Resist composition and resist film forming method using same

Abstract

By means of the present invention, it is possible to provide a resist composition containing a resin (A) and a solvent (B) containing a compound (B1) represented by general formula (b-1), the content of an active ingredient being 45 mass% or less based on the total amount of the resist composition. (In formula (b-1), R0 is an alkyl group having 1-10 carbon atoms, an aryl group having 6-10 carbon atoms, or an acyl group having 1-10 carbon atoms, and R1 is a hydrogen atom or an alkyl group having 1-10 carbon atoms. ) # imgabs0 #.

Description

Technical Field

[0001] The present invention relates to a resist composition and a resist film forming method using the resist composition. Background Art

[0002] In the manufacture of semiconductor elements or liquid crystal elements, fine processing using photolithography is performed using photoresist materials. In particular, in the manufacture of semiconductor elements, in recent years, with the high integration and high speed of LSI, the pattern size is required to be further refined. In order to cope with such fine pattern size, the light source for lithography used in forming resist patterns is being shortened from KrF excimer laser (248nm) to ArF excimer laser (193nm).

[0003] For example, Patent Document 1 discloses an invention involving a positive resist composition using a resin in which the hydroxyl groups in the carboxyl groups of (meth)acrylic acid are protected with an acid-dissociable dissolution-inhibiting group as a photoresist material suitable for forming a resist pattern using an ArF excimer laser.

[0004] In addition, in recent years, in addition to the refinement of pattern size, three-dimensional structure devices have been developed to achieve large-capacity memory by stacking memory cells. In addition, in the manufacture of three-dimensional structure devices, a resist pattern is currently formed after manufacturing a thick film resist film with a high film thickness.

[0005] Prior art literature Patent Literature Patent Document 1: Japanese Patent Application Publication No. 2003-241385 Summary of the invention

[0006] Problems to be solved by the invention Thus, the photoresist material used in manufacturing various devices such as semiconductor elements and liquid crystal elements has different properties required for each device. Therefore, a photoresist material capable of forming a resist film suitable for manufacturing various devices is required.

[0007] Technical solutions for solving technical problems The present invention provides a resist composition containing a resin and a solvent containing a compound having a specific structure and limiting the content of an active ingredient to a specified value or less, and a resist film forming method using the resist composition. That is, the present invention is as follows.

[0008] <1> A resist composition comprising a resin (A) and a solvent (B) containing a compound (B1) represented by the following general formula (b-1), The content of the active ingredient in the resist composition is 45% by mass or less based on the total amount.

[0009] [In the above formula (b-1), R 0 is an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, or an acyl group having 1 to 10 carbon atoms, R 1 It is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms.

[0010] <2> The resist composition according to <1> above, wherein the solvent (B) does not contain methyl 2-methoxyisobutyrate (MBM), methyl 2-formyloxyisobutyrate (FBM), and methyl 2-acetoxyisobutyrate (ABM).

[0011] <3> The resist composition according to <1> or <2>, further comprising at least one additive (C) selected from the group consisting of a photosensitizer and an acid generator.

[0012] <4> The resist composition according to any one of <1> to <3>, wherein R in the general formula (b-1) 0 is methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, cyclopropyl, cyclopentyl, cyclohexyl, phenyl, naphthyl, formyl, acetyl, propionyl or benzoyl.

[0013] <5> The resist composition according to any one of <1> to <4>, wherein R in the general formula (b-1) 1 It is a hydrogen atom, a methyl group, an ethyl group, a n-propyl group, an isopropyl group, a n-butyl group, an isobutyl group, a sec-butyl group or a tert-butyl group.

[0014] <6> The resist composition according to any one of <1> to <5>, wherein the solvent (B) contains a compound represented by the following general formula (b-2) as a solvent (B2) other than the compound (B1).

[0015] [In the above formula (b-2), R 1 It is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms.

[0016] <7> The resist composition according to <6>, wherein the solvent (B) contains at least one selected from methyl α-hydroxyisobutyrate and α-hydroxyisobutyric acid as the solvent (B2).

[0017] <8> The resist composition according to <6> or <7>, comprising less than 100% by mass of the solvent (B2) based on the total amount (100% by mass) of the resist composition.

[0018] <9> The resist composition according to any one of <1> to <8>, wherein the resin (A) comprises a novolac resin (A1).

[0019] <10> The resist composition according to any one of <1> to <8>, wherein the resin (A) comprises a resin (A2) having at least one of a structural unit (a2-1) derived from a compound containing a phenolic hydroxyl group and a structural unit (a2-2) that can be decomposed by the action of an acid, an alkali or heat to form an acidic functional group.

[0020] <11> The resist composition according to any one of <1> to <8>, wherein the resin (A) comprises a resin (A3) having a structural unit (a3-1) having an adamantane structure.

[0021] <12> The resist composition according to <11>, wherein the resin (A3) is a copolymer including a structural unit (a3-1) and a structural unit (a3-2) having a lactone structure.

[0022] <13> The resist composition according to <11> or <12>, wherein the content of the structural unit (a3-1α) having an adamantane structure substituted with a hydroxyl group is less than 50 mol % based on the total amount of the structural units of the resin (A3).

[0023] <14> The resist composition according to any one of <1> to <8>, wherein the resin (A) comprises a resin (A4) having any two or more structural units selected from a structural unit (a2-1) derived from a compound containing a phenolic hydroxyl group, a structural unit (a2-2) that can be decomposed by the action of an acid, an alkali or heat to form an acidic functional group, a structural unit (a3-1) having an adamantane structure and a structural unit (a3-2) having a lactone structure.

[0024] <15> The resist composition according to any one of <6> to <8>, comprising 100% by mass or less of the solvent (B2) based on the total amount (100% by mass) of the compound (B1).

[0025] <16> A method for forming a resist film, comprising: Step (1): a step of applying the resist composition described in any one of <1> to <15> above onto a substrate to form a coating film; Step (2): a step of performing a heat treatment after step (1); and Step (3): a step of forming a resist pattern.

[0026] Effects of the Invention The resist composition according to a preferred embodiment of the present invention can form a resist film suitable for manufacturing various devices even though the content of the effective component including the resin is limited to a predetermined value or less. DETAILED DESCRIPTION

[0027] [Resist composition] The resist composition of the present invention contains a resin (A) (hereinafter also referred to as "component (A)") and a solvent (B) (hereinafter also referred to as "component (B)") containing a compound (B1) represented by the general formula (b-1). The resist composition of the present invention is used to form a resist film, but the "resist film" does not include a film for a resist underlayer (for example, a resist auxiliary film such as a resist intermediate layer film or a resist underlayer film).

[0028] The resist composition of one embodiment of the present invention preferably further contains at least one additive (C) selected from a photosensitizer and an acid generator (hereinafter also referred to as “component (C)”).

[0029] Furthermore, in the resist composition of the present invention, the content of the active ingredient is limited to 45% by mass or less based on the total amount (100% by mass) of the resist composition.

[0030] In this specification, the "active ingredient" refers to the components contained in the resist composition excluding the component (B). Specifically, it corresponds to the resin (A) and the additive (C), and the acid crosslinking agent, acid diffusion control agent, dissolution accelerator, dissolution control agent, sensitizer, surfactant, organic carboxylic acid or phosphorus oxygen acid or its derivative, dye, pigment, adhesion promoter, antihalation agent, storage stabilizer, defoaming agent, shape improver, etc. that can be contained as other additives described later.

[0031] Generally, for example, in order to manufacture a three-dimensional structure device, it is necessary to form a thick resist film. However, when a resist composition having a small resin content is used, it is difficult to form a thick resist film.

[0032] In this regard, the resist composition of the present invention can be made into a photoresist material capable of forming a thick resist film even if the content of the active ingredient including the resin is reduced to 45% by mass or less by using the compound represented by the general formula (b-1) as a solvent. In addition, the resist composition of the present invention is also economically excellent because the content of the active ingredient is reduced to 45% by mass or less.

[0033] In addition, in the resist composition of one embodiment of the present invention, the content of the active ingredient can be appropriately set to 42 mass % or less, 40 mass % or less, 36 mass % or less, 31 mass % or less, 26 mass % or less, 23 mass % or less, 20 mass % or less, 18 mass % or less, 16 mass % or less, 12 mass % or less, 10 mass % or less, 6 mass % or less, or 3 mass % or less, based on the total amount (100 mass %) of the resist composition, depending on the application.

[0034] On the other hand, the lower limit of the content of the active ingredient can also be appropriately set according to the application, and can be 1 mass % or more, 2 mass % or more, 4 mass % or more, 7 mass % or more, or 10 mass % or more relative to the total amount (100 mass %) of the resist composition.

[0035] The content of the active ingredient can be appropriately selected from the respective options of the upper limit and the lower limit described above, and can be specified in any combination.

[0036] In addition, in the resist composition of one embodiment of the present invention, from the viewpoint of preparing a photoresist material capable of forming a thick resist film, the content ratio of the component (A) as an active ingredient is preferably 50 to 100 mass %, more preferably 60 to 100 mass %, further preferably 70 to 100 mass %, further preferably 75 to 100 mass %, and particularly preferably 80 to 100 mass % relative to the total amount (100 mass %) of the active ingredients contained in the resist composition.

[0037] The resist composition of one embodiment of the present invention may contain other components in addition to the above-mentioned components (A) to (C) depending on the application.

[0038] Among them, in the resist composition of one embodiment of the present invention, the total content of components (A), (B) and (C) is preferably 30 to 100 mass %, more preferably 40 to 100 mass %, further preferably 60 to 100 mass %, further preferably 80 to 100 mass %, and particularly preferably 90 to 100 mass %, based on the total amount (100 mass %) of the resist composition.

[0039] Hereinafter, the details of each component contained in the resist composition of one embodiment of the present invention will be described.

[0040] <Ingredient (A): Resin> The resin (A) contained in the resist composition of one embodiment of the present invention is not particularly limited, and known resins for photoresists such as those for g-line, i-line, KrF excimer laser, ArF excimer laser, EUV, and EB can be used, and can be appropriately selected according to the application. In this specification, "resin" refers to a compound having a predetermined structure in addition to a polymer having a predetermined structural unit.

