Curable resin composition and cured product

Abstract

The invention provides a curable resin composition and a cured product. The curable resin composition can obtain a coating film with good dry etching resistance and heat curing property. The curable resin composition contains at least one polymer selected from the group consisting of (1) and (2). (1) A polymer containing a structure derived from a polymerizable monomer (A1) having an alicyclic structure and / or an aromatic ring structure and a cyclic ether group; (2) A polymer including a structure derived from a polymerizable monomer (A2) having a cyclic ether group and a structure derived from a polymerizable monomer (B) having an alicyclic structure and / or an aromatic ring structure.

Description

Technical Field

[0001] The present invention relates to a curable resin composition. More specifically, it relates to a curable resin composition capable of obtaining a cured product suitable for an underlayer film for a resist or the like. Background Art

[0002] In recent years, with the high integration and high speed of LSIs, finer patterning has been required for their pattern processing. In lithography using an ArF excimer laser (193 nm), the essential resolution limit derived from the light source wavelength has been exceeded by utilizing the optical characteristics of process materials and improving process equipment.

[0003] In the field of photoresists, various methods for forming finer wiring patterns have been developed, and one of them is the multilayer resist method. In the multilayer resist method, after forming one or more layers such as an underlayer film for a resist and an antireflection film on a substrate, a normal photoresist pattern based on lithography is formed thereon. Then, the wiring pattern is transferred to the substrate by dry etching. In the technology of the multilayer resist method, one of the important components is the underlayer film for a resist. The underlayer film for a resist is required to have low viscosity, high dry-etch resistance, and low light reflectivity.

[0004] In addition, in the multilayer resist method, when coating the upper-layer photoresist, in order not to cause film damage or film roughness of the underlayer film for a resist, the underlayer film for a resist is cured by heating after being coated on the substrate. Therefore, the underlayer film for a resist is required to show good curing reactivity during heating, and to show high solvent resistance. In addition, in order to prevent device contamination, it is also required not to generate outgassing or film damage during heat curing.

[0005] Recently, further finer patterning has been required, and along with this, the aspect ratio of the resist pattern has become higher, so the possibility of collapse of the resist pattern has increased. Therefore, for the underlayer film for a resist, high substrate adhesion for suppressing the collapse of the resist pattern is required (for example, refer to Patent Document 1).

[0006] Prior Art Documents

[0007] Patent Documents

[0008] Patent Document 1: Japanese Patent No. 5440755 Summary of the Invention

[0009] Problems to be Solved by the Invention

[0010] In order to enable further finer patterning, a curable resin composition having high dry-etch resistance, good reactivity (high solvent resistance), low volatility during heating, and high substrate adhesion is required.

[0011] An object of the present invention is to provide a curable resin composition capable of obtaining a coating film having good dry-etch resistance and heat-curing properties.

[0012] Method for solving the problem

[0013] The present inventors conducted intensive studies to solve the above problems, and as a result, found that by using a polymer having a specific structure in a curable resin composition, the dry-etch resistance and heat-curing properties of the resulting cured product can be improved, thereby completing the present invention.

[0014] That is, the present invention relates to a curable resin composition containing at least one polymer selected from the following (1) and (2).

[0015] (1) A polymer containing a structure derived from a polymerizable monomer (A1) having at least one of an alicyclic structure and an aromatic ring structure and a cyclic ether group.

[0016] (2) A polymer containing a structure derived from a polymerizable monomer (A2) having a cyclic ether group and a structure derived from a polymerizable monomer (B) having at least one of an alicyclic structure and an aromatic ring structure.

[0017] In addition, the present invention relates to a cured product or an underlayer film of a resist of the above composition.

[0018] Effect of the invention

[0019] According to the present invention, a curable resin composition capable of obtaining a coating film having good dry-etch resistance and heat-curing properties can be provided. Detailed description of the invention

[0020] Hereinafter, an embodiment of the present invention will be described. The present invention is not limited to the following embodiments, and can be appropriately modified and implemented within the scope not impairing the effects of the present invention.

[0021] In the present specification, “(meth)acrylate” means one or both of acrylate and methacrylate.

[0022] The curable resin composition of the present invention contains at least one polymer selected from the following (1) and (2).

[0023] (1) A polymer (1) containing a structure derived from a polymerizable monomer (A1) having at least one of an alicyclic structure and an aromatic ring structure and a cyclic ether group.

[0024] (2) A polymer (2) containing a structure derived from a polymerizable monomer (A2) having a cyclic ether group and a structure derived from a polymerizable monomer (B) having at least one of an alicyclic structure and an aromatic ring structure.

