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. A curable resin composition having a cyclic ether group and at least one of an alicyclic structure and an aromatic ring structure, and containing a polymer obtained by modifying at least some of the cyclic ether group with a compound having a functional group and at least one of an alicyclic structure and 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, the pattern processing thereof has been required to be increasingly miniaturized. 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, low light reflectivity, etc.

[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, 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 miniaturization 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 miniaturization, 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 etching resistance and heat curability.

[0012] Method for solving the problem

[0013] The inventors of the present invention conducted intensive studies to solve the above problems, and as a result, found that by using a polymer having a specified structure in a curable resin composition, the dry etching resistance and heat curability 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 having at least one of an alicyclic structure and an aromatic ring structure and a cyclic ether group, and containing a polymer obtained by modifying at least a part of the cyclic ether group with a compound having at least one of the alicyclic structure and the aromatic ring structure and a functional group.

[0015] In addition, the present invention relates to a cured product of the above composition or an underlayer film for a resist.

[0016] Effect of the invention

[0017] According to the present invention, a curable resin composition capable of obtaining a coating film having good dry etching resistance and heat curability can be provided. Detailed description of the invention

[0018] 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 without impairing the effects of the present invention.

[0019] In the present specification, “(meth)acrylate” means one or both of acrylate and methacrylate.

[0020] The curable resin composition of the present invention has at least one of an alicyclic structure and an aromatic ring structure and a cyclic ether group. And it contains a polymer obtained by modifying at least a part of the cyclic ether group with a compound having at least one of the above alicyclic structure and aromatic ring structure and a functional group.

[0021] By including the above polymer, a curable resin composition can be obtained, which can obtain a coating film having good dry etching resistance and heat curability. In particular, it is possible to achieve both dry etching resistance and heat curability of the resin alone.

[0022] The above polymer used in the present invention is obtained, for example, by reacting a compound having at least one of an alicyclic structure and an aromatic ring structure and a functional group with a polymer obtained by polymerizing a polymerizable monomer having a cyclic ether group to modify at least a part of the cyclic ether group.

[0023] In the present invention, the "polymerizable monomer" refers to a compound having a polymerizable unsaturated group. Examples of the polymerizable unsaturated group possessed by the polymerizable monomer include 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. 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.

[0024] In addition, the number of polymerizable unsaturated groups possessed by the polymerizable monomer may be 1 or 2 or more.

[0025] (Polymerizable monomer having a cyclic ether group)

[0026] The polymerizable monomer having a cyclic ether group is preferably a compound represented by the following general formula (A).

[0027] [Chemical formula 1]

[0028]

[0029] R 1 is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and L 1 is a single bond or a divalent linking group, and Z is an epoxy group, an oxetanyl group, an alkyl oxetanyl group having 4 to 10 carbon atoms, or an epoxy cycloalkyl group having 5 to 10 carbon atoms.

[0030] In the general formula (A), as the alkyl group having 1 to 6 carbon atoms of R 1 , methyl, ethyl, etc. can be cited. R 1 is preferably a hydrogen atom or a methyl group.

[0031] As the divalent linking group of L 1 , groups formed by combining two or more selected from alkylene group, arylene group, ether bond (-O-), ester bond (-COO-), carbonyl group (-CO-), or alkylene group, arylene group, ether bond, and carbonyl group can be cited.

[0032] As the arylene group of L 1 , for example, an arylene group having 6 to 18 carbon atoms can be cited, and an arylene group having 6 to 14 carbon atoms is preferred. The arylene group can be a monocyclic or a condensed ring. Specific examples of the arylene group include phenylene group, naphthylene group, etc.

[0033] As the alkyl group of L 1 , for example, an alkyl group having 1 to 10 carbon atoms can be cited. The alkyl group can be linear, branched, or cyclic.

[0034] L 1The alkylene and arylene groups may further have substituents, and examples of such substituents include alkyl groups having 1 to 6 carbon atoms, hydroxyl groups, halogen atoms, and the like.

