ [H] is an example of the boron-containing compound, and the total atoms derived from the cations of the photoacid generator are the sum of all atoms derived from the cations of each photoacid generator, and the molar ratio of hydrogen atoms derived from the cations of the photoacid generator is the molar ratio of the total hydrogen atoms derived from the cations of each photoacid generator. Ｂ２

[0049] is taken as an example to explain this, the total atoms derived from the cations of the boron-containing compound is the sum of all atoms derived from the cations of each boron-containing compound, and the molar ratio of hydrogen atoms derived from the cations of the boron-containing compound is intended to be the molar ratio of the sum of hydrogen atoms derived from the cations of each boron-containing compound.

[0281] The B1 value and B2 value can be calculated by calculating the atomic ratios contained in a resist composition when the structures and contents of the photoacid generator, boron-containing compound, and acid diffusion controller in the resist composition are known. Even when the constituent components are unknown, the atomic ratios of the resist composition can be calculated by analytical techniques such as elemental analysis of a resist film obtained by evaporating the solvent component of the resist composition.

[0282] As described above, the B1 value and B2 value are 0.115 or more, but are preferably 0.130 or more in terms of achieving better effects of the present invention, being able to form a pattern with a smaller LER, being able to form a pattern with better resolution, and / or being able to achieve even better sensitivity. There is no particular upper limit, but if the B1 value and B2 value are too large, the light transmittance of the resist film decreases, the optical image profile in the resist film deteriorates, and as a result, it becomes difficult to obtain a good pattern shape. Therefore, the upper limit is preferably 0.240 or less, and more preferably 0.220 or less.

[0283] [Method of forming a resist film and a pattern] The procedure of the method of forming a pattern using the resist composition is not particularly limited, but it is preferable that the method include the following steps: Step 1: forming a resist film on a substrate using the resist composition Step 2: exposing the resist film to light Step 3: developing the exposed resist film using a developer The procedure of each of the above steps will be described in detail below.

[0284] <Step 1: Resist Film Forming Step> Step 1 is a step of forming a resist film on a substrate using a resist composition. The definition of the resist composition is as described above.

[0285] A method for forming a resist film on a substrate using a resist composition includes, for example, applying the resist composition to the substrate. It is preferable to filter the resist composition before application, if necessary. The pore size of the filter is preferably 0.1 μm or less, more preferably 0.05 μm or less, and even more preferably 0.03 μm or less. The filter is preferably made of polytetrafluoroethylene, polyethylene, or nylon.

[0286] The resist composition can be applied onto a substrate (e.g., silicon, silicon dioxide coated) 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 resist 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.

[0287] 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.

[0288] 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 is used, the thickness of the resist film is more preferably 10 to 65 nm, and even more preferably 15 to 50 nm. When ArF immersion exposure is used, the thickness of the resist film is more preferably 10 to 120 nm, and even more preferably 15 to 90 nm.

[0289] 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 2013-61648 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 resist 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.

[0290] <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 have a wavelength of 250 nm or less, more preferably 220 nm or less, and far ultraviolet light having a wavelength of 1 to 200 nm, specifically, KrF excimer laser (248 nm), ArF excimer laser (193 nm), F ２ Excimer laser (157 nm), EUV (13.5 nm), X-ray, and electron beam are particularly preferred.

[0291] After exposure, it is preferable to bake (heat) the film before developing. Baking promotes the reaction of the exposed areas, resulting in better sensitivity and pattern shape. The heating temperature is preferably 80 to 150°C, more preferably 80 to 140°C, and even more preferably 80 to 130°C. The heating time is preferably 10 to 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. This process is also called post-exposure baking.

[0292] <Step 3: Development Step> Step 3 is a step of developing the exposed resist film using a developer to form a pattern. The developer may be either an organic solvent-based developer (a developer containing an organic solvent) or an alkaline developer, but an organic solvent-based developer is preferred.

[0293] 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 left to stand 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). Furthermore, 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.

[0294] The organic solvent contained in the organic solvent-based developer is preferably at least one 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.

[0295] The ClogP value of the organic solvent contained in the organic solvent-based developer is not particularly limited, but is preferably 0.00 or more, and more preferably 1.00 or more. When two or more organic solvents are contained, the ClogP value of the mixed solvent thereof is preferably within the above range.

[0296] Examples of ketone solvents include 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, acetone, 2-heptanone (methyl amyl ketone), 4-heptanone, 1-hexanone, 2-hexanone, diisobutyl ketone, cyclohexanone, methylcyclohexanone, phenylacetone, methyl ethyl ketone, methyl isobutyl ketone, acetylacetone, acetonylacetone, ionone, diacetonyl alcohol, acetylcarbinol, acetophenone, methyl naphthyl ketone, isophorone, and propylene carbonate.

[0297] Examples of ester-based solvents include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, pentyl acetate, isopentyl acetate, amyl acetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl-3-ethoxypropionate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate, butyl butanoate, methyl 2-hydroxyisobutyrate, isoamyl acetate, isobutyl isobutyrate, and butyl propionate.

[0298] As the alcohol-based solvent, the amide-based solvent, the ether-based solvent, and the hydrocarbon-based solvent, for example, the solvents disclosed in paragraphs

[0715] to

[0718] of the specification of U.S. Patent Application Publication No. 2016 / 0070167 can be used.

[0299] The above solvents may be mixed in plural, or may be mixed with a solvent other than the above or with 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 solvent-based developer is preferably 50 to 100% by mass, more preferably 80 to 100% by mass, even more preferably 90 to 100% by mass, and particularly preferably 95 to 100% by mass, based on the total amount of the developer.