[0041] The weight average molecular weight (Mw) of the resin used in one embodiment of the present invention is preferably 400 to 50,000, more preferably 1,000 to 40,000, and even more preferably 1,000 to 30,000.

[0042] In the resist composition of the present invention, the content of the component (A) can be appropriately set to 45 mass % or less, 42 mass % or less, 40 mass % or less, 35 mass % or less, 31 mass % or less, 26 mass % or less, 23 mass % or less, 20 mass % or less, 18 mass % or less, 16 mass % or less, 12 mass % or less, 10 mass % or less, 6 mass % or less, or 3 mass % or less, based on the total amount (100 mass %) of the resist composition, depending on the application.

[0043] The lower limit of the content of component (A) can also be appropriately set depending on the application, and may be 1% by mass or more, 2% by mass or more, 4% by mass or more, 7% by mass or more, or 10% by mass or more based on the total amount (100% by mass) of the resist composition.

[0044] The content of the component (A) can be appropriately selected from the respective options of the upper limit and the lower limit described above, and can be specified in any combination.

[0045] For example, when the resin (A) is used as a photoresist material for manufacturing a liquid crystal element for ultraviolet exposure such as g-line or i-line, the resin (A) preferably contains a novolac resin (A1).

[0046] When used as a photoresist material for KrF excimer laser, the resin (A) preferably contains a resin (A2) having at least one of a structural unit derived from a compound containing a phenolic hydroxyl group and a structural unit that can be decomposed by the action of an acid, an alkali or heat to form an acidic functional group.

[0047] When the material is used as a photoresist material for ArF excimer laser or the like, the resin (A) preferably includes a resin (A3) including a structural unit having an adamantane structure.

[0048] When a photoresist material for EUV is prepared, the resin (A) preferably comprises a resin (A4) having any two or more structural units selected from a structural unit derived from a compound containing a phenolic hydroxyl group, a structural unit that can be decomposed by the action of an acid, an alkali or heat to form an acidic functional group, a structural unit having an adamantane structure and a structural unit having a lactone structure (excluding resin (A2) and resin (A3).

[0049] The resin (A) contained in the resist composition of one embodiment of the present invention may contain only one selected from the resins (A1), (A2), (A3) and (A4), or may contain two or more of them in combination.

[0050] Furthermore, the resin (A) may contain other resins other than the resins (A1), (A2), (A3) and (A4).

[0051] Among them, the total content ratio of the resins (A1), (A2), (A3) and (A4) in the resin (A) used in one embodiment of the present invention is preferably 60 to 100 mass %, more preferably 70 to 100 mass %, further preferably 80 to 100 mass %, further preferably 90 to 100 mass %, and particularly preferably 95 to 100 mass % relative to the total amount (100 mass %) of the resin (A).

[0052] Hereinafter, these resins (A1), (A2), (A3) and (A4) will be described.

[0053] [Novolac type resin (A1)] Examples of the novolac resin (A1) used in one embodiment of the present invention include resins obtained by reacting phenols with at least one of aldehydes and ketones in the presence of an acidic catalyst (e.g., hydrochloric acid, sulfuric acid, oxalic acid, etc.). The novolac resin (A1) is not particularly limited, and a known resin can be used, for example, the resins listed in Japanese Patent Application Publication No. 2009-173623, International Patent Publication No. 2013-024778, and International Patent Publication No. 2015-137485 can be applied.

[0054] Examples of the phenols include phenol, o-cresol, m-cresol, p-cresol, 2,3-dimethylphenol, 2,5-dimethylphenol, 3,4-dimethylphenol, 3,5-dimethylphenol, 2,4-dimethylphenol, 2,6-dimethylphenol, 2,3,5-trimethylphenol, 2,3,6-trimethylphenol, 2-tert-butylphenol, 3-tert-butylphenol, 4-tert-butylphenol, 2-methylresorcinol, 4-methylresorcinol, catechol, 5-methylresorcinol, 4-tert-butylcatechol, 2-methoxyphenol, 3-methoxyphenol, 2-propylphenol, 3-propylphenol, 4-propylphenol, 2-isopropylphenol, 2-methoxy-5-methylphenol, 2-tert-butyl-5-methylphenol, thymol, isothymol, 4,4'-biphenol, 1-naphthol, 2-naphthol, hydroxyanthracene, hydroxypyrene, 2,6-dihydroxynaphthalene and 2,6-dihydroxynaphthalene, etc.

[0055] These phenols may be used alone or in combination of two or more.

[0056] Examples of the aldehydes include formaldehyde, paraformaldehyde, trioxane, acetaldehyde, propionaldehyde, benzaldehyde, phenylacetaldehyde, α-phenylpropionaldehyde, β-phenylpropionaldehyde, benzaldehyde, 4-biphenylaldehyde, o-hydroxybenzaldehyde, m-hydroxybenzaldehyde, p-hydroxybenzaldehyde, o-chlorobenzaldehyde, m-chlorobenzaldehyde, p-chlorobenzaldehyde, o-methylbenzaldehyde, m-methylbenzaldehyde, p-methylbenzaldehyde, p-ethylbenzaldehyde, 3,4-dimethylbenzaldehyde, p-propylbenzaldehyde, p-butylbenzaldehyde, terephthalaldehyde, 1-naphthaldehyde, and 2-naphthaldehyde.

[0057] Examples of ketones include acetone, methyl ethyl ketone, diethyl ketone, acetophenone, and benzophenone.

[0058] These aldehydes and ketones may be used alone or in combination of two or more.

[0059] Among these, the novolac resin (A1) used in one embodiment of the present invention is preferably a resin obtained by condensation reaction of cresol and aldehydes, more preferably a resin obtained by condensation reaction of at least one of m-cresol and p-cresol with at least one of formaldehyde and paraformaldehyde, and still more preferably a resin obtained by using m-cresol and p-cresol in combination and condensing them with at least one of formaldehyde and paraformaldehyde.

[0060] When m-cresol and p-cresol are used in combination, the blending ratio of m-cresol to p-cresol as raw materials [m-cresol / p-cresol] is preferably 10 / 90 to 90 / 10, more preferably 20 / 80 to 80 / 20, and even more preferably 50 / 50 to 70 / 30 in terms of mass ratio.

[0061] The novolac-type resin (A1) used in one embodiment of the present invention may be a commercially available product such as “EP4080G” and “EP4050G” (both manufactured by Asahi Organic Materials Co., Ltd., cresol novolac resin).

[0062] The weight average molecular weight (Mw) of the novolac resin (A1) used in one embodiment of the present invention is preferably 500 to 30,000, more preferably 1,000 to 20,000, further preferably 1,000 to 15,000, and further preferably 1,000 to 10,000.

[0063] [Resin (A2)] The resin (A2) used in one embodiment of the present invention is not particularly limited, and a known resin can be used. It is preferably a resin having at least one of a structural unit (a2-1) derived from a compound containing a phenolic hydroxyl group and a structural unit (a2-2) that can be decomposed by the action of an acid, an alkali or heat to form an acidic functional group. A copolymer having both the structural unit (a2-1) and the structural unit (a2-2) is more preferred.

[0064] The resin having at least one of the structural unit (a2-1) and the structural unit (a2-2) can increase the solubility in an alkaline developer.

[0065] In the resin (A2) used in one embodiment of the present invention, the total content ratio of the structural unit (a2-1) and the structural unit (a2-2) is preferably 30 mol% or more, more preferably 50 mol% or more, further preferably 60 mol% or more, further preferably 70 mol% or more, and particularly preferably 80 mol% or more, relative to the total amount (100 mol%) of the structural units of the resin (A2).

[0066] In addition, when the resin (A2) used in one embodiment of the present invention is a copolymer having both the structural unit (a2-1) and the structural unit (a2-2), the content ratio of the structural unit (a2-1) to the structural unit (a2-2) [(a2-1) / (a2-2)] is preferably 1 / 10 to 10 / 1 in terms of molar ratio, more preferably 1 / 5 to 8 / 1, further preferably 1 / 2 to 6 / 1, and further preferably 1 / 1 to 4 / 1.

[0067] Examples of the phenolic hydroxyl group-containing compound constituting the structural unit (a2-1) include hydroxystyrenes (o-hydroxystyrene, m-hydroxystyrene, p-hydroxystyrene) and isopropenylphenols (o-isopropenylphenol, m-isopropenylphenol, p-isopropenylphenol), and hydroxystyrene is preferred.

[0068] Examples of the acidic functional group that can be decomposed and formed by the action of an acid, a base or heat in the structural unit (a2-2) include a phenolic hydroxyl group and a carboxyl group.

[0069] Examples of monomers capable of forming a structural unit having a phenolic hydroxyl group include hydroxy(α-methyl)styrenes protected by an acetal group, such as p-(1-methoxyethoxy)styrene, p-(1-ethoxyethoxy)styrene, p-(1-n-propoxyethoxy)styrene, p-(1-isopropoxyethoxy)styrene, p-(1-cyclohexyloxyethoxy)styrene, and α-methyl substituted products thereof; and p-acetoxystyrene, tert-butoxycarbonylstyrene, tert-butoxystyrene, and α-methyl substituted products thereof.

[0070] These may be used alone or in combination of two or more.

[0071] Examples of the monomer capable of forming a structural unit of a carboxyl group include (meth)acrylic acid esters protected with an acid-decomposable ester group such as tert-butyl (meth)acrylate, tetrahydropyranyl (meth)acrylate, 2-methoxybutyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 2-tert-butoxycarbonylethyl (meth)acrylate, 2-benzyloxycarbonylethyl (meth)acrylate, 2-phenoxycarbonylethyl (meth)acrylate, 2-cyclohexyloxycarbonyl (meth)acrylate, 2-isobornyloxycarbonylethyl (meth)acrylate, and 2-tricyclodecanyloxycarbonylethyl (meth)acrylate.

[0072] These may be used alone or in combination of two or more.

[0073] Among these, the monomer constituting the structural unit (a2-2) is preferably at least one selected from tert-butyl (meth)acrylate, tetrahydropyranyl (meth)acrylate, 2-cyclohexyloxycarbonylethyl (meth)acrylate and p-(1-ethoxyethoxy)styrene.

[0074] The resin (A2) used in one embodiment of the present invention may be any resin having at least one of the structural unit (a2-1) and the structural unit (a2-2) as described above, and may have other structural units besides these.

