Composition for forming resist underlayer film

Abstract

This composition for forming a resist underlayer film contains: a polymer having a unit structure represented by formula (1); and a solvent. (In formula (1), A each independently represents a hydrogen atom, a methyl group, or an ethyl group, and Q1 and Q2 each independently represent a divalent group having an aromatic hydrocarbon ring. X1 and X2 each independently represent a single bond or -C(=O)-.)

Description

Composition for forming resist underlayer film

[0001] The present invention relates to a composition for forming a resist underlayer film, a resist underlayer film, a laminate, a method for producing a semiconductor element, and a method for forming a pattern.

[0002] Lithography processes using resist compositions have been used in the manufacture of semiconductor devices. With the increasing integration density of semiconductor devices, there is a demand for finer patterns, such as wiring patterns. To achieve this, short-wavelength light such as KrF excimer lasers (wavelength 248 nm) and ArF excimer lasers (wavelength 193 nm) is used. When using these short-wavelength light sources, the effects of diffuse reflection and standing waves from the substrate become significant problems. Therefore, a method of providing an antireflective coating (bottom antireflective coating) between the resist film and the substrate has been widely adopted.

[0003] In general, increasing the refractive index of an antireflective film is effective for preventing reflection. Therefore, in order to obtain a resist underlayer film with a high n value (refractive index), a resist underlayer film-forming composition for lithography has been proposed, which contains a polymer having a disulfide bond in its main chain and a solvent (see Patent Document 1).

[0004] International Publication No. 2009 / 096340

[0005] The technology described in Patent Document 1 provides a resist underlayer film having a high refractive index of about 1.9. However, as semiconductor devices become more diverse, lithography processes also become more diverse. However, the refractive index of a resist underlayer film does not necessarily have to be high; the refractive index required varies depending on the lithography process, and a resist underlayer film having a relatively low refractive index is sometimes required.

[0006] An object of the present invention is to provide a composition for forming a resist underlayer film that can provide a resist underlayer film having a relatively low refractive index, as well as methods for producing a resist underlayer film, a laminate, and a semiconductor element, and a pattern formation method that use the composition for forming a resist underlayer film.

[0007] The present inventors have conducted extensive research to solve the above problems, and as a result have found that the above problems can be solved, and have completed the present invention having the following gist.

[0008] That is, the present invention includes the following: [1] A composition for forming a resist underlayer film, comprising a polymer having a unit structure represented by the following formula (1), and a solvent. (In formula (1), each A independently represents a hydrogen atom, a methyl group, or an ethyl group; Q １ and Q ２ each independently represents a divalent group having an aromatic hydrocarbon ring. １ and X ２ each independently represents a single bond or —C(═O)—. [2] Q in the formula (1) １ is expressed by the following formula (2), and Q ２ is represented by any one of the following formulas (3-1) to (3-3): (In formula (2) and formulas (3-1) to (3-3), R ａ each independently represents an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or an alkenyl group having 2 to 10 carbon atoms. W represents a single bond, —CH ２ -, -C(CH ３ ) ２ -, -C(CF ３ ) ２ -, -CO-, -O-, -S- or SO ２represents -. Each m independently represents an integer of 0 to 2. Each n independently represents an integer of 0 to 4. * represents a bond. [3] The composition for forming a resist underlayer film according to [1] or [2], wherein the solvent comprises at least one selected from the group consisting of alkylene glycol monoalkyl ethers and monocarboxylic acid esters of alkylene glycol monoalkyl ethers. [4] The composition for forming a resist underlayer film according to any one of [1] to [3], further comprising a crosslinking agent. [5] The composition for forming a resist underlayer film according to any one of [1] to [4], further comprising a curing catalyst. [6] A resist underlayer film that is a cured product of the composition for forming a resist underlayer film according to any one of [1] to [5]. [7] A laminate comprising: a semiconductor substrate; and the resist underlayer film according to [6]. [8] A method for manufacturing a semiconductor device, comprising: forming a resist underlayer film on a semiconductor substrate using the composition for forming a resist underlayer film according to any one of [1] to [5], and forming a resist film on the resist underlayer film. [9] A method for forming a pattern, comprising: forming a resist underlayer film on a semiconductor substrate using the composition for forming a resist underlayer film according to any one of [1] to [5], forming a resist film on the resist underlayer film, irradiating the resist film with light and then developing the resist film to obtain a resist pattern, and etching the resist underlayer film using the resist pattern as a mask.

[0009] According to the present invention, it is possible to provide a composition for forming a resist underlayer film that can provide a resist underlayer film having a relatively low refractive index, as well as methods for producing a resist underlayer film, a laminate, and a semiconductor element, and a pattern formation method, all of which use the composition for forming a resist underlayer film.

[0010] (Composition for forming a resist underlayer film) The composition for forming a resist underlayer film of the present invention contains a polymer (hereinafter may be referred to as polymer (A)) and a solvent (hereinafter may be referred to as solvent (B)). The composition for forming a resist underlayer film may also contain a crosslinking agent (hereinafter may be referred to as crosslinking agent (C)), a curing catalyst (hereinafter may be referred to as curing catalyst (D)), and the like.

[0011] <Polymer (A)> The polymer (A) has a unit structure represented by the following formula (1). (In formula (1), each A independently represents a hydrogen atom, a methyl group, or an ethyl group; Q １ and Q ２ each independently represents a divalent group having an aromatic hydrocarbon ring. １ and X ２ each independently represents a single bond or —C(═O)—.

[0012] The polymer (A) contained in the composition for forming a resist underlayer film has a unit structure represented by formula (1), whereby Q １ and Q ２ The aromatic hydrocarbon ring in the formula (I) can lower the refractive index of the resist underlayer film obtained from the composition for forming a resist underlayer film.

[0013] Q １ and Q ２ The number of carbon atoms is not particularly limited, and may be, for example, 6 to 30 or 6 to 20.

[0014] From the viewpoint of suitably obtaining the effects of the present invention, Q in formula (1) １ From the viewpoint of suitably obtaining the effects of the present invention, Q in formula (1) is preferably represented by the following formula (2). ２ is preferably represented by any one of the following formulas (3-1) to (3-3). (In formula (2) and formulas (3-1) to (3-3), R ａ each independently represents an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or an alkenyl group having 2 to 10 carbon atoms. W represents a single bond, —CH ２ -, -C(CH３ ) ２ -, -C(CF ３ ) ２ -, -CO-, -O-, -S- or SO ２ Each m independently represents an integer of 0 to 2. Each n independently represents an integer of 0 to 4. * represents a bond.

[0015] Examples of the alkyl group having 1 to 10 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, a cyclopropyl group, an n-butyl group, an i-butyl group, an s-butyl group, a t-butyl group, a cyclobutyl group, a 1-methyl-cyclopropyl group, a 2-methyl-cyclopropyl group, an n-pentyl group, a 1-methyl-n-butyl group, a 2-methyl-n-butyl group, a 3-methyl-n-butyl group, a 1,1-dimethyl-n-propyl group, a 1,2-dimethyl-n-propyl group, a 2,2-dimethyl-n-propyl group, and a 1-ethyl-n-propyl group. cyclopentyl, 1-methylcyclobutyl, 2-methylcyclobutyl, 3-methylcyclobutyl, 1,2-dimethylcyclopropyl, 2,3-dimethylcyclopropyl, 1-ethylcyclopropyl, 2-ethylcyclopropyl, n-hexyl, 1-methyl-n-pentyl, 2-methyl-n-pentyl, 3-methyl-n-pentyl, 4-methyl-n-pentyl, 1,1-dimethyl-n-butyl, 1,2-dimethyl-n-butyl, 1,3-dimethyl-n-butyl, 2, 2-dimethyl-n-butyl group, 2,3-dimethyl-n-butyl group, 3,3-dimethyl-n-butyl group, 1-ethyl-n-butyl group, 2-ethyl-n-butyl group, 1,1,2-trimethyl-n-propyl group, 1,2,2-trimethyl-n-propyl group, 1-ethyl-1-methyl-n-propyl group, 1-ethyl-2-methyl-n-propyl group, cyclohexyl group, 1-methyl-cyclopentyl group, 2-methyl-cyclopentyl group, 3-methyl-cyclopentyl group, 1-ethyl-cyclobutyl group, 2-ethyl-cyclobutyl group, 3-ethyl-cyclobutyl group, 1,2-dimethyl-cyclobutyl group, 1,3-dimethyl-cyclobutyl group, 2,2-dimethyl-cyclobutyl group, 2,3-dimethyl-cyclobutyl group, 2,4-dimethyl-cyclobutyl group, 3,3-dimethyl-cyclobutyl group, 1-n-propyl-cyclopropyl group, 2-n-propyl-cyclopropyl group, 1-i-propyl-cyclopropyl group, 2-i-propyl-cyclopropyl group, 1,2,2-trimethyl-cyclopropyl group, 1,2,3-trimethyl-cyclopropyl group, 2,2,Examples include a 3-trimethyl-cyclopropyl group, a 1-ethyl-2-methyl-cyclopropyl group, a 2-ethyl-1-methyl-cyclopropyl group, a 2-ethyl-2-methyl-cyclopropyl group, and a 2-ethyl-3-methyl-cyclopropyl group.