[0025] By including at least one of the above-mentioned polymer (1) and polymer (2), a curable resin composition can be obtained, and a coating film with good dry etching resistance and heat curability can be obtained. In particular, by using polymer (1) and / or polymer (2), it is possible to achieve both dry etching resistance and heat curability of the resin alone.

[0026] (Polymer (1) and Polymer (2))

[0027] In the present invention, the "polymerizable monomer" refers to a compound having a polymerizable unsaturated group. As the polymerizable unsaturated groups of the polymerizable monomer (A1), polymerizable monomer (A2), and polymerizable monomer (B), groups containing C═C such as (meth)acryloyl group, (meth)acryloyloxy group, (meth)acryloylamino group, vinyl group, vinyl ether group, allyl group, styryl group, maleimide group, etc. can be cited. Among them, from the viewpoints of easy availability of raw materials and good polymerization reactivity, (meth)acryloyl group, (meth)acryloyloxy group, and vinyl group are preferred.

[0028] In addition, the number of polymerizable unsaturated groups possessed by the polymerizable monomer may be 1 or 2 or more.

[0029] The polymerizable monomer (A1) is preferably a compound represented by the following general formula (A1-1).

[0030] [Chemical formula 1]

[0031]

[0032] In the general formula (A1-1), R 11 is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, L 11 is a divalent linking group containing at least an arylene group, and Z is an epoxy group, an oxetanyl group, an alkyloxetanyl group having 4 to 10 carbon atoms, or an epoxycycloalkyl group having 5 to 10 carbon atoms.

[0033] In the general formula (A1-1), as the alkyl group having 1 to 6 carbon atoms of R 11 , methyl group, ethyl group, etc. can be cited. R 11 is preferably a hydrogen atom or a methyl group.

[0034] L 11 is a divalent linking group containing an arylene group. For example, a group composed only of an arylene group, a group formed by combining an arylene group with one or more selected from an alkylene group and an ether bond (-O-), etc. can be cited. L 11 is preferably a divalent linking group composed of a combination of an arylene group, an ether bond, and an alkylene group.

[0035] As L 11The arylene group, for example, may be an arylene group having 6 to 18 carbon atoms, preferably an arylene group having 6 to 14 carbon atoms. The arylene group may be a monocyclic ring or a fused ring. Specific examples of the arylene group include a phenylene group, a naphthylene group, etc.

[0036] As L 11 The alkylene group, for example, may be an alkylene group having 1 to 10 carbon atoms. The alkylene group may be linear, branched, or cyclic.

[0037] L 11 The alkylene group and arylene group of L may further have substituents. Examples of the substituents include an alkyl group having 1 to 6 carbon atoms, a hydroxyl group, a halogen atom, etc.

[0038] As the alkyloxetanyl group having 4 to 10 carbon atoms for Z, 3-methyloxetanyl, 3-ethyloxetanyl, 2-methyloxetanyl, 2-ethyloxetanyl can be cited.

[0039] As the epoxycycloalkyl group having 5 to 10 carbon atoms, 3,4-epoxycyclohexyl, 3-methyl-3,4-epoxycyclohexyl, 2,5-epoxycyclohexyl, 4,5-epoxycyclooctyl, 3,4-epoxycyclooctyl, 2,3-epoxycyclopentyl, 3,4-epoxycyclopentyl can be cited.

[0040] Z is preferably an epoxy group.

[0041] Specific examples of the compound represented by the general formula (A1-1) include 4-vinylbenzyl glycidyl ether, 2-[(4-vinylphenoxy)methyl]oxirane, 2-(4-vinylphenoxy)oxirane, 2-[2-(4-vinylphenyl)ethyl]oxirane, 3-[(4-vinylphenoxy)methyl]oxetane, 2-[[4-(1-methylethenyl)phenoxy]methyl]oxirane, 2-[(4-vinylphenoxy)methyl]oxetane, 2-[[4-(2-propenyl)phenoxy]methyl]oxirane, 2-[(3-vinylphenyl)methyl]oxirane, 3-[(4-vinyl-2-methylphenoxy)methyl]oxetane, 2-(4-vinylphenoxy)tetrahydrofuran.

[0042] The polymerizable monomer (A1) can be produced by a known method and commercially available products can be used.

[0043] The polymerizable monomer (A2) having a cyclic ether group is preferably a compound represented by the following general formula (A2-1).