[0035] L 1 Preferably a single bond, alkylene, phenylene, ether bond, ester bond; a group formed by combining an alkylene group and an ester bond; a group formed by combining an alkylene group, a phenylene group and an ether bond or a group formed by combining an alkylene group, an ester bond and an ether bond.

[0036] Examples of the alkyloxetanyl group having 4 to 10 carbon atoms for Z include 3-methyloxetanyl, 3-ethyloxetanyl, 2-methyloxetanyl, and 2-ethyloxetanyl.

[0037] Examples of the epoxycycloalkyl group having 5 to 10 carbon atoms include 3,4-epoxycyclohexyl, 3-methyl-3,4-epoxycyclohexyl, 2,5-epoxycyclohexyl, 4,5-epoxycyclooctyl, 3,4-epoxycyclooctyl, 2,3-epoxycyclopentyl, and 3,4-epoxycyclopentyl.

[0038] Z is preferably an epoxy group.

[0039] Specific examples of the compound represented by the general formula (A) include epoxy group-containing (meth)acrylate compounds such as 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, (meth)acrylic acid glycidyl ester, (meth)acrylic acid 4-hydroxybutyl ester glycidyl ether, and (meth)acrylic acid epoxycyclohexylmethyl ester; (meth)acrylate compounds containing an oxetanyl group such as methyl acrylate (3-ethyloxetanyl-3-yl); and mono(meth)acrylated products of diglycidyl ether compounds such as dihydroxybenzene diglycidyl ether, dihydroxynaphthalene diglycidyl ether, biphenol diglycidyl ether, and bisphenol diglycidyl ether.

[0040] The compound represented by the general formula (A) can be produced by a known method or a commercially available product can be used. As commercially available products of the compound represented by the general formula (A), for example, commercially available SR-378 (manufactured by Sartomer) of glycidyl acrylate, commercially available Light Ester G (manufactured by Kyoeisha Chemical Co., Ltd.), Blemmer G (manufactured by Nippon Oil & Fats Co., Ltd.), SR-379 (manufactured by Sartomer), OXE-10, OXE-30 (manufactured by Osaka Organic Chemical Industry Co., Ltd.), CYCLOMER M100 (manufactured by Daicel Corporation) of glycidyl methacrylate, etc. can be cited.

[0041] (Compound having at least one of an alicyclic structure and an aromatic ring structure and a functional group)

[0042] The compound having at least one of an alicyclic structure and an aromatic ring structure and a functional group (hereinafter referred to as compound B) is preferably a compound represented by the following general formula (B).

[0043] [Chemical formula 2]

[0044] Y-L 21 -X(B)

[0045] In the above general formula (B), L 21 is a single bond or a divalent linking group, X is an aromatic group or an alicyclic hydrocarbon group, and Y is a functional group.

[0046] L 21 Examples of L are the same as the above L 1 L 21 is preferably a single bond.

[0047] 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. In addition, the aryl group is a monocyclic or condensed ring, preferably a monocyclic or condensed ring having 2 to 8 condensation numbers, and more preferably a monocyclic or condensed ring having 2 to 4 condensation numbers. Specifically, phenyl, naphthyl, anthryl, etc. can be exemplified.

[0048] As the alicyclic hydrocarbon group, for example, dicyclopentyl, isobornyl, adamantyl, etc. can be cited.

[0049] X is preferably an aromatic group, and particularly preferably naphthyl or anthryl.

[0050] Y as the functional group may be a group that reacts with a cyclic ether group, and for example, a thiol group, a carboxyl group, an amino group, a hydroxyl group can be cited. A thiol group or a carboxyl group is preferred.

[0051] Examples of the compound represented by the general formula (B) include 1-naphthoic acid, 2-naphthoic acid, 9-anthracene carboxylic acid, 2-anthracene carboxylic acid, 3-anthracene carboxylic acid, 2-naphthyl mercaptan, 1-naphthol, 2-naphthol, etc. Compound B can be used alone, or two or more thereof can be combined.

[0052] Compound B can be produced by a known method. Alternatively, commercially available products can be used as Compound B.

