Resist underlayer film-forming composition and resist underlayer film

Abstract

Provided are: a resist underlayer film-forming composition capable of improving sensitivity further than before, in an EB exposure method or an EUV exposure method; and a resist underlayer film.　The present invention pertains to a resist underlayer film-forming composition for forming a resist underlayer film, the composition comprising a polysaccharide (A) having a hydroxy group and a solvent (B). Moreover, the present invention pertains to a resist underlayer film-forming composition, wherein the polysaccharide (A) is cyclodextrin.

Description

Composition for forming resist underlayer film and resist underlayer film

[0001] The present invention relates to a composition for forming a resist underlayer film and a resist underlayer film.

[0002] In semiconductor devices such as large-scale integrated circuits (LSIs), the formation of finer patterns is required as integration density increases, and in recent years, the minimum pattern size has reached 100 nm or less. The formation of such finer patterns in semiconductor devices has been made possible by shortening the wavelength of the light source in exposure equipment and improving resist materials. Currently, immersion lithography is used, in which exposure is performed through water using deep ultraviolet ArF (argon fluoride) excimer laser light with a wavelength of 193 nm. Regarding resist materials, various ArF-compatible resist materials based on acrylic resins have been developed.

[0003] Furthermore, as next-generation exposure technologies, EB exposure using an electron beam (EB) or EUV (extreme ultraviolet) exposure using soft X-rays with a wavelength of 13.5 nm as a light source is being studied, and pattern sizes are being further refined to 30 nm or less. However, with such refinement of pattern sizes, line edge roughness (LER) of the resist pattern sidewall and line width roughness (LWR) of the resist pattern increase, raising concerns about adverse effects on device performance. Although studies have been conducted to suppress these issues by optimizing exposure tools, resist materials, and process conditions, satisfactory results have not been obtained. Note that LWR and LER are related, and improving LWR will also improve LER.

[0004] In order to solve the above problems, an invention has been disclosed that relates to a resist underlayer film that is a baked product of a coating film of a composition for forming a resist underlayer film, which contains a polymer having at least one of a unit structure having a polycyclic aromatic hydrocarbon structure and a unit structure having a maleimide structure (see Patent Document 1).

[0005] International Publication No. 2023 / 106364

[0006] In pattern formation by EB exposure or EUV exposure, there is a demand for improving LWR and LER as described above, and also for achieving high sensitivity that enables pattern formation even when exposure energy is low.

[0007] The present invention provides a composition for forming a resist underlayer film and a resist underlayer film that can improve sensitivity compared to conventional methods in an EB exposure method or an EUV exposure method.

[0008] The present inventors conducted extensive research to solve the above-mentioned problems, and as a result, found that the above-mentioned problems can be solved, and completed the present invention having the following gist. That is, the present invention includes the following. [1] A composition for forming a resist underlayer film, the composition comprising a polysaccharide (A) having a hydroxy group and a solvent (B). [2] The composition for forming a resist underlayer film according to [1], wherein the polysaccharide (A) is cyclodextrin. [3] The composition for forming a resist underlayer film according to [1] or [2], further comprising a polymer (C), wherein the polymer (C) comprises a unit structure represented by the following formula (C-1): (In formula (C-1), R １ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. １ represents an oxygen atom or an optionally substituted amino group. １represents a monovalent group having 1 to 20 carbon atoms.) [4] The composition for forming a resist underlayer film according to [3], wherein the mass ratio (A:C) of the polysaccharide (A) to the polymer (C) in the composition is 70:30 to 5:95. [5] The composition for forming a resist underlayer film according to any one of [1] to [4], wherein the solvent (B) contains at least one selected from the group consisting of a carboxylic acid having a hydroxy group, a linear or cyclic alkyl ketone, a cyclic lactone, an alkylene glycol monoalkyl ether, a monocarboxylic acid ester of an alkylene glycol monoalkyl ether, and an alkoxycarboxylic acid ester of an alkylene glycol monoalkyl ether. [6] The composition for forming a resist underlayer film according to any one of [1] to [5], further containing a crosslinking agent (D). [7] The composition for forming a resist underlayer film according to [6], wherein the crosslinking agent (D) is at least one selected from the group consisting of an aminoplast crosslinking agent and a phenoplast crosslinking agent. [8] The composition for forming a resist underlayer film according to any one of [1] to [7], further comprising a curing catalyst (E). [9] The composition for forming a resist underlayer film according to any one of [1] to [8], which is used in an EB or EUV exposure process.