[0300] In terms of achieving better effects of the present invention, it is preferable that the organic solvent-based developer contains a first organic solvent and a second organic solvent, and it is more preferable that the boiling point of the first organic solvent is higher than the boiling point of the second organic solvent and that the ClogP value of the first organic solvent is larger than the ClogP value of the second organic solvent.

[0301] In order to obtain a more excellent effect of the present invention, it is preferable that the organic solvent-based developer contains a first organic solvent and a second organic solvent, and it is more preferable that the evaporation rate of the second organic solvent is faster than that of the first organic solvent. In particular, the greater the difference in evaporation rate between the second organic solvent and the first organic solvent, the more preferable. One indicator of the evaporation rate of an organic solvent is the vapor pressure at 20°C. It is preferable that the vapor pressure of the second organic solvent is higher than that of the first organic solvent, and it is preferable that the vapor pressure difference between the second organic solvent and the first organic solvent is 0.2 kPa or more. In particular, the vapor pressure difference between the second organic solvent and the first organic solvent is more preferably 0.5 kPa or more, even more preferably 0.8 kPa or more, and particularly preferably 1.0 kPa or more. The mechanism of action of the organic solvent-based developer having the above composition is not clear, but it is presumed that this is because the use of the organic solvent-based developer having the above composition suppresses swelling of the resist pattern due to the developer.

[0302] The content ratio of the first organic solvent to the second organic solvent in the organic solvent-based developer is not particularly limited, but in terms of achieving better effects of the present invention, the mass ratio of the content of the first organic solvent to the content of the second organic solvent is preferably 10 / 90 to 50 / 50, and more preferably 10 / 90 to 30 / 70.

[0303] The second organic solvent in the organic solvent-based developer is preferably the ketone solvent or the ester solvent, more preferably an ester solvent, still more preferably an ester solvent having 6 or less carbon atoms, and particularly preferably butyl acetate, in terms of achieving better effects of the present invention. The first organic solvent is not particularly limited, but is preferably an organic solvent having a ClogP value of 3.00 or more, and more preferably a hydrocarbon solvent (preferably a hydrocarbon solvent having 10 or more carbon atoms, such as undecane).

[0304] The organic solvent-based developer preferably contains a hydrocarbon solvent and an ester solvent having 6 or less carbon atoms, and the mass ratio of the contents of the hydrocarbon solvent and the ester solvent having 6 or less carbon atoms is preferably 10 / 90 to 50 / 50, more preferably 10 / 90 to 30 / 70, and even more preferably 10 / 90 to 25 / 75, in terms of further improving the effects of the present invention.

[0305] The alkaline developer is preferably an aqueous alkaline solution containing an alkali. The type of alkaline aqueous solution is not particularly limited, but examples include aqueous alkaline solutions containing a quaternary ammonium salt, such as tetramethylammonium hydroxide, an inorganic alkali, a primary amine, a secondary amine, a tertiary amine, an alcohol amine, or a cyclic amine. Of these, the alkaline developer is preferably an aqueous solution of a quaternary ammonium salt, such as tetramethylammonium hydroxide (TMAH). Appropriate amounts of alcohols, surfactants, and the like may be added to the alkaline developer. The alkaline concentration of the alkaline developer is usually preferably 0.1 to 20% by mass. The pH of the alkaline developer is usually preferably 10.0 to 15.0.

[0306] <Other Steps> The pattern formation method preferably includes, after step 3, a step of cleaning with a rinse liquid.

[0307] The rinse liquid used in the rinse step after the development step using an organic solvent-based developer is preferably an organic solvent-based rinse liquid. The organic solvent contained in the rinse liquid is preferably at least one organic solvent selected from the group consisting of hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents, and ether solvents. Examples of hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents, and ether solvents include those similar to those described for the developer containing an organic solvent.

[0308] In order to obtain a more excellent effect of the present invention, the organic solvent-based rinse solution preferably contains a first organic solvent and a second organic solvent, and more preferably the boiling point of the first organic solvent is higher than the boiling point of the second organic solvent and the ClogP value of the first organic solvent is higher than the ClogP value of the second organic solvent, where the boiling points refer to boiling points at 1 atmosphere (760 mmHg).

[0309] The content ratio of the first organic solvent to the second organic solvent in the organic solvent-based rinse liquid is not particularly limited; however, in terms of achieving better effects of the present invention, the mass ratio of the content of the first organic solvent to the content of the second organic solvent is preferably 10 / 90 to 50 / 50, and more preferably 10 / 90 to 30 / 70.

[0310] In the organic solvent-based rinse solution, the second organic solvent is preferably the ketone solvent or the ester solvent, more preferably an ester solvent, and even more preferably butyl acetate or isoamyl butyrate, in terms of achieving the effects of the present invention more effectively. The first organic solvent is not particularly limited, but is preferably an organic solvent having a ClogP value of 3.00 or more, and more preferably a hydrocarbon solvent (preferably a hydrocarbon solvent having 10 or more carbon atoms, such as undecane).

[0311] The rinse liquid used in the rinse step after the development step using an alkaline developer can be, for example, pure water. A suitable amount of surfactant may be added to the pure water. A suitable amount of surfactant may be added to the rinse liquid.

[0312] 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 substrate surface (spray method). The pattern formation method 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).

[0313] 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.