[0016] Examples of the alkoxy group having 1 to 10 carbon atoms include a methoxy group, an ethoxy group, an n-propoxy group, an i-propoxy group, an n-butoxy group, an i-butoxy group, an s-butoxy group, a t-butoxy group, an n-pentyloxy group, a 1-methyl-n-butoxy group, a 2-methyl-n-butoxy group, a 3-methyl-n-butoxy group, a 1,1-dimethyl-n-propoxy group, a 1,2-dimethyl-n-propoxy group, a 2,2-dimethyl-n-propoxy group, a 1-ethyl-n-propoxy group, an n-hexyloxy group, a 1-methyl-n-pentyloxy group, a 2-methyl-n-pentyloxy group, a 3-methyl-n-pentyloxy group, a 4-methyl-n -pentyloxy group, 1,1-dimethyl-n-butoxy group, 1,2-dimethyl-n-butoxy group, 1,3-dimethyl-n-butoxy group, 2,2-dimethyl-n-butoxy group, 2,3-dimethyl-n-butoxy group, 3,3-dimethyl-n-butoxy group, 1-ethyl-n-butoxy group, 2-ethyl-n-butoxy group, 1,1,2-trimethyl-n-propoxy group, 1,2,2-trimethyl-n-propoxy group, 1-ethyl-1-methyl-n-propoxy group, 1-ethyl-2-methyl-n-propoxy group, cyclopentyloxy group, cyclohexyloxy group, norbornyoxy group, adamantyloxy group, and the like.

[0017] Examples of the alkenyl group having 2 to 10 carbon atoms include ethenyl, 1-propenyl, 2-propenyl, 1-methyl-1-ethenyl, 1-butenyl, 2-butenyl, 3-butenyl, 2-methyl-1-propenyl, 2-methyl-2-propenyl, 1-ethylethenyl, 1-methyl-1-propenyl, 1-methyl-2-propenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl, 1-n-propylethenyl, 1-methyl-1-butenyl, 1-methyl-2-butenyl, and 1-methyl-3-butenyl. nyl group, 2-ethyl-2-propenyl group, 2-methyl-1-butenyl group, 2-methyl-2-butenyl group, 2-methyl-3-butenyl group, 3-methyl-1-butenyl group, 3-methyl-2-butenyl group, 3-methyl-3-butenyl group, 1,1-dimethyl-2-propenyl group, 1-i-propylethenyl group, 1,2-dimethyl-1-propenyl group, 1,2-dimethyl-2-propenyl group, 1-cyclopentenyl group, 2-cyclopentenyl group, 3-cyclopentenyl group, 1-hexenyl group, 2-hexenyl group, 3-hexenyl group, 4-hexenyl group, 5-hexenyl group xenyl group, 1-methyl-1-pentenyl group, 1-methyl-2-pentenyl group, 1-methyl-3-pentenyl group, 1-methyl-4-pentenyl group, 1-n-butylethenyl group, 2-methyl-1-pentenyl group, 2-methyl-2-pentenyl group, 2-methyl-3-pentenyl group, 2-methyl-4-pentenyl group, 2-n-propyl-2-propenyl group, 3-methyl-1-pentenyl group, 3-methyl-2-pentenyl group, 3-methyl-3-pentenyl group, 3-methyl-4-pentenyl group, 3-ethyl-3-butenyl group, 4-methyl-1-pentenyl group, 4-methyl-2-pentenyl group, 4-methyl-3-pentenyl group, 4-methyl-4-pentenyl group, 1,1-dimethyl-2-butenyl group, 1,1-dimethyl-3-butenyl group, 1,2-dimethyl-1-butenyl group, 1,2-dimethyl-2-butenyl group, 1,2-dimethyl-3-butenyl group, 1-methyl-2-ethyl-2-propenyl group, 1-s-butylethenyl group, 1,3-dimethyl-1-butenyl group, 1,3-dimethyl-2-butenyl group, 1,3-dimethyl-3-butenyl group, 1-i-butylethenyl group, 2,2-dimethyl-3-butenyl group,3-dimethyl-1-butenyl group, 2,3-dimethyl-2-butenyl group, 2,3-dimethyl-3-butenyl group, 2-i-propyl-2-propenyl group, 3,3-dimethyl-1-butenyl group, 1-ethyl-1-butenyl group, 1-ethyl-2-butenyl group, 1-ethyl-3-butenyl group, 1-n-propyl-1-propenyl group, 1-n-propyl-2-propenyl group, 2-ethyl-1-butenyl group, 2-ethyl-2-butenyl group, 2-ethyl-3-butenyl group, 1,1,2-trimethyl-2-propenyl group, 1-t-butylethenyl group, 1-methyl-1-ethyl-2-propenyl group, 1-ethyl-2-methyl-1-propenyl group, 1-ethyl-2-methyl-2-propenyl group, 1-i-propyl-1-propenyl Examples of the cyclopentyl group include an aryl group, a 1-i-propyl-2-propenyl group, a 1-methyl-2-cyclopentenyl group, a 1-methyl-3-cyclopentenyl group, a 2-methyl-1-cyclopentenyl group, a 2-methyl-2-cyclopentenyl group, a 2-methyl-3-cyclopentenyl group, a 2-methyl-4-cyclopentenyl group, a 2-methyl-5-cyclopentenyl group, a 2-methylene-cyclopentyl group, a 3-methyl-1-cyclopentenyl group, a 3-methyl-2-cyclopentenyl group, a 3-methyl-3-cyclopentenyl group, a 3-methyl-4-cyclopentenyl group, a 3-methyl-5-cyclopentenyl group, a 3-methylene-cyclopentyl group, a 1-cyclohexenyl group, a 2-cyclohexenyl group, and a 3-cyclohexenyl group.

[0018] From the viewpoint of more suitably obtaining the effects of the present invention, m in formula (2) is preferably 0 or 1, and more preferably 0. From the viewpoint of more suitably obtaining the effects of the present invention, m in formula (3-1) is preferably 0 or 1.

[0019] From the viewpoint of more suitably obtaining the effects of the present invention, n in formula (2) and formulas (3-1) to (3-3) is preferably each independently an integer of 0 to 2, more preferably 0 or 1, and particularly preferably 0.

[0020] R ａ As the alkyl group, an alkyl group having 1 to 4 carbon atoms and an alkoxy group having 1 to 4 carbon atoms are preferred.

[0021] Examples of the structure represented by the following formula (1-a) in formula (1) include the structures exemplified below. (In formula (1-a), Q １ is Q in formula (1) １ * represents a bond.) * represents a bond.

[0022] Examples of the structure represented by the following formula (1-b) in formula (1) include the structures exemplified below. (In formula (1-b), Q ２ , X １ , and X ２ is Q in formula (1) ２ , X １ , and X ２ are synonymous with the above. * represents a bond.) * represents a bond.

[0023] The polymer may further have a monovalent group represented by the following formula (E): The monovalent group represented by formula (E) is located, for example, at the terminal of the polymer. (In formula (E), p represents 0 or 1. Z represents a monovalent group having 1 to 20 carbon atoms. * represents a bond.)

[0024] The number of carbon atoms in Z is preferably 6 to 20. Z has, for example, an aromatic hydrocarbon ring. Examples of the aromatic hydrocarbon ring include a benzene ring, a naphthalene ring, and an anthracene ring. For example, in formula (E), Z has an aromatic hydrocarbon ring, and a carbon atom constituting the aromatic hydrocarbon ring is bonded to the carbonyl carbon atom in formula (E).

[0025] Examples of Z in formula (E) include groups represented by the following formula (E-1). (In formula (E-1), q represents an integer of 0 to 2. r represents an integer of 0 to 4. R ｂ each independently represents a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms. * represents a bond.

[0026] Examples of the monovalent group represented by formula (E) include the following groups. * represents a bond.