[10] A resist underlayer film, which is a cured product of the composition for forming a resist underlayer film according to any one of [1] to [9].

[11] A laminate comprising: a semiconductor substrate; and the resist underlayer film according to

[10] .

[12] 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 [9]; and forming a resist film on the resist underlayer film.

[13] A pattern forming 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 [1] to [9]; forming a resist film on the resist underlayer film; irradiating the resist film with EB or EUV 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 and a resist underlayer film that can improve sensitivity in an EB exposure method or an EUV exposure method compared to conventional methods.

[0010] (Composition for forming a resist underlayer film) An example of the composition for forming a resist underlayer film of the present invention contains a polysaccharide having a hydroxy group (A) and a solvent (B).

[0011] <Polysaccharide (A) Having Hydroxy Groups> The polysaccharide (A) is not particularly limited, and examples thereof include polysaccharides composed of monosaccharide molecules derived from pentoses having five carbon atoms and hexoses having six carbon atoms. There is no particular limitation on the number of monosaccharide molecules constituting the polysaccharide (A), but it is preferable that three or more monosaccharide molecules are bonded together. The polysaccharide (A) having hydroxy groups is sufficient as long as it has at least one hydroxy group, and the hydrogen atoms of the hydroxy groups of the polysaccharide (A) may be substituted.

[0012] As the polysaccharide (A) described above, cyclodextrin is preferred. Examples of cyclodextrin include cyclodextrins selected from the group consisting of α-cyclodextrin in which six glucose units are bonded, β-cyclodextrin in which seven glucose units are bonded, and γ-cyclodextrin in which eight glucose units are bonded, or derivatives of these cyclodextrins. As the cyclodextrin, β-cyclodextrin or a β-cyclodextrin derivative is particularly preferred.

[0013] The cyclodextrin derivative is a glucose unit represented by the following formula (1) in which one or more hydroxy groups have been substituted with other substituents, and it is sufficient that the cyclodextrin derivative has one or more units substituted with hydroxy groups. The hydroxy group substitution in the cyclodextrin derivative is preferably in the range of 10 to 90% of all hydroxy groups. The other substituents are not particularly limited, and examples thereof include alkyl groups, hydroxyalkyl groups, and acetyl groups.

[0014] As the cyclodextrin derivative, for example, those represented by the following formulas (1-1) to (1-3) are suitable.

[0015] The content of the polysaccharide (A) in the composition for forming a resist underlayer film is preferably 5% by mass or more and 100% by mass or less, more preferably 10% by mass or more and 90% by mass or less, and particularly preferably 15% by mass or more and 80% by mass or less, based on the solid content of the composition.

[0016] <Solvent (B)> The solvent (B) is not particularly limited and may be water or an organic solvent. Examples of the organic solvent include a carboxylic acid having a hydroxy group, a linear or cyclic alkyl ketone, a cyclic lactone, an alkylene glycol alkyl ether, and an alkylene glycol monoalkyl ether carboxylic acid ester (a monocarboxylic acid ester of an alkylene glycol monoalkyl ether, and an alkoxycarboxylic acid ester of an alkylene glycol monoalkyl ether).

[0017] Examples of carboxylic acids having a hydroxy group include ethyl lactate, propyl lactate, isopropyl lactate, butyl lactate, isobutyl lactate, ethyl hydroxyacetate, ethyl 2-hydroxy-2-methylpropionate, ethyl 2-hydroxypropionate, and methyl 2-hydroxy-3-methylbutyrate.

[0018] Examples of linear or cyclic alkyl ketones include methyl ethyl ketone, cyclopentanone, and cyclohexanone.

[0019] An example of the cyclic lactone is γ-butyrolactone.

[0020] Examples of alkylene glycol alkyl ethers include alkylene glycol monoalkyl ethers and alkylene glycol dialkyl ethers. Examples of alkylene glycol monoalkyl ethers include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether (1-methoxy-2-propanol), propylene glycol monoethyl ether (1-ethoxy-2-propanol), methyl isobutyl carbinol, and propylene glycol monobutyl ether. Examples of alkylene glycol dialkyl ethers include diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether, diethylene glycol dibutyl ether, propylene glycol monomethyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether, propylene glycol dipropyl ether, and propylene glycol dibutyl ether.