[0053] (Polymerization of Polymerizable Monomer Having Cyclic Ether Group)

[0054] Within the range that does not impair the effects of the present invention, the polymer used in the present invention may contain structural units of polymerizable monomers other than the polymerizable monomer having a cyclic ether group.

[0055] In the polymer, the content ratio of the structure derived from the polymerizable monomer having a cyclic ether group is, for example, 50% by mass or more, 70% by mass or more, 90% by mass or more, 95% by mass or more with respect to the whole polymer. Substantially, it can be 100% by mass. When it is substantially 100% by mass, the polymer may contain a structure derived from inevitable impurities.

[0056] The content ratio of each polymerization unit in the polymer can be controlled by adjusting the blending amount of the polymerizable monomers in the polymerization components. 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 with respect to the total amount of the polymerization components used.

[0057] The polymerization form of the polymer is not particularly limited, and it can be produced based on polymerization mechanisms such as radical polymerization method, cationic polymerization method, anionic polymerization method, etc., by solution polymerization method, bulk polymerization method, emulsion polymerization method, etc. For example, if it is a radical polymerization method, the polymer can be produced by introducing a polymerizable monomer mixture into an organic solvent and adding a general radical polymerization initiator.

[0058] As the polymerization initiator, various polymerization initiators can be used. Examples include peroxides such as tert-butyl peroxy-2-ethylhexanoate, benzoyl peroxide, diacyl peroxide, azo compounds such as azobisisobutyronitrile, dimethyl azobisisobutyrate, phenylazotriphenylmethane, and metal chelates such as Mn(acac)3.

[0059] As needed, chain transfer agents such as lauryl mercaptan, 2-mercaptoethanol, ethyl mercaptoacetate, octyl mercaptoacetate, and thiol compounds having a coupling group such as γ-mercaptopropyltrimethoxysilane can also be used as additives such as chain transfer agents.

[0060] Examples of the organic solvent include alcohol solvents such as ethanol, isopropanol, n-butanol, isobutanol, and tert-butanol; ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and methyl amyl ketone; ester solvents such as methyl acetate, ethyl acetate, butyl acetate, methyl lactate, ethyl lactate, and 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, and butyl 2-methoxypropionate; polar solvents such as dimethylformamide, dimethyl sulfoxide, and N-methylpyrrolidone; ether solvents such as methyl cellosolve, cellosolve, butyl cellosolve, butyl carbitol, and 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, and propylene glycol monobutyl ether acetate; halogen solvents such as 1,1,1-trichloroethane and chloroform; cyclic ether solvents such as tetrahydrofuran and dioxane; aromatic solvents such as benzene, toluene, and xylene; fluorinated solvents such as perfluorooctane and perfluorotributylamine, etc.

[0061] These solvents may be used alone or in combination of two or more.

[0062] The polymer may be a block copolymer or a random copolymer, but a random copolymer is preferred. In addition, it may be a radical copolymer or a living copolymer, but a radical copolymer is preferred.

[0063] By polymerizing a polymerizable monomer having a cyclic ether group, for example, a polymer A containing a structural unit represented by the following general formula (A1) can be obtained.

[0064] [Chemical formula 3]

[0065]

[0066] In the above general formula, R 1 is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, L 1 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.

[0067] R 1 、L 1 and Z are the same as those in the above general formula (A).

[0068] The polymer is preferably a random copolymer. For example, when two polymerizable monomers are used, it is preferably a copolymer in which the structure derived from polymerizable monomer 1 and the structure derived from polymerizable monomer 2 are randomly arranged.

[0069] In the present invention, it is preferred that the polymer does not contain a block structure. For example, in the case of using two polymerizable monomers, it is preferred not to contain a block copolymer formed by linking a block having a structure derived from polymerizable monomer 1 and a block having a structure derived from polymerizable monomer 2, and more preferably not to contain a block having a structure derived from polymerizable monomer 1 and / or a block having a structure derived from polymerizable monomer 2.

[0070] In the production of block polymers, metal catalysts are usually required, and the resulting block polymers inevitably contain 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 its production and does not contain metal impurities, it can avoid adverse effects on the resist performance.