[0044] [Chemical formula 2]

[0045]

[0046] In the above general formula (A2-1), R 12 is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and L 12 is a single bond or a divalent linking group, and Z is an epoxy group, an oxetanyl group, an alkyloxetanyl group having 4 to 10 carbon atoms, or an epoxycycloalkyl group having 5 to 10 carbon atoms.

[0047] R 12 Specific examples of the alkyl group having 1 to 6 carbon atoms of R are the same as those of the above R 11 above.

[0048] As the divalent linking group of L 12 above, examples include an alkylene group, an arylene group, or a group formed by combining two or more selected from an alkylene group, an arylene group, and an ether bond (-O-).

[0049] L 12 Examples of the alkylene group and arylene group of L are the same as those of the above L 11 above.

[0050] L 12 is preferably a single bond.

[0051] Examples of Z are the same as those of Z in the above general formula (A1-1).

[0052] Specific examples of the compound represented by the general formula (A2-1) include epoxy group-containing (meth)acrylate compounds such as glycidyl (meth)acrylate, 4-hydroxybutyl glycidyl ether (meth)acrylate, and cyclohexylmethyl glycidyl ether (meth)acrylate; (meth)acrylate compounds containing an oxetanyl group such as (3-ethyloxetanyl-3-yl)methyl acrylate; and mono-(meth)acrylated products of diglycidyl ether compounds such as dihydroxybenzene diglycidyl ether, dihydroxynaphthalene diglycidyl ether, biphenol diglycidyl ether, and bisphenol diglycidyl ether.

[0053] The polymerizable monomer (A2) can be produced by a known method or a commercially available product can be used.

[0054] Examples of commercially available products of the polymerizable monomer (A2) include SR-378 (manufactured by Sartomer) as a commercially available product of glycidyl acrylate; Light Ester G (manufactured by Kyoeisha Chemical Co., Ltd.), Blemmer G (manufactured by NOF Corporation), SR-379 (manufactured by Sartomer), OXE-10, OXE-30 (manufactured by Osaka Organic Chemical Industry Co., Ltd.), CYCLOMER M100 (manufactured by Daicel Corporation), etc. as commercially available products of glycidyl methacrylate.

[0055] The polymerizable monomer (B) having at least one of an alicyclic structure and an aromatic ring structure is preferably a compound represented by the following general formula (B-1).

[0056] [Chemical Formula 3]

[0057]

[0058] In the above general formula (B-1), R 21 is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and L 21 is a single bond or a divalent linking group, and X is an aromatic group or an alicyclic hydrocarbon group.

[0059] R 21 Specific examples of the alkyl group having 1 to 6 carbon atoms of are the same as those of the above R 11 above.

[0060] L 21 Examples of are the same as those of the above L 12 above.

[0061] As the aromatic group of X, an aryl group having 6 to 18 carbon atoms is preferred, and an aryl group having 6 to 14 carbon atoms is more preferred. Further, the aryl group is a monocyclic or condensed ring, preferably a monocyclic or condensed ring having 2 to 8 condensation rings, more preferably a monocyclic or condensed ring having 2 to 4 condensation rings. Specifically, phenyl, naphthyl, anthryl, etc. can be exemplified.

[0062] As the alicyclic hydrocarbon group, for example, dicyclopentyl, isobornyl, adamantyl, etc. can be cited.

[0063] Specific examples of the compound represented by the general formula (B-1) include benzyl (meth)acrylate, 1-naphthylmethyl (meth)acrylate, dicyclopentyloxyethyl (meth)acrylate, isobornyloxyethyl (meth)acrylate, isobornyl (meth)acrylate, adamantyl (meth)acrylate, dimethyladamantyl (meth)acrylate, hydroxyadamantyl (meth)acrylate, dicyclopentyl (meth)acrylate, dicyclopentenyl (meth)acrylate, etc.

[0064] The polymerizable monomer (B) can be produced by a known method.

[0065] In addition, commercially available products can be used as the polymerizable monomer (B).

[0066] The polymerizable monomer (B) can be a single kind or two or more kinds.

[0067] The polymer (1) is obtained by polymerizing a polymerization component containing the above polymerizable monomer (A1).

[0068] In the present invention, the "polymerization component" refers to the components that constitute the polymer, excluding solvents, polymerization initiators, etc. that do not constitute the polymer. Within the range that does not impair the effects of the present invention, the polymer (1) may contain structural units of polymerizable monomers other than the polymerizable monomer (A1).

[0069] In the polymer (1), the content ratio of the structure derived from the polymerizable monomer (A1) relative to the whole polymer (1) is, for example, 50% by mass or more, 70% by mass or more, 90% by mass or more, 95% by mass or more. Substantially, it may be 100% by mass. When it is substantially 100% by mass, the polymer (1) may contain structures derived from unavoidable impurities.