[0075] Examples of monomers constituting such other structural units include: (meth) alkyl acrylates; hydroxyl-containing monomers; epoxy-containing monomers; alicyclic structure-containing monomers; olefins such as ethylene, propylene, and isobutylene; halogenated olefins such as vinyl chloride and vinylidene chloride; diene monomers such as butadiene, isoprene, and chloroprene; aromatic vinyl monomers such as styrene, α-methylstyrene, p-methylstyrene, p-chlorostyrene, and p-methoxystyrene; cyano-containing vinyl monomers such as (meth) acrylonitrile and vinylidene cyanide; (meth) acrylamides such as (meth) acrylamide, N,N-dimethyl (meth) acrylamide, and N,N-dihydroxymethyl (meth) acrylamide; heteroatom-containing alicyclic vinyl monomers such as (meth) acryloylmorpholine, N-vinyl pyrrolidone, and N-vinyl caprolactam, etc.

[0076] Examples of the alkyl (meth)acrylate include compounds other than the monomer constituting the structural unit (a2-2), such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate (n-propyl (meth)acrylate, isopropyl (meth)acrylate), and the like.

[0077] Examples of the hydroxyl group-containing monomer include hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate.

[0078] The carbon number of the alkyl group of the hydroxyalkyl (meth)acrylate is preferably 1 to 10, more preferably 1 to 8, further preferably 1 to 6, and further preferably 2 to 4. The alkyl group may be a linear or branched chain group.

[0079] Examples of the epoxy group-containing monomer include epoxy group-containing (meth)acrylates such as glycidyl (meth)acrylate, β-methyl glycidyl (meth)acrylate, (3,4-epoxycyclohexyl)methyl (meth)acrylate, and 3-epoxycyclo-2-hydroxypropyl (meth)acrylate; glycidyl crotonate, and allyl glycidyl ether.

[0080] Examples of the alicyclic structure-containing monomer include cycloalkyl (meth)acrylates such as cyclopropyl (meth)acrylate, cyclobutyl (meth)acrylate, cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, cycloheptyl (meth)acrylate, and cyclooctyl (meth)acrylate, isobornyl (meth)acrylate, and dicyclopentenyl (meth)acrylate.

[0081] In addition, the resin (A2) used in one embodiment of the present invention may include a structural unit derived from adamantyl (meth)acrylate as a structural unit derived from an alicyclic structure-containing monomer. This resin corresponds to the resin (A2) and also corresponds to the resin (A3) described below.

[0082] The resin (A2) used in one embodiment of the present invention may have a structural unit derived from a monomer selected from esters of compounds having two or more hydroxyl groups in the molecule such as divalent or higher polyols, polyether diols, polyester diols, and (meth)acrylic acid, adducts of compounds having two or more epoxy groups in the molecule represented by epoxy resins and (meth)acrylic acid, and condensates of compounds having two or more amino groups in the molecule and (meth)acrylic acid.

[0083] Examples of such monomers include (poly)alkylene glycol (derivative) di(meth)acrylates such as ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, butylene glycol di(meth)acrylate, trimethylolpropane di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, tricyclodecane dimethanol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, N,N'-methylenebis(meth)acrylamide, di(meth)acrylates of ethylene glycol adducts or propylene glycol adducts of bisphenol A, and epoxy (meth)acrylates such as (meth)acrylic acid adducts of bisphenol A diglycidyl ether.

[0084] The weight average molecular weight (Mw) of the resin (A2) used in one embodiment of the present invention is preferably 400 to 50,000, more preferably 1,000 to 40,000, further preferably 1,000 to 30,000, and further preferably 1,000 to 25,000.

[0085] [Resin (A3)] The resin (A3) used in one embodiment of the present invention is not particularly limited, and a known resin can be used. A resin having a structural unit (a3-1) having an adamantane structure, preferably a structural unit that can be decomposed by the action of an acid to form an acidic functional group, can be used. In addition, from the viewpoint of solubility in a solvent and adhesion to a substrate, a copolymer having a structural unit (a3-1) and a structural unit (a3-2) having a lactone structure is preferably used in practical terms.

[0086] Furthermore, at least one of the hydrogen atoms bonded to the carbon atom of the adamantane structure included in the structural unit (a3-1) may be substituted with a substituent R.

[0087] Similarly, at least one of the hydrogen atoms bonded to the carbon atom constituting the lactone structure of the structural unit (a3-2) may be substituted with a substituent R.

[0088] Examples of the substituent R include an alkyl group having 1 to 6 carbon atoms, a hydroxyalkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom), a deuterium atom, a hydroxyl group, an amino group, a nitro group, a cyano group, and a group represented by the following formula (i) or (ii).

[0089] In the above formula (i) or (ii), R a and R b Each of them is independently an alkyl group having 1 to 6 carbon atoms, a hydroxyalkyl group having 1 to 6 carbon atoms, or a cycloalkyl group having 3 to 6 carbon atoms.

[0090] m is an integer of 1 to 10, preferably an integer of 1 to 6, more preferably an integer of 1 to 3, and further preferably an integer of 1 to 2.

[0091] A is an alkylene group having 1 to 6 carbon atoms (preferably 1 to 4 carbon atoms, more preferably 2 to 3 carbon atoms).

[0092] Examples of the alkylene group include a methylene group, an ethylene group, a n-propylene group, an isopropylene group, a 1,4-butylene group, a 1,3-butylene group, a tetramethylene group, a 1,5-pentylene group, a 1,4-pentylene group, and a 1,3-pentylene group.

[0093] In the resin (A3) used in one embodiment of the present invention, the content of the structural unit (a3-1α) having an adamantane structure substituted with a hydroxyl group as the structural unit (a3-1) is preferably less than 50 mol%, more preferably less than 44 mol%, further preferably less than 39 mol%, and further preferably less than 34 mol%, relative to the total amount (100 mol%) of the structural units of the resin (A3).

[0094] In one embodiment of the present invention, the structural unit (a3-1) is preferably a structural unit (a3-1-1) represented by the following formula (a3-1-i) or a structural unit (a3-1-2) represented by the following formula (a3-1-ii).

[0095] In the above formula, n is each independently an integer of 0 to 14, preferably an integer of 0 to 4, more preferably an integer of 0 to 2, and further preferably an integer of 0 to 1.

[0096] R x are each independently a hydrogen atom or a methyl group.

[0097] R is independently a substituent R which the adamantane structure may have, and specifically, as described above, is preferably an alkyl group having 1 to 6 carbon atoms, and more preferably an alkyl group having 1 to 3 carbon atoms.

[0098] X 1 Each independently represents a single bond, an alkylene group having 1 to 6 carbon atoms, or a divalent linking group represented by any of the following formulae.

[0099] In the above formula, *1 indicates the position of bonding to the oxygen atom in the above formula (a3-1-i) or (a3-1-ii), and *2 indicates the position of bonding to the carbon atom of the adamantane structure. 1 It represents an alkylene group having 1 to 6 carbon atoms.

[0100] In one embodiment of the present invention, the structural unit (a3-2) is preferably any of a structural unit (a3-2-1) represented by the following formula (a3-2-i), a structural unit (a3-2-2) represented by the following formula (a3-2-ii), and a structural unit (a3-2-3) represented by the following formula (a3-2-iii).

[0101] In the above formula, n1 is an integer of 0-5, preferably an integer of 0-2, and more preferably an integer of 0-1.

[0102] n2 is an integer of 0-9, preferably an integer of 0-2, and more preferably an integer of 0-1.

[0103] n3 is an integer of 0-9, preferably an integer of 0-2, and more preferably an integer of 0-1.

[0104] R y A hydrogen atom or a methyl group.

[0105] R is independently a substituent R that the lactone structure may have, and specifically, as described above, is preferably an alkyl group having 1 to 6 carbon atoms, and more preferably an alkyl group having 1 to 3 carbon atoms. When there are multiple Rs, the multiple Rs may be the same group or different groups.

[0106] X 2 It is a single bond, an alkylene group having 1 to 6 carbon atoms, or a divalent linking group represented by any of the following formulae.

[0107] In the above formula, *1 indicates the position of bonding to the oxygen atom in the above formula (a3-2-i), (a3-2-ii) or (a3-2-iii), and *2 indicates the position of bonding to the carbon atom of the lactone structure. 1 It represents an alkylene group having 1 to 6 carbon atoms.

[0108] Furthermore, the resin (A3) used in one embodiment of the present invention may have other structural units in addition to the structural units (a3-1) and (a3-2).

[0109] Examples of such other structural units include structural units derived from (meth) alkyl acrylates; monomers containing hydroxyl groups; monomers containing epoxy groups; monomers containing alicyclic structures; olefins such as ethylene, propylene, and isobutylene; halogenated olefins such as vinyl chloride and vinylidene chloride; diene monomers such as butadiene, isoprene, and chloroprene; and monomers such as styrene, α-methylstyrene, vinyltoluene, acrylonitrile, (meth)acrylamide, (meth)acrylonitrile, (meth)acryloylmorpholine, and N-vinylpyrrolidone. The details of these monomers are the same as those described in the resin (A2) section.

[0110] In the resin (A3) used in one embodiment of the present invention, the total content of the structural units (a3-1) and (a3-2) is preferably 30 to 100 mol%, more preferably 50 to 100 mol%, further preferably 70 to 100 mol%, further preferably 80 to 100 mol%, and particularly preferably 90 to 100 mol%, relative to the total amount (100 mol%) of the structural units of the resin (A3).

[0111] The weight average molecular weight (Mw) of the resin (A3) used in one embodiment of the present invention is preferably 400 to 50,000, more preferably 2,000 to 40,000, further preferably 3,000 to 30,000, and further preferably 4,000 to 20,000.

[0112] The molecular weight distribution (Mw / Mn) of the resin (A3) is preferably 6.0 or less, more preferably 5.0 or less, further preferably 4.0 or less, further preferably 3.2 or less, and is preferably 1.01 or more, more preferably 1.05 or more, further preferably 1.1 or more.