[0027] A polymer having a unit structure represented by formula (1) can be synthesized, for example, by the following methods: (I): Reaction of a compound represented by the following formula (1A) with a compound represented by the following formula (1B): (II): Reaction of a compound represented by the following formula (1A), a compound represented by the following formula (1B), and a compound represented by the following formula (EA): (In formula (1A), Q １ is Q in formula (1) １ In formula (1B), A, Q ２ , X １ , and X ２ are A and Q in formula (1). ２ , X １ , and X ２ In formula (EA), p and Z have the same meanings as p and Z in formula (E), respectively.

[0028] The above reaction may be carried out in the presence of a catalyst, for example. Examples of the catalyst include quaternary phosphonium salts such as tetrabutylphosphonium bromide and ethyltriphenylphosphonium bromide, and quaternary ammonium salts such as benzyltriethylammonium chloride. The amount of catalyst used can be selected appropriately from the range of 0.1 to 10 mass% based on the total mass of the reaction raw materials used in the reaction. Optimal reaction temperature and time can be selected from the ranges of, for example, 50 to 160°C and 2 to 50 hours.

[0029] The mass proportion of the unit structure represented by formula (1) in the polymer (A) is not particularly limited, but is preferably 50 mass % or more, more preferably 60 mass % or more, and particularly preferably 80 mass % or more.

[0030] The weight average molecular weight of the polymer (A) is not particularly limited, but is preferably from 1,000 to 30,000, more preferably from 2,000 to 20,000, and particularly preferably from 2,500 to 15,000.

[0031] The content of the polymer (A) in the composition for forming a resist underlayer film is not particularly limited, but from the viewpoint of suitably obtaining the effects of the present invention, it is preferably 40% by mass to 100% by mass, more preferably 50% by mass to 98% by mass, and particularly preferably 65% ​​by mass to 95% by mass, based on the film-constituting components. In the present invention, the film-constituting components refer to components other than the solvent contained in the composition.

[0032] <Solvent (B)> The solvent (B) is not particularly limited and may be water or an organic solvent. Examples of the organic solvent include alkylene glycol monoalkyl ethers and monocarboxylic acid esters of alkylene glycol monoalkyl ethers.

[0033] Examples of the alkylene group of the alkylene glycol monoalkyl ether include alkylene groups having 2 to 4 carbon atoms. Examples of the alkyl group of the alkylene glycol monoalkyl ether include alkyl groups having 1 to 4 carbon atoms. Examples of the number of carbon atoms of the alkylene glycol monoalkyl ether include 3 to 8. Examples of the alkylene glycol monoalkyl ether include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, and propylene glycol monoethyl ether.

[0034] Examples of the alkylene group of the monocarboxylic acid ester of alkylene glycol monoalkyl ether include alkylene groups having 2 to 4 carbon atoms. Examples of the alkyl group of the monocarboxylic acid ester of alkylene glycol monoalkyl ether include alkyl groups having 1 to 4 carbon atoms. Examples of the monocarboxylic acid of the monocarboxylic acid ester of alkylene glycol monoalkyl ether include saturated monocarboxylic acids having 2 to 4 carbon atoms. Examples of saturated monocarboxylic acids having 2 to 4 carbon atoms include acetic acid, propionic acid, and butyric acid. Examples of the number of carbon atoms of the monocarboxylic acid ester of alkylene glycol monoalkyl ether include those having 5 to 10 carbon atoms. Examples of the monocarboxylic acid ester of alkylene glycol monoalkyl ether include methyl cellosolve acetate, ethyl cellosolve acetate, propylene glycol monomethyl ether acetate, and propylene glycol propyl ether acetate.

[0035] Other organic solvents include, for example, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol, toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, cycloheptanone, 4-methyl-2-pentanol, methyl 2-hydroxyisobutyrate, ethyl 2-hydroxyisobutyrate, ethyl ethoxyacetate, 2-hydroxyethyl acetate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl 3-ethoxypropionate, methyl pyruvate, ethyl pyruvate, ethyl acetate, butyl acetate, ethyl lactate, butyl lactate, 2-heptanone, methoxycyclopentane, anisole, γ-butyrolactone, N-methylpyrrolidone, N,N-dimethylformamide, and N,N-dimethylacetamide.

[0036] Among these solvents (B), alkylene glycol monoalkyl ethers and monocarboxylic acid esters of alkylene glycol monoalkyl ethers are preferred.

[0037] These solvents (B) may be used alone or in combination of two or more.

[0038] The mass proportion of the organic solvent in the solvent (B) is not particularly limited, but is preferably 50 mass % to 100 mass %.

[0039] The content of the solvent (B) in the composition for forming a resist underlayer film is not particularly limited, but is preferably 50% by mass to 99.99% by mass, more preferably 75% by mass to 99.95% by mass, and particularly preferably 90% by mass to 99.9% by mass.

[0040] <Crosslinking Agent (C)> The crosslinking agent (C) is not particularly limited. The crosslinking agent (C) has a structure different from that of the polymer (A).

[0041] The crosslinking agent (C) is preferably an aminoplast crosslinking agent or a phenoplast crosslinking agent. The aminoplast crosslinking agent is an addition condensation product of a compound having an amino group, such as melamine or guanamine, with formaldehyde. The phenoplast crosslinking agent is an addition condensation product of a compound having a phenolic hydroxy group with formaldehyde.

[0042] Examples of the crosslinking agent (C) include compounds having two or more of the following structures. (In the structure, R １０１ represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxyalkyl group having 2 to 6 carbon atoms. * represents a bond.) The bond is bonded to, for example, a nitrogen atom or a carbon atom constituting an aromatic hydrocarbon ring.

[0043] R １０１ is preferably a hydrogen atom, a methyl group, an ethyl group or a group represented by the following structure. (In the structure, R １０２ represents a methyl group or an ethyl group. * represents a bond.

[0044] The crosslinking agent (C) is preferably a melamine compound, a guanamine compound, a glycoluril compound, a urea compound, or a compound having a phenolic hydroxy group, which may be used alone or in combination of two or more.

[0045] Examples of the melamine compound include hexamethylol melamine, hexamethoxymethyl melamine, a compound in which 1 to 6 methylol groups of hexamethylol melamine have been methoxymethylated, or a mixture thereof, hexamethoxyethyl melamine, hexaacyloxymethyl melamine, a compound in which 1 to 6 methylol groups of hexamethylol melamine have been acyloxymethylated, or a mixture thereof.

[0046] Examples of the guanamine compound include tetramethylolguanamine, tetramethoxymethylguanamine, a compound in which one to four methylol groups of tetramethylolguanamine are methoxymethylated, or a mixture thereof; tetramethoxyethylguanamine, tetraacyloxyguanamine, a compound in which one to four methylol groups of tetramethylolguanamine are acyloxymethylated, or a mixture thereof; and the like.

[0047] Examples of glycoluril compounds include tetramethylol glycoluril, tetramethoxy glycoluril, tetramethoxymethyl glycoluril, compounds in which one to four methylol groups of tetramethylol glycoluril are methoxymethylated or mixtures thereof, and compounds in which one to four methylol groups of tetramethylol glycoluril are acyloxymethylated or mixtures thereof.

[0048] The glycoluril compound may be, for example, a glycoluril derivative represented by the following formula (1E). (In formula (1E), four R １ each independently represents a methyl group or an ethyl group, R ２ and R ３ each independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a phenyl group.

[0049] Examples of the glycoluril derivative represented by the formula (1E) include compounds represented by the following formulas (1E-1) to (1E-6).

[0050] The glycoluril derivative represented by formula (1E) can be obtained, for example, by reacting a glycoluril derivative represented by the following formula (2E) with at least one compound represented by the following formula (3d).

[0051] (In formula (2E), R ２ and R ３ each independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a phenyl group; R ４ each independently represents an alkyl group having 1 to 4 carbon atoms.

[0052] (In formula (3d), R １ represents a methyl group or an ethyl group.)

[0053] Examples of glycoluril derivatives represented by formula (2E) include compounds represented by formulas (2E-1) to (2E-4) below. Furthermore, examples of compounds represented by formula (3d) include compounds represented by formulas (3d-1) and (3d-2) below.

[0054] Examples of the urea compound include tetramethylol urea, tetramethoxymethyl urea, tetramethylol urea compounds in which one to four methylol groups are methoxymethylated, or mixtures thereof, and tetramethoxyethyl urea.