[0021] Examples of alkylene glycol monoalkyl ether carboxylic acid esters include monocarboxylic acid esters of alkylene glycol monoalkyl ethers and alkoxycarboxylic acid esters of alkylene glycol monoalkyl ethers. Examples of monocarboxylic acid esters of alkylene glycol monoalkyl ethers include alkylene glycol monoalkyl ether acetates. Examples of alkylene glycol monoalkyl ether acetates include methyl cellosolve acetate, ethyl cellosolve acetate, propylene glycol monomethyl ether acetate (1-methoxy-2-propanol monoacetate), propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether acetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, and ethylene glycol monobutyl ether acetate. Examples of the alkoxycarboxylic acid ester of alkylene glycol monoalkyl ether include 2-methoxyethyl methyl carbonate, 2-ethoxyethyl methyl carbonate, 2-ethoxyethyl ethyl carbonate, and 2-propoxyethyl methyl carbonate.

[0022] Specific examples of other solvents include toluene, xylene, ethyl ethoxyacetate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl 3-ethoxypropionate, methyl pyruvate, ethyl pyruvate, methyl formate, ethyl formate, propyl formate, isopropyl formate, butyl formate, isobutyl formate, amyl formate, isoamyl formate, methyl acetate, ethyl acetate, amyl acetate, isoamyl acetate, hexyl acetate, methyl propionate, ethyl propionate, propyl propionate, isopropyl propionate, butyl propionate, isobutyl propionate, methyl butyrate, ethyl butyrate, propyl butyrate, isopropyl butyrate, butyl butyrate, isobutyl butyrate, and ethyl hydroxyacetate. Examples of suitable solvents include methyl 3-methoxy-2-methylpropionate, methyl methoxyacetate, ethyl ethoxyacetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-methoxybutyl acetate, 3-methoxypropyl acetate, 3-methyl-3-methoxybutyl acetate, 3-methyl-3-methoxybutylpropionate, 3-methyl-3-methoxybutyl butyrate, methyl acetoacetate, methyl propyl ketone, methyl butyl ketone, 2-heptanone, 3-heptanone, 4-heptanone, N,N-dimethylformamide, N-methylacetamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, and 4-methyl-2-pentanol.

[0023] Among these solvents (B), alkylene glycol monoalkyl ethers and monocarboxylic acid esters of alkylene glycol monoalkyl ethers are preferred.

[0024] These solvents (B) may be used alone or in combination of two or more.

[0025] The mass proportion of the organic solvent in the solvent (B) is not particularly limited, but is preferably 50 mass % to 100 mass %.

[0026] 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.

[0027] <Polymer (C)> The composition for forming a resist underlayer film preferably further contains a polymer (C). The polymer (C) is not particularly limited, but preferably contains a unit structure represented by the following formula (C-1): (In formula (C-1), R １ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. １ represents an oxygen atom or an optionally substituted amino group. １ represents a monovalent group having 1 to 20 carbon atoms.

[0028] Examples of the alkyl group having 1 to 3 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, a cyclopropyl group, etc. Among these, a methyl group is preferred.

[0029] Examples of the monovalent group having 1 to 20 carbon atoms include an alkyl group, an alkenyl group, an alkoxy group, a hydroxyalkyl group, a fluoroalkenyl group, a fluoroalkoxy group, a carboxy group, a hydroxy group, an alkyloxycarbonyl group, a cyano group, a nitro group, etc. Among these, an alkyl group, a hydroxyalkyl group, and an alkyloxycarbonyl group are preferred.

[0030] Suitable examples of the unit structure contained in the polymer (C) include the following.

[0031] The polymer (C) preferably has, in its side chain, one or more polymerizable multiple bonds selected from the group consisting of a carbon-carbon double bond, a carbon-carbon triple bond, a carbon-nitrogen double bond, and a carbon-nitrogen triple bond.

[0032] The polymer (C) has, for example, a (meth)acryloyl group, a vinylaryl group (for example, a styryl group), a vinyloxy group, an allyl group, or the like, in a side chain as the group having a polymerizable multiple bond.

[0033] The polymer (C) is, for example, a polymer (C-2) obtained by polymerizing a polymerizable unsaturated bond of a compound having a group having a polymerizable unsaturated bond. The polymer (C-2) may be a homopolymer or a copolymer. Examples of the group having a polymerizable unsaturated bond include a (meth)acryloyl group, a vinylaryl group (e.g., a styryl group), a vinyloxy group, and an allyl group.

