Curable resin composition and cured product

Abstract

To provide a curable resin composition which can form a coating film having excellent dry etching resistance and excellent heat-curing properties.SOLUTION: A curable resin composition including a polymer that includes at least one selected from an alicyclic structure and an aromatic ring structure, and a cyclic ether group, where at least part of the cyclic ether group is modified with a compound including at least one selected from the alicyclic structure and the aromatic ring structure, and a functional group.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a curable resin composition. More specifically, the present invention relates to a curable resin composition from which a cured product suitable for a resist underlayer film or the like can be obtained.

Background Art

[0002] In recent years, with the increasing integration and speed of LSIs, finer patterning has been required for their pattern processing. In photolithography using ArF excimer laser light (193 nm), by utilizing the optical properties of process materials and improving process equipment, it has become possible to exceed the inherent resolution limit derived from the wavelength of the light source.

[0003] In the field of photoresists, various methods for forming finer wiring patterns have been developed, one of which is the multilayer resist method. In the multilayer resist method, one or more layers called a resist underlayer film, an antireflection film, etc. are formed on a substrate, and then a resist pattern is formed thereon by ordinary photolithography. Next, the wiring pattern is transferred to the substrate by dry etching. In the technology of the multilayer resist method, one of the important members is the resist underlayer film. The resist underlayer film is required to have low viscosity, high dry etching resistance, low light reflectivity, etc.

[0004] Also, in the multilayer resist method, in order to prevent film loss and film roughness of the resist underlayer film during coating of the upper-layer photoresist, the resist underlayer film is cured by heating after being coated on the substrate. Therefore, the resist underlayer film is required to exhibit good curing reactivity and high solvent resistance during heating. Also, in order to prevent equipment contamination, it is required that no outgas is generated and no film loss occurs during heat curing.

[0005] Recently, further miniaturization has been required, and accordingly, the aspect ratio of the resist pattern has increased, raising concerns about the collapse of the resist pattern. Therefore, in the resist underlayer film, high substrate adhesion is required to suppress the collapse of the resist pattern (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] In order to enable further miniaturization, a curable resin composition having high dry etching resistance, good reactivity (high solvent resistance), low volatility during heating, and high substrate adhesion is required. 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.

Means for Solving the Problems

[0008] As a result of intensive studies to solve the above problems, the present inventors have found that by using a polymer having a predetermined structure in a curable resin composition, the dry etching resistance and heat curability of the resulting cured product can be improved, and the present invention has been completed.

[0009] That is, the present invention relates to a curable resin composition containing a polymer modified with a compound having at least one of an alicyclic structure and an aromatic ring structure and a cyclic ether group, and at least a part of the cyclic ether group having at least one of the alicyclic structure and the aromatic ring structure and a functional group. The present invention also relates to a cured product of the above composition or a resist underlayer film.

Effects of the Invention

[0010] 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.

Embodiments for Carrying Out the Invention

[0011] Hereinafter, an embodiment of the present invention will be described. The present invention is not limited to the following embodiments, and can be implemented with appropriate modifications within a range that does not impair the effects of the present invention. In the present specification, “(meth)acrylate” means one or both of acrylate and methacrylate.

[0012] 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 at least a part of the cyclic ether group contains a polymer modified with a compound having at least one of the alicyclic structure and the aromatic ring structure and a functional group. By including the above polymer, a curable resin composition capable of obtaining a coating film having good dry etching resistance and heat curability can be obtained. In particular, compatibility between dry etching resistance and heat curability of the resin alone can be achieved.

[0013] The polymer used in the present invention can be obtained, for example, by reacting a polymer obtained by polymerizing a polymerizable monomer having a cyclic ether group with a compound having at least one of an alicyclic structure and an aromatic ring structure and a functional group to modify at least a part of the cyclic ether group. In the present invention, the “polymerizable monomer” means a compound having a polymerizable unsaturated group. Examples of the polymerizable unsaturated group of the polymerizable monomer include C═C-containing groups such as (meth)acryloyl group, (meth)acryloyloxy group, (meth)acryloylamino group, vinyl group, vinyl ether group, allyl group, styryl group, and maleimide group. Among these, (meth)acryloyl group, (meth)acryloyloxy group, and vinyl group are preferable because of the easy availability of raw materials and good polymerization reactivity. Also, the number of polymerizable unsaturated groups of the polymerizable monomer may be one or two or more.