[0071] In addition, the production of block copolymers generally involves complicated management. Specifically, if the monomer that becomes the second block is introduced at a low polymerization rate of the first block, capping may be 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 incorporation of polymerization-inactivating substances such as oxygen that hinder block formation. The curable resin composition of the present invention is also excellent in terms of not involving complicated production management.

[0072] The polymer (polymer A) obtained from a polymerizable monomer having a cyclic ether group is reacted with the above compound B for modification, thereby obtaining a polymer containing, for example, structural units represented by the following general formulas (A1) and (B1).

[0073] [Chemical formula 4]

[0074]

[0075] In the above general formula, R 1 is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, L 1 is a single bond or a divalent linking group, L 2 is a divalent linking group containing a structure derived from the above functional 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, and X is an aromatic group or an alicyclic hydrocarbon group.

[0076] R 1 、L 1 、Z and X are the same as in the above general formulas (A) and (B).

[0077] As L 2The divalent linking group containing a structure derived from a functional group is a group formed by the reaction of a functional group such as a thiol group or a carboxyl group with a Z group such as an epoxy group. As an example, the structure represented by the following general formula (M) can be cited.

[0078] [Chemical Formula 5]

[0079]

[0080] In the above general formula (M), R 1 is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and L 22 is a divalent linking group having a hydroxyl group, and L 21 is a single bond or a divalent linking group, and X is an aromatic group or an alicyclic hydrocarbon group.

[0081] R 1 , L 21 and X are the same as those in the above general formulas (A) and (B).

[0082] L 22 For example, it is an alkylene group having a hydroxyl group generated by the reaction of an epoxy group and a carboxyl group.

[0083] In one embodiment, relative to 100 mol of the structural unit represented by the general formula (A1), the structural unit represented by the general formula (B1) is 10 to 200 mol, preferably 20 to 180 mol, more preferably 30 to 160 mol.

[0084] In one embodiment, the polymer does not contain a fluorine atom.

[0085] In one embodiment, the polymer does not contain a silicon atom.

[0086] Polymer A and compound B can be reacted, for example, by heating and stirring in a solvent in the presence of a catalyst.

[0087] As the solvent, the same organic solvents as those used in the polymerization of the above polymerizable monomer having a cyclic ether group can be used.

[0088] The catalyst can be appropriately selected considering the functional groups of polymer A and compound B. For example, amine compounds such as trimethylamine, triethylamine, N-methylmorpholine, pyridine, 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), 1,5-diazabicyclo[4.3.0]non-5-ene (DBN), 1,4-diazabicyclo[2.2.2]octane (DABCO), tri-n-butylamine, dimethylbenzylamine, butylamine, octylamine, monoethanolamine, diethanolamine, triethanolamine, imidazole, 1-methylimidazole, 2,4-dimethylimidazole, 1,4-diethylimidazole, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-(N-phenyl)aminopropyltrimethoxysilane, 3-(2-aminoethyl)aminopropyltrimethoxysilane, 3-(2-aminoethyl)aminopropylmethyldimethoxysilane, tetramethylammonium hydroxide, etc.; quaternary ammonium salts such as trioctylmethylammonium chloride, trioctylmethylammonium acetate; phosphine compounds such as trimethylphosphine, tributylphosphine, triphenylphosphine; phosphonium salts such as tetramethylphosphonium chloride, tetraethylphosphonium chloride, tetrapropylphosphonium chloride, tetrabutylphosphonium chloride, tetrabutylphosphonium bromide, trimethyl(2-hydroxypropyl)phosphonium chloride, ethyltriphenylphosphonium bromide, methyltriphenylphosphonium bromide, triphenylphosphonium chloride, benzylphosphonium chloride; organotin compounds such as dibutyltin dilaurate, octyltin trilaurate, octyltin diacetate, dioctyltin diacetate, dioctylditin dineodecanoate, dibutyltin diacetate, tin octoate, 1,1,3,3-tetrabutyl-1,3-dilauroylstannoxane; organometallic compounds such as zinc octoate, bismuth octoate; inorganic tin compounds such as tin octoate; inorganic metal compounds, etc. In addition, alkaline earth metal hydroxides, alkali metal carbonates, and alkali metal hydroxides can also be used. These catalysts can be used alone or in combination of two or more. When used, these catalysts can be used in the form of a solution of about 10 to 55% by mass, or in the form of a solid.