[0070] The polymer (2) is obtained by polymerizing a polymerization component containing the above polymerizable monomer (A2) and polymerizable monomer (B).

[0071] In the polymerization of the polymer (2), the compounding amount of the polymerizable monomer (B) can be appropriately set. For example, it is 10 to 300 parts by mass, preferably 15 to 250 parts by mass, more preferably 30 to 200 parts by mass, further preferably 30 to 150 parts by mass, and particularly preferably 50 to 140 parts by mass relative to 100 parts by mass of the polymerizable monomer (A2).

[0072] Within the range that does not impair the effects of the present invention, the polymer (2) may contain structural units of polymerizable monomers other than the polymerizable monomer (A2) and polymerizable monomer (B). For example, it may contain structural units derived from the polymerizable monomer (A1).

[0073] In the polymer (2), the total content ratio of the structures derived from the polymerizable monomers (A2) and (B) relative to the whole polymer (2) is, for example, 50% by mass or more, 70% by mass or more, 90% by mass or more, 95% by mass or more. Substantially, it may be 100% by mass. When it is substantially 100% by mass, the polymer (2) may contain structures derived from unavoidable impurities.

[0074] The content ratio of each polymerization unit in the polymer (1) and polymer (2) can be controlled by adjusting the compounding amount of the polymerizable monomers in the polymerization component.

[0075] The ratio of the structure derived from each polymerizable monomer in the polymer is a value calculated from the mass ratio of each polymerizable monomer relative to the total amount of the polymerization components used.

[0076] In one embodiment, the polymer (1) and polymer (2) do not contain fluorine atoms.

[0077] In one embodiment, the polymer (1) and polymer (2) do not contain silicon atoms.

[0078] The polymerization forms of polymer (1) and polymer (2) are not particularly limited and can be produced by solution polymerization, bulk polymerization, emulsion polymerization, etc. based on polymerization mechanisms such as radical polymerization, cationic polymerization, anionic polymerization, etc. For example, if it is radical polymerization, the polymer can be produced by adding a polymerizable monomer mixture to an organic solvent and adding a general radical polymerization initiator.

[0079] As the polymerization initiator, various polymerization initiators can be used, such as peroxides like tert-butyl peroxy-2-ethylhexanoate, benzoyl peroxide, diacyl peroxide, azo compounds like azobisisobutyronitrile, dimethyl azobisisobutyrate, phenylazotriphenylmethane, and metal chelates like Mn(acac)3, etc.

[0080] If necessary, chain transfer agents such as lauryl mercaptan, 2-mercaptoethanol, ethyl mercaptoacetate, octyl mercaptoacetate, and thiol compounds with a coupling group like γ-mercaptopropyltrimethoxysilane can also be used as additives such as chain transfer agents.

[0081] Examples of the organic solvent include alcohol solvents such as ethanol, isopropyl alcohol, n-butanol, isobutanol, tert-butanol; ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, methyl amyl ketone; ester solvents such as methyl acetate, ethyl acetate, butyl acetate, methyl lactate, ethyl lactate, butyl lactate; monocarboxylic ester solvents such as methyl 2-oxypropionate, ethyl 2-oxypropionate, propyl 2-oxypropionate, butyl 2-oxypropionate, methyl 2-methoxypropionate, ethyl 2-methoxypropionate, propyl 2-methoxypropionate, butyl 2-methoxypropionate; polar solvents such as dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone; ether solvents such as methyl cellosolve, cellosolve, butyl cellosolve, butyl carbitol, ethyl cellosolve acetate; solvents of propylene glycol and its esters such as propylene glycol, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monobutyl ether acetate; halogen solvents such as 1,1,1-trichloroethane, chloroform; cyclic ether solvents such as tetrahydrofuran, dioxane; aromatic solvents such as benzene, toluene, xylene; fluorinated solvents such as perfluorooctane, perfluorotributylamine, etc.

[0082] These solvents can be used alone or in combination of two or more.

[0083] Polymer (1) and polymer (2) can be block copolymers or random copolymers, but random copolymers are preferred. In addition, they can also be radical copolymers or living copolymers, but radical copolymers are preferred.

[0084] The polymer (1) and the polymer (2) are preferably random copolymers. For example, in the case of the polymer (2) containing the polymerizable monomer (A2) and the polymerizable monomer (B) in the polymerization components, a copolymer in which the structures derived from the polymerizable monomer (A2) and the structures derived from the polymerizable monomer (B) are randomly arranged is preferred.