[0113] [Resin (A4)] The resin (A4) used in one embodiment of the present invention is not particularly limited as long as it is a resin having any two or more structural units of a structural unit (a2-1) derived from a compound containing a phenolic hydroxyl group, a structural unit (a2-2) that can be decomposed by the action of an acid, an alkali or heat to form an acidic functional group, a structural unit (a3-1) having an adamantane structure and a structural unit (a3-2) having a lactone structure (excluding resin (A2) and resin (A3). A known resin can be used. For example, the resins listed in the book "40 Years of Photolithography", International Patent Gazette No. 2014-175275, International Patent Gazette No. 2015-115613, International Patent Gazette No. 2020-137935, International Patent Gazette No. 2021-029395, and International Patent Gazette No. 2021-029396 can be used.

[0114] The weight average molecular weight (Mw) of the resin (A4) used in one embodiment of the present invention is preferably 400 to 50,000, more preferably 2,000 to 40,000, further preferably 3,000 to 30,000, and further preferably 4,000 to 20,000.

[0115] The molecular weight distribution (Mw / Mn) of the resin (A4) is preferably 6.0 or less, more preferably 5.0 or less, further preferably 4.0 or less, further preferably 3.2 or less, and is preferably 1.01 or more, more preferably 1.05 or more, further preferably 1.1 or more.

[0116] <Component (B): Solvent> The resist composition according to one embodiment of the present invention contains a solvent (B) containing a compound (B1) represented by the following general formula (b-1).

[0117] The compound (B1) may be used alone or in combination of two or more.

[0118] In the above formula (b-1), R 0 is an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, or an acyl group having 1 to 10 carbon atoms, R 1 It is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms.

[0119] In one embodiment of the present invention, R in the general formula (b-1) is 0 Preferred are methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, cyclopropyl, cyclopentyl, cyclohexyl, phenyl, naphthyl, formyl, acetyl, propionyl or benzoyl, more preferably methyl, acetyl or formyl.

[0120] In one embodiment of the present invention, R in the general formula (b-1) is 1 It is preferably a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group or a tert-butyl group, and more preferably a methyl group, an isopropyl group, an n-butyl group or an isobutyl group.

[0121] In one embodiment of the present invention, the solvent (B) preferably does not contain methyl 2-methoxyisobutyrate (MBM), methyl 2-formyloxyisobutyrate (FBM), and methyl 2-acetoxyisobutyrate (ABM) from the viewpoints of increasing the film thickness, usability at high temperatures, and improving in-plane uniformity.

[0122] In the resist composition of one embodiment of the present invention, the solvent (B) preferably contains a compound represented by the following general formula (b-2) as a solvent (B2) other than the compound (B1).

[0123] In the above formula (b-2), R 1 It is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. The alkyl group may be a linear alkyl group or a branched alkyl group.

[0124] As able to act as R 1 Examples of the alkyl group include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, heptyl, octyl, 2-ethylhexyl, nonyl and decyl.

[0125] Among these, in one embodiment of the present invention, R in the above general formula (b-2) 1 Preferred is a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group or a tert-butyl group.

[0126] In particular, among the solvents (B), it is preferred that the solvent (B2) contains at least one selected from methyl 2-hydroxyisobutyrate (HBM) and 2-hydroxyisobutyric acid.

[0127] In the resist composition of one embodiment of the present invention, examples of the solvent (B2) include: lactones such as γ-butyrolactone; ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl n-amyl ketone, methyl isoamyl ketone, and 2-heptanone; polyols such as ethylene glycol, diethylene glycol, propylene glycol, and dipropylene glycol; compounds having an ester bond such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, and dipropylene glycol monoacetate; monoalkyl ethers such as monomethyl ether, monoethyl ether, monopropyl ether, and monobutyl ether of the above polyols such as 1-methoxy-2-propanol or the above compounds having an ester bond, or monophenyl ethers having an ether bond; Compounds; cyclic ethers such as dioxane, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl β-methoxyisobutyrate, methyl methoxypropionate, ethyl ethoxypropionate, methyl β-formyloxyisobutyrate, methyl 3-hydroxyisobutyrate and other esters other than compound (B1); aromatic organic solvents such as anisole, ethyl benzyl ether, tolyl methyl ether, diphenyl ether, dibenzyl ether, phenethyl ether, butylphenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene and mesitylene; dimethyl sulfoxide (DMSO) and the like.

[0128] These solvents (B2) may be used alone or in combination of two or more.

[0129] Among them, from the viewpoint of producing a photoresist material capable of forming a thick resist film, in the resist composition of the present invention, the content ratio of the compound (B1) in the component (B) is preferably 20 to 100 mass %, more preferably 30 to 100 mass %, further preferably 50 to 100 mass %, further preferably 60 to 100 mass %, and particularly preferably 70 to 100 mass % relative to the total amount (100 mass %) of the component (B) contained in the resist composition.

[0130] In the resist composition of one embodiment of the present invention, the content of the compound (B1) is preferably 66.67% by mass or more, based on the total amount (100% by mass) of the solvent (B), from the viewpoint of thickening the resist composition and the usability at high temperatures, more preferably 80% by mass or more, from the viewpoint of improving the in-plane uniformity of the resist film, further preferably 90% by mass or more, from the viewpoint of improving the storage stability of the resist composition, further more preferably 99% by mass or more, from the viewpoint of improving the solubility of the effective ingredient in the resist film, and particularly preferably 99.9% by mass or more, from the viewpoint of suppressing defects in the resist film.

[0131] In addition, in the component (B) used in one embodiment of the present invention, as a solvent (B2), from the viewpoint of solubility of the acid generator used in the resist composition, it is preferred to contain one or more of methyl 3-hydroxyisobutyrate and 1-methoxy-2-propanol. From the viewpoint of obtaining a rectangular resist pattern, it is preferred to contain methyl 3-hydroxyisobutyrate. From the viewpoint of obtaining a resist film with high in-plane uniformity, it is preferred to contain 1-methoxy-2-propanol. Among them, the mixing method of methyl 3-hydroxyisobutyrate or 1-methoxy-2-propanol is not particularly limited, and it can be contained by any method of adding methyl 3-hydroxyisobutyrate or 1-methoxy-2-propanol to compound (B1), or by generating or mixing as a by-product in the production process of compound (B1).

[0132] The content of the solvent (B2) is not limited, but is preferably less than 100% by mass, more preferably 50% by mass or less, 40% by mass or less, 30% by mass or less, 20% by mass or less, 10% by mass or less, 5% by mass or less, 1% by mass or less, further preferably 0.1% by mass or less, and particularly preferably 0.01% by mass or less, based on the total amount (100% by mass) of the resist composition, from the viewpoint of improving productivity by shortening the drying time of the coating film. It is preferably 0.0001% by mass or more, more preferably 0.001% by mass or more, from the viewpoint of improving the storage stability of the resist composition, and more preferably 0.01% by mass or more, from the viewpoint of improving the solubility of the active ingredient of the resist composition. It is further preferably 0.01% by mass or more, from the viewpoint of suppressing defects in the resist film.

[0133] The content of the solvent (B2) is preferably 100% by mass or less, more preferably 50% by mass or less, 40% by mass or less, 30% by mass or less, 20% by mass or less, 10% by mass or less, 5% by mass or less, 1% by mass or less, further preferably 0.1% by mass or less, and particularly preferably 0.01% by mass or less, based on the total amount (100% by mass) of the compound (B1), from the viewpoint of improving productivity by shortening the drying time of the resist composition. From the viewpoint of improving the storage stability of the resist composition, it is preferably 0.0001% by mass or more, from the viewpoint of improving the solubility of the active ingredient of the resist composition, it is more preferably 0.001% by mass or more, and from the viewpoint of suppressing defects in the resist film, it is further preferably 0.01% by mass or more.

[0134] In addition, the content of 1-methoxy-2-propanol is preferably 1 to 98% by mass, more preferably 16 to 98% by mass, based on the total amount (100% by mass) of the resist composition, from the viewpoint of in-plane uniformity of the coating film. In addition, the content of 1-methoxy-2-propanol is preferably 1 to 99% by mass, more preferably 30 to 99% by mass, based on the total amount (100% by mass) of the compound (B1).

[0135] In the resist composition of the present invention, the content of component (B) can be appropriately set depending on the application, and can be 50 mass % or more, 54 mass % or more, 58 mass % or more, 60 mass % or more, 65 mass % or more, 69 mass % or more, 74 mass % or more, 77 mass % or more, 80 mass % or more, 82 mass % or more, 84 mass % or more, 88 mass % or more, 90 mass % or more, 94 mass % or more, or 97 mass % or more, based on the total amount (100 mass %) of the resist composition.

[0136] The content of the component (B) may have an upper limit value appropriately set depending on the content of the component (A), and may be 99% by mass or less, 98% by mass or less, 96% by mass or less, 93% by mass or less, 91% by mass or less, 86% by mass or less, 81% by mass or less, 76% by mass or less, 71% by mass or less, 66% by mass or less, or 61% by mass or less, based on the total amount (100% by mass) of the resist composition.

[0137] The content of the component (B) can be appropriately selected from the respective options of the upper limit and the lower limit described above, and can be specified in any combination.

[0138] <Component (C): an additive selected from a photosensitizer and an acid generator> The resist composition according to one embodiment of the present invention preferably contains at least one additive (C) selected from the group consisting of a photosensitizer and an acid generator.

[0139] Here, the component (C) may be used alone or in combination of two or more.

[0140] In the resist composition of one embodiment of the present invention, the content of the component (C) is preferably 0.01 to 80 parts by mass, more preferably 0.05 to 65 parts by mass, further preferably 0.1 to 50 parts by mass, and further preferably 0.5 to 30 parts by mass, relative to 100 parts by mass of the resin (A) contained in the resist composition.

[0141] Hereinafter, the photosensitizer and the acid generator contained as the component (C) will be described.

[0142] [Photosensitive agent] The photosensitizer that can be selected as the component (C) is not particularly limited as long as it can be used as a photosensitive component in a general positive resist composition.

[0143] The photosensitizer may be used alone or in combination of two or more.

[0144] Examples of the photosensitizer used in one embodiment of the present invention include a reaction product of an acid chloride and a compound having a functional group (hydroxyl group, amino group, etc.) that can condense with the acid chloride.

[0145] Examples of the acid chloride include naphthoquinonediazidesulfonyl chloride and benzoquinonediazidesulfonyl chloride. Specific examples include 1,2-naphthoquinonediazide-5-sulfonyl chloride and 1,2-naphthoquinonediazide-4-sulfonyl chloride.