[0034] For example, in polymer (C), the polymerizable multiple bond is bonded to the main chain of polymer (C) via a linking group having a structure obtained by reacting an epoxy group with a nucleophilic functional group. Examples of the nucleophilic functional group include one or more selected from the group consisting of a carboxy group, a hydroxy group, an amino group, and a thiol group. The hydroxy group may or may not be a phenolic hydroxy group. When an epoxy group reacts with a carboxy group, the reaction proceeds as follows, forming the following structure (S1): (In the formula, * represents a bond.)

[0035] Furthermore, for example, in polymer (C), the polymerizable multiple bond is bonded to the main chain of polymer (C) via a linking group having a structure obtained by reaction of an isocyanate group with a nucleophilic functional group. In this case, the nucleophilic functional group may be, for example, one or more selected from the group consisting of a hydroxy group, an amino group, and a thiol group. The hydroxy group may or may not be a phenolic hydroxy group.

[0036] The polymer (C) preferably has a unit structure represented by the following formula (Z) as the unit structure represented by formula (C-1). (In formula (Z), R １ is R in formula (C-1) １ It is synonymous with L. １ represents a divalent group represented by the following formula (Q1): ２ represents the monovalent group having a polymerizable multiple bond. (In formula (Q1), *1 represents R in formula (Z) １*2 represents a bond bonded to the carbon atom bonded to L in formula (Z). ２ represents a bond bonded to X. １ represents an oxygen atom or an optionally substituted amino group. ２ represents a linking group.

[0037] In addition, Y in the above formula (C-1) １ is L in formula (Z). ２ and X in formula (Q1) ２ In this relationship, it is expressed by formula (Q2). (In formula (Q2), *3 represents X in formula (C-1) １ represents a bond bonded to X. ２ represents a linking group. ２ represents the monovalent group having a polymerizable multiple bond.

[0038] X ２ The number of carbon atoms in is not particularly limited, and may be, for example, 1 to 10. Examples of the divalent group represented by formula (Q1) include a divalent group having a structure obtained by reacting an epoxy group with a nucleophilic functional group, and a divalent group having a structure obtained by reacting an isocyanate group with a nucleophilic functional group.

[0039] Examples of the divalent group represented by formula (Q1) include the following divalent groups (L1-1) to (L1-7). (wherein *1 represents R in formula (Z) １ *2 represents a bond bonded to the carbon atom bonded to L in formula (Z). ２ represents a bond bonded to

[0040] L ２ is a monovalent group having a polymerizable multiple bond. The monovalent group may be the polymerizable multiple bond itself. The number of carbon atoms in the monovalent group is not particularly limited, but may be, for example, 1 to 20 or 1 to 10.

[0041] L ２ Examples of the group include the following monovalent groups (L2-1) to (L2-81). (In the formula, * represents a bond.)

[0042] Examples of the combinations of the divalent groups (L1-1) to (L1-7) and the monovalent groups (L2-1) to (L2-7) include the following combinations.・Combination of (L1-1) and (L2-1) ・Combination of (L1-1) and (L2-2) ・Combination of (L1-1) and (L2-7) ・Combination of (L1-2) and (L2-3) ・Combination of (L1-2) and (L2-4) ・Combination of (L1-2) and (L2-7) ・Combination of (L1-3) and (L2-3) ・Combination of (L1-3) and (L2-4) ・Combination of (L1-4) and (L2-7) ・Combination of (L1-5) and (L2-5) ・Combination of (L1-7) and (L2-6) Note that the combination of (L1-1) and (L2-1) and the combination of (L1-2) and (L2-3) are synonymous. The combination of (L1-1) and (L2-2) has the same meaning as the combination of (L1-2) and (L2-4).

[0043] In addition, L in the unit structure represented by formula (Z) １ -L ２ preferably has a structure represented by the following formula (Za), (Zb) or (Zc). (In formulas (Za) to (Zc), R ２ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. *a and *b represent bonds, with *a being on the main chain side of polymer (C) and *b being on the terminal side of the side chain of polymer (C). *b may also be a bond to a hydrogen atom.

[0044] Examples of the unit structure represented by formula (Z) include the following unit structures.