[0314] The resist composition and various materials used in the pattern formation method of the present specification (e.g., solvent, developer, rinse, anti-reflective coating-forming composition, top coat-forming composition, etc.) preferably do not contain impurities such as metals. The content of impurities contained in these materials is preferably 1 mass ppm or less, more preferably 10 mass ppb or less, even more preferably 100 mass ppt or less, particularly preferably 10 mass ppt or less, and most preferably 1 mass ppt or less. There is no particular lower limit, and 0 mass ppt or more is preferred. Here, examples of metal impurities include Na, K, Ca, Fe, Cu, Mg, Al, Li, Cr, Ni, Sn, Ag, As, Au, Ba, Cd, Co, Pb, Ti, V, W, and Zn.

[0315] Examples of methods for removing impurities such as metals from various materials include filtration using a filter. Details of filtration using a filter are described in paragraph

[0321] of WO 2020 / 004306.

[0316] Methods for reducing impurities such as metals contained in various materials include, for example, selecting raw materials with a low metal content as raw materials for the various materials, filtering the raw materials for the various materials, and performing distillation under conditions that minimize contamination as much as possible, for example by lining the inside of the apparatus with Teflon (registered trademark).

[0317] In addition to filter filtration, impurities may be removed using an adsorbent, or a combination of filter filtration and an adsorbent may be used. Known adsorbents can be used as the adsorbent, including inorganic adsorbents such as silica gel and zeolite, and organic adsorbents such as activated carbon. In order to reduce impurities such as metals contained in the various materials, it is necessary to prevent the incorporation of metal impurities during the manufacturing process. Whether metal impurities have been sufficiently removed from the manufacturing equipment can be confirmed by measuring the content of metal components contained in the cleaning solution used to clean the manufacturing equipment. The content of metal components contained in the used cleaning solution is preferably 100 parts per trillion (ppt) by mass or less, more preferably 10 ppt by mass or less, and even more preferably 1 ppt by mass or less. There is no particular lower limit, and 0 ppt by mass or more is preferred.

[0318] 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, more preferably 5% by mass or less. There is no particular lower limit, but 0.01% by mass or more is preferred. 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, antistatically treated polyethylene, polypropylene, or fluororesin (such as polytetrafluoroethylene or perfluoroalkoxy resin), can be used.

[0319] [Method for Manufacturing an Electronic Device] The present specification 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. Preferred embodiments of the electronic device of the present specification include those installed in electrical and electronic devices (such as home appliances, office automation (OA), media-related devices, optical devices, and communication devices).

[0320] 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.

[0321] [Various Components of Actinic Ray-Sensitive or Radiation-Sensitive Resin Composition] [Resin (A)] Resins (A) (Resins A-1 to A-12) shown in Table 2 below are shown below. Resin A was synthesized according to the synthesis method for Resin A-1 (Synthesis Example 1) described below and a known method. Table 1 shows the content (mol %; corresponding from left to right), weight average molecular weight (Mw), and polydispersity (Mw / Mn) of each repeating unit shown below. The weight average molecular weight (Mw), number average molecular weight (Mn), and polydispersity (Mw / Mn) of Resins A-1 to A-12 were measured as polystyrene equivalent values ​​using a Gel Permeation Chromatography (GPC) apparatus (Tosoh Corporation, HLC-8120GPC) (solvent: tetrahydrofuran, flow rate (sample injection amount): 10 μL, column: Tosoh Corporation TSK gel Multipore HXL-M, column temperature: 40° C., flow rate: 1.0 mL / min, detector: differential refractive index detector).

[0322]

[0323]

[0324]

[0325] Synthesis Example 1 Synthesis of Resin A-1 Cyclohexanone (194.3 g) was placed in a three-neck flask under a nitrogen stream and heated to 80°C. To this was added each monomer from which the repeating units shown in Table 1 were derived so that Resin A-1 had the repeating units shown in Table 1, and then a solution of polymerization initiator V-601 (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., 2.17 g) dissolved in cyclohexanone (105 g) was added dropwise over 6 hours. After completion of the dropwise addition, the reaction was continued for another 2 hours at 80°C. After allowing to cool, the reaction solution was added dropwise to a mixed solution of methanol and water over 20 minutes. Next, the precipitate precipitated by the dropwise addition was collected by filtration and dried to obtain Resin A-1 (31.6 g).

[0326] [Boron-Containing Compounds] <Cation Moiety> The structures of the cation moieties (cations B-1 to B-17) of the boron-containing compounds shown in Table 2 below are shown below.

[0327]

[0328]

[0329] <Anion Moiety> The structures of the anion moieties (anions C-1 to C-24) of the boron-containing compounds shown in Table 2 below are shown below.

[0330]

[0331]

[0332] [Photoacid Generator] <Cation Moiety> The structure of the cation moiety of the photoacid generator shown in Table 2 below is the same as the cation moiety of the boron-containing compound shown in the upper part (cations B-1 to B-17).

[0333] <Anion Moiety> The structures of the anion moieties (anions D-1 to D-18) of the photoacid generators shown in Table 2 below are shown below.

[0334]

[0335]

[0336] [Photodegradable base] <Cation moiety> The structure of the cation moiety of the photodegradable base shown in Table 2 below is the same as the cation moiety of the boron-containing compound shown in the upper part (cations B-1 to B-17).

[0337] <Anion Moiety> The structures of the anion moieties (anions E-1 to E-4) of the photodegradable bases shown in Table 2 below are shown below.

[0338]

[0339]

[0340] [Basic Compounds] The structures of the basic compounds (basic compounds F-1 to F-4) shown in Table 2 below are shown below.