[0055] Examples of the compound having a phenolic hydroxy group include compounds represented by the following formula (G-1) or (G-2). (In formula (G-1) and formula (G-2), Q １ represents a single bond or a monovalent organic group. １ and R ４ R represents an alkyl group having 2 to 10 carbon atoms, or an alkyl group having 2 to 10 carbon atoms and an alkoxy group having 1 to 10 carbon atoms. ２ and R ５ R represents a hydrogen atom or a methyl group. ３ and R ６n represents an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 40 carbon atoms. １ is 1≦n １ an integer ≦3, n ２ is 2≦n ２ n is an integer ≦5 ３ is 0≦n ３ an integer ≦3, n ４ is 0≦n ４ an integer ≦3, 3≦(n １ +n ２ +n ３ +n ４ ) represents an integer ≦6. ５ is 1≦n ５ an integer ≦3, n ６ is 1≦n ６ n is an integer ≦4 ７ is 0≦n ７ an integer ≦3, n ８ is 0≦n ８ an integer ≦3, 2≦(n ５ +n ６ +n ７ +n ８ ) represents an integer of ≦5. m1 represents an integer of 2 to 10.

[0056] Examples of compounds having a phenolic hydroxy group include compounds represented by the following formula (G-3) or formula (G-4): The compound represented by formula (G-1) or formula (G-2) may be obtained by reacting a compound represented by the following formula (G-3) or formula (G-4) with a hydroxyl group-containing ether compound or an alcohol having 2 to 10 carbon atoms. (In formula (G-3) and formula (G-4), Q ２ represents a single bond or a divalent organic group. ８ , R ９ , R １１ and R １２ R represents a hydrogen atom or a methyl group. ７ and R １０ n represents an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 40 carbon atoms. ９ is 1≦n ９ an integer ≦3, n １０ is 2≦n １０ n is an integer ≦5１１ is 0≦n １１ an integer ≦3, n １２ is 0≦n １２ an integer ≦3, 3≦(n ９ +n １０ +n １１ +n １２ ) represents an integer ≦6. １３ is 1≦n １３ an integer ≦3, n １４ is 1≦n １４ n is an integer ≦4 １５ is 0≦n １５ an integer ≦3, n １６ is 0≦n １６ an integer ≦3, 2≦(n １３ +n １４ +n １５ +n １６ ) represents an integer of ≦5. m2 represents an integer of 2 to 10. ２ In the above, the m2-valent organic group includes, for example, an m2-valent organic group having 1 to 4 carbon atoms.

[0057] Examples of the compound represented by formula (G-1) or formula (G-2) include the following compounds:

[0058] Examples of the compound represented by formula (G-3) or formula (G-4) include the following compounds: The above compound is available as a product of Asahi Organic Chemicals Co., Ltd. and Honshu Chemical Industry Co., Ltd. An example of the product is TMOM-BP, a product name of Asahi Organic Chemicals Co., Ltd.

[0059] Among these, glycoluril compounds are preferred, specifically tetramethylol glycoluril, tetramethoxy glycoluril, tetramethoxymethyl glycoluril, tetramethylol glycoluril compounds in which one to four methylol groups have been methoxymethylated or mixtures thereof, and tetramethylol glycoluril compounds in which one to four methylol groups have been acyloxymethylated or mixtures thereof, with tetramethoxymethyl glycoluril being more preferred.

[0060] The molecular weight of the crosslinking agent (C) is not particularly limited, but is preferably 500 or less.

[0061] The content of the crosslinking agent (C) in the composition for forming a resist underlayer film is not particularly limited, but is, for example, 1% by mass to 70% by mass, and preferably 5% by mass to 60% by mass, relative to the polymer (A).

[0062] <Curing Catalyst (D)> The curing catalyst (D) contained as an optional component in the composition for forming a resist underlayer film may be either a thermal acid generator or a photoacid generator, but it is preferable to use a thermal acid generator. Examples of the thermal acid generator include sulfonic acid compounds and carboxylic acid compounds such as p-toluenesulfonic acid, trifluoromethanesulfonic acid, pyridinium-p-toluenesulfonate (pyridinium-p-toluenesulfonic acid), pyridinium phenolsulfonic acid, pyridinium-p-hydroxybenzenesulfonic acid (pyridinium p-phenolsulfonate salt), pyridinium-trifluoromethanesulfonic acid, salicylic acid, camphorsulfonic acid, 5-sulfosalicylic acid, 4-chlorobenzenesulfonic acid, 4-hydroxybenzenesulfonic acid, benzenedisulfonic acid, 1-naphthalenesulfonic acid, citric acid, benzoic acid, hydroxybenzoic acid, N-methylmorpholine-p-toluenesulfonic acid, N-methylmorpholine-p-hydroxybenzenesulfonic acid, and N-methylmorpholine-5-sulfosalicylic acid.

[0063] Examples of the photoacid generator include an onium salt compound, a sulfonimide compound, and a disulfonyldiazomethane compound.

[0064] Examples of the onium salt compound include iodonium salt compounds such as diphenyliodonium hexafluorophosphate, diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoro-normal butanesulfonate, diphenyliodonium perfluoro-normal octanesulfonate, diphenyliodonium camphorsulfonate, bis(4-tert-butylphenyl)iodonium camphorsulfonate, and bis(4-tert-butylphenyl)iodonium trifluoromethanesulfonate; and sulfonium salt compounds such as triphenylsulfonium hexafluoroantimonate, triphenylsulfonium nonafluoro-normal butanesulfonate, triphenylsulfonium camphorsulfonate, and triphenylsulfonium trifluoromethanesulfonate.

[0065] Examples of the sulfonimide compound include N-(trifluoromethanesulfonyloxy)succinimide, N-(nonafluoronormalbutanesulfonyloxy)succinimide, N-(camphorsulfonyloxy)succinimide, and N-(trifluoromethanesulfonyloxy)naphthalimide.

[0066] Examples of the disulfonyldiazomethane compound include bis(trifluoromethylsulfonyl)diazomethane, bis(cyclohexylsulfonyl)diazomethane, bis(phenylsulfonyl)diazomethane, bis(p-toluenesulfonyl)diazomethane, bis(2,4-dimethylbenzenesulfonyl)diazomethane, and methylsulfonyl-p-toluenesulfonyldiazomethane.

[0067] The curing catalyst (D) may be used alone or in combination of two or more.

[0068] When the curing catalyst (D) is used, the content of the curing catalyst (D) relative to the crosslinking agent (C) is, for example, 0.1% by mass to 50% by mass, and preferably 1% by mass to 30% by mass.

[0069] <Other Components> A surfactant may be further added to the composition for forming a resist underlayer film in order to prevent pinholes, striations, etc., and to further improve the coatability for preventing surface irregularities.

[0070] Examples of surfactants include linear or branched alkylbenzenesulfonic acids (e.g., dodecylbenzenesulfonic acid, etc.), polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, and polyoxyethylene oleyl ether, polyoxyethylene alkylaryl ethers such as polyoxyethylene octylphenol ether and polyoxyethylene nonylphenol ether, polyoxyethylene-polyoxypropylene block copolymers, sorbitan fatty acid esters such as sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, sorbitan trioleate, and sorbitan tristearate, and polyoxyethylene sorbitan monolaurate. nonionic surfactants such as polyoxyethylene sorbitan fatty acid esters, such as polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, and polyoxyethylene sorbitan tristearate; fluorine-based surfactants such as Eftop EF301, EF303, and EF352 (trade names, manufactured by Tochem Products Co., Ltd.), Megafac F171, F173, and R-30 (trade names, manufactured by DIC Corporation), Fluorad FC430 and FC431 (trade names, manufactured by Sumitomo 3M Limited), Asahiguard AG710, Surflon S-382, SC101, SC102, SC103, SC104, SC105, and SC106 (trade names, manufactured by AGC Inc.); and organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.). The amount of these surfactants to be added is usually 2.0 mass % or less, and preferably 1.0 mass % or less, based on the total solid content of the composition for forming a resist underlayer film. These surfactants may be added alone or in combination of two or more.

[0071] The solid content of the composition for forming a resist underlayer film of the present invention, that is, the content of components excluding the solvent, is, for example, 0.01% by mass to 10% by mass.

[0072] (Resist Underlayer Film) The resist underlayer film of the present invention is a cured product of the composition for forming a resist underlayer film described above. The resist underlayer film can be produced, for example, by applying the composition for forming a resist underlayer film described above onto a semiconductor substrate and baking the applied composition.

[0073] Examples of semiconductor substrates onto which the resist underlayer film-forming composition can be applied include silicon wafers, germanium wafers, and wafers of compound semiconductors such as gallium arsenide, indium phosphide, gallium nitride, indium nitride, and aluminum nitride.