[0014] (Polymerizable monomer having a cyclic ether group) The polymerizable monomer having a cyclic ether group is preferably a compound represented by the following general formula (A).

[0015] [Chemical 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, 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.)

[0016] In general formula (A), R 1 Examples of the alkyl group having 1 to 6 carbon atoms include a methyl group and an ethyl group. R 1 is preferably a hydrogen atom or a methyl group. L 1 Examples of the divalent linking group of L include an alkylene group, an arylene group, an ether bond (-O-), an ester bond (-COO-), a carbonyl group (-CO-), or a group formed by combining two or more selected from an alkylene group, an arylene group, an ether bond, and a carbonyl group.

[0017] L 1 Examples of the arylene group of L include an arylene group having 6 to 18 carbon atoms, and an arylene group having 6 to 14 carbon atoms is preferable. The arylene group may be a monocyclic ring or a condensed ring. Specific examples of the arylene group include a phenylene group and a naphthylene group. L 1 Examples of the alkylene group of L include an alkylene group having 1 to 10 carbon atoms. The alkylene group may be linear, branched, or cyclic. L 1The alkylene group and arylene group may further have a substituent, and examples of the substituent include an alkyl group having 1 to 6 carbon atoms, a hydroxyl group, a halogen atom, etc.

[0018] L 1 is preferably a single bond, an alkylene group, a phenylene group, an ether bond, an ester bond; a group combining an alkylene group and an ester bond, a group combining an alkylene group, a phenylene group and an ether bond, or a group combining an alkylene group, an ester bond and an ether bond.

[0019] Examples of the alkyloxetanyl group having 4 to 10 carbon atoms for Z include a 3-methyloxetanyl group, a 3-ethyloxetanyl group, a 2-methyloxetanyl group, and a 2-ethyloxetanyl group. Examples of the epoxycycloalkyl group having 5 to 10 carbon atoms include a 3,4-epoxycyclohexyl group, a 3-methyl-3,4-epoxycyclohexyl group, a 2,5-epoxycyclohexyl group, a 4,5-epoxycyclooctyl group, a 3,4-epoxycyclooctyl group, a 2,3-epoxycyclopentyl group, and a 3,4-epoxycyclopentyl group. Z is preferably an epoxy group.

[0020] Specific examples of the compound represented by the general formula (A) include, for example, 4-vinylbenzyl glycidyl ether, 2-[(4-ethenylphenoxy)methyl]oxirane, 2-(4-ethenylphenoxy)oxirane, 2-[2-(4-ethenylphenyl)ethyl]oxirane, 3-[(4-ethenylphenoxy)methyl]oxetane, 2-[[4-(1-methylethenyl)phenoxy]methyl]oxirane, 2-[(4-ethenylphenoxy)methyl]oxetane, 2-[[4-(2-propenyl)phenoxy]methyl]oxirane, 2-[(3-ethenylphenyl)methyl]oxirane, 3-[(4-ethenyl-2-methylphenoxy)methyl]oxetane, 2-(4-ethenylphenoxy)tetrahydrofuran, glycidyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate glycidyl ether, epoxycyclohexylmethyl (meth)acrylate and other epoxy group-containing (meth)acrylate compounds; (3-ethyloxetan-3-yl)methyl acrylate and other oxetanyl group-containing (meth)acrylate compounds; mono(meth)acrylate compounds of diglycidyl ether compounds such as dihydroxybenzene diglycidyl ether, dihydroxynaphthalene diglycidyl ether, biphenol diglycidyl ether, bisphenol diglycidyl ether, etc.