[0146] Examples of the compound having a functional group that can condense with an acid chloride include hydroquinone, resorcinol, 2,4-dihydroxybenzophenone, 2,3,4-trihydroxybenzophenone, 2,4,6-trihydroxybenzophenone, 2,4,4'-trihydroxybenzophenone, 2,3,4,4'-tetrahydroxybenzophenone, 2,2',4,4'-tetrahydroxybenzophenone, and 2,2',3,4,6'-pentahydroxybenzophenone. Hydroxybenzophenones, bis(2,4-dihydroxyphenyl)methane, bis(2,3,4-trihydroxyphenyl)methane, bis(2,4-dihydroxyphenyl)propane and other hydroxyphenylalkanes, 4,4',3",4"-tetrahydroxy-3,5,3',5'-tetramethyltriphenylmethane, 4,4',2",3",4"-pentahydroxy-3,5,3',5'-tetramethyltriphenylmethane and other hydroxytriphenylmethanes, etc.

[0147] Moreover, as the photosensitizer used in one embodiment of the present invention, a commercially available product such as “DTEP-350” (manufactured by Daito Chemix Co., Ltd., a naphthoquinone diazide type photosensitizer) may be used.

[0148] [Acid generator] The acid generator that can be selected as the component (C) may be any compound that can directly or indirectly generate an acid by irradiation with radiation such as visible light, ultraviolet light, excimer laser, electron beam, extreme ultraviolet light (EUV), X-ray, and ion beam.

[0149] Specifically, as a preferred acid generator, a compound represented by any of the following general formulas (c-1) to (c-8) is preferred.

[0150] (Compound represented by general formula (c-1)) In the above formula (c-1), R 13Each independently represents a hydrogen atom, a linear, branched or cyclic alkyl group, a linear, branched or cyclic alkoxy group, a hydroxyl group or a halogen atom.

[0151] X － It is a sulfonate ion or a halide ion having an alkyl group, an aryl group, a halogenated alkyl group or a halogenated aryl group.

[0152] The compound represented by the general formula (c-1) is preferably selected from triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium nonafluoro-n-butanesulfonate, diphenyltolylsulfonium nonafluoro-n-butanesulfonate, triphenylsulfonium perfluoro-n-octanesulfonate, diphenyl-4-methylphenylsulfonium trifluoromethanesulfonate, di-2,4,6-trimethylphenylsulfonium trifluoromethanesulfonate, diphenyl-4-tert-butoxyphenylsulfonium trifluoromethanesulfonate, diphenyl 4-tert-butoxyphenylsulfonium nonafluoro-n-butanesulfonate, diphenyl-4-hydroxyphenylsulfonium trifluoromethanesulfonate, bis(4-fluorophenyl)-4-hydroxyphenylsulfonium trifluoromethanesulfonate, diphenyl-4-hydroxyphenylsulfonium nonafluoro-n-butanesulfonate, bis(4-hydroxyphenyl)-phenylsulfonium trifluoromethanesulfonate, tris(4-methoxyphenyl)sulfonium trifluoromethanesulfonate, tris(4-fluorophenyl)sulfonium trifluoromethanesulfonate, tris(4-methoxyphenyl)sulfonium trifluoromethanesulfonate At least one of phenylsulfonium p-toluenesulfonate, triphenylsulfonium benzenesulfonate, diphenyl-2,4,6-trimethylphenyl-p-toluenesulfonate, diphenyl-2,4,6-trimethylphenylsulfonium-2-trifluoromethylbenzenesulfonate, diphenyl-2,4,6-trimethylphenylsulfonium-4-trifluoromethylbenzenesulfonate, diphenyl-2,4,6-trimethylphenylsulfonium-2,4-difluorobenzenesulfonate, diphenyl-2,4,6-trimethylphenylsulfonium hexafluorobenzenesulfonate, diphenylnaphthylsulfonium trifluoromethanesulfonate, diphenyl-4-hydroxyphenylsulfonium p-toluenesulfonate, triphenylsulfonium-10-camphorsulfonate, diphenyl-4-hydroxyphenylsulfonium-10-camphorsulfonate and cyclo(1,3-perfluoropropanedisulfonyl)imide.

[0153] (Compound represented by general formula (c-2)) In the above formula (c-2), R 14 Each independently represents a hydrogen atom, a linear, branched or cyclic alkyl group, a linear, branched or cyclic alkoxy group, a hydroxyl group or a halogen atom.

[0154] X － It is a sulfonate ion or a halide ion having an alkyl group, an aryl group, a halogenated alkyl group or a halogenated aryl group.

[0155] The compound represented by the general formula (c-2) is preferably selected from bis(4-tert-butylphenyl)iodonium trifluoromethanesulfonate, bis(4-tert-butylphenyl)iodonium nonafluoro-n-butanesulfonate, bis(4-tert-butylphenyl)iodonium perfluoro-n-octanesulfonate, bis(4-tert-butylphenyl)iodonium p-toluenesulfonate, bis(4-tert-butylphenyl)iodonium benzenesulfonate, bis(4-tert-butylphenyl)iodonium-2-trifluoromethylbenzenesulfonate, bis(4-tert-butylphenyl)iodonium-4-trifluoromethylbenzenesulfonate, bis(4-tert-butylphenyl)iodonium-2,4-difluorobenzenesulfonate, bis(4-tert-butylphenyl)iodonium hexafluorobenzenesulfonate, bis(4-tert-butylphenyl)iodonium 10-camphorsulfonate, diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoro-n-octanesulfonate, At least one of fluoro-n-butanesulfonate, diphenyliodonium perfluoro-n-octanesulfonate, diphenyliodonium p-toluenesulfonate, diphenyliodonium benzenesulfonate, diphenyliodonium 10-camphorsulfonate, diphenyliodonium-2-trifluoromethylbenzenesulfonate, diphenyliodonium-4-trifluoromethylbenzenesulfonate, diphenyliodonium-2,4-difluorobenzenesulfonate, diphenyliodonium hexafluorobenzenesulfonate, bis(4-trifluoromethylphenyl)iodonium trifluoromethanesulfonate, bis(4-trifluoromethylphenyl)iodonium nonafluoro-n-butanesulfonate, bis(4-trifluoromethylphenyl)iodonium perfluoro-n-octanesulfonate, bis(4-trifluoromethylphenyl)iodonium p-toluenesulfonate, bis(4-trifluoromethylphenyl)iodonium benzenesulfonate and bis(4-trifluoromethylphenyl)iodonium 10-camphorsulfonate.

[0156] (Compound represented by general formula (c-3)) In the above formula (c-3), Q is an alkylene group, an arylene group or an alkyleneoxy group. 15 is an alkyl group, an aryl group, a halogenated alkyl group or a halogenated aryl group.

[0157] The compound represented by the general formula (c-3) is preferably N-(trifluoromethylsulfonyloxy)succinimide, N-(trifluoromethylsulfonyloxy)phthalimide, N-(trifluoromethylsulfonyloxy)diphenylmaleimide, N-(trifluoromethylsulfonyloxy)bicyclo[2.2.1]hept-5-ene-2,3-dicarboximide, N-(trifluoromethylsulfonyloxy)naphthyl imide, N-(10-camphorsulfonyloxy)succinimide, N-(10-camphorsulfonyloxy)phthalimide, N-(trifluoromethylsulfonyloxy)bicyclo[2.2.1]hept-5-ene-2,3-dicarboximide, N-(trifluoromethylsulfonyloxy)naphthyl imide, (10-Camphorsulfonyloxy)diphenylmaleimide, N-(10-camphorsulfonyloxy)bicyclo[2.2.1]hept-5-ene-2,3-dicarboximide, N-(10-camphorsulfonyloxy)naphthyl imide, N-(n-octanesulfonyloxy)bicyclo[2.2.1]hept-5-ene-2,3-dicarboximide, N-(n-octanesulfonyloxy)naphthyl imide, N-(p-toluenesulfonyloxy)bicyclo[2.2.1]hept-5-ene-2,3-dicarboximide, N-(p-toluenesulfonyloxy) Naphthyl imide, N-(2-trifluoromethylbenzenesulfonyloxy)bicyclo[2.2.1]hept-5-ene-2,3-dicarboximide, N-(2-trifluoromethylbenzenesulfonyloxy)naphthyl imide, N-(4-trifluoromethylbenzenesulfonyloxy)bicyclo[2.2.1]hept-5-ene-2,3-dicarboximide, N-(4-trifluoromethylbenzenesulfonyloxy)naphthyl imide, N-(perfluorobenzenesulfonyloxy)bicyclo[2.2.1]hept-5-ene-2,3-dicarboximide, N-(perfluorobenzenesulfonyloxy)naphthyl At least one of imide, N-(1-naphthalenesulfonyloxy)bicyclo[2.2.1]hept-5-ene-2,3-dicarboximide, N-(1-naphthalenesulfonyloxy)naphthyl imide, N-(nonafluoro-n-butanesulfonyloxy)bicyclo[2.2.1]hept-5-ene-2,3-dicarboximide, N-(nonafluoro-n-butanesulfonyloxy)naphthyl imide, N-(perfluoro-n-octanesulfonyloxy)bicyclo[2.2.1]hept-5-ene-2,3-dicarboximide and N-(perfluoro-n-octanesulfonyloxy)naphthyl imide.

[0158] (Compound represented by general formula (c-4)) In the above formula (c-4), R 16 Each independently represents a linear, branched or cyclic alkyl group, aryl group, heteroaryl group or aralkyl group, and at least one hydrogen atom of these groups may be substituted by any substituent.

[0159] The compound represented by the general formula (c-4) is preferably at least one selected from diphenyl disulfone, di(4-methylphenyl) disulfone, dinaphthyl disulfone, di(4-tert-butylphenyl) disulfone, di(4-hydroxyphenyl) disulfone, di(3-hydroxynaphthyl) disulfone, di(4-fluorophenyl) disulfone, di(2-fluorophenyl) disulfone and di(4-trifluoromethylphenyl) disulfone.

[0160] (Compound represented by general formula (c-5)) In the above formula (c-5), R 17 Each independently represents a linear, branched or cyclic alkyl group, aryl group, heteroaryl group or aralkyl group, and at least one hydrogen atom of these groups may be substituted by any substituent.