[0074] When a semiconductor substrate having an inorganic film formed on its surface is used, the inorganic film can be formed by, for example, ALD (atomic layer deposition), CVD (chemical vapor deposition), reactive sputtering, ion plating, vacuum deposition, or spin coating (spin-on glass: SOG). Examples of the inorganic film include a polysilicon film, a silicon oxide film, a silicon nitride film, a BPSG (Boro-Phospho Silicate Glass) film, a titanium nitride film, a titanium nitride oxide film, a tungsten film, a gallium nitride film, and a gallium arsenide film.

[0075] The resist underlayer film-forming composition of the present invention is applied to such a semiconductor substrate by a suitable application method such as a spinner or coater. The composition is then baked using a heating means such as a hot plate to form a resist underlayer film. The baking conditions are appropriately selected from a baking temperature of 100°C to 400°C and a baking time of 0.3 to 60 minutes. A baking temperature of 120°C to 350°C and a baking time of 0.5 to 30 minutes are preferred, and a baking temperature of 150°C to 300°C and a baking time of 0.8 to 10 minutes are more preferred.

[0076] The refractive index (n value) of the resist underlayer film at a wavelength of 193 nm is not particularly limited, but may be, for example, 1.30 to 1.50, or 1.30 to 1.45. The extinction coefficient (k value) of the resist underlayer film at a wavelength of 193 nm is not particularly limited, but may be, for example, 0.23 to 0.50, or 0.25 to 0.45. These optical constants can be measured, for example, by the following method. That is, the n value (refractive index) and k value (extinction coefficient or absorption coefficient) of the coating at a wavelength of 193 nm are measured using a spectroscopic ellipsometer (VUV-VASE VU-302, manufactured by J.A. Woollam Co.). The coating can be formed, for example, by applying the composition to be tested to a silicon wafer using a spinner at a rotation speed of 1500 rpm, and baking on a hot plate at 205°C for 1 minute.

[0077] The thickness of the resist underlayer film may be, for example, 0.001 μm (1 nm) to 10 μm, 0.002 μm (2 nm) to 1 μm, 0.005 μm (5 nm) to 0.5 μm (500 nm), 0.001 μm (1 nm) to 0.05 μm (50 nm), 0.002 μm (2 nm) to 0.05 μm (50 nm), 0.003 μm (3 nm) to 0.05 μm (50 nm), 0.004 μm (4 nm) to 0.05 μm (50 nm), 0.005 μm ( 0.003 μm (3 nm) to 0.02 μm (20 nm), 0.005 μm (5 nm) to 0.02 μm (20 nm), 0.003 μm (3 nm) to 0.01 μm (10 nm), 0.005 μm (5 nm) to 0.01 μm (10 nm), 0.003 μm (3 nm) to 0.006 μm (6 nm), or 0.005 μm (5 nm).

[0078] (Laminate) The laminate of the present invention includes a semiconductor substrate and the resist underlayer film of the present invention. Examples of the semiconductor substrate include the semiconductor substrates described above. The resist underlayer film is disposed on the semiconductor substrate, for example.

[0079] (Method for manufacturing a semiconductor element, method for forming a pattern) The method for manufacturing a semiconductor element of the present invention includes at least the following steps: forming a resist underlayer film on a semiconductor substrate using the composition for forming a resist underlayer film of the present invention, and forming a resist film on the resist underlayer film.

[0080] The pattern forming method of the present invention includes at least the following steps: forming a resist underlayer film on a semiconductor substrate using the composition for forming a resist underlayer film of the present invention, forming a resist film on the resist underlayer film, irradiating the resist film with light and then developing the resist film to obtain a resist pattern, and etching the resist underlayer film using the resist pattern as a mask.

[0081] Typically, a resist film is formed on the resist underlayer film. The thickness of the resist film is, for example, 3,000 nm or less, 2,000 nm or less, 1,800 nm or less, 1,500 nm or less, or 1,000 nm or less. The lower limit is 100 nm, 80 nm, 50 nm, 30 nm, 20 nm, or 10 nm.

[0082] The resist film formed on the resist underlayer film by a known method (e.g., coating and baking a resist composition) is not particularly limited as long as it is responsive to the light used for irradiation. Both negative and positive photoresists can be used. Examples of photoresists include positive photoresists composed of a novolak resin and a 1,2-naphthoquinone diazide sulfonic acid ester, chemically amplified photoresists composed of a binder having a group that decomposes in the presence of an acid to increase the alkaline dissolution rate and a photoacid generator, chemically amplified photoresists composed of a low molecular weight compound that decomposes in the presence of an acid to increase the alkaline dissolution rate of the photoresist, an alkali-soluble binder, and a photoacid generator, chemically amplified photoresists composed of a binder having a group that decomposes in the presence of an acid to increase the alkaline dissolution rate of the photoresist, a low molecular weight compound that decomposes in the presence of an acid to increase the alkaline dissolution rate of the photoresist, and a photoacid generator, and resists containing metal elements. Examples of such photoresists include V146G (trade name) manufactured by JSR Corporation, APEX-E (trade name) manufactured by Shipley Co., Ltd., PAR710 (trade name) manufactured by Sumitomo Chemical Co., Ltd., and AR2772 and SEPR430 (trade names) manufactured by Shin-Etsu Chemical Co., Ltd. Further examples include fluorine-containing polymer photoresists such as those described in Proc. SPIE, Vol. 3999, 330-334 (2000), Proc. SPIE, Vol. 3999, 357-364 (2000), and Proc. SPIE, Vol. 3999, 365-374 (2000).

[0083] Also, WO2019 / 188595, WO2019 / 187881, WO2019 / 187803, WO2019 / 167737, WO2019 / 167725, WO2019 / 187445, WO2019 / 167419, WO2019 / 123842, WO2019 / 054282, WO2019 / 058945, WO2019 / 058890, WO2019 / 039290, WO2019 / 044259, WO2019 / 044231, WO2019 / 026549, WO2018 / 193954, WO201 9 / 172054, WO2019 / 021975, WO2018 / 230334, WO2018 / 194123, JP 2018-180525, WO2018 / 190088, JP 2018-070596, JP 2018-028090, JP 2016-153409, JP 2016-130240, JP 2016-108325, JP 2016-047920, JP 2016-035570, JP 2016-035567, JP 2016-035565, JP 2019-101417, JP 2019-117373, JP 2019-052294, JP 2019-008280, JP 2019-008279, JP 2019-003176, JP 2019-003175, JP 2018-197853, JP 2019-191298, JP 2019-061217, JP 2018-045152, JP 2018-022039, JP 2016-090441, JP 2015-10878, JP 2012-168279, JP 2012-022261, JP 2012-022258, JP 2011-043749, JP 2010-18 1857, JP 2010-128369, WO2018 / 031896, JP 2019-113855, WO2017 / 156388, WO2017 / 066319, JP 2018-41099, WO2016 / 065120, WO2015 / 026482, JP 2016-29498, JP 2011-253185, etc., radiation-sensitive resin compositions, so-called resist compositions such as high-resolution patterning compositions based on organometallic solutions, and metal-containing resist compositions can be used, but are not limited to these.

[0084] Examples of the resist composition include the following compositions.

[0085] An actinic ray-sensitive or radiation-sensitive resin composition comprising: Resin A having a repeating unit having an acid-decomposable group in which a polar group is protected with a protecting group that is cleaved by the action of an acid; and a compound represented by the following general formula (121):

[0086] In the general formula (121), m represents an integer of 1 to 6. １ and R ２ each independently represents a fluorine atom or a perfluoroalkyl group. １ is -O-, -S-, -COO-, -SO ２ - or -SO ３ - represents. ２ represents an alkylene group which may have a substituent or a single bond. １ represents a cyclic organic group which may have a substituent. ＋ represents a cation.

[0087] A radiation-sensitive resin composition comprising: a polymer having a first structural unit represented by the following formula (31) and a second structural unit represented by the following formula (32) containing an acid-dissociable group; and an acid generator.

[0088] In formula (31), Ar is a group obtained by removing (n+1) hydrogen atoms from an arene having 6 to 20 carbon atoms. １ is a hydroxy group, a sulfanyl group, or a monovalent organic group having 1 to 20 carbon atoms. n is an integer of 0 to 11. When n is 2 or more, multiple R １ are the same or different. ２ is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. ３ is a monovalent group having 1 to 20 carbon atoms containing the above acid-dissociable group. Z is a single bond, an oxygen atom, or a sulfur atom. R ４ is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0089] A resist composition comprising: a resin (A1) containing a structural unit having a cyclic carbonate structure, a structural unit represented by the following formula, and a structural unit having an acid labile group; and an acid generator.