[0021] The compound represented by the general formula (A) can be produced by a known method, or a commercially available product may be used. Commercially available products of the compound represented by the general formula (A) include, for example, SR-378 (manufactured by Sartomer Co., Ltd.), which is a commercially available product of glycidyl acrylate; Light Ester G (manufactured by Kyoeisha Chemical Co., Ltd.), Brenmer G (manufactured by Nippon Oil & Fats Co., Ltd.), SR-379 (manufactured by Sartomer Co., Ltd.), OXE-10, OXE-30 (manufactured by Osaka Organic Chemical Industry Co., Ltd.), Cyclomer M100 (manufactured by Daicel Corporation), etc., which are commercially available products of glycidyl methacrylate.

[0022] (A compound having at least one of an alicyclic structure and an aromatic ring structure, and a functional group) A 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).

[0023] [Chemical formula] (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, Y is a functional group.)

[0024] Examples of L 21 are the same as those of L 1 above. L 21 is preferably a single bond. As the aromatic group of X, an aryl group having 6 to 18 carbon atoms is preferable, and an aryl group having 6 to 14 carbon atoms is more preferable. The aryl group is a monocyclic or condensed ring, preferably a monocyclic or condensed ring having 2 to 8 condensed rings, and more preferably a monocyclic or condensed ring having 2 to 4 condensed rings. Specifically, a phenyl group, a naphthyl group, an anthracenyl group, etc. are exemplified. Examples of the alicyclic hydrocarbon group include a dicyclopentanyl group, an isobornyl group, an adamantyl group, etc. X is preferably an aromatic group, and particularly preferably a naphthyl group or an anthracenyl group. Y, which is a functional group, may be a group that reacts with a cyclic ether group, and examples thereof include a thiol group, a carboxyl group, an amino group, and a hydroxyl group. A thiol group or a carboxyl group is preferable.

[0025] Examples of the compound represented by the general formula (B) include 1-naphthoic acid, 2-naphthoic acid, 9-anthracenecarboxylic acid, 2-anthracenecarboxylic acid, 3-anthracenecarboxylic acid, 2-naphthalenethiol, 1-naphthol, 2-naphthol, etc. Compound B may be used alone or in combination of two or more. Compound B can be produced by a known method. Alternatively, a commercially available product may be used as Compound B.

[0026] (Polymerization of a polymerizable monomer having a cyclic ether group) The polymer used in the present invention may contain a structural unit of a polymerizable monomer other than the polymerizable monomer having a cyclic ether group, as long as the effects of the present invention are not impaired. In the polymer, the content 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, based on the whole polymer. It may be substantially 100% by mass. When it is substantially 100% by mass, the polymer may contain a structure derived from inevitable impurities.

[0027] The content of each polymerization unit in the polymer can be controlled by adjusting the blending amount of the polymerizable monomer 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 to the total amount of the polymerization components used.

[0028] The polymerization form of the polymer is not particularly limited, and it can be produced by a solution polymerization method, a bulk polymerization method, an emulsion polymerization method, etc., based on a polymerization mechanism such as a radical polymerization method, a cationic polymerization method, an anionic polymerization method. For example, in the case of a radical polymerization method, a polymer can be produced by charging a polymerizable monomer mixture into an organic solvent and adding a general-purpose radical polymerization initiator.

[0029] As the polymerization initiator, various ones can be used, and examples include peroxides such as t-butylperoxy-2-ethylhexanoate, benzoyl peroxide, and diacyl peroxide; azo compounds such as azobisisobutyronitrile, dimethyl azobisisobutyrate, and phenylazotriphenylmethane; and metal chelate compounds such as Mn(acac)3. If necessary, chain transfer agents such as lauryl mercaptan, 2-mercaptoethanol, ethylthioglycolic acid, octylthioglycolic acid, etc., and thiol compounds having a coupling group such as γ-mercaptopropyltrimethoxysilane may be used as additives such as chain transfer agents.

[0030] Examples of the organic solvent include alcohol solvents such as ethanol, isopropyl alcohol, n-butanol, iso-butanol, tert-butanol, etc.; ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, methyl amyl ketone, etc.; ester solvents such as methyl acetate, ethyl acetate, butyl acetate, methyl lactate, ethyl lactate, butyl lactate, etc.; monocarboxylic acid 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, etc.; polar solvents such as dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone, etc.; ether solvents such as methyl cellosolve, cellosolve, butyl cellosolve, butyl carbitol, ethyl cellosolve acetate, etc.; 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, etc.; halogen solvents such as 1,1,1-trichloroethane, chloroform, etc.; cyclic ether solvents such as tetrahydrofuran, dioxane, etc.; aromatic solvents such as benzene, toluene, xylene, etc.; fluorinated solvents such as perfluorooctane, perfluorotri-n-butylamine, etc. These solvents can be used alone or in combination of two or more.