[0161] The compound represented by the general formula (c-5) is preferably at least one selected from α-(methylsulfonyloxyimino)-benzyl acetonitrile, α-(methylsulfonyloxyimino)-4-methoxybenzyl acetonitrile, α-(trifluoromethylsulfonyloxyimino)-benzyl acetonitrile, α-(trifluoromethylsulfonyloxyimino)-4-methoxybenzyl acetonitrile, α-(ethylsulfonyloxyimino)-4-methoxybenzyl acetonitrile, α-(propylsulfonyloxyimino)-4-methylbenzyl acetonitrile, and α-(methylsulfonyloxyimino)-4-bromobenzyl acetonitrile.

[0162] (Compound represented by general formula (c-6)) In the above formula (c-6), R 18 Each of the above groups is independently a halogenated alkyl group having one or more chlorine atoms and one or more bromine atoms. The halogenated alkyl group preferably has 1 to 5 carbon atoms.

[0163] (Compounds represented by general formula (c-7) and (c-8)) In the above formulas (c-7) and (c-8), R 19 and R 20 Each of them is independently an alkyl group having 1 to 3 carbon atoms (such as methyl, ethyl, n-propyl, isopropyl, etc.), a cycloalkyl group having 3 to 6 carbon atoms (such as cyclopentyl, cyclohexyl, etc.), an alkoxy group having 1 to 3 carbon atoms (such as methoxy, ethoxy, propoxy, etc.), or an aryl group having 6 to 10 carbon atoms (such as phenyl, toluoyl, naphthyl), and is preferably an aryl group having 6 to 10 carbon atoms.

[0164] L 19 and L 20Each independently represents an organic group having a 1,2-naphthoquinonediazide group, and specifically preferably a 1,2-quinonediazidesulfonyl group such as a 1,2-naphthoquinonediazide-4-sulfonyl group, a 1,2-naphthoquinonediazide-5-sulfonyl group, or a 1,2-naphthoquinonediazide-6-sulfonyl group, and more preferably a 1,2-naphthoquinonediazide-4-sulfonyl group or a 1,2-naphthoquinonediazide-5-sulfonyl group.

[0165] P is an integer from 1 to 3, q ​​is an integer from 0 to 4, and 1≤p+q≤5.

[0166] J 19 It is a single bond, an alkylene group having 1 to 4 carbon atoms, a cycloalkylene group having 3 to 6 carbon atoms, a phenylene group, a group represented by the following formula (c-7-i), a carbonyl group, an ester group, an amide group, or -O-.

[0167] Y 19 is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 10 carbon atoms, and X 20 Each independently represents a group represented by the following formula (c-8-i).

[0168] In the above formula (c-8-i), Z 22 R is independently an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, or an aryl group having 6 to 10 carbon atoms. 22 Each of them is independently an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms; and r is an integer of 0-3.

[0169] As the acid generator used in one embodiment of the present invention, other acid generators other than the compound represented by any of the general formulae (c-1) to (c-8) may be used.

[0170] Examples of such other acid generators include bis(p-toluenesulfonyl)diazomethane, bis(2,4-dimethylphenylsulfonyl)diazomethane, bis(tert-butylsulfonyl)diazomethane, bis(n-butylsulfonyl)diazomethane, bis(isobutylsulfonyl)diazomethane, bis(isopropylsulfonyl)diazomethane, bis(n-propylsulfonyl)diazomethane, bis(cyclohexylsulfonyl)diazomethane, bis(isopropylsulfonyl)diazomethane, 1,3-bis(cyclohexylsulfonylazomethylsulfonyl)propane, 1,4-bis(phenylsulfonyl)diazomethane, and bis(isopropylsulfonyl)diazomethane. Bissulfonyldiazomethanes such as 1,6-bis(phenylsulfonylazomethylsulfonyl)hexane and 1,10-bis(cyclohexylsulfonylazomethylsulfonyl)decane, halogen-containing triazine derivatives such as 2-(4-methoxyphenyl)-4,6-(bistrichloromethyl)-1,3,5-triazine, 2-(4-methoxynaphthyl)-4,6-(bistrichloromethyl)-1,3,5-triazine, tris(2,3-dibromopropyl)-1,3,5-triazine and tris(2,3-dibromopropyl)isocyanurate, etc.

[0171] <Other additives> The resist composition of one embodiment of the present invention may contain other components besides the above-mentioned components (A) to (C).

[0172] Examples of other components include one or more selected from acid crosslinking agents, acid diffusion control agents, dissolution accelerators, dissolution control agents, sensitizers, surfactants, organic carboxylic acids, or phosphorus oxyacids or derivatives thereof.

[0173] The content of each of these other components can be appropriately selected depending on the type of the component or the type of the resin (A), and is preferably 0.001 to 100 parts by mass, more preferably 0.01 to 70 parts by mass, further preferably 0.1 to 50 parts by mass, and further preferably 0.3 to 30 parts by mass, relative to 100 parts by mass of the resin (A) contained in the resist composition.

[0174] (Acid crosslinker) The acid crosslinking agent may be appropriately selected according to the type of the resin (A) as long as it is a compound having a crosslinkable group capable of crosslinking with the resin (A).

[0175] Examples of the acid crosslinking agent used in one embodiment of the present invention include methylol-containing compounds such as melamine compounds containing methylol, benzoguanamine compounds containing methylol, urea compounds containing methylol, glycoluril compounds containing methylol, and phenol compounds containing methylol; alkoxyalkyl-containing compounds such as melamine compounds containing alkoxyalkyl, benzoguanamine compounds containing alkoxyalkyl, urea compounds containing alkoxyalkyl, glycoluril compounds containing alkoxyalkyl, and phenol compounds containing alkoxyalkyl; carboxymethyl-containing compounds such as melamine compounds containing carboxymethyl, benzoguanamine compounds containing carboxymethyl, urea compounds containing carboxymethyl, glycoluril compounds containing carboxymethyl, and phenol compounds containing carboxymethyl; and epoxy compounds such as bisphenol A type epoxy compounds, bisphenol F type epoxy compounds, bisphenol S type epoxy compounds, novolac resin type epoxy compounds, resol resin type epoxy compounds, and poly(hydroxystyrene) type epoxy compounds.

[0176] These acid cross-linking agents may be used alone or in combination of two or more.

[0177] (Acid Diffusion Controller) The acid diffusion controller is an additive having the functions of controlling the diffusion of the acid generated by the acid generator in the resist film by irradiation with radiation and preventing an undesired chemical reaction in the unexposed region.

[0178] The acid diffusion controller used in one embodiment of the present invention is not particularly limited, and examples thereof include radiation-decomposable basic compounds such as nitrogen atom-containing basic compounds, basic sulfonium compounds, and basic iodonium compounds.

[0179] These acid diffusion control agents may be used alone or in combination of two or more.

[0180] (Dissolution accelerator) The dissolution accelerator is an additive that has the function of improving the solubility of the resin (A) in the developer and appropriately increasing the dissolution rate of the resin (A) during development.

[0181] The dissolution accelerator used in one embodiment of the present invention is not particularly limited, and examples thereof include phenolic compounds such as bisphenols and tris(hydroxyphenyl)methane.

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

[0183] (Dissolution Control Agent) The dissolution control agent is an additive that has the function of controlling the solubility of the resin (A) in a developer when the solubility of the resin (A) is too high, and appropriately reducing the dissolution rate during development.

[0184] The dissolution control agent used in one embodiment of the present invention is not particularly limited, and examples thereof include aromatic hydrocarbons such as phenanthrene, anthracene, and acenaphthene; ketones such as acetophenone, benzophenone, and phenylnaphthyl ketone; and sulfones such as methyl phenyl sulfone, diphenyl sulfone, and dinaphthyl sulfone.

[0185] These dissolution control agents may be used alone or in combination of two or more.

[0186] (Sensitizer) The sensitizer is an additive that absorbs the energy of irradiated radiation and transfers the energy to the acid generator to increase the amount of acid generated, and can improve the apparent sensitivity of the resist.

[0187] Examples of the sensitizer used in one embodiment of the present invention include benzophenones, biacetyl compounds, pyrenes, phenothiazines, and fluorene compounds.

[0188] These sensitizers may be used alone or in combination of two or more.

[0189] (Surfactant) The surfactant is an additive that has the function of improving the coating property and striation of the resist composition, the developability of the resist, and the like.

[0190] As the surfactant used in one embodiment of the present invention, any of anionic surfactants, cationic surfactants, nonionic surfactants and amphoteric surfactants can be used, preferably nonionic surfactants. As nonionic surfactants, for example, polyoxyethylene higher alkyl ethers, polyoxyethylene higher alkyl phenyl ethers, higher fatty acid diesters of polyethylene glycol, etc. can be cited.

[0191] These surfactants may be used alone or in combination of two or more.

[0192] (Organic carboxylic acid or phosphorus oxygen acid or its derivatives) The organic carboxylic acid or phosphorus oxoacid or its derivative is an additive having a function of preventing sensitivity deterioration or improving resist pattern shape, storage stability, and the like.

[0193] The organic carboxylic acid used in one embodiment of the present invention is not particularly limited, and examples thereof include malonic acid, citric acid, malic acid, succinic acid, benzoic acid, salicylic acid, etc. In addition, examples of phosphorus oxyacids or derivatives thereof include phosphoric acid, di-n-butyl phosphate, diphenyl phosphate and other phosphoric acid or esters thereof derivatives, phosphonic acid, dimethyl phosphonate, di-n-butyl phosphonate, phenyl phosphonate, diphenyl phosphonate, dibenzyl phosphonate and other phosphonic acid or esters thereof derivatives, and phosphinic acid, phosphinic acid phenyl phosphite and other phosphinic acid or esters thereof derivatives.

[0194] These may be used alone or in combination of two or more.

[0195] (Other ingredients) Furthermore, the resist composition of one embodiment of the present invention may contain a dye, a pigment, an adhesion promoter, an antihalation agent, a storage stabilizer, a defoaming agent, a shape improver, and the like in addition to the above-mentioned other components.

[0196] [Method for forming resist film] As described above, the resist composition of one embodiment of the present invention can form a thick resist film suitable for manufacturing various devices even though the content of the effective component including the resin is limited to a predetermined value or less.