[0341]

[0342] [Solvents] The solvents (solvents G-1 to G-6) shown in Table 2 below are as follows: G-1: Propylene glycol monomethyl ether acetate (PGMEA) G-2: Propylene glycol monomethyl ether (PGME) G-3: Cyclohexanone G-4: Ethyl lactate G-5: γ-butyrolactone G-6: Diacetone alcohol

[0343] [Developer, Rinse] The developers and rinses shown in Tables 3 and 4 below are as follows: H-1: 2.38 wt % TMAH aqueous solution H-2: Butyl acetate H-3: Isopropyl acetate H-4: Butyl acetate: n-undecane = 90:10 (mass ratio) H-5: Butyl acetate: n-undecane = 80:20 (mass ratio) H-6: Butyl acetate: n-undecane = 70:30 (mass ratio)

[0344] [Preparation of Resist Composition] The components shown in Table 2 were mixed to obtain a mixed solution, and the resulting mixed solution was then filtered through a polyethylene filter with a pore size of 0.03 μm to prepare a resist composition. The solids concentration of the resist composition was adjusted appropriately so that it could be applied to the film thickness shown in Tables 3 and 4. The solids content refers to all components other than the solvent. Table 2 is shown below. In the "Optical Absorption Properties" column in Table 2, the "A Value" is a value calculated based on the above-mentioned formula (1). In the "B1 Value or B2 Value" column, the "B1 Value" is a value calculated based on the above-mentioned formula (2), and the "B2 Value" is a value calculated based on the above-mentioned formula (3). In the "B1 Value or B2 Value" column, the B2 value is specifically shown for compositions Re-7, Re-22, Re-23, Re-28, and Re-49, which do not contain an acid diffusion controller that is an onium salt compound. Furthermore, for compositions containing an acid diffusion controller that is an onium salt compound other than the above compositions, the B1 value is shown. Furthermore, in the column "C1 value or C2 value," the "C1 value" is a value calculated based on the above formula (4), and the "C2 value" is a value calculated based on the above formula (5). In the column "C1 value or C2 value," specifically, the C2 value is shown for compositions Re-7, Re-22, Re-23, Re-28, and Re-49 that do not contain an acid diffusion controller that is a salt compound. Furthermore, for compositions containing an acid diffusion controller that is a salt compound other than the above compositions, the C1 value is shown.

[0345]

[0346]

[0347]

[0348]

[0349] [Pattern Formation and Evaluation (1)] [Pattern Formation by EUV Exposure] An underlayer film-forming composition, E2Stack (registered trademark) 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 resist composition shown in Table 3 was applied thereon, and a resist film was formed under the conditions (film thickness and pre-bake) shown in Table 3. This resulted in a silicon wafer having a resist film. The silicon wafer having the resist film obtained by the above procedure was subjected to pattern irradiation using an EUV scanner NXE3400B (NA 0.33, dipole modified illumination (FlexRay)) manufactured by ASML. A mask with a line size of 25 nm and a line:space ratio of 1:1 was used as the reticle. Thereafter, only in cases where a description is given in Table 3, the wafer was baked (Post Exposure Bake; PEB) under the conditions shown in Table 3 using a coater / developer CLEAN TRAC LITHIUS Pro Z manufactured by Tokyo Electron Limited, and then developed by puddling for 30 seconds with the developer shown in Table 3. Only in cases where a description is given in Table 3, the wafer was rotated at a rotation speed of 1000 rpm while being rinsed by pouring the rinse solution shown in Table 3 for 10 seconds, and then the wafer was rotated at a rotation speed of 4000 rpm for 30 seconds, thereby obtaining a line and space pattern with a pitch of 50 nm.

[0350] [Evaluation] <Optimum Exposure Dose (Sensitivity)> The pattern formed by the EUV exposure was measured for the line width of the line and space pattern while changing the exposure dose using a length-measuring scanning electron microscope (SEM: Scanning Electron Microscope (CG-6300, manufactured by Hitachi High-Technologies Corporation)). The exposure dose at which the line width became 25 nm was determined, and this was designated as the optimum exposure dose (mJ / cm). ２ The smaller this value, the better the performance.

[0351] <Space width at which bridge defects begin to occur during L / S pattern formation (bridge margin)> When exposing a line and space pattern (line:space = 1:1) with a line width of 25 nm, the exposure dose was changed from the above sensitivity, and the space width at which bridges began to occur between spaces was determined as an index of the "bridge margin." A smaller value indicates better performance.

[0352] <Line Edge Roughness (LER)> At an exposure dose showing the above sensitivity, a line pattern (L / S=1 / 1) was measured at 30 arbitrary points in a length direction of 50 μm, and the distance from a reference line where the edge should be located was measured using a scanning electron microscope (CG-6300 manufactured by Hitachi High-Technologies Corporation), and the standard deviation was determined to calculate 3σ. A smaller value indicates better performance.

[0353] <Resolution> The limiting resolving power (the minimum line width at which a line and a space (line:space=1:1) are separated and resolved) at the exposure dose indicating the above sensitivity was taken as the resolution (unit: nm). A smaller value indicates better performance.

[0354]

[0355]

[0356] The results shown in Table 3 clearly show that the resist compositions of the examples have a narrower space width at which bridge defects begin to occur during L / S pattern formation. It is also clear that the resist compositions of the examples have excellent sensitivity and are capable of forming patterns with excellent LER and resolution. Furthermore, a comparison of Examples 1-56 to 1-59, Examples 1-60 to 1-64, and Examples 1-65 to 1-69 confirms that when the developer is an organic solvent-based developer that contains a hydrocarbon solvent and an ester solvent having 6 or fewer carbon atoms (preferably, when the mass ratio of the hydrocarbon solvent to the ester solvent having 6 or fewer carbon atoms is 10 / 90 to 30 / 70, and more preferably, when this mass ratio is 20 / 80 to 30 / 70), the space width at which bridge defects begin to occur during L / S pattern formation is narrower, and a pattern with even better resolution can be formed.