[0031] The polymer may be a block copolymer or a random copolymer, but a random copolymer is preferred. Also, it may be a free radical copolymer or a living copolymer, but a free radical copolymer is preferred. 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.

[0032] [Chemical formula] (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, 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.) R 1 , L 1 and Z are the same as those in the general formula (A) described above.

[0033] 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.

[0034] Preferably in the present invention, the polymer does not contain a block structure. For example, when two polymerizable monomers are used, preferably it does not contain a block copolymer in which a block of the structure derived from polymerizable monomer 1 and a block of the structure derived from polymerizable monomer 2 are linked, and more preferably it does not contain a block of the structure derived from polymerizable monomer 1 and / or a block of the structure derived from polymerizable monomer 2. The production of block polymers generally requires a metal catalyst, and the resulting block polymers inevitably contain metal impurities. In nanometer-order lithography, even trace amounts of metal impurities may affect the resist performance. On the other hand, the curable resin composition of the present invention does not require a metal catalyst for production and does not contain metal impurities, so it is possible to avoid adverse effects on the resist performance. In addition, the production of block copolymers generally involves complicated management. Specifically, if a monomer that will form the second block is introduced when the polymerization rate of the first block is low, there is a risk that the block formation will be insufficient. On the other hand, if a monomer that will form the second block is introduced when the polymerization rate of the first block is high, deactivation of the active terminal may occur, and there is a risk that the polymerization reaction will not proceed sufficiently. In addition, measures are also required to prevent the incorporation of polymerization deactivating substances such as oxygen that interfere with block formation. The curable resin composition of the present invention is excellent also in that the production management is not complicated.

[0035] By reacting and modifying the polymer (polymer A) obtained from a polymerizable monomer having a cyclic ether group with the above-described compound B, for example, a polymer containing structural units represented by the following general formulas (A1) and (B1) can be obtained.

[0036] [Chemical formula] (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 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, X is an aromatic group or an alicyclic hydrocarbon group.)

[0037] R 1 , L 1 , Z and X are the same as those in the above-described general formulas (A) and (B). L 2 The divalent linking group containing a structure derived from the functional group, which is L 2 , 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, a structure represented by the following general formula (M) can be mentioned.

[0038] [Chemical formula] (In the general formula (M), R 1 is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, L 22 is a divalent linking group having a hydroxyl group, L 21 is a single bond or a divalent linking group, X is an aromatic group or an alicyclic hydrocarbon group.)

[0039] R 1 , L 21 and X are the same as those in the above general formulas (A) and (B). L 22 is, for example, an alkylene group having a hydroxyl group formed by the reaction of an epoxy group and a carboxyl group.

[0040] In one embodiment, based on 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.

[0041] In one embodiment, the polymer does not contain a fluorine atom. In one embodiment, the polymer does not contain a silicon atom.

[0042] The polymer A and the compound B can be reacted, for example, by heating and stirring in a solvent in the presence of a catalyst. As the solvent, an organic solvent similar to the polymerization of the polymerizable monomer having the above-mentioned cyclic ether group can be used. 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]undecene-7 (DBU), 1,5-diazabicyclo[4.3.0]nonene-5 (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; 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-hydroxylpropyl)phosphonium chloride, ethyltriphenylphosphonium bromide, methyltriphenylphosphonium bromide, triphenylphosphonium chloride, benzylphosphonium chloride; organotin compounds such as dibutyltin dilaurate, octyltin trilaurate, octyltin diacetate, dioctyltin diacetate, dioctyltin dineodecanoate, dibutyltin diacetate, tin octylate, 1,1,3,3-tetrabutyl-1,3-dodecanoyldistannoxane; organometallic compounds such as zinc octylate, bismuth octylate; inorganic tin compounds such as tin octoate; inorganic metal compounds, etc. Also, alkaline earth metal hydroxides, alkali metal carbonates, alkali metal hydroxides, etc. can be used.These catalysts can be used alone or in combination of two or more. When in use, these catalysts may be used in the form of a solution of about 10 to 55% by mass, or may be used in a solid form. The heating temperature is, for example, 30°C to 200°C, and the reaction time is about 1 hour to 30 hours. The compounding amount of compound B with respect to 100 parts by mass of polymer A is preferably 5 to 150 parts by mass, particularly preferably 10 to 100 parts by mass, and even more preferably 20 to 80 parts by mass.