[0045] An example of the polymer (C) containing the unit structure represented by formula (Z) can be obtained, for example, by reacting a glycidyl (meth)acrylate polymer with a compound (M1) having a polymerizable multiple bond and a carboxy group, as shown below. The glycidyl (meth)acrylate polymer may be a homopolymer or a copolymer. Examples of the copolymer include a copolymer of glycidyl (meth)acrylate and 2-hydroxyethyl (meth)acrylate, and a copolymer of glycidyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate.

[0046] (In the formula, R １ , and L ２ respectively represent R in formula (Z). １ , and L ２ is synonymous with

[0047] The reaction can be carried out in the presence of a catalyst such as tetrabutylphosphonium bromide.

[0048] Examples of the compound (M1) having a polymerizable multiple bond and a carboxy group include acrylic acid, methacrylic acid, 4-vinylbenzoic acid, sorbic acid, tetrolic acid, tiglic acid, 1-cyclohexene-1-carboxylic acid, 2-benzylacrylic acid, trans-cinnamic acid, trans-4-methoxycinnamic acid, α-phenylcinnamic acid, monomethyl fumarate, α-cyanocinnamic acid, 4-nitrocinnamic acid, and 3-nitrocinnamic acid.

[0049] Another example of the polymer (C) containing the unit structure represented by formula (Z) can be obtained, for example, by reacting a (meth)acrylate polymer having a hydroxy group with a compound (M2) having a polymerizable multiple bond and an isocyanate group, as shown below. The (meth)acrylate polymer having a hydroxy group may be a homopolymer or a copolymer. (In the formula, R １ , and L ２ respectively represent R in formula (Z). １ , and L ２ It is synonymous with R １１ represents a divalent organic group.１２ represents a single bond or a divalent organic group. １１ is, for example, an alkylene group having 1 to 4 carbon atoms. １２ is, for example, a single bond or an alkylene group having 1 to 4 carbon atoms.

[0050] The polymer (C) may have, for example, a unit structure represented by the following formula (Z2), a unit structure represented by the following formula (Z3), or a unit structure represented by the following formula (Z4). Of these, the unit structures represented by formula (Z2) and formula (Z4) are examples of the unit structure represented by formula (C-1). Note that the unit structures represented by formula (Z2) and formula (Z4) are different structures from the unit structure represented by formula (Z). (In formula (Z2), R ２ is R in formula (C-1) １ It is synonymous with L. ３ represents a monovalent group having 1 to 20 carbon atoms. ２ is R in formula (C-1) １ Ar represents a benzene ring or a naphthalene ring; ４ is a hydroxy group, a cyano group, a nitro group, or an amino group (-NH ２ ) represents. ５ represents a halogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms. m1 represents an integer of 0 to 3. m2 represents an integer of 0 to 5, provided that the sum of m1 and m2 is 0 to 5. When m1 is 2 or 3, multiple L ４ may be the same or different. When m2 is 2 to 5, multiple L ５ may be the same or different. ２ is R in formula (C-1) １ It is synonymous with L. ６ represents a monovalent organic group selected from an alkyl group having 1 to 10 carbon atoms and an aryl group having 6 to 40 carbon atoms, and at least one hydrogen atom of the alkyl group and the aryl group may be substituted with a hydroxy group or an alkoxy group having 1 to 6 carbon atoms.

[0051] L in formula (Z2) ３The monovalent group having 1 to 20 carbon atoms represents, for example, a monovalent organic group selected from an alkyl group having 1 to 10 carbon atoms and an aryl group having 6 to 40 carbon atoms, and at least one hydrogen atom of the alkyl group and the aryl group may be substituted with a hydroxy group. In addition, the alkyl group may have an oxygen atom inserted between carbon atoms. In addition, L ３ Examples of the monovalent group having 1 to 20 carbon atoms include groups represented by the following formula (Z2-1). (In formula (Z2-1), L ３ａ represents an optionally substituted alkyl group having 1 to 6 carbon atoms, or an optionally substituted aromatic hydrocarbon group. ３ａ Examples of the aromatic hydrocarbon group in L include a phenyl group and a naphthyl group. ３ａ Examples of the substituent in the optionally substituted alkyl group having 1 to 6 carbon atoms include a halogen atom and a hydroxy group. The number of substituents may be one or more. When there are more than one substituent, the multiple substituents may be the same or different. ３ａ Examples of the substituent in the optionally substituted aromatic hydrocarbon group include a halogen atom, a hydroxy group, and an alkyl group having 1 to 3 carbon atoms which may be substituted with a halogen atom. The number of substituents may be one or more. When there are multiple substituents, the multiple substituents may be the same or different.