[0085] In the present invention, it is preferred that the polymer (1) and the polymer (2) do not contain a block structure. For example, in the case of the polymer (2), it is preferred not to contain a block copolymer formed by linking a block of the structure derived from the polymerizable monomer (A2) and a block of the structure derived from the polymerizable monomer (B), and more preferably not to contain a block of the structure derived from the polymerizable monomer (A2) and / or a block of the structure derived from the polymerizable monomer (B).

[0086] In the production of block polymers, metal catalysts are usually required, and the resulting block polymers contain inevitable metal impurities. In nanoscale lithography, even trace amounts of metal impurities may affect the resist performance. On the other hand, since the curable resin composition of the present invention does not require a metal catalyst in the production and does not contain metal impurities, it is possible to avoid adverse effects on the resist performance.

[0087] In addition, the production of block copolymers generally has complicated management. Specifically, if the monomer that becomes the second block is introduced at a low polymerization rate of the first block, end-capping may become insufficient. On the other hand, if the monomer that becomes the second block is introduced at a high polymerization rate of the first block, inactivation of the active terminal may occur, and the polymerization reaction may not proceed sufficiently. In addition, countermeasures are also required to prevent the mixing of polymerization deactivating substances such as oxygen that hinder block formation. In terms of not having complicated production management, the curable resin composition of the present invention is also excellent.

[0088] The weight average molecular weight (Mw) of the polymer (1) and the polymer (2) is preferably in the range of 2,000 to 80,000, and more preferably in the range of 3,000 to 50,000.

[0089] The weight average molecular weight of the polymer is measured by the method described in the examples.

[0090] In addition to the above-mentioned polymer (1) and polymer (2), the curable resin composition of the present invention may further contain various additives such as a solvent, other resins, a surfactant, a dye, a filler, a crosslinking agent, and a dissolution promoter. For example, by dissolving at least one of the polymer (1) and the polymer (2) in a solvent, a resist composition for coating is obtained.

[0091] As solvents, for example, ketones such as acetone, methyl ethyl ketone, cyclohexanone, cyclopentanone, cycloheptanone, 2-heptanone, methyl isobutyl ketone, butyrolactone, etc.; alcohols such as methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, tert-butanol, pentanol, heptanol, octanol, nonanol, decanol, etc.; ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, dioxane, etc.; alcohol ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, etc.; esters such as ethyl formate, propyl formate, butyl formate, methyl acetate, ethyl acetate, butyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, butyl propionate, methyl butyrate, ethyl butyrate, butyl butyrate, propyl butyrate, ethyl lactate, butyl lactate, etc.; monocarboxylic acid esters such as methyl 2-oxypropionate, ethyl 2-oxypropionate, propyl 2-oxypropionate, butyl 2-oxypropionate, methyl 2-methoxypropionate, ethyl 2-methoxypropionate, propyl 2-methoxypropionate, butyl 2-methoxypropionate, etc.; cellosolve acetates such as cellosolve acetate, methyl cellosolve acetate, ethyl cellosolve acetate, propyl cellosolve acetate, butyl cellosolve acetate, etc.; propylene glycols such as propylene glycol, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monobutyl ether acetate, etc.; diethylene glycols such as diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, etc.; halogenated hydrocarbons such as trichloroethylene, Freon solvents, HCFC, HFC, etc.; fully fluorinated solvents such as perfluorooctane; aromatic compounds such as toluene, xylene, etc.; polar solvents such as dimethylacetamide, dimethylformamide, N-methylacetamide, N-methylpyrrolidone, etc.

[0092] These solvents can be used alone or in combination of two or more.

[0093] The curable resin composition of the present invention can be suitably used for a composition for lithography, a composition for forming an underlayer film for a resist, etc. The curable resin composition can be made into a cured product by heating, drying, etc. as needed.

[0094] When the curable resin composition of the present invention is used for the purpose of an underlayer film for a resist (BARC film), the above polymer (1) and / or polymer (2) and various additives such as solvents, other resins, surfactants, dyes, fillers, crosslinking agents, dissolution promoters, etc. as needed can be added to prepare a composition for an underlayer film for a resist. In addition, the curable resin composition of the present invention can also be made into a composition for lithography.

[0095] The composition for lithography or the composition for an underlayer film for a resist can be prepared by mixing the above respective components and using a stirrer, etc. In addition, when the composition for an underlayer film for a resist contains fillers, pigments, etc., a dispersion device such as a dissolver, a homogenizer, a three-roll mill, etc. can be used for dispersion or mixing for preparation.