[0090] [In the formula, R ２ represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom; X １ represents a single bond, —CO—O—*, or —CO—NR ４ -*, * represents a bond to -Ar, R ４ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and Ar represents an aromatic hydrocarbon group having 6 to 20 carbon atoms which may have one or more groups selected from the group consisting of a hydroxy group and a carboxyl group.]

[0091] Examples of the resist film include the following.

[0092] A resist film comprising a base resin comprising a repeating unit represented by the following formula (a1) and / or a repeating unit represented by the following formula (a2), and a repeating unit that generates an acid bonded to a polymer main chain upon exposure:

[0093] (In formula (a1) and formula (a2), R Ａ are each independently a hydrogen atom or a methyl group. １ and R ２ are each independently a tertiary alkyl group having 4 to 6 carbon atoms. ３ are each independently a fluorine atom or a methyl group, and m is an integer of 0 to 4. １ X is a single bond, a phenylene group, or a naphthylene group, or a linking group having 1 to 12 carbon atoms and containing at least one selected from an ester bond, a lactone ring, a phenylene group, and a naphthylene group. ２ is a single bond, an ester bond, or an amide bond.

[0094] Examples of resist materials include the following:

[0095] A resist material comprising a polymer having a repeating unit represented by the following formula (b1) or (b2):

[0096] (In formula (b1) and formula (b2), R Ａ is a hydrogen atom or a methyl group. １is a single bond or an ester group. ２ is a linear, branched or cyclic alkylene group having 1 to 12 carbon atoms or an arylene group having 6 to 10 carbon atoms, and some of the methylene groups constituting the alkylene group may be substituted with an ether group, an ester group or a lactone ring-containing group; and X ２ At least one hydrogen atom contained in X is substituted with a bromine atom. ３ Rf is a single bond, an ether group, an ester group, or a linear, branched, or cyclic alkylene group having 1 to 12 carbon atoms, and some of the methylene groups constituting the alkylene group may be substituted with an ether group or an ester group. １ ~Rf ４ are each independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group, but at least one is a fluorine atom or a trifluoromethyl group. １ and Rf ２ may combine to form a carbonyl group. １ ~R ５ are each independently a linear, branched, or cyclic alkyl group having 1 to 12 carbon atoms, a linear, branched, or cyclic alkenyl group having 2 to 12 carbon atoms, an alkynyl group having 2 to 12 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, or an aryloxyalkyl group having 7 to 12 carbon atoms, in which some or all of the hydrogen atoms may be substituted with a hydroxy group, a carboxy group, a halogen atom, an oxo group, a cyano group, an amide group, a nitro group, a sultone group, a sulfone group, or a sulfonium salt-containing group, and in which some of the methylene groups constituting these groups may be substituted with an ether group, an ester group, a carbonyl group, a carbonate group, or a sulfonate ester group. １ and R ２ may be bonded to form a ring together with the sulfur atom to which they are attached.

[0097] A resist material comprising a base resin containing a polymer containing a repeating unit represented by the following formula (a):

[0098] (In formula (a), R Ａis a hydrogen atom or a methyl group. １ is a hydrogen atom or an acid labile group. ２ is a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms, or a halogen atom other than bromine. １ X is a single bond, a phenylene group, or a linear, branched or cyclic alkylene group having 1 to 12 carbon atoms which may contain an ester group or a lactone ring. ２ is -O-, -O-CH ２ - or -NH-. m is an integer of 1 to 4. u is an integer of 0 to 3. However, m+u is an integer of 1 to 4.

[0099] A resist composition that generates an acid upon exposure, and whose solubility in a developer changes due to the action of the acid, comprising: a base component (A) whose solubility in a developer changes due to the action of the acid; and a fluorine additive component (F) that exhibits decomposition in an alkaline developer, wherein the fluorine additive component (F) comprises a fluororesin component (F1) that has a structural unit (f1) that includes a base dissociable group, and a structural unit (f2) that includes a group represented by the following general formula (f2-r-1):

[0100] [In formula (f2-r-1), Rf ２１ are each independently a hydrogen atom, an alkyl group, an alkoxy group, a hydroxy group, a hydroxyalkyl group, or a cyano group. n" is an integer of 0 to 2. * is a bond.

[0101] The structural unit (f1) includes a structural unit represented by the following general formula (f1-1) or a structural unit represented by the following general formula (f1-2).

[0102] [In formulas (f1-1) and (f1-2), each R is independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. X is a divalent linking group that does not have an acid-dissociable site. A ａｒｙｌ represents a divalent aromatic cyclic group which may have a substituent. ０１ is a single bond or a divalent linking group. ２are each independently an organic group having a fluorine atom.

[0103] The light irradiation is carried out, for example, through a mask (reticle) for forming a predetermined pattern. For example, i-line (365 nm), KrF excimer laser (248 nm), or ArF excimer laser (193 nm) is used. The composition for forming a resist underlayer film of the present invention is preferably applied for irradiation with a KrF excimer laser (248 nm) or an ArF excimer laser (193 nm), and more preferably for irradiation with an ArF excimer laser (193 nm). The light exposure amount is not particularly limited.

[0104] After the light irradiation and before the development, baking (PEB: Post Exposure Bake) may be performed. The baking temperature is not particularly limited, but is preferably 60°C to 150°C, more preferably 70°C to 120°C, and particularly preferably 75°C to 110°C. The baking time is not particularly limited, but is preferably 1 second to 10 minutes, more preferably 10 seconds to 5 minutes, and particularly preferably 30 seconds to 3 minutes.

[0105] For example, an alkaline developer is used for development. The development temperature can be, for example, 5°C to 50°C. The development time can be, for example, 10 seconds to 300 seconds. Examples of alkaline developers that can be used include aqueous solutions of alkalis such as inorganic alkalis (e.g., sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia); primary amines (e.g., ethylamine and n-propylamine); secondary amines (e.g., diethylamine and di-n-butylamine); tertiary amines (e.g., triethylamine and methyldiethylamine); alcohol amines (e.g., dimethylethanolamine and triethanolamine); quaternary ammonium salts (e.g., tetramethylammonium hydroxide, tetraethylammonium hydroxide, and choline); and cyclic amines (e.g., pyrrole and piperidine). Furthermore, the aqueous solutions of the alkalis can be used by adding an appropriate amount of alcohols (e.g., isopropyl alcohol) or a nonionic surfactant. Among these, preferred developers are aqueous solutions of quaternary ammonium salts, more preferably aqueous solutions of tetramethylammonium hydroxide and choline. Furthermore, surfactants and the like can also be added to these developers. Alternatively, development may be carried out with an organic solvent such as butyl acetate instead of an alkaline developer, and the portions of the photoresist where the alkaline dissolution rate is not improved may be developed.

[0106] Next, the resist underlayer film is etched using the formed resist pattern as a mask. The etching may be dry etching or wet etching, but dry etching is preferred. If the inorganic film is formed on the surface of the semiconductor substrate used, the surface of the inorganic film is exposed. If the inorganic film is not formed on the surface of the semiconductor substrate used, the surface of the semiconductor substrate is exposed. Thereafter, the semiconductor substrate is processed by a known method (e.g., dry etching), thereby manufacturing a semiconductor device.

[0107] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples. The apparatus used is as follows.

[0108] The weight-average molecular weights of the polymers shown in the following examples were measured by gel permeation chromatography (hereinafter abbreviated as GPC). A GPC device manufactured by Tosoh Corporation was used for the measurement, and the measurement conditions were as follows: Column temperature: 40°C, Flow rate: 0.35 ml / min, Eluent: tetrahydrofuran (THF), Standard sample: polystyrene (Tosoh Corporation).

[0109] Synthesis Example 1 A reaction flask containing 20.00 g of a propylene glycol monomethyl ether solution of 1,6-bis(2,3-epoxypropan-1-yloxy)naphthalene (manufactured by DIC Corporation, trade name: WR-400), 1.27 g of isophthalic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.09 g of tetrabutylsulfonium bromide (manufactured by Hokko Chemical Industry Co., Ltd.), and 1.05 g of propylene glycol monomethyl ether was heated and stirred at 105° C. for 24 hours under a nitrogen atmosphere. The resulting reaction product corresponded to formula (X1), and had a weight average molecular weight Mw of 7,300 as measured by GPC in terms of polystyrene.

[0110] Formula (X1)

[0111] Synthesis Example 2 2.00 g of resorcinol diglycidyl ether (product name: Denacol EX-201-IM, manufactured by Nagase ChemteX Corporation), 1.44 g of isophthalic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.11 g of tetrabutylsulfonium bromide (manufactured by Hokko Chemical Industry Co., Ltd.), and 20.12 g of propylene glycol monomethyl ether were placed in a reaction flask, and the mixture was heated and stirred at 105° C. for 24 hours under a nitrogen atmosphere. The resulting reaction product corresponded to formula (X2), and had a weight average molecular weight Mw of 9,100 as measured by GPC in terms of polystyrene.