[0052] L ５ Examples of the halogen atom in L include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. ５ Examples of the alkyl group having 1 to 6 carbon atoms in the formula (L) include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, a cyclopropyl group, an n-butyl group, and an i-butyl group. ６Examples of the alkoxy group having 1 to 6 carbon atoms in the formula (I) include a methoxy group, an ethoxy group, a propoxy group, and a butoxy group. m1 represents an integer of 0 to 3 and may be 0, 1, 2, or 3. m2 represents an integer of 0 to 5 and may be 0, 1, 2, 3, 4, or 5.

[0053] L ３ and L ６ Examples of the aryl group having 6 to 40 carbon atoms represented by L include a phenyl group, an o-methylphenyl group, an m-methylphenyl group, a p-methylphenyl group, an o-chlorophenyl group, an m-chlorophenyl group, a p-chlorophenyl group, an o-fluorophenyl group, a p-fluorophenyl group, an o-methoxyphenyl group, a p-methoxyphenyl group, a p-nitrophenyl group, a p-cyanophenyl group, an α-naphthyl group, a β-naphthyl group, an o-biphenylyl group, an m-biphenylyl group, a p-biphenylyl group, a 1-anthryl group, a 2-anthryl group, a 9-anthryl group, a 1-phenanthryl group, a 2-phenanthryl group, a 3-phenanthryl group, a 4-phenanthryl group, and a 9-phenanthryl group. ６ Examples of the alkoxy group having 1 to 6 carbon atoms include a methoxy group, an ethoxy group, a propoxy group, and a butoxy group.

[0054] Examples of the monomers used to derive formula (Z2) include the following compounds:

[0055] Examples of the monomers used to derive formula (Z3) include the following compounds: Me represents a methyl group.

[0056] Examples of the monomers used to derive formula (Z4) include the following compounds:

[0057] Examples of polymer (C) include the polymers described in WO 2015 / 178235, the contents of which are incorporated herein by reference in their entirety to the same extent as if set forth herein.

[0058] The proportion of the unit structure represented by formula (C-1) in polymer (C) described above is not particularly limited, but the proportion (mass %) of the unit structure represented by formula (C-1) relative to the solid content of polymer (C) may be, for example, 10 mass % or more and 100 mass % or less, and preferably 20 mass % or more and 100 mass % or less. Polymer (C) may contain structures other than the unit structure represented by formula (C-1). In such cases, the molar proportion of the other structures in the total structure of polymer (C) is, for example, more than 0 mass % and 50 mass % or less.

[0059] The molecular weight of the polymer (C) is not particularly limited. The lower limit of the weight average molecular weight of the polymer (C) is, for example, 500, 1,000, 2,000, or 3,000. The upper limit of the weight average molecular weight of the polymer (C) is, for example, 100,000, 50,000, 30,000, 20,000, or 10,000.

[0060] The mass ratio (A:C) of the polysaccharide (A) to the polymer (C) in the composition is preferably 100:0 to 5:95, more preferably 85:15 to 15:85, and particularly preferably 70:30 to 30:70.

[0061] <Crosslinking Agent (D)> The composition for forming a resist underlayer film preferably further contains a crosslinking agent (D). The crosslinking agent (D) has a structure different from that of the polymer (C).

[0062] The crosslinking agent (D) 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.

[0063] Examples of the crosslinking agent (D) 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.

[0064] 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 hydrogen atom, a methyl group, or an ethyl group. * represents a bond.

[0065] The crosslinking agent (D) 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.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] Examples of the glycoluril derivative represented by the formula (1E) include compounds represented by the following formulas (1E-1) to (1E-6).

[0071] 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).

[0072] (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.

[0073] (In formula (3d), R １ represents a methyl group or an ethyl group.)

[0074] 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.

[0075] 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.

[0076] 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 ６ n 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≦n５ an integer ≦3, n ６ is 1≦n ６ an integer ≦4, n 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.

[0077] 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 ≦5 １１ 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 an integer ≦4, n １５ is 0≦n １５ an integer ≦3, n １６ is 0≦n １６an 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.

[0078] Examples of the compound represented by formula (G-1) or formula (G-2) include the following compounds:

[0079] 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.