[0357] On the other hand, it was confirmed that the resist compositions of the comparative examples did not provide the desired effects.

[0358] [Pattern Formation and Evaluation (2)] [Pattern Formation by EUV Exposure] An underlayer film-forming composition SHB-A940 (manufactured by Shin-Etsu Chemical Co., Ltd.) 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. Resist compositions (Re-1 to Re-6) shown in Table 2 above were applied thereon to form resist films under the conditions (film thickness and pre-bake) shown in Table 4. This resulted in silicon wafers having resist films. The silicon wafers having the resist films obtained by the above procedure were subjected to pattern irradiation using an EUV scanner NXE3400 (NA 0.33, σ 0.9 / 0.7, dipole illumination) manufactured by ASML. A mask with a line size of 18 nm and a line:space ratio of 1:1 was used as the reticle. Thereafter, only if otherwise specified, the wafer was baked (Post Exposure Bake; PEB) under the conditions shown in Table 4 using a coater / developer CLEAN TRAC LITHIUS Pro Z manufactured by Tokyo Electron Limited, and then developed by puddling for 30 seconds with the developer shown in Table 4. Only if otherwise specified in Table 4, the wafer was rotated at a rotation speed of 1000 rpm and rinsed by pouring the rinse solution shown in Table 4 over it for 10 seconds, and then the wafer was rotated at a rotation speed of 4000 rpm for 30 seconds, thereby obtaining a line and space pattern with a pitch of 36 nm.

[0359] [Evaluation] <Optimum Exposure Dose (Sensitivity)> The pattern formed by the EUV exposure was measured for the line width of the line and space pattern while changing the exposure dose using a length measuring scanning electron microscope (SEM: Scanning Electron Microscope (CG-6300 manufactured by Hitachi High-Technologies Corporation)). The exposure dose at which the line width became 18 nm was determined, and this was designated as the optimum exposure dose (mJ / cm ２ The smaller this value, the better the performance.

[0360] <<Space width at which bridge defects begin to occur when forming an L / S pattern (bridge margin)>> When exposing a line and space pattern (line:space = 1:1) with a line width of 18 nm, the irradiation amount was changed from the above sensitivity, and the space width (nm) at which bridges began to occur between spaces was determined as an index of the "bridge margin." The smaller this value, the narrower the space distance required to prevent bridge defects and the better the performance.

[0361] <Line Edge Roughness (LER)> At an exposure dose showing the above sensitivity, a line pattern having a line width of 18 nm (L / S=1 / 1) was randomly selected at 30 points in a length direction of 50 μm, and the distance from a reference line where the edge should be located was measured using a scanning electron microscope (CG-6300 manufactured by Hitachi High-Technologies Corporation), and the standard deviation was determined to calculate 3σ. A smaller value indicates better performance.

[0362] <Resolution> The limiting resolving power (the minimum line width at which a line and a space (line:space=1:1) are separated and resolved) at the exposure dose indicating the above sensitivity was taken as the resolution (unit: nm). A smaller value indicates better performance.

[0363]

[0364] The results shown in Table 4 clearly show that the resist compositions of the examples have a narrow space width at which bridge defects begin to occur during L / S pattern formation. It is also clear that the resist compositions of the examples have excellent sensitivity and are capable of forming patterns with excellent LER and resolution.

[0365] Furthermore, a comparison of Examples 2-1 to 2-3 confirmed that when the resist composition satisfies Requirement 2 or Requirement 3, it is possible to form a pattern with a narrower space width at which bridge defects begin to occur during L / S pattern formation, better sensitivity, and even more excellent LER. Furthermore, a comparison of Examples 2-1 and 2-4 confirmed that when the developer is an organic solvent-based developer that contains an ester-based solvent and a hydrocarbon-based solvent having 6 or less carbon atoms, it is possible to form a pattern with a narrower space width at which bridge defects begin to occur during L / S pattern formation, and even more excellent LER and resolution.

[0366] On the other hand, it was confirmed that the resist compositions of the comparative examples did not provide the desired effects.

Claims

1. An actinic ray-sensitive or radiation-sensitive resin composition comprising: a resin having a group that decomposes under the action of an acid to generate a polar group; a photoacid generator; and a boron-containing compound, An actinic ray-sensitive or radiation-sensitive resin composition that satisfies Requirement 1. Requirement 1: The value A obtained by formula (1) is 0.120 or more. Formula (1): A = ([H Ａ × 0.04 + [C Ａ × 1.0 + [N Ａ × 2.1 + [O Ａ × 3.6 + [F Ａ × 5.6 + [S Ａ × 1.5 + [B Ａ × 0.5 + [I Ａ × 39.5) / ([H Ａ × 1 + [C Ａ × 12 + [N Ａ × 14 + [O Ａ × 16 + [F Ａ × 19 + [S Ａ × 32 + [B Ａ × 11 + [I Ａ × 127) In formula (1), [H Ａ ] represents the molar ratio of hydrogen atoms derived from the total solid content to all atoms of the total solid content in the composition, and [C Ａ ] represents the molar ratio of carbon atoms originating from the total solid content to all atoms in the total solid content in the composition, and [N Ａ ] represents the molar ratio of nitrogen atoms derived from the total solid content to all atoms in the total solid content in the composition, and [O Ａ ] represents the molar ratio of oxygen atoms derived from the total solid content to all atoms in the total solid content in the composition, and [F Ａ ] represents the molar ratio of fluorine atoms derived from the total solid content to all atoms in the total solid content in the composition, and [S Ａ ] represents the molar ratio of sulfur atoms derived from the total solid content to all atoms in the total solid content in the composition, and [B Ａ ] represents the molar ratio of boron atoms derived from the total solid content to all atoms in the total solid content in the composition, and [I Ａ ] represents the molar ratio of iodine atoms derived from the total solid content to all atoms in the total solid content in the composition.