[0096] In order to form an underlayer film for a resist from a composition for an underlayer film for a resist, for example, there is the following method: Coating the above-mentioned composition for an underlayer film for a resist on an object to be subjected to lithography such as a silicon substrate, drying it under temperature conditions of 100 to 200 °C, and then further heating and curing it under temperature conditions of 250 to 400 °C. Subsequently, a resist pattern is formed by performing a normal lithography operation on this underlayer film, and a dry etching treatment is performed using a halogen-based plasma gas or the like, whereby a resist pattern based on a multilayer resist method can be formed.

[0097] Examples

[0098] Hereinafter, the present invention will be specifically described by way of examples and comparative examples. It should be noted that the present invention is not limited to the following examples.

[0099] The measurement conditions of GPC for the resins obtained in the following examples and comparative examples are as described below.

[0100] [GPC Measurement Conditions]

[0101] Measurement device: "Empower 3 Advanced Polymer Chromatography" manufactured by Waters

[0102] Column: "ACQUITY APC XT45 4.6 mm Φ × 150 mm" manufactured by Waters + "ACQUITY APC XT200 4.6 mm Φ × 75 mm" manufactured by Waters

[0103] Detector: Differential refractometer (RID)

[0104] Data processing:

[0105] Measurement conditions: Column temperature 40 °C

[0106] Elution solvent: Tetrahydrofuran (THF)

[0107] Flow rate: 0.6 mL / minute

[0108] Measurement method: Polystyrene standard method

[0109] Example 1 (Preparation of curable resin composition (A-1))

[0110] Into a four-necked flask equipped with a thermometer, a cooling tube, and a stirrer, 35.5 g of glycidyl methacrylate, 55.6 g of isobornyl methacrylate, and 6.4 g of dimethyl 2,2'-azobis(isobutyrate) were charged and dissolved in 97.5 g of methyl isobutyl ketone as a reaction solvent. After dissolution, the mixture was stirred and reacted under reflux at 80 °C for 8 hours using a mantle heater. After the reaction, the solvent was removed by distillation under reduced pressure from the resin solution, and vacuum drying was performed to obtain a resin. The weight-average molecular weight (Mw) of the resin obtained by the GPC method was 11,486.

[0111] 2.00 g of the obtained resin was dissolved in 8 g of propylene glycol monomethyl ether acetate, and precision filtration was performed using a 0.1-μm PTFE disk filter to obtain a curable resin composition (A-1).

[0112] Example 2 (Preparation of curable resin composition (A-2))

[0113] The charged amounts of the starting materials were set to 32.7 g of glycidyl methacrylate, 51.1 g of isobornyl methacrylate, 11.7 g of dimethyl 2,2'-azobis(isobutyrate), and 95.6 g of methyl isobutyl ketone as the reaction solvent. Otherwise, the same operations as in Example 1 were performed to obtain a resin and a curable resin composition (A-2).

[0114] The Mw of the obtained resin was 5,858.

[0115] Example 3 (Preparation of curable resin composition (A-3))

[0116] The charged amounts of the starting materials were set to 17.1 g of glycidyl methacrylate, 26.4 g of benzyl acrylate, 3.0 g of dimethyl 2,2'-azobis(isobutyrate), and 139.6 g of methyl isobutyl ketone as the reaction solvent. Otherwise, the same operations as in Example 1 were performed to obtain a resin and a curable resin composition (A-3).

[0117] The Mw of the obtained resin was 7,885.

[0118] Example 4 (Preparation of curable resin composition (A-4))

[0119] The charged amounts of the starting materials were set to 14.2 g of glycidyl methacrylate, 22.0 g of 1-naphthylmethyl acrylate, 2.5 g of dimethyl 2,2'-azobis(isobutyrate), and 116.2 g of methyl isobutyl ketone as the reaction solvent. Otherwise, the same operations as in Example 1 were performed to obtain a resin and a curable resin composition (A-4).

[0120] The Mw of the obtained resin was 9,487.

[0121] Example 5 (Preparation of curable resin composition (A-5))

[0122] The input amounts of the starting materials were set as 79.9 g of 4-vinylbenzyl glycidyl ether, 5.6 g of 2,2'-azobis(isobutyric acid) dimethyl ester, and 85.5 g of methyl isobutyl ketone as the reaction solvent. After dissolution, the mixture was stirred and reacted under reflux at 80 °C for 16 hours using a mantle heater. Otherwise, the operation was the same as in Example 1 to obtain a resin and a curable resin composition (A-5).