[0080] 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.

[0081] The molecular weight of the crosslinking agent (D) is not particularly limited, but is preferably 1,000 or less.

[0082] The content of the crosslinking agent (D) 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 (C).

[0083] <Curing Catalyst (E)> The composition for forming a resist underlayer film preferably further contains a curing catalyst (E). Examples of the curing catalyst include an acid generator. While both a thermal acid generator and a photoacid generator can be used as the acid generator, 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, and hydroxybenzoic acid.

[0084] Examples of the photoacid generator include an onium salt compound, a sulfonimide compound, and a disulfonyldiazomethane compound.

[0085] 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.

[0086] Examples of the sulfonimide compound include N-(trifluoromethanesulfonyloxy)succinimide, N-(nonafluoronormalbutanesulfonyloxy)succinimide, N-(camphorsulfonyloxy)succinimide, and N-(trifluoromethanesulfonyloxy)naphthalimide.

[0087] 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.

[0088] The acid generators may be used singly or in combination of two or more.

[0089] When an acid generator is used, the content of the acid generator relative to the crosslinking agent described below is, for example, 0.1% by mass to 50% by mass, and preferably 1% by mass to 30% by mass.

[0090] <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 further improve coating properties for surface unevenness. Any polymer other than the polymer (C) may also be added. Examples of such polymers include the polymers described in International Publication No. 2013 / 018802 and polymers containing hydroxyarene.

[0091] Examples of surfactants include 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; polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate; nonionic surfactants such as polyoxyethylene sorbitan fatty acid esters, such as 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.

[0092] The composition for forming a resist underlayer film may contain a polymerization inhibitor (radical trapping agent) as necessary. Examples of the polymerization inhibitor include 2,6-diisobutylphenol, 3,5-di-tert-butylphenol, 3,5-di-tert-butylcresol, hydroquinone, hydroquinone monomethyl ether, pyrogallol, tert-butylcatechol, and 4-methoxy-1-naphthol. The content of the polymerization inhibitor in the composition for forming a resist underlayer film is not particularly limited, but is preferably 1 mass % or less based on the solid content.

[0093] 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.

[0094] (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.

[0095] 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.

[0096] 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.

[0097] 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.

[0098] 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 (5 nm) to 0.05 μm (5 0 nm), 0.003 μm (3 nm) to 0.03 μm (30 nm), 0.003 μm (3 nm) to 0.02 μm (20 nm), 0.005 μm (5 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).

[0099] The method for measuring the film thickness of the resist underlayer film in this specification is as follows: Name of measuring device: Ellipso film thickness measuring device RE-3100 (SCREEN Corporation) SWE (single wavelength ellipsometer) mode Arithmetic mean of 8 points (for example, measuring 8 points at 1 cm intervals in the X direction of the wafer)

[0100] (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.

[0101] (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.

[0102] 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 EB or EUV and then developing the resist film to obtain a resist pattern, and etching the resist underlayer film using the resist pattern as a mask.

[0103] Typically, a resist layer is formed on the resist underlayer film. The film thickness of the resist layer 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 or more, 80 nm or more, 50 nm or more, 30 nm or more, 20 nm or more, or 10 nm or more.

[0104] 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 EB or EUV used for irradiation. Both negative and positive photoresists can be used. In this specification, resists responsive to EB are also referred to as photoresists. 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 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 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 an acid to increase the alkaline dissolution rate, a low-molecular-weight compound that decomposes in 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).

[0105] 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.

[0106] Examples of the resist composition include the following compositions.

[0107] 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):

[0108] 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.

[0109] A metal-containing film-forming composition for extreme ultraviolet or electron beam lithography, comprising a compound having a metal-oxygen covalent bond and a solvent, wherein the metal element constituting the compound belongs to Periods 3 to 7 of Groups 3 to 15 of the periodic table.

[0110] A radiation-sensitive resin composition comprising a polymer having a first unit structure represented by the following formula (31) and a second unit structure represented by the following formula (32) containing an acid-dissociable group, and an acid generator:

[0111] 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 ４is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0112] A resist composition comprising: a resin (A1) including a unit structure having a cyclic carbonate structure, a unit structure represented by the following formula, and a unit structure having an acid labile group; and an acid generator.

[0113] [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.]

[0114] Examples of the resist film include the following.

[0115] 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:

[0116] (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.