[0043] 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. The weight average molecular weight of the polymer is measured by the method described in the examples.

[0044] In addition to the above-mentioned polymers, the curable resin composition of the present invention may contain various additives such as solvents, other resins, surfactants, dyes, fillers, crosslinking agents, and dissolution accelerators. For example, by dissolving the polymer in a solvent, a resist composition for coating is obtained. 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-propyl alcohol, iso-propyl alcohol, n-butyl alcohol, iso-butyl alcohol, tert-butyl alcohol, 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 esters 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, HCFC, and HFC;Fully fluorinated solvents such as perfluorooctane, aromatics such as toluene and xylene; polar solvents such as dimethylacetamide, dimethylformamide, N-methylacetamide, and N-methylpyrrolidone can be mentioned. These solvents may be used alone or in combination of two or more.

[0045] The curable resin composition of the present invention can be suitably used for compositions for lithography, compositions for forming a resist underlayer film, etc. The curable resin composition can be made into a cured product, for example, by heating and drying as necessary. When the curable resin composition of the present invention is used for a resist underlayer film (BARC film) application, in addition to the polymer described above, various additives such as a solvent, other resins, a surfactant, a dye, a filler, a crosslinking agent, and a dissolution accelerator can be added as necessary to obtain a composition for a resist underlayer film. Further, the curable resin composition of the present invention can also be made into a composition for lithography.

[0046] The composition for lithography or the composition for a resist underlayer film can be prepared by blending the above components and mixing them using a stirrer or the like. When the composition for a resist underlayer film contains a filler or a pigment, it can be adjusted by dispersing or mixing using a dispersing device such as a dissolver, a homogenizer, or a three-roll mill.

[0047] To form a resist underlayer film from the composition for a resist underlayer film, for example, there is a method of applying the above-described composition for a resist underlayer film onto an object to be subjected to photolithography such as a silicon substrate, drying it under temperature conditions of 100 to 200°C, and then further heat-curing it under temperature conditions of 250 to 400°C. Next, a resist pattern is formed by performing a normal photolithography operation on this underlayer film, and a resist pattern by a multilayer resist method can be formed by performing a dry etching treatment with a halogen-based plasma gas or the like.

Examples

[0048] 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.

[0049] The measurement conditions of GPC for the resins obtained in the following Examples and Comparative Examples are as follows. [GPC Measurement Conditions] Measuring device: "Empower3 Advanced Polymer Chromatography" manufactured by Waters Column: "ACQUITY APC XT45 4.6mmΦ×150mm" manufactured by Waters + "ACQUITY APC XT200 4.6mmΦ×75mm" manufactured by Waters Detector: Differential refractometer (RID) Data processing: Measurement conditions: Column temperature 40°C Developing solvent Tetrahydrofuran (THF) Flow rate 0.6 mL / min Measurement method: Polystyrene standard method

[0050] Example 1 (Preparation of curable resin composition (A-1)) 42.7 g of glycidyl methacrylate and 3.0 g of 2,2'-azobis(isobutyric acid)dimethyl were charged into a four-necked flask equipped with a thermometer, a condenser, and a stirrer, and dissolved in 136.9 g of propylene glycol monomethyl ether acetate as a reaction solvent. After dissolution, the mixture was stirred and reacted for 8 hours under reflux at 80°C 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, the temperature was raised to 80°C, and the mixture was stirred and reacted for 6 hours. After the reaction, the solvent was distilled off 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. 2.00 g of the obtained resin was dissolved in 8 g of propylene glycol monomethyl ether acetate and subjected to precision filtration with a 0.1 μm PTFE disk filter to obtain a curable resin composition (A-1).