[0089] The heating temperature is, for example, 30°C to 200°C, and the reaction time is about 1 hour to 30 hours.

[0090] The compounding amount of compound B is preferably 5 to 150 parts by mass, particularly preferably 10 to 100 parts by mass, and further preferably 20 to 80 parts by mass, based on 100 parts by mass of polymer A.

[0091] The weight-average molecular weight (Mw) of polymer (1) and polymer (2) is preferably in the range of 1,000 to 80,000, more preferably in the range of 2,000 to 50,000.

[0092] The weight-average molecular weight of the polymer is measured by the method described in the examples.

[0093] In addition to the above polymers, the curable resin composition of the present invention may further contain various additives such as solvents, other resins, surfactants, dyes, fillers, crosslinking agents, and dissolution promoters. For example, by dissolving the polymer in a solvent, a resist composition for coating can be obtained.

[0094] Examples of the solvent include ketones such as acetone, methyl ethyl ketone, cyclohexanone, cyclopentanone, cycloheptanone, 2-heptanone, methyl isobutyl ketone, and butyrolactone; alcohols such as methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, tert-butanol, pentanol, heptanol, octanol, nonanol, and decanol; ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and dioxane; alcohol ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, and propylene glycol monopropyl ether; 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, and butyl lactate; 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, and butyl 2-methoxypropionate; cellosolve acetates such as cellosolve acetate, methyl cellosolve acetate, ethyl cellosolve acetate, propyl cellosolve acetate, and butyl cellosolve acetate; propylene glycols such as propylene glycol, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, and propylene glycol monobutyl ether acetate; diethylene glycols such as diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, and diethylene glycol methyl ethyl ether; halogenated hydrocarbons such as trichloroethylene, Freon solvents, HCFCs, and HFCs; fully fluorinated solvents such as perfluorooctane; aromatics such as toluene and xylene; and polar solvents such as dimethylacetamide, dimethylformamide, N-methylacetamide, and N-methylpyrrolidone.

[0095] These solvents can be used alone or in combination of two or more.

[0096] The curable resin composition of the present invention can be suitably used for a composition for lithography, a composition for forming an underlayer film of a resist, etc. The curable resin composition can be made into a cured product by heating, drying, etc. as needed.

[0097] When the curable resin composition of the present invention is used for the purpose of an underlayer film (BARC film) of a resist, various additives such as the above polymer and, if necessary, a solvent, other resins, surfactants, dyes, fillers, crosslinking agents, and dissolution promoters can be added to prepare a composition for an underlayer film of a resist. In addition, the curable resin composition of the present invention can also be made into a composition for lithography.

[0098] A composition for lithography or a composition for an underlayer film of a resist can be prepared by mixing the above-described respective components using a stirrer or the like. Further, in the case where the composition for an underlayer film of a resist contains a filler and a pigment, a dissolver, a homogenizer, a three-roll mill or other dispersing devices can be used for dispersion or mixing to prepare the composition.

[0099] In order to form an underlayer film of a resist from the composition for an underlayer film of a resist, for example, there is the following method: The above-described composition for an underlayer film of a resist is applied onto an object to be subjected to lithography such as a silicon substrate, dried under temperature conditions of 100 to 200°C, and then further heat-cured 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.

[0100] Examples

[0101] 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.

[0102] The measurement conditions of GPC for the resins obtained in the following examples and comparative examples are as described below.