[0197] The method for forming the resist film is not particularly limited, and examples thereof include a method including the following step (1), and a method including steps (2) to (3) is also preferred.

[0198] Step (1): a step of applying the resist composition according to one embodiment of the present invention described above onto a substrate to form a coating film.

[0199] Step (2): A step of performing a heat treatment after step (1).

[0200] Step (3): a step of forming a resist pattern.

[0201] <Process (1)> In step (1), the substrate on which the coating film is formed is not particularly limited, and examples thereof include electronic component substrates, substrates on which a predetermined wiring pattern is formed, and more specifically, silicon wafers, metal substrates such as copper, chromium, iron, and aluminum, and glass substrates. The material of the wiring pattern is not particularly limited, and examples thereof include copper, aluminum, nickel, and gold.

[0202] In addition, regarding the substrate used in one embodiment of the present invention, as required, the surface of the side where the above-mentioned coating is formed may have a lower film formed by a material selected from organic materials and inorganic materials. When using such a substrate with a lower film, the above-mentioned coating is formed on the lower film.

[0203] In addition, examples of the underlayer film-forming material for forming the underlayer film include the underlayer film-forming composition described in International Publication No. 2016 / 021511.

[0204] The substrate used in one embodiment of the present invention may be surface treated by applying a pre-wetting agent to the surface of the side on which the coating film is to be formed, as necessary.

[0205] Generally speaking, a considerable amount of resist composition will be scattered from the periphery where the circumferential speed is significantly greater than the center position, and the increase in the consumption of the resist composition becomes a problem. In view of this problem, by applying a pre-wetting agent on the surface of the substrate, the resist composition on the substrate is easily diffused, and the supply of the resist composition can be reduced.

[0206] Examples of the pre-wetting agent include cyclohexanone, ethyl lactate, and methyl-3-methoxypropionate. A specific surface treatment method using the pre-wetting agent is not particularly limited, and an example thereof includes the method described in Japanese Patent Application Laid-Open No. 2004-39828.

[0207] As a coating method for coating the resist composition on the substrate, a known method can be appropriately adopted, and examples thereof include spin coating, cast coating, roll coating, etc. As described above, the resist composition of one embodiment of the present invention can form a thick coating film by these coating methods.

[0208] <Process (2)> In one embodiment of the present invention, as step (2), it is preferred to perform a heat treatment after step (1). The heat treatment can improve the adhesion between the substrate and the resist film.

[0209] The heating temperature of the heat treatment in this step can be appropriately set according to the composition of the resist composition, and is preferably 20 to 250°C, and more preferably 20 to 150°C.

[0210] <Process (3)> Step (3) is a step of exposing the formed resist film to light via a desired mask pattern to form a predetermined resist pattern.

[0211] Examples of radiation irradiated during exposure include visible light, ultraviolet rays represented by g-line (wavelength 436 nm) and i-line (wavelength 365 nm), far ultraviolet rays represented by ArF excimer laser (wavelength 193 nm) and KrF excimer laser (wavelength 248 nm), excimer lasers, electron beams, extreme ultraviolet rays (EUV), X-rays represented by synchrotron radiation, and ion beams.

[0212] From the viewpoint of stably forming a fine pattern with high precision during exposure, it is preferred to perform a heat treatment after irradiating with radiation. The heating temperature of the heat treatment is preferably 20 to 250°C, more preferably 20 to 150°C.

[0213] Next, the exposed resist film is developed with a developer, thereby forming a predetermined resist pattern.

[0214] As the developer used, it is preferred to select a solvent having a solubility parameter (SP value) close to that of the resin (A) contained in the resist composition, and examples thereof include polar solvents such as ketone solvents, ester solvents, alcohol solvents, amide solvents, and ether solvents, hydrocarbon solvents, or alkaline aqueous solutions. In addition, examples of alkaline compounds contained in the alkaline aqueous solution include mono-, di-, or tri-alkylamines; mono-, di-, or trialkanolamines; heterocyclic amines; tetraalkylammonium hydroxides; choline; 1,8-diazabicyclo[5,4,0]-7-undecene, 1,5-diazabicyclo[4,3,0]-5-nonene, and the like.

[0215] Examples of the developing method include a method of immersing a substrate in a tank filled with a developer for a certain period of time (immersion method), a method of developing by making the developer bulge on the substrate surface and remain stationary for a certain period of time using surface tension (paddle method), a method of spraying the developer on the substrate surface (spray method), and a method of continuously applying the developer on a substrate rotating at a certain speed while scanning a developer coating nozzle at a certain speed (dynamic dispense method).

[0216] The development time is not particularly limited, but is preferably 10 to 90 seconds.

[0217] After development, a step of replacing the solvent with another solvent to stop development may be performed.

[0218] Furthermore, after development, it is preferable to perform a washing step using a rinse solution containing an organic solvent.

[0219] The rinsing liquid used in the rinsing step after development is not particularly limited as long as it does not dissolve the formed resist pattern, and a solution containing a general organic solvent or water can be used.

[0220] As the rinse liquid, it is preferable to use a rinse liquid containing at least one organic solvent selected from the group consisting of hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents, and ether solvents.

[0221] The time for performing the rinsing step is not particularly limited, but is preferably 10 seconds to 90 seconds.

[0222] In the rinsing step, the substrate after development is rinsed using a rinse liquid containing the above-mentioned organic solvent. The method of the rinse treatment is not particularly limited, and examples thereof include a method of continuously coating the rinse liquid on a substrate rotating at a certain speed (spin coating method), a method of immersing the substrate in a tank filled with the rinse liquid for a certain period of time (immersion method), and a method of spraying the rinse liquid on the surface of the substrate (spraying method).

[0223] After forming the resist pattern, etching can be performed to obtain a patterned wiring board. The etching method can be performed by a known method such as dry etching using plasma gas and wet etching using an alkaline solution, a cupric chloride solution, a ferric chloride solution, or the like.

[0224] After the resist pattern is formed, plating may be performed.

[0225] The plating method is not particularly limited, and examples thereof include copper plating, solder plating, nickel plating, and gold plating.

[0226] The remaining resist pattern after etching can be stripped off using an organic solvent.

[0227] The organic solvent is not particularly limited, and examples thereof include PGMEA (propylene glycol monomethyl ether acetate), PGME (propylene glycol monomethyl ether), EL (ethyl lactate), etc. The stripping method is not particularly limited, and examples thereof include an immersion method, a spray method, etc. In addition, the wiring substrate on which the resist pattern is formed may be a multilayer wiring substrate, or may have a small-diameter through hole.

[0228] In the present embodiment, the wiring board may be formed by a lift-off method, which is a method of forming a resist pattern, vapor-depositing a metal in a vacuum, and then dissolving the resist pattern with a solution.

[0229] Example The present invention will be described below using examples, but the present invention is not limited to these examples. The measured values ​​in the examples were measured using the following methods or devices.

[0230] (1) Film thickness The film thickness of the coating film formed from the resist composition was measured using a film thickness measurement system (device name: "F20", manufactured by Filmetrics) in a constant temperature and humidity chamber at a temperature of 23° C. and a humidity of 50% (relative humidity).

[0231] (2) Content ratio of the structural unit of the resin use 13 C-NMR (model "JNM-ECA500, manufactured by JEOL Ltd., 125 MHz), using deuterated chloroform as solvent, 13 The quantitative mode of C was integrated 1024 times to measure the content ratio of the structural unit of the resin.

[0232] (3) Weight average molecular weight (Mw), number average molecular weight (Mn), and molecular weight distribution (Mw / Mn) of the resin The Mw and Mn of the resin were measured by gel permeation chromatography (GPC) under the following conditions using polystyrene as a standard substance.

[0233] Device name: LaChrom series manufactured by Hitachi Detector: RI detector L-2490 ·Chromatographic column: 2 TSKgelGMHHR-M manufactured by Tosoh Corporation + guard column HHR-H Solvent: THF (with stabilizer) Flow rate 1mL / min Column temperature: 40℃ Then, the ratio of the calculated Mw to Mn of the resin [Mw / Mn] is calculated as the value of the molecular weight distribution of the resin.

[0234] The solvents used in the following Examples and Comparative Examples are as follows.

[0235] <Ingredients (B1)> ABM: 2-acetoxyisobutyric acid methyl ester. In the above general formula (b-1), R 0 is acetyl and R 1 A compound containing methyl.

[0236] iPAIB: 2-acetoxyisobutyric acid isopropyl ester. In the above general formula (b-1), R 0 is acetyl and R 1 It is an isopropyl compound.

[0237] <Ingredient (B2)> ·PGMEA: Propylene glycol monomethyl ether acetate ·HBM: 2-Hydroxyisobutyric Acid Methyl Ester [Resist composition containing liquid crystal resin] Examples 1a to 7a, Comparative Examples 1a to 6a As the liquid crystal resin, cresol novolac resin EP4080G (manufactured by Asahi Organic Materials Co., Ltd.) was used.

[0238] 84 parts by mass of the cresol novolac resin and 16 parts by mass of a naphthoquinone diazo type photosensitive agent (trade name "DTEP-350", manufactured by Daito Chemix Co., Ltd.) were dissolved and mixed in solvents of the types and blending ratios shown in Table 1 to prepare resist compositions having the concentrations of active ingredients (the cresol novolac resin and the photosensitive agent) shown in Table 1.

[0239] Then, using the prepared resist composition, on a silicon wafer, spin coating was performed at 1500 rpm to form a coating film, and the coating film was pre-dried at 110° C. for 90 seconds to form a resist film. The film thickness of 5 positions selected arbitrarily on the resist film was measured, and the average value of the film thickness of the 5 positions was calculated as the average film thickness. The results are shown in Table 1.

[0240] [Table 1] According to Table 1, the resist compositions prepared in Examples 1a to 4a can form thicker resist films than the resist compositions of Comparative Examples 1a to 6a having the same resin component concentration. It can also be seen that the resist compositions prepared in Examples 5a to 7a can form thicker resist films than the resist compositions of Comparative Examples 1a to 3a having the same resin component concentration. In particular, in Examples 1a to 4a, it can be seen that thicker resist films can be formed even when the content of the liquid crystal resin is as low as 20 to 30% by mass.