[0051] Example 2 (Preparation of curable resin composition (A-2)) A resin and a curable resin composition (A-2) were obtained in the same manner as in Example 1, except that 1-naphthoic acid was changed to 2-naphthoic acid. The Mw of the obtained resin was 22,279.

[0052] Example 3 (Preparation of curable resin composition (A-3)) A resin and a curable resin composition (A-3) were obtained in the same manner as in Example 2, except that the charged amounts of starting materials were 53.3 g of glycidyl methacrylate, 3.7 g of 2,2'-azobis(isobutyric acid)dimethyl, 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. The Mw of the obtained resin was 34,610.

[0053] Example 4 (Preparation of curable resin composition (A-4)) A resin and a curable resin composition (A-4) were obtained in the same manner as in Example 2, except that after stirring for 8 hours under reflux at 80°C, the charged amounts of raw materials were 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 and stirred for 10 hours for reaction. The Mw of the obtained resin was 2,517.

[0054] Example 5 (Preparation of curable resin composition (A-5)) 53.3 g of glycidyl methacrylate and 3.7 g of 2,2’-azobis(isobutyric acid)dimethyl were charged 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-anthracenecarboxylic acid, 1.5 g of ethyltriphenylphosphonium bromide, and 243.6 g of propylene glycol monomethyl ether acetate were added, the temperature was raised to 100 °C, and the mixture was stirred and reacted for 4 hours. After the reaction, the solvent was distilled off 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. The obtained resin was used to obtain a curable resin composition (A-5) in the same manner as in Example 1.

[0055] Example 6 (Preparation of curable resin composition (A-6)) 53.3 g of glycidyl methacrylate and 3.7 g of 2,2’-azobis(isobutyric acid)dimethyl were charged 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, the temperature was raised to 80 °C, and the mixture was stirred and reacted for 10 hours. After the reaction, the solvent was distilled off 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. The obtained resin was used to obtain a curable resin composition (A-6) in the same manner as in Example 1.

[0056] Example 7 (Preparation of curable resin composition (A-7)) Into a four-necked flask equipped with a thermometer, a cooling tube, and a stirrer, 79.9 g of 4-vinylbenzyl glycidyl ether and 6.0 g of 2,2’-azobis(isobutyric acid) dimethyl were charged 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 ethyl triphenylphosphonium bromide, and 80.9 g of propylene glycol monomethyl ether acetate were added, the temperature was raised to 80 °C, and the mixture was stirred and reacted for 6 hours. After the reaction, the solvent was distilled off 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. The obtained resin was used to obtain a curable resin composition (A-7) in the same manner as in Example 1.

[0057] Comparative Example 1 (Preparation of curable resin composition (A-8)) Into a four-necked flask equipped with a thermometer, a cooling tube, and a stirrer, 75.1 g of methyl methacrylate and 5.3 g of 2,2’-azobis(isobutyric acid) dimethyl were charged and dissolved in 80.4 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. After the reaction, the solvent was distilled off under reduced pressure from the resin solution, and vacuum drying was performed to obtain a resin. The Mw of the obtained resin was 12,430. The obtained resin was used to obtain a curable resin composition (A-8) in the same manner as in Example 1.

[0058] Comparative Example 2 (Preparation of curable resin composition (A-9)) Into a four-necked flask equipped with a thermometer, a cooling tube, and a stirrer, 92.4 g of glycidyl methacrylate and 6.5 g of 2,2'-azobis(isobutyric acid) dimethyl were charged and dissolved in 98.9 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 to obtain a resin. The Mw of the obtained resin was 14,452. The obtained resin was used to obtain a curable resin composition (A-9) in the same manner as in Example 1.

[0059] Comparative Example 3 (Preparation of curable resin composition (A-10)) A resin and a curable resin composition (A-10) were obtained in the same manner as in Comparative Example 2, except that the starting materials were charged with 35.2 g of benzyl methacrylate, 2.5 g of 2,2'-azobis(isobutyric acid) dimethyl, and 113.1 g of propylene glycol monomethyl ether acetate as the reaction solvent. The Mw of the obtained resin was 10,765.