2. The actinic ray-sensitive or radiation-sensitive resin composition according to claim 1 , further comprising an acid diffusion controller.

3. the photoacid generator is an onium salt compound, the boron-containing compound is a salt compound; When the composition contains an acid diffusion controller that is a salt compound, requirement 4 is satisfied; 3. The actinic ray-sensitive or radiation-sensitive resin composition according to claim 1, which satisfies requirement 5 when the composition does not contain an acid diffusion controller that is a salt compound. Requirement 4: The C1 value calculated by formula (4) is 0.115 or more. Equation (4): C1 = ([H Ｃ１ × 0.04 + [C Ｃ１ × 1.0 + [N Ｃ１ × 2.1 + [O Ｃ１ × 3.6 + [F Ｃ１ × 5.6 + [S Ｃ１ × 1.5 + [B Ｃ１ × 0.5 + [I Ｃ１ × 39.5) / ([H Ｃ１ × 1 + [C Ｃ１ × 12 + [N Ｃ１ × 14 + [O Ｃ１ × (16 + [F Ｃ１ × 19 + [S Ｃ１ × 32 + [B Ｃ１ × 11 + [I Ｃ１ × 127) It should be noted that there seems to be a small error in the original text where the coefficient of oxygen in the denominator of the formula is "16 + [F", which may be a typo. The translation is made according to the original text as much as possible. In formula (4), [H Ｃ１ [C] represents the molar ratio of the sum of hydrogen atoms derived from cations of the photoacid generator, the boron-containing compound, and the acid diffusion controller to the sum of all atoms derived from cations of the photoacid generator, the boron-containing compound, and the acid diffusion controller. Ｃ１ ] represents the molar ratio of the total of carbon atoms derived from cations of the photoacid generator, the total of carbon atoms derived from cations of the boron-containing compound, and the total of carbon atoms derived from cations of the acid diffusion controller to the total of all atoms derived from cations of the photoacid generator, the total of all atoms derived from cations of the boron-containing compound, and the total of all atoms derived from cations of the acid diffusion controller. Ｃ１ [O] represents the molar ratio of the sum of nitrogen atoms derived from cations of the photoacid generator, the sum of nitrogen atoms derived from cations of the boron-containing compound, and the acid diffusion controller to the sum of all atoms derived from cations of the photoacid generator, the sum of all atoms derived from cations of the boron-containing compound, and the acid diffusion controller. Ｃ１ [F] represents the molar ratio of the sum of oxygen atoms derived from cations of the photoacid generator, oxygen atoms derived from cations of the boron-containing compound, and oxygen atoms derived from cations of the acid diffusion controller to the sum of all atoms derived from cations of the photoacid generator, all atoms derived from cations of the boron-containing compound, and all atoms derived from cations of the acid diffusion controller. Ｃ１ [S] represents the molar ratio of the sum of fluorine atoms derived from cations of the photoacid generator, fluorine atoms derived from cations of the boron-containing compound, and fluorine atoms derived from cations of the acid diffusion controller to the sum of all atoms derived from cations of the photoacid generator, all atoms derived from cations of the boron-containing compound, and all atoms derived from cations of the acid diffusion controller. Ｃ１ [B] represents the molar ratio of the sum of sulfur atoms derived from cations of the photoacid generator, sulfur atoms derived from cations of the boron-containing compound, and sulfur atoms derived from cations of the acid diffusion controller to the sum of all atoms derived from cations of the photoacid generator, all atoms derived from cations of the boron-containing compound, and all atoms derived from cations of the acid diffusion controller. Ｃ１ [I] represents the molar ratio of the sum of boron atoms derived from cations of the photoacid generator, boron atoms derived from cations of the boron-containing compound, and boron atoms derived from cations of the acid diffusion controller to the sum of all atoms derived from cations of the photoacid generator, all atoms derived from cations of the boron-containing compound, and all atoms derived from cations of the acid diffusion controller. Ｃ１ ] represents the molar ratio of the sum of iodine atoms derived from cations of the photoacid generator, iodine atoms derived from cations of the boron-containing compound, and iodine atoms derived from cations of the acid diffusion controller to the sum of all atoms derived from cations of the photoacid generator, all atoms derived from cations of the boron-containing compound, and all atoms derived from cations of the acid diffusion controller. Requirement 5: The C2 value calculated by formula (5) is 0.115 or more. Formula (5): C2 = ([H Ｃ２ × 0.04 + [C Ｃ２ × 1.0 + [N Ｃ２ × 2.1 + [O Ｃ２ × 3.6 + [F Ｃ２ × 5.6 + [S Ｃ２ × 1.5 + [B Ｃ２ × 0.5 + [I Ｃ２ × 39.5) / ([H Ｃ２ × 1 + [C Ｃ２ × 12 + [N Ｃ２ × 14 + [O Ｃ２ × 16 + [F Ｃ２ × 19 + [S Ｃ２ × 32 + [B Ｃ２ × 11 + [I Ｃ２ × 127) In formula (5), [H Ｃ２ [C] represents the molar ratio of the sum of hydrogen atoms derived from the cation of the photoacid generator and the cation of the boron-containing compound to the sum of all atoms derived from the cation of the photoacid generator and the cation of the boron-containing compound. Ｃ２ ] represents the molar ratio of the sum of carbon atoms derived from the cations of the photoacid generator and the boron-containing compound to the sum of all atoms derived from the cations of the photoacid generator and the boron-containing compound. Ｃ２ ] represents the molar ratio of the sum of nitrogen atoms derived from the cation of the photoacid generator and the nitrogen atoms derived from the cation of the boron-containing compound to the sum of all atoms derived from the cation of the photoacid generator and the boron-containing compound. Ｃ２ ] represents the molar ratio of the sum of oxygen atoms derived from the cation of the photoacid generator and the oxygen atoms derived from the cation of the boron-containing compound to the sum of all atoms derived from the cation of the photoacid generator and the boron-containing compound. Ｃ２ ] represents the molar ratio of the sum of fluorine atoms derived from the cations of the photoacid generator and the boron-containing compound to the sum of all atoms derived from the cations of the photoacid generator and the boron-containing compound. Ｃ２ [B] represents the molar ratio of the sum of sulfur atoms derived from the cation of the photoacid generator and the sulfur atoms derived from the cation of the boron-containing compound to the sum of all atoms derived from the cation of the photoacid generator and the boron-containing compound. Ｃ２ [I] represents the molar ratio of the sum of the boron atoms derived from the cations of the photoacid generator and the boron atoms derived from the cations of the boron-containing compound to the sum of all atoms derived from the cations of the photoacid generator and the boron-containing compound. Ｃ２ ] represents the molar ratio of the sum of iodine atoms derived from cations of the photoacid generator and cations of the boron-containing compound to the sum of all atoms derived from cations of the photoacid generator and all atoms derived from cations of the boron-containing compound.