[0241] [Resist composition containing resin for KrF] Examples 1b to 7b, Comparative Examples 1b to 6b As the KrF resin, a copolymer having a structural unit of hydroxystyrene / t-butyl acrylate / styrene=3 / 1 / 1 (molar ratio) (manufactured by Maruzen Petrochemical Co., Ltd., Mw=12,000) was used.

[0242] The above copolymers were mixed with mixed solvents of the types and blending ratios shown in Table 2 to prepare resist compositions having the concentrations of the active ingredient (resin for KrF) shown in Table 2.

[0243] Then, using the prepared resist composition, on a silicon wafer, spin coating was performed at 1500 rpm to form a coating film, and the coating film was pre-baked at 110° C. for 90 seconds to form a resist film. The film thickness of 5 positions selected arbitrarily on the resist film was measured, and the average value of the film thickness of the 5 positions was calculated as the average film thickness. The results are shown in Table 2.

[0244] [Table 2] As can be seen from Table 2, the resist compositions prepared in Examples 1b to 7b can form thicker resist films than the resist compositions of Comparative Examples 1b to 6b having the same resin component concentration.

[0245] [Resist composition containing resin and acid generator] Resist compositions of Examples A1-1 to 2-3 and Comparative Examples A1-1 to 2-1 were prepared with the formulations shown in Tables 3 and 4, and the solubility of the liquid crystal resin (i), KrF resin (ii), ArF resin (iii), underlayer film resin (iv) and acid generators (i) and (ii) was evaluated.

[0246] <Solvent> ABM: 2-acetoxyisobutyric acid methyl ester (synthesized according to WO2020 / 004466) iPAIB: 2-acetoxyisobutyric acid isopropyl ester (synthesized according to WO2020 / 004466) HBM: 2-Hydroxyisobutyric Acid Methyl Ester (Made by Mitsubishi Gas Chemical) PGMEA: Propylene glycol monomethyl ether acetate (manufactured by Tokyo Chemical Industry Co., Ltd.) <Resin> The following resins were used.

[0247] (i) Cresol novolac resin EP4080G (manufactured by Asahi Organic Materials Co., Ltd.) (ii) Copolymer having structural units of hydroxystyrene / tert-butyl acrylate / styrene = 3 / 1 / 1 (molar ratio) (manufactured by Maruzen Petrochemical Co., Ltd., Mw = 12,000) (iii) A copolymer having structural units of MADM (2-methyl-2-adamantyl methacrylate) / GBLM (α-methacryloyloxy-γ-butyrolactone) = 25 / 75 (molar ratio) (Mn = 3770) (iv) XBisN-1: 13-(biphenyl-4-yl)-13H-dibenzoxanthene-3,10-diol (synthesized with reference to WO2013 / 024778.)

[0248] <Acid Generator> (i) WPAG-336 (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) (ii) WPAG-145 (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) Resins were added to the resist compositions shown in Tables 3 and 4 so that the resin concentrations were (i) 30 wt %, (ii) 35 wt %, (iii) 15 wt %, and (iv) 25 wt %, and an acid generator was added so that the concentration of the acid generator shown in Tables 3 and 4 was 1 wt %. The state after stirring at room temperature for 24 hours was evaluated by visual observation according to the following criteria.

[0249] Evaluation S: Dissolution (confirmed clear solution by visual inspection).

[0250] Evaluation A: Almost dissolved (a mostly clear solution was confirmed by visual inspection).

[0251] Evaluation C: Insoluble (a turbid solution was confirmed by visual observation).

[0252] [Table 3] [Table 4] As can be seen from Table 3, the resist compositions prepared in Examples A1-1 to A1-3 were superior to the resist composition of Comparative Example A1-1 in solubility in the resin and the acid generator, and various resist compositions could be prepared.

[0253] As can be seen from Table 4, the resist compositions prepared in Examples A2-1 to A2-3 were superior in solubility to the resin and the acid generator as compared with the resist composition of Comparative Example A2-1, and various resist compositions could be prepared.

[0254] <Resist performance> The following resist performance evaluation was performed using the resin (iii) (MADM / GBLM=25 / 75). The obtained results are shown in Table 5.

[0255] Pattern evaluation: Evaluation S: A rectangular resist pattern was formed.

[0256] Evaluation A: A substantially rectangular resist pattern was formed.

[0257] Evaluation C: A rectangular resist pattern was not formed.

[0258] Pattern film thickness: Evaluation A: Has etching resistance required for pattern transfer.

[0259] Evaluation C: Did not have etching resistance required for pattern transfer.

[0260] (Preparation of Resist Composition) Resist compositions were prepared in the proportions shown in Table 5. Among the components of the resist compositions in Table 5, the following compounds were used as the acid generator (C).

[0261] P-1: Triphenylsulfonium trifluoro-1-butanesulfonate (Sigma-Aldrich) [Table 5] (Evaluation method of resist performance of resist composition) After the uniform resist composition is spin-coated on a clean silicon wafer, it is dried before exposure (PB) using a hot plate at 90°C to form a resist film with a thickness of 50nm. For the obtained resist film, an electron beam drawing device (ELS-7500, manufactured by Elionix Co., Ltd.) is used to irradiate the electron beam with a line width and spacing (Line and Space) set to 1:1 at an interval of 500nm. After the irradiation, the resist film is heated at 90°C for 90 seconds, immersed in an alkaline developer of 2.38% by mass of tetramethylammonium hydroxide (TMAH) for 60 seconds, and developed. Thereafter, the resist film is washed with ultrapure water for 30 seconds and dried to form a resist pattern. For the formed resist pattern, the line width and spacing (Line and Space) are observed using a scanning electron microscope (S-4800 manufactured by Hitachi HighTechnologies Co., Ltd.), and the reactivity is evaluated by electron beam irradiation of the resist composition.

[0262] Regarding the evaluation of the resist pattern, Example A3-1 and Comparative Example A3-1 were both irradiated with electron beams with a line width and spacing (Line and Space) set to 1:1 at intervals of 500 nm, and good resist patterns were obtained. In addition, regarding the film thickness of the resist pattern, it can be confirmed that the film thickness of Example A3-1 and Example A3-2 is relatively thick, and has sufficient etching resistance for transferring the resist pattern. On the other hand, it can be confirmed that the film thickness of Comparative Example A3-1 is relatively thin, and does not have the etching resistance required for pattern transfer.

[0263] Thus, when the resist composition satisfying the conditions of the present embodiment is used, a good resist pattern shape can be provided compared with the resist composition of Comparative Example A3-1 which does not satisfy the conditions.

[0264] As long as the above-mentioned conditions of the present embodiment are satisfied, the same effects are exhibited also in cases other than the resist compositions described in the Examples.

Claims

1. A resist composition, characterized in that: A resin (A) and a solvent (B) containing a compound (B1) represented by the following general formula (b-1), The content of the active ingredient based on the total amount of the resist composition is 45% by mass or less, In the formula (b-1), R 0 is an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, or an acyl group having 1 to 10 carbon atoms, R 1 It is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms.

2. The resist composition according to claim 1, wherein: The solvent (B) does not contain methyl 2-methoxyisobutyrate (MBM), methyl 2-formyloxyisobutyrate (FBM) and methyl 2-acetoxyisobutyrate (ABM).

3. The resist composition according to claim 1 or 2, characterized in that: The composition further contains at least one additive (C) selected from the group consisting of a photosensitizer and an acid generator.

4. The resist composition according to any one of claims 1 to 3, wherein: In the general formula (b-1), R 0 is methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, cyclopropyl, cyclopentyl, cyclohexyl, phenyl, naphthyl, formyl, acetyl, propionyl or benzoyl.

5. The resist composition according to any one of claims 1 to 4, characterized in that: In the general formula (b-1), R 1 It is a hydrogen atom, a methyl group, an ethyl group, a n-propyl group, an isopropyl group, a n-butyl group, an isobutyl group, a sec-butyl group or a tert-butyl group.

6. The resist composition according to any one of claims 1 to 5, wherein: The solvent (B) includes a compound represented by the following general formula (b-2) as a solvent (B2) other than the compound (B1): In the general formula (b-2), R 1 It is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms.

7. The resist composition according to claim 6, wherein: The solvent (B) contains at least one selected from methyl α-hydroxyisobutyrate and α-hydroxyisobutyric acid as the solvent (B2).

8. The resist composition according to claim 6 or 7, wherein: The resist composition contains the solvent (B2) in an amount of less than 100% by mass based on 100% by mass of the total amount of the resist composition.

9. The resist composition according to any one of claims 1 to 8, wherein: The resin (A) includes a novolac type resin (A1).

10. The resist composition according to any one of claims 1 to 8, wherein: The resin (A) includes a resin (A2) having at least one of a structural unit (a2-1) derived from a phenolic hydroxyl group-containing compound and a structural unit (a2-2) that can be decomposed by an acid, a base or heat to form an acidic functional group.

11. The resist composition according to any one of claims 1 to 8, wherein: The resin (A) includes a resin (A3) having a structural unit (a3-1) having an adamantane structure.

12. The resist composition according to claim 11, wherein: The resin (A3) is a copolymer including a structural unit (a3-1) and a structural unit (a3-2) having a lactone structure.

13. The resist composition according to claim 11 or 12, characterized in that: The content of the structural unit (a3-1α) having an adamantane structure substituted with a hydroxyl group is less than 50 mol % based on the total amount of the structural units of the resin (A3).

14. The resist composition according to any one of claims 1 to 8, wherein: The resin (A) includes a resin (A4) having any two or more structural units selected from a structural unit (a2-1) derived from a compound containing a phenolic hydroxyl group, a structural unit (a2-2) that can be decomposed by the action of an acid, an alkali or heat to form an acidic functional group, a structural unit (a3-1) having an adamantane structure and a structural unit (a3-2) having a lactone structure.

15. The resist composition according to any one of claims 6 to 8, wherein: The solvent (B2) is contained in an amount of 100% by mass or less based on the total amount (100% by mass) of the compound (B1).

16. A method for forming a resist film, characterized in that: include: Step (1): a step of applying the resist composition according to any one of claims 1 to 15 on a substrate to form a coating film; Step (2): a step of performing a heat treatment after step (1); and Step (3): a step of forming a resist pattern.

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