[0103] [GPC Measurement Conditions]

[0104] Measurement device: "Empower 3 Advanced Polymer Chromatography" manufactured by Waters

[0105] Column: "ACQUITY APC XT45 4.6 mmΦ × 150 mm" manufactured by Waters + "ACQUITY APC XT200 4.6 mmΦ × 75 mm" manufactured by Waters

[0106] Detector: Differential refractometer (RID)

[0107] Data processing:

[0108] Measurement conditions: Column temperature 40°C

[0109] Elution solvent: Tetrahydrofuran (THF)

[0110] Flow rate: 0.6 mL / minute

[0111] Measurement method: Polystyrene standard method

[0112] Example 1 (Preparation of curable resin composition (A-1))

[0113] In a four-necked flask equipped with a thermometer, a cooling tube, and a stirrer, 42.7 g of glycidyl methacrylate and 3.0 g of 2,2'-azobis(isobutyric acid) dimethyl ester were added and dissolved in 136.9 g of propylene glycol monomethyl ether acetate as a reaction solvent. After dissolution, the mixture was stirred and reacted under reflux at 80 °C for 8 hours using a mantle heater. Then, 25.9 g of 1-naphthoic acid, 1.1 g of ethyltriphenylphosphonium bromide, and 80.9 g of propylene glycol monomethyl ether acetate were added, and the temperature was raised to 80 °C, followed by stirring and reacting for 6 hours. 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 23,525.

[0114] 2.00 g of the obtained resin was dissolved in 8 g of propylene glycol monomethyl ether acetate and precisely filtered using a 0.1-μm PTFE disk filter to obtain a curable resin composition (A-1).

[0115] Example 2 (Preparation of curable resin composition (A-2))

[0116] Except for changing 1-naphthoic acid to 2-naphthoic acid, the same operations as in Example 1 were carried out to obtain a resin and a curable resin composition (A-2).

[0117] The Mw of the obtained resin was 22,279.

[0118] Example 3 (Preparation of curable resin composition (A-3))

[0119] The input amounts of the starting materials were set as 53.3 g of glycidyl methacrylate, 3.7 g of 2,2'-azobis(isobutyric acid) dimethyl ester, 57.1 g of propylene glycol monomethyl ether acetate as a reaction solvent, 32.3 g of 2-naphthoic acid, 1.3 g of ethyltriphenylphosphonium bromide, and 243.6 g of propylene glycol monomethyl ether acetate. Except for this, the same operations as in Example 2 were carried out to obtain a resin and a curable resin composition (A-3). The Mw of the obtained resin was 34,610.

[0120] Example 4 (Preparation of curable resin composition (A-4))

[0121] The input amounts of the raw materials after stirring for 8 hours under reflux at 80 °C were set as 25.9 g of 2-naphthoic acid, 2.2 g of triethylamine, and 84.1 g of propylene glycol monomethyl ether acetate, and the temperature was raised to 80 °C, followed by stirring and reacting for 10 hours. Except for this, the same operations as in Example 2 were carried out to obtain a resin and a curable resin composition (A-4).

[0122] The Mw of the obtained resin was 2,517.

[0123] Example 5 (Preparation of curable resin composition (A-5))

[0124] 53.3 g of glycidyl methacrylate and 3.7 g of 2,2'-azobis(isobutyric acid) dimethyl ester were placed into a four-necked flask equipped with a thermometer, a cooling tube, and a stirrer, and dissolved in 57.1 g of propylene glycol monomethyl ether acetate as a reaction solvent. After dissolution, the mixture was stirred and reacted under reflux at 80 °C for 8 hours using a mantle heater. Then, 41.7 g of 9-anthracene carboxylic acid, 1.5 g of ethyltriphenylphosphonium bromide, and 243.6 g of propylene glycol monomethyl ether acetate were added, and the temperature was raised to 100 °C, followed by stirring and reacting for 4 hours. 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 40,935.

[0125] For the obtained resin, the same operations as in Example 1 were carried out to obtain a curable resin composition (A-5).