[0123] The Mw of the obtained resin was 8,549.

[0124] Example 6 (Preparation of curable resin composition (A-6))

[0125] The input amounts of the starting materials were set as 17.1 g of 4-vinylbenzyl glycidyl ether, 15.5 g of benzyl methacrylate, 4.6 g of 2,2'-azobis(isobutyric acid) dimethyl ester, and 104.6 g of methyl isobutyl ketone as the reaction solvent. Otherwise, the operation was the same as in Example 5 to obtain a resin and a curable resin composition (A-6).

[0126] The Mw of the obtained resin was 6,145.

[0127] Example 7 (Preparation of curable resin composition (A-7))

[0128] The input amounts of the starting materials were set as 41.9 g of 4-vinylbenzyl glycidyl ether, 37.7 g of 1-naphthyl methyl acrylate, 5.6 g of 2,2'-azobis(isobutyric acid) dimethyl ester, and 85.1 g of methyl isobutyl ketone as the reaction solvent. Otherwise, the operation was the same as in Example 5 to obtain a resin and a curable resin composition (A-7).

[0129] The Mw of the obtained resin was 13,568.

[0130] Comparative Example 1 (Preparation of curable resin composition (A-8))

[0131] The input amounts of the starting materials were set as 75.1 g of methyl methacrylate, 5.3 g of 2,2'-azobis(isobutyric acid) dimethyl ester, and 80.4 g of propylene glycol monomethyl ether acetate as the reaction solvent. Otherwise, the operation was the same as in Example 5 to obtain a resin and a curable resin composition (A-8).

[0132] The Mw of the obtained resin was 12,430.

[0133] Comparative Example 2 (Preparation of curable resin composition (A-9))

[0134] The input amounts of the starting materials were set as 92.4 g of glycidyl methacrylate, 6.5 g of dimethyl 2,2'-azobis(isobutyrate), and 98.9 g of propylene glycol monomethyl ether acetate as the reaction solvent. Except for this, the operation was the same as in Example 1, and a resin and a curable resin composition (A-9) were obtained.

[0135] The Mw of the obtained resin was 14,452.

[0136] Comparative Example 3 (Preparation of curable resin composition (A-10))

[0137] The input amounts of the starting materials were set as 35.2 g of benzyl methacrylate, 2.5 g of dimethyl 2,2'-azobis(isobutyrate), and 113.1 g of propylene glycol monomethyl ether acetate as the reaction solvent. Except for this, the operation was the same as in Example 1, and a resin and a curable resin composition (A-10) were obtained.

[0138] The Mw of the obtained resin was 10,765.

[0139] Comparative Example 4 (Preparation of curable resin composition (A-11))

[0140] Except for using EPICLON N-680 (manufactured by DIC Corporation) as the resin, the operation was the same as in Example 1, and a curable resin composition (A-11) was obtained.

[0141] Comparative Example 5 (Preparation of curable resin composition (A-12))

[0142] Except for using EPICLON HP-7200 (manufactured by DIC Corporation) as the resin, the operation was the same as in Example 1, and a curable resin composition (A-12) was obtained.

[0143] [Evaluation]

[0144] Using the curable resin compositions prepared in the examples and comparative examples, the dry etching resistance, volatility (residual film characteristics during heating), heat curability (solvent resistance of the heat-cured film), and substrate adhesion were evaluated.

[0145] (1) Dry etching resistance

[0146] After coating the obtained curable resin composition on a 5-inch diameter silicon wafer using a spin coater, it was heated on a hot plate at 100 °C for 60 seconds in an atmosphere with an oxygen concentration of 20 vol%, to obtain a silicon wafer with an underlayer resist film. Using an etching device (manufactured by Samco: RIE-200NL), the formed underlayer resist film was etched under the conditions of CF4 (CF4: 89 sccm, pressure: 2.0 Pa, RF power: 100 W, processing time: 180 seconds). The film thickness before and after the etching treatment was measured at this time, the etching rate was calculated, and the dry etching resistance was evaluated. The evaluation criteria are as follows.

[0147] ○: When the etching rate is 75 nm / minute or less

[0148] ×: When the etching rate exceeds 75 nm / minute

[0149] The evaluation results are shown in Tables 1 and 2.

[0150] (2) Volatility (film residue characteristics during heating)

[0151] After coating the obtained curable resin composition on a 5-inch diameter silicon wafer using a spin coater, it was heated on a hot plate at 100 °C for 60 seconds in an atmosphere with an oxygen concentration of 20 vol% to fabricate a silicon wafer with an underlayer resist film. Then, it was heated (hard baked) at 250 °C for 600 seconds on a hot plate, and the volatility was evaluated based on the film thickness change before and after hard baking. The evaluation criteria are as follows.