[0117] Examples of resist materials include the following:

[0118] A resist material comprising a polymer having a repeating unit represented by the following formula (b1) or (b2):

[0119] (In formula (b1) and formula (b2), R Ａ is a hydrogen atom or a methyl group. １ is 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 ２may be bonded to form a ring together with the sulfur atom to which they are attached.

[0120] A resist material comprising a base resin containing a polymer containing a repeating unit represented by the following formula (a):

[0121] (In formula (a), R Ａ is 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.

[0122] 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):

[0123] [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.

[0124] 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).

[0125] [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. ２ are each independently an organic group having a fluorine atom.

[0126] The resist composition may be a metal-containing resist. Metal-containing resists are also called metal oxide resists (MOR), and a representative example is a tin oxide-based resist. Examples of metal oxide resist materials include coating compositions containing metal oxo-hydroxo networks having organic ligands via metal-carbon bonds and / or metal carboxylate bonds, as described in JP-A-2019-113855. One example of a metal-containing resist uses a peroxo ligand as a radiation-sensitive stabilizing ligand. Details of peroxo-based metal oxo-hydroxo compounds are described, for example, in the patent document described in paragraph

[0011] of JP-A-2019-532489. Examples of such patent documents include U.S. Pat. No. 9,176,377 B2, U.S. Patent Application Publication No. 2013 / 0224652 A1, U.S. Pat. No. 9,310,684 B2, U.S. Patent Application Publication No. 2016 / 0116839 A1, and U.S. Patent Application Publication No. 15 / 291738.

[0127] A coating comprising a metal oxo-hydroxo network with organic ligands via metal carbon bonds and / or metal carboxylate bonds.

[0128] Inorganic oxo / hydroxo-based compositions.

[0129] a coating solution comprising an organic solvent; a first organometallic composition having the formula R ｚ SnO （２－（ｚ／２）－（ｘ／２）） (OH) ｘ (where 0<z≦2 and 0<(z+x)≦4), formula R′ ｎSnX ４－ｎ wherein n=1 or 2, or mixtures thereof, where R and R′ are independently hydrocarbyl groups having 1 to 31 carbon atoms, and X is a ligand having a hydrolyzable bond to Sn, or a combination thereof; and a hydrolyzable metal compound having the formula MX′ ｖ wherein M is a metal selected from groups 2 to 16 of the periodic table of the elements, v is a number from 2 to 6, and X' is a ligand having a hydrolyzable M-X bond or a combination thereof.

[0130] an organic solvent and a solution of the formula RSnO （３／２－ｘ／２） (OH) ｘ and a first organometallic compound of the formula: wherein 0<x<3, wherein the solution contains from about 0.0025M to about 1.5M tin, and R is an alkyl or cycloalkyl group having from 3 to 31 carbon atoms, the alkyl or cycloalkyl group being bonded to the tin at a secondary or tertiary carbon atom.

[0131] An aqueous inorganic patterning precursor solution comprising a mixture of water, metal suboxide cations, polyatomic inorganic anions, and radiation-sensitive ligands comprising peroxide groups.

[0132] Other examples of metal-containing resists include those described in JP 2011-253185 A, WO 2015 / 026482, WO 2016 / 065120, WO 2017 / 066319, WO 2017 / 156388, WO 2018 / 031896, JP 2020-122959 A, JP 2020-122960 A, WO 2019 / 099981, WO 2019 / 199467, WO 2019 / 195522, WO 2019 / 195522, WO 2020 / 210660, WO 2021 / 011367, and WO 2021 / 016229. The contents of these are incorporated herein in their entirety to the same extent as if set forth in full.

[0133] The method for forming a metal-containing resist film from a metal-containing resist is not particularly limited, and examples include a method in which a coating-type resist material (a composition for forming a metal-containing resist film) that is a metal-containing resist is coated and baked.

[0134] The metal-containing resist film may also be formed by vapor deposition. Examples of methods for forming a metal-containing resist film by vapor deposition include the method described in JP 2017-116923 A. The contents of JP 2017-116923 A are incorporated herein by reference to the same extent as if fully set forth herein. In JP 2017-116923 A, the metal-containing resist film of the present invention is referred to as a metal oxide-containing film.

[0135] The EB or EUV irradiation is carried out, for example, through a mask (reticle) for forming a predetermined pattern, and EUV (extreme ultraviolet) or