[0060] Comparative Example 4 (Preparation of curable resin composition (A-11)) A curable resin composition (A-11) was obtained in the same manner as in Example 1, except that EPICLON N-680 (trade name, manufactured by DIC Corporation) was used as the resin.

[0061] Comparative Example 5 (Preparation of curable resin composition (A-12)) A curable resin composition (A-12) was obtained in the same manner as in Example 1, except that EPICLON HP-7200 (trade name, manufactured by DIC Corporation) was used as the resin.

[0062] [Evaluation] Using the curable resin compositions prepared in the examples and comparative examples, dry etching resistance, volatility (remaining film characteristics during heating), heat curability (solvent resistance of the heat-cured film), and substrate adhesion were evaluated.

[0063] (1) Dry etching resistance The obtained curable resin composition was applied onto a 5-inch diameter silicon wafer using a spin coater, and then 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 a resist underlayer film. The formed resist underlayer film was etched using an etching apparatus (Samco: RIE-200NL) under the conditions of CF4 (CF4: 89 sccm, pressure: 2.0 Pa, RF power: 100 W, treatment time: 180 seconds). The film thickness before and after the etching treatment was measured to calculate the etching rate and evaluate the dry etching resistance. The evaluation criteria are as follows. ○: When the etching rate is 75 nm / min or less ×: When the etching rate exceeds 75 nm / min The evaluation results are shown in Table 1 and Table 2.

[0064] (2) Volatility (film residue characteristics during heating) After the obtained curable resin composition was applied onto a 5-inch diameter silicon wafer using a spin coater, it was heated at 100 °C for 60 seconds on a hot plate in an atmosphere with an oxygen concentration of 20 vol% to prepare a silicon wafer with a resist underlayer film. Next, this was heated (hard baked) at 250 °C for 600 seconds in a hot plate, and the volatility was evaluated from the film thickness change before and after the hard bake. The evaluation criteria are as follows. ○: When the film residue ratio is 80% or more ×: When the film residue ratio is less than 80% The evaluation results are shown in Table 1 and Table 2.

[0065] (3) Heat curability (solvent resistance of the heat-cured film) The silicon wafer with the cured product after hard bake 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 at 100 °C for 60 seconds on a hot plate. The heat curability was evaluated from the film thickness change in this process. The evaluation criteria are as follows. ○: When the film residue ratio is 80% or more ×: When the film residue ratio is less than 80% The evaluation results are shown in Table 1 and Table 2.

[0066] (4) Substrate adhesion The obtained curable resin composition was applied onto a 10 cm square non-alkali glass substrate using a spin coater. Then, it was heated at 100 °C for 60 seconds on a hot plate in an atmosphere with an oxygen concentration of 20 vol% to prepare a glass substrate with a resist underlayer film. An aluminum stud and the resist underlayer film were joined using an adhesive. After standing at 23 °C for 24 hours, the stud was pulled at a speed of 1.6 MPa / second using a coating film adhesion tester manufactured by All Good Co., and the load at the time of peeling was measured. The evaluation results are shown in Table 1 and Table 2.

[0067]

Table 1

[0068]

Table 2

[0069] From Table 1 and Table 2, it can be confirmed 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 a polymer modified with a compound having at least one of an alicyclic structure and an aromatic ring structure and a cyclic ether group, and at least a part of the cyclic ether group 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). 【Chemical Formula 6】 (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, 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). 【Chemical 7】 (In the general formula (A), 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, 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 a structural unit represented by the general formula (A1) with a compound represented by the following general formula (B). 【Chemical 8】 (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, 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). 【Chemical Formula 9】 (In the general formula (M), R １ is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, L ２２ is a divalent linking group having a hydroxyl group, L ２１ is a single bond or a divalent linking group, X is an aromatic group or an alicyclic hydrocarbon group.)

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

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 a resist underlayer film.

9. A resist underlayer film which is a cured product of the composition for forming a resist underlayer film 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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