[0152] ○: When the film residue rate is 80% or more

[0153] ×: When the film residue rate is less than 80%

[0154] The evaluation results are shown in Tables 1 and 2.

[0155] (3) Heat curability (solvent resistance of heat-cured film)

[0156] The silicon wafer with the cured product after hard baking prepared in the above volatility (film residue characteristics during heating) test was immersed in propylene glycol monomethyl ether acetate for 60 seconds, and then heated and dried on a hot plate at 100 °C for 60 seconds. The heat curability was evaluated from the film thickness change in this process. The evaluation criteria are as follows.

[0157] ○: When the film residue rate is 80% or more

[0158] ×: When the film residue rate is less than 80%

[0159] The evaluation results are shown in Tables 1 and 2.

[0160] (4) Substrate adhesion

[0161] After applying the obtained curable resin composition onto an alkali-free glass substrate with a size of 10 cm square using a spin coater, it was heated on a hot plate at 100 °C for 60 seconds in an atmosphere with an oxygen concentration of 20 vol% to produce a glass substrate with an under-resist film. An aluminum bolt was joined to the under-resist film using an adhesive. After standing at 23 °C for 24 hours, the bolt was stretched at a speed of 1.6 MPa / second using a film adhesion tester manufactured by ALLGOOD Co., and the load at the time of peeling was measured. The evaluation results are shown in Tables 1 and 2.

[0162] [Table 1]

[0163] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Dry etching resistance ○ ○ ○ ○ ○ ○ ○ Volatility ○ ○ ○ ○ ○ ○ ○ Heat curability ○ ○ ○ ○ ○ ○ ○ Substrate adhesion [MPa] 8.3 7.9 8.2 8.1 8.7 9.3 10.5

[0164] [Table 2]

[0165] Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Dry etching resistance × × ○ ○ ○ Volatility ○ ○ × ○ × Heat curability × × × × × Substrate adhesion [MPa] 4.0 10.1 4.8 9.7 6.6

[0166] It can be confirmed from Tables 1 and 2 that the cured product obtained from the curable resin composition of the present invention has high dry etching resistance, low volatility during heating, good heat curability (high solvent resistance), and high substrate adhesion.

Claims

1. A curable resin composition containing at least one polymer selected from the following (1) and (2), (1) A polymer having a structure derived from a polymerizable monomer (A1) having at least one of an alicyclic structure and an aromatic ring structure and a cyclic ether group; (2) A polymer having a structure derived from a polymerizable monomer (A2) having a cyclic ether group and a structure derived from a polymerizable monomer (B) having at least one of an alicyclic structure and an aromatic ring structure.

2. The curable resin composition according to claim 1, wherein The polymerizable monomer (A1) is a compound represented by the following general formula (A1-1), In the general formula (A1-1), R 11 is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms L 11 is a divalent linking group containing at least an arylene group, Z is an epoxy group, an oxetanyl group, an alkyloxetanyl group having 4 to 10 carbon atoms, or an epoxycycloalkyl group having 5 to 10 carbon atoms.

3. The curable resin composition according to claim 1, wherein, The polymerizable monomer (A2) is a compound represented by the following general formula (A2-1), In the general formula (A2-1), R 12 is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, L 12 is a single bond or a divalent linking group, Z is an epoxy group, an oxetanyl group, an alkyloxetanyl group having 4 to 10 carbon atoms, or an epoxycycloalkyl group having 5 to 10 carbon atoms.

4. The curable resin composition according to claim 1, wherein, The polymerizable monomer (B) is a compound represented by the following general formula (B-1), In the general formula (B-1), R 21 is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, L 21 is a single bond or a divalent linking group, X is an aromatic group or an alicyclic hydrocarbon group.

5. The curable resin composition according to claim 1, wherein, The content of the structure derived from the polymerizable monomer (B) in the polymer of (2) is 30 to 150 parts by mass relative to 100 parts by mass of the polymerizable monomer (A2).

6. The curable resin composition according to any one of claims 1 to 5, which is a composition for lithography.

7. The curable resin composition according to any one of claims 1 to 5, which is a composition for forming an underlayer film for a resist.

8. An underlayer film for a resist, which is a cured product of the composition for forming an underlayer film for a resist according to claim 7.

9. A cured product of the curable resin composition according to any one of claims 1 to 5.

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