[0126] Example 6 (Preparation of curable resin composition (A-6))

[0127] 53.3 g of glycidyl methacrylate and 3.7 g of 2,2'-azobis(isobutyric acid) dimethyl ester were placed into a four-necked flask equipped with a thermometer, a cooling tube, and a stirrer, and dissolved in 57.1 g of propylene glycol monomethyl ether acetate as a reaction solvent. After dissolution, the mixture was stirred and reacted under reflux at 80 °C for 8 hours using a mantle heater. Then, 30.1 g of 2-naphthalenethiol, 1.3 g of ethyltriphenylphosphonium bromide, and 209.5 g of propylene glycol monomethyl ether acetate were added, and the temperature was raised to 80 °C, followed by stirring and reacting for 10 hours. 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 24,324.

[0128] For the obtained resin, the same operations as in Example 1 were carried out to obtain a curable resin composition (A-6).

[0129] Example 7 (Preparation of curable resin composition (A-7))

[0130] 79.9 g of 4-vinylbenzyl glycidyl ether and 6.0 g of 2,2'-azobis(isobutyric acid) dimethyl ester were placed into a four-necked flask equipped with a thermometer, a cooling tube, and a stirrer, and dissolved in 85.5 g of propylene glycol monomethyl ether acetate as a reaction solvent. After dissolution, the mixture was stirred and reacted under reflux at 80 °C for 16 hours using a mantle heater. Then, 25.9 g of 2-naphthoic acid, 1.1 g of ethyltriphenylphosphonium bromide, and 80.9 g of propylene glycol monomethyl ether acetate were added, and the temperature was raised to 80 °C, followed by stirring and reacting for 6 hours. 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 12,224.

[0131] For the obtained resin, the same operations as in Example 1 were carried out to obtain a curable resin composition (A-7).

[0132] Comparative Example 1 (Preparation of curable resin composition (A-8))

[0133] 75.1 g of methyl methacrylate and 5.3 g of 2,2'-azobis(isobutyric acid) dimethyl ester were put into a four-necked flask equipped with a thermometer, a condenser, and a stirrer, and dissolved in 80.4 g of propylene glycol monomethyl ether acetate as a reaction solvent. After dissolution, the reaction was stirred under reflux at 80 °C for 16 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 carried out to obtain a resin. The Mw of the obtained resin was 12,430.

[0134] For the obtained resin, the same operations as in Example 1 were carried out to obtain a curable resin composition (A-8).

[0135] Comparative Example 2 (Preparation of curable resin composition (A-9))

[0136] 92.4 g of glycidyl methacrylate and 6.5 g of 2,2'-azobis(isobutyric acid) dimethyl ester were put into a four-necked flask equipped with a thermometer, a condenser, and a stirrer, and dissolved in 98.9 g of propylene glycol monomethyl ether acetate as a reaction solvent. After dissolution, the reaction was stirred under reflux at 80 °C for 8 hours using a mantle heater to obtain a resin. The Mw of the obtained resin was 14,452.

[0137] For the obtained resin, the same operations as in Example 1 were carried out to obtain a curable resin composition (A-9).

[0138] Comparative Example 3 (Preparation of curable resin composition (A-10))

[0139] The amounts of starting materials were set as 35.2 g of benzyl methacrylate, 2.5 g of 2,2'-azobis(isobutyric acid) dimethyl ester, and 113.1 g of propylene glycol monomethyl ether acetate as a reaction solvent. Except for this, the same operations as in Comparative Example 2 were carried out to obtain a resin and a curable resin composition (A-10).

[0140] The Mw of the obtained resin was 10,765.

[0141] Comparative Example 4 (Preparation of curable resin composition (A-11))

[0142] Except for using EPICLON N-680 (manufactured by DIC Corporation, trade name) as the resin, the same operations as in Example 1 were carried out to obtain a curable resin composition (A-11).

[0143] Comparative Example 5 (Preparation of Curable Resin Composition (A-12))

[0144] A curable resin composition (A-12) was obtained in the same manner as in Example 1, except that EPICLON HP-7200 (manufactured by DIC Corporation, trade name) was used as the resin.

[0145] [Evaluation]

[0146] Using the curable resin compositions prepared in the examples and comparative examples, dry-etch resistance, volatility (remaining film characteristics during heating), heat-curing property (solvent resistance of the heat-cured film), and substrate adhesion were evaluated.