[0112] Formula (X2)

[0113] Synthesis Example 3 A reaction flask containing 15.00 g of a propylene glycol monomethyl ether solution of 1,6-bis(2,3-epoxypropan-1-yloxy)naphthalene (manufactured by DIC Corporation, trade name: WR-400), 5.65 g of resorcinol diglycidyl ether (product name: Denacol EX-201-IM, manufactured by Nagase ChemteX Corporation), 1.31 g of isophthalic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.10 g of tetrabutylsulfonium bromide (manufactured by Hokko Chemical Industry Co., Ltd.), and 1.39 g of propylene glycol monomethyl ether was heated and stirred at 105° C. for 24 hours under a nitrogen atmosphere. The resulting reaction product corresponded to formula (X3), and had a weight average molecular weight Mw of 6,600 as measured by GPC in terms of polystyrene.

[0114] Formula (X3)

[0115] Synthesis Example 4 3.00 g of 1,4-dihydroanthracene-9,10-diylbis(glycidyl ether) (product name: YX8800, manufactured by Mitsubishi Chemical Corporation), 3.61 g of isophthalic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.39 g of tetrabutylsulfonium bromide (manufactured by Hokko Chemical Industry Co., Ltd.), and 38.17 g of propylene glycol monomethyl ether were placed in a reaction flask, and the mixture was heated and stirred at 105° C. for 24 hours under a nitrogen atmosphere. The resulting reaction product corresponded to formula (X4), and had a weight average molecular weight Mw of 6,500 as measured by GPC in terms of polystyrene.

[0116] Formula (X4)

[0117] Synthesis Example 5 A reaction flask containing 40.00 g of a propylene glycol monomethyl ether solution of 1,6-bis(2,3-epoxypropan-1-yloxy)naphthalene (manufactured by DIC Corporation, trade name: WR-400), 2.18 g of isophthalic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.32 g of 9-anthracenecarboxylic acid, 0.18 g of tetrabutylsulfonium bromide (manufactured by Hokko Chemical Industry Co., Ltd.), and 2.06 g of propylene glycol monomethyl ether was heated and stirred at 105° C. for 24 hours under a nitrogen atmosphere. The resulting reaction product corresponded to formula (X5), and had a weight average molecular weight Mw of 7,300 as measured by GPC relative to polystyrene standards.

[0118] Formula (X5)

[0119] Comparative Synthesis Example 1 A reaction flask containing 10.00 g of monoallyl diglycidyl isocyanuric acid (product name: MA-DGICA, manufactured by Shikoku Chemicals Corporation), 8.96 g of 3,3'-dithiopropionic acid, 0.66 g of ethyltriphenylphosphonium bromide, and 78.47 g of propylene glycol monomethyl ether was heated and stirred at 100°C for 23 hours under a nitrogen atmosphere. The resulting reaction product corresponded to formula (X6), and had a weight average molecular weight Mw of 2800 as measured by GPC in terms of polystyrene.

[0120] Formula (X6)

[0121] Example 1 11.53 g of a solution (solid content concentration 15.12% by mass) containing the polymer obtained in Synthesis Example 1 was mixed with 0.17 g of tetramethoxymethyl glycoluril (manufactured by Nippon Cytec Industries Co., Ltd., product name: POWDERLINK (registered trademark) 1174) as a crosslinking agent, 0.06 g of pyridinium-p-toluenesulfonic acid as a crosslinking catalyst, and 0.002 g of a fluorine-based surfactant (product name: Megafac R-40, manufactured by DIC Corporation) as a surfactant. The resulting mixture was dissolved in 78.42 g of propylene glycol monomethyl ether and 9.80 g of propylene glycol monomethyl ether acetate to prepare a solution. The mixture was then filtered using a polyethylene microfilter with a pore size of 0.05 μm to prepare a composition for forming a resist underlayer film.

[0122] Example 2 10.60 g of a solution (solid content concentration 15.12% by mass) containing the polymer obtained in Synthesis Example 1 was mixed with 0.16 g of tetramethoxymethyl glycoluril (manufactured by Nippon Cytec Industries Co., Ltd., product name: POWDERLINK (registered trademark) 1174) as a crosslinking agent, 0.06 g of pyridinium-p-toluenesulfonic acid as a crosslinking catalyst, 0.17 g of VP-2500 (manufactured by Nippon Soda Co., Ltd.) as an additive, and 0.002 g of a fluorine-based surfactant (product name: Megafac R-40, manufactured by DIC Corporation) as a surfactant. The resulting mixture was dissolved in 79.20 g of propylene glycol monomethyl ether and 9.80 g of propylene glycol monomethyl ether acetate to prepare a solution. The mixture was then filtered using a polyethylene microfilter with a pore size of 0.05 μm to prepare a composition for forming a resist underlayer film.

[0123] Example 3 11.53 g of a solution (solids concentration 15.12 mass%) containing the polymer obtained in Synthesis Example 1 was mixed with 0.17 g of Nikalac (registered trademark) MW-390 (manufactured by Sanwa Chemical Co., Ltd.) as a crosslinking agent, 0.06 g of pyridinium-p-toluenesulfonic acid as a crosslinking catalyst, and 0.002 g of a fluorine-based surfactant (product name: Megafac R-40, manufactured by DIC Corporation) as a surfactant. The resulting mixture was dissolved in 78.42 g of propylene glycol monomethyl ether and 9.80 g of propylene glycol monomethyl ether acetate to prepare a solution. The mixture was then filtered using a polyethylene microfilter with a pore size of 0.05 μm to prepare a composition for forming a resist underlayer film.

[0124] Example 4 10.60 g of a solution (solid content concentration 15.12 mass%) containing the polymer obtained in Synthesis Example 1 was mixed with 0.16 g of Nikalac (registered trademark) MW-390 (manufactured by Sanwa Chemical Co., Ltd.) as a crosslinking agent, 0.06 g of pyridinium-p-toluenesulfonic acid as a crosslinking catalyst, 0.17 g of VP-2500 (manufactured by Nippon Soda Co., Ltd.) as an additive, and 0.002 g of a fluorine-based surfactant (product name: Megafac R-40, manufactured by DIC Corporation) as a surfactant. The resulting mixture was dissolved in 79.20 g of propylene glycol monomethyl ether and 9.80 g of propylene glycol monomethyl ether acetate to prepare a solution. The mixture was then filtered using a polyethylene microfilter with a pore size of 0.05 μm to prepare a composition for forming a resist underlayer film.

[0125] Example 5 11.53 g of a solution (solid content concentration 15.12 mass%) containing the polymer obtained in Synthesis Example 1 was mixed with 0.17 g of 3,3',5,5'-tetrakis(methoxymethyl)-4,4'-dihydroxybiphenyl (product name: TMOM-BP, manufactured by Honshu Chemical Industry Co., Ltd.) as a crosslinking agent, 0.06 g of pyridinium-p-toluenesulfonic acid as a crosslinking catalyst, and 0.002 g of a fluorine-based surfactant (product name: Megafac R-40, manufactured by DIC Corporation) as a surfactant. The resulting mixture was dissolved in 78.42 g of propylene glycol monomethyl ether and 9.80 g of propylene glycol monomethyl ether acetate to prepare a solution. The mixture was then filtered using a polyethylene microfilter with a pore size of 0.05 μm to prepare a composition for forming a resist underlayer film.

[0126] Example 6 12.18 g of a solution (solid content concentration 14.31% by mass) containing the polymer obtained in Synthesis Example 2 was mixed with 0.17 g of tetramethoxymethyl glycoluril (manufactured by Nippon Cytec Industries Co., Ltd., product name: POWDERLINK (registered trademark) 1174) as a crosslinking agent, 0.06 g of pyridinium-p-toluenesulfonic acid as a crosslinking catalyst, and 0.002 g of a fluorine-based surfactant (product name: Megafac R-40, manufactured by DIC Corporation) as a surfactant. The resulting mixture was dissolved in 78.75 g of propylene glycol monomethyl ether and 9.80 g of propylene glycol monomethyl ether acetate to prepare a solution. The mixture was then filtered using a polyethylene microfilter with a pore size of 0.05 μm to prepare a composition for forming a resist underlayer film.