4. the composition comprises an acid diffusion control agent; The actinic ray-sensitive or radiation-sensitive resin composition according to claim 3 , wherein the acid diffusion controller is not a salt compound.

5. the composition comprises an acid diffusion control agent; The actinic ray-sensitive or radiation-sensitive resin composition according to claim 3 , wherein the acid diffusion controller is a salt compound.

6. The actinic ray-sensitive or radiation-sensitive resin composition according to claim 5 , wherein the acid diffusion controller is an onium salt compound.

7. The actinic ray-sensitive or radiation-sensitive resin composition according to claim 3 , wherein the photoacid generator comprises a cation containing a fluorine atom.

8. A resist film formed using the actinic ray-sensitive or radiation-sensitive resin composition according to claim 3.

9. forming a resist film on a substrate using the actinic ray-sensitive or radiation-sensitive resin composition according to claim 3; exposing the resist film to light; and developing the exposed resist film with a developer to form a pattern.

10. The pattern formation method according to claim 9 , wherein the developer contains an organic solvent.

11. The pattern formation method according to claim 10 , wherein the developer contains an ester-based solvent having 6 or less carbon atoms and a hydrocarbon-based solvent.

12. A method for manufacturing an electronic device, comprising the pattern formation method according to claim 9.

13. the photoacid generator is an onium salt compound, the boron-containing compound is a salt compound; When the composition contains an acid diffusion controller that is an onium salt compound, requirement 2 is satisfied; The actinic ray-sensitive or radiation-sensitive resin composition according to claim 1, which satisfies Requirement 3 when the composition does not contain an acid diffusion controller that is an onium salt compound. Requirement 2: The B1 value calculated by formula (2) is 0.115 or more. Formula (2): B1 = ([H Ｂ１ × 0.04 + [C Ｂ１ × 1.0 + [N Ｂ１ × 2.1 + [O Ｂ１ × 3.6 + [F Ｂ１ × 5.6 + [S Ｂ１ × 1.5 + [B Ｂ１ × 0.5 + [I Ｂ１ × 39.5) / ([H Ｂ１ × 1 + [C Ｂ１ × 12 + [N Ｂ１ × 14 + [O Ｂ１ × 16 + [F Ｂ１ × 19 + [S Ｂ１ × 32 + [B Ｂ１ × 11 + [I Ｂ１ × 127) In formula (2), [H Ｂ１ [C] represents the molar ratio of the sum of hydrogen atoms derived from cations of the photoacid generator, the boron-containing compound, and the acid diffusion controller to the sum of all atoms derived from cations of the photoacid generator, the boron-containing compound, and the acid diffusion controller. Ｂ１ ] represents the molar ratio of the total of carbon atoms derived from cations of the photoacid generator, the total of carbon atoms derived from cations of the boron-containing compound, and the total of carbon atoms derived from cations of the acid diffusion controller to the total of all atoms derived from cations of the photoacid generator, the total of all atoms derived from cations of the boron-containing compound, and the total of all atoms derived from cations of the acid diffusion controller. Ｂ１ [O] represents the molar ratio of the sum of nitrogen atoms derived from cations of the photoacid generator, the sum of nitrogen atoms derived from cations of the boron-containing compound, and the acid diffusion controller to the sum of all atoms derived from cations of the photoacid generator, the sum of all atoms derived from cations of the boron-containing compound, and the acid diffusion controller. Ｂ１ [F] represents the molar ratio of the sum of oxygen atoms derived from cations of the photoacid generator, oxygen atoms derived from cations of the boron-containing compound, and oxygen atoms derived from cations of the acid diffusion controller to the sum of all atoms derived from cations of the photoacid generator, all atoms derived from cations of the boron-containing compound, and all atoms derived from cations of the acid diffusion controller. Ｂ１ [S] represents the molar ratio of the sum of fluorine atoms derived from cations of the photoacid generator, fluorine atoms derived from cations of the boron-containing compound, and fluorine atoms derived from cations of the acid diffusion controller to the sum of all atoms derived from cations of the photoacid generator, all atoms derived from cations of the boron-containing compound, and all atoms derived from cations of the acid diffusion controller. Ｂ１ [B] represents the molar ratio of the sum of sulfur atoms derived from cations of the photoacid generator, sulfur atoms derived from cations of the boron-containing compound, and sulfur atoms derived from cations of the acid diffusion controller to the sum of all atoms derived from cations of the photoacid generator, all atoms derived from cations of the boron-containing compound, and all atoms