[0147] (1) Dry-etch resistance

[0148] 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 apparatus (manufactured by Samco Inc.: 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, the etching rate was calculated, and the dry-etch resistance was evaluated. The evaluation criteria are as follows.

[0149] ○: When the etching rate is 75 nm / minute or less

[0150] ×: When the etching rate exceeds 75 nm / minute

[0151] The evaluation results are shown in Tables 1 and 2.

[0152] (2) Volatility (remaining film characteristics during heating)

[0153] 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 on a hot plate at 250 °C (hard bake) for 600 seconds, and the volatility was evaluated based on the film thickness change before and after the hard bake. The evaluation criteria are as follows.

[0154] ○: When the remaining film rate is 80% or more

[0155] ×: When the remaining film rate is less than 80%

[0156] The evaluation results are shown in Tables 1 and 2.

[0157] (3) Heat-curing property (solvent resistance of the heat-cured film)

[0158] The silicon wafer with the cured product after hard baking prepared in the above-mentioned volatility (residual film characteristics during heating) test was immersed in propylene glycol monomethyl ether acetate for 60 seconds, and then dried by heating on a hot plate at 100 °C for 60 seconds. The heat curability was evaluated by the film thickness change in this process. The evaluation criteria are as follows.

[0159] ○: When the residual film ratio is 80% or more

[0160] ×: When the residual film ratio is less than 80%

[0161] The evaluation results are shown in Tables 1 and 2.

[0162] (4) Substrate adhesion

[0163] After the obtained curable resin composition was coated on a 10 cm square non-alkali glass substrate 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%, and a glass substrate with an anti-resist underlayer film was fabricated. An aluminum bolt was joined to the anti-resist underlayer film using an adhesive. After standing at 23 °C for 24 hours, the bolt was pulled 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.

[0164] [Table 1]

[0165] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Dry etching resistance ○ ○ ○ ○ ○ ○ ○ Volatility ○ ○ ○ ○ ○ ○ ○ Heat curability ○ ○ ○ ○ ○ ○ ○ Substrate adhesion [MPa] 11.2 12.1 11.7 10.1 10.1 7.7 9.9

[0166] [Table 2]

[0167] 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

[0168] 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 having at least one of an alicyclic structure and an aromatic ring structure and a cyclic ether group, and comprising a polymer obtained by modifying at least a part of the cyclic ether group with a compound having at least one of the alicyclic structure and the aromatic ring structure and a functional group.

2. The curable resin composition according to claim 1, wherein, The polymer contains structural units represented by the following general formulas (A1) and (B1), In the general formula, R 1 is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, L 1 is a single bond or a divalent linking group, L 2 is a divalent linking group containing a structure derived from the functional 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, and X is an aromatic group or an alicyclic hydrocarbon group.

3. The curable resin composition according to claim 2, wherein, The structural unit represented by the general formula (A1) is a structure derived from a polymerizable monomer represented by the following general formula (A), In the general formula (A), R 1 is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and L 1 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.

4. The curable resin composition according to claim 2, wherein, The polymer is obtained by modifying a polymer containing the structural unit represented by the general formula (A1) with a compound represented by the following general formula (B), Y-L 21 -X(B) In the general formula (B), L 21 is a single bond or a divalent linking group, X is an aromatic group or an alicyclic hydrocarbon group, and Y is a functional group.

5. The curable resin composition according to claim 2, wherein, The structural unit represented by the general formula (B1) is a structure represented by the following general formula (M), In the general formula (M), R 1 is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and L 22 is a divalent linking group having a hydroxyl group, and L 21 is a single bond or a divalent linking group, and X is an aromatic group or an alicyclic hydrocarbon group.

6. The curable resin composition according to claim 2, wherein, With respect to 100 mol of the structural unit represented by the general formula (A1), the structural unit represented by the general formula (B1) is 10 to 200 mol.

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

8. The curable resin composition according to any one of claims 1 to 6, which is a composition for forming an underlayer film for a resist.

9. 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 8.

10. A cured product of the curable resin composition according to any one of claims 1 to 6.

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