[0127] Example 7 11.91 g of a solution (solid content concentration 15.57% by mass) containing the polymer obtained in Synthesis Example 3 was mixed with 0.17 g of tetramethoxymethyl glycoluril (manufactured by Nippon Cytec Industries Co., Ltd., product name: POWDERLINK (registered trademark) 1174) as a crosslinking agent, 0.06 g of pyridinium-p-toluenesulfonic acid as a crosslinking catalyst, and 0.002 g of a fluorine-based surfactant (product name: Megafac R-40, manufactured by DIC Corporation) as a surfactant. The resulting mixture was dissolved in 78.42 g of propylene glycol monomethyl ether and 9.80 g of propylene glycol monomethyl ether acetate to prepare a solution. The mixture was then filtered using a polyethylene microfilter with a pore size of 0.05 μm to prepare a composition for forming a resist underlayer film.

[0128] Example 8 11.91 g of a solution (solid content concentration 15.57% by mass) containing the polymer obtained in Synthesis Example 3 was mixed with 0.17 g of Nikalac (registered trademark) MW-390 (manufactured by Sanwa Chemical Co., Ltd.) as a crosslinking agent, 0.06 g of pyridinium-p-toluenesulfonic acid as a crosslinking catalyst, and 0.002 g of a fluorine-based surfactant (product name: Megafac R-40, manufactured by DIC Corporation) as a surfactant. The resulting mixture was dissolved in 78.42 g of propylene glycol monomethyl ether and 9.80 g of propylene glycol monomethyl ether acetate to prepare a solution. The mixture was then filtered using a polyethylene microfilter with a pore size of 0.05 μm to prepare a composition for forming a resist underlayer film.

[0129] Example 9 11.60 g of a solution (solids concentration 15.02% by mass) containing the polymer obtained in Synthesis Example 4 was mixed with 0.17 g of 3,3',5,5'-tetrakis(methoxymethyl)-4,4'-dihydroxybiphenyl (product name: TMOM-BP, manufactured by Honshu Chemical Industry Co., Ltd.) as a crosslinking agent, 0.06 g of pyridinium-p-toluenesulfonic acid as a crosslinking catalyst, and 0.002 g of a fluorine-based surfactant (product name: Megafac R-40, manufactured by DIC Corporation) as a surfactant. The resulting mixture was dissolved in 78.34 g of propylene glycol monomethyl ether and 9.80 g of propylene glycol monomethyl ether acetate to prepare a solution. The mixture was then filtered using a polyethylene microfilter with a pore size of 0.05 μm to prepare a composition for forming a resist underlayer film.

[0130] Example 10 11.91 g of a solution (solids concentration 14.64 mass%) containing the polymer obtained in Synthesis Example 5 was mixed with 0.17 g of 3,3',5,5'-tetrakis(methoxymethyl)-4,4'-dihydroxybiphenyl (product name: TMOM-BP, manufactured by Honshu Chemical Industry Co., Ltd.) as a crosslinking agent, 0.06 g of pyridinium-p-toluenesulfonic acid as a crosslinking catalyst, and 0.002 g of a fluorine-based surfactant (product name: Megafac R-40, manufactured by DIC Corporation) as a surfactant. The resulting mixture was dissolved in 78.04 g of propylene glycol monomethyl ether and 9.80 g of propylene glycol monomethyl ether acetate to prepare a solution. The mixture was then filtered using a polyethylene microfilter with a pore size of 0.05 μm to prepare a composition for forming a resist underlayer film.

[0131] Comparative Example 1 4.11 g of a solution (solids concentration 17.76% by mass) containing the polymer obtained in Comparative Synthesis Example 1 was mixed with 0.18 g of tetramethoxymethyl glycoluril (manufactured by Nippon Cytec Industries Co., Ltd., product name: POWDERLINK (registered trademark) 1174) as a crosslinking agent, 0.06 g of 4-hydroxybenzenesulfonic acid as a crosslinking catalyst, 0.01 g of bis(4-hydroxyphenyl)sulfone as an additive, and 0.007 g of a fluorine-based surfactant (product name: Megafac R-40, manufactured by DIC Corporation) as a surfactant. The resulting mixture was dissolved in 85.76 g of propylene glycol monomethyl ether and 9.91 g of propylene glycol monomethyl ether acetate to prepare a solution. The mixture was then filtered using a polyethylene microfilter with a pore size of 0.05 μm to prepare a composition for forming a resist underlayer film.

[0132] [Resist Solvent Resistance Test] Each of the resist underlayer film-forming compositions prepared in Examples 1 to 10 and Comparative Example 1 was applied (spin coated) onto a silicon wafer using a spin coater. The coated silicon wafer was heated on a hot plate at 215°C for 1 minute to form a resist underlayer film. Next, to confirm the resist solvent resistance of the resist underlayer film, the silicon wafer on which the resist underlayer film had been formed was immersed for 1 minute in a solvent mixture of propylene glycol monomethyl ether (PGME) and propylene glycol monomethyl ether acetate (PGMEA) in a weight ratio of 7:3 (PGME:PGMEA=7:3), spin-dried, and then baked at 100°C for 30 seconds. The thickness of the resist underlayer film before and after immersion in the mixed solvent was measured using an optical interference film thickness meter (product name: Nanospec 6100, manufactured by Nanometrics Japan Co., Ltd.).

[0133] Resist solvent resistance was evaluated by calculating the film thickness reduction rate (%) of the resist underlayer film removed by solvent immersion using the following formula. The results are shown in Table 1. If the film thickness reduction rate was approximately 2% or less, it was deemed to have sufficient resist solvent resistance and was evaluated as "good." The results are shown in Table 1. Film thickness reduction rate (%) = [(A - B) ÷ A] x 100 A: Film thickness before solvent immersion B: Film thickness after solvent immersion

[0134]

[0135] [Measurement of Optical Constants] Each of the resist underlayer film-forming compositions prepared in Examples 1 to 10 and Comparative Example 1 was applied onto a silicon wafer using a spinner at a rotation speed of 1500 rpm. The resist underlayer film was then baked on a hot plate at 215°C for 1 minute to form a resist underlayer film. The n value (refractive index) and k value (extinction coefficient or absorption coefficient) of each of these resist underlayer films were measured at a wavelength of 193 nm using a spectroscopic ellipsometer (VUV-VASE VU-302, manufactured by J.A. Woollam Co.). The results are shown in Table 2.

[0136]

[0137] The results in Table 2 show that the resist underlayer film obtained from the composition for forming a resist underlayer film of the present invention has a sufficiently low n value for light with a wavelength of 193 nm, compared to resist underlayer films obtained from known compositions for forming a resist underlayer film.

Claims

1. A resist underlayer film-forming composition comprising a polymer having a unit structure represented by the following formula (1) and a solvent. (In formula (1), each A independently represents a hydrogen atom, a methyl group, or an ethyl group, and Q １ and Q ２ each independently represent a divalent group having an aromatic hydrocarbon ring. X １ and X ２ each independently represent a single bond or -C(=O)-.) 2. Q in the formula (1) １ is represented by the following formula (2), and Q ２ is represented by any one of the following formulas (3-1) to (3-3), the resist underlayer film-forming composition according to claim 1. (In formula (2) and formulas (3-1) to (3-3), R ａ each independently represents an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or an alkenyl group having 2 to 10 carbon atoms. W represents a single bond, -CH ２ -, -C(CH ３ )) ２ -, -C(CF ３ )) ２ -, -CO-, -O-, -S- or SO ２ -. m each independently represents an integer of 0 to 2. n each independently represents an integer of 0 to 4. * represents a bond.) 3. The composition for forming a resist underlayer film according to claim 1, wherein the solvent contains at least one selected from the group consisting of alkylene glycol monoalkyl ethers and monocarboxylic acid esters of alkylene glycol monoalkyl ethers.

4. The composition for forming a resist underlayer film according to claim 1, further comprising a crosslinking agent.

5. The composition for forming a resist underlayer film according to claim 1, further comprising a curing catalyst.

6. A resist underlayer film which is a cured product of the composition for forming a resist underlayer film according to any one of claims 1 to 5.

7. A laminate comprising a semiconductor substrate and the resist underlayer film according to claim 6.

8. A method for manufacturing a semiconductor device, comprising: forming a resist underlayer film on a semiconductor substrate using the composition for forming a resist underlayer film according to any one of claims 1 to 5; and forming a resist film on the resist underlayer film.

9. A patterning method, comprising: forming a resist underlayer film on a semiconductor substrate using the composition for forming a resist underlayer film according to any one of claims 1 to 5; forming a resist film on the resist underlayer film; irradiating the resist film with light, then developing the resist film to obtain a resist pattern; and etching the resist underlayer film using the resist pattern as a mask.

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