derived from cations of the acid diffusion controller. Ｂ１ [I] represents the molar ratio of the sum of boron atoms derived from cations of the photoacid generator, boron atoms derived from cations of the boron-containing compound, and boron atoms derived from cations of the acid diffusion controller to the sum of all atoms derived from cations of the photoacid generator, all atoms derived from cations of the boron-containing compound, and all atoms derived from cations of the acid diffusion controller. Ｂ１ ] represents the molar ratio of the sum of iodine atoms derived from cations of the photoacid generator, iodine atoms derived from cations of the boron-containing compound, and iodine atoms derived from cations of the acid diffusion controller to the sum of all atoms derived from cations of the photoacid generator, all atoms derived from cations of the boron-containing compound, and all atoms derived from cations of the acid diffusion controller. Requirement 3: The B2 value calculated by formula (3) is 0.115 or more. Formula (3): B2 = ([H Ｂ２ × 0.04 + [C Ｂ２ × 1.0 + [N Ｂ２ × 2.1 + [O Ｂ２ × 3.6 + [F Ｂ２ × 5.6 + [S Ｂ２ × 1.5 + [B Ｂ２ × 0.5 + [I Ｂ２ × 39.5) / ([H Ｂ２ × 1 + [C Ｂ２ × 12 + [N Ｂ２ × 14 + [O Ｂ２ × 16 + [F Ｂ２ × 19 + [S Ｂ２ × 32 + [B Ｂ２ × 11 + [I Ｂ２ × 127) In formula (3), [H Ｂ２ [C] represents the molar ratio of the sum of hydrogen atoms derived from the cation of the photoacid generator and the cation of the boron-containing compound to the sum of all atoms derived from the cation of the photoacid generator and the cation of the boron-containing compound. Ｂ２ ] represents the molar ratio of the sum of carbon atoms derived from the cations of the photoacid generator and the boron-containing compound to the sum of all atoms derived from the cations of the photoacid generator and the boron-containing compound. Ｂ２ ] represents the molar ratio of the sum of nitrogen atoms derived from the cation of the photoacid generator and the nitrogen atoms derived from the cation of the boron-containing compound to the sum of all atoms derived from the cation of the photoacid generator and the boron-containing compound. Ｂ２ ] represents the molar ratio of the sum of oxygen atoms derived from the cation of the photoacid generator and the oxygen atoms derived from the cation of the boron-containing compound to the sum of all atoms derived from the cation of the photoacid generator and the boron-containing compound. Ｂ２ ] represents the molar ratio of the sum of fluorine atoms derived from the cations of the photoacid generator and the boron-containing compound to the sum of all atoms derived from the cations of the photoacid generator and the boron-containing compound. Ｂ２ [B] represents the molar ratio of the sum of sulfur atoms derived from the cation of the photoacid generator and the sulfur atoms derived from the cation of the boron-containing compound to the sum of all atoms derived from the cation of the photoacid generator and the boron-containing compound. Ｂ２ [I] represents the molar ratio of the sum of the boron atoms derived from the cations of the photoacid generator and the boron atoms derived from the cations of the boron-containing compound to the sum of all atoms derived from the cations of the photoacid generator and the boron-containing compound. Ｂ２ ] represents the molar ratio of the sum of iodine atoms derived from cations of the photoacid generator and cations of the boron-containing compound to the sum of all atoms derived from cations of the photoacid generator and all atoms derived from cations of the boron-containing compound.

14. The actinic ray-sensitive or radiation-sensitive resin composition according to claim 13 , wherein the photoacid generator comprises a cation containing a fluorine atom.

15. The actinic ray-sensitive or radiation-sensitive resin composition according to claim 13, further comprising an acid diffusion controller.

16. The actinic ray-sensitive or radiation-sensitive resin composition according to claim 15, wherein the acid diffusion controller is an onium salt compound.

17. A resist film formed using the actinic ray-sensitive or radiation-sensitive resin composition according to claim 13.

18. A process for forming a resist film on a substrate using the actinic ray-sensitive or radiation-sensitive resin composition according to claim 13; exposing the resist film to light; and developing the exposed resist film with a developer to form a pattern.

19. The pattern formation method according to claim 18 , wherein the developer contains an organic solvent.

20. 20. The pattern formation method according to claim 19, wherein the developer contains an ester-based solvent having 6 or less carbon atoms and a hydrocarbon-based solvent.

21. A method for manufacturing an electronic device, comprising the pattern formation method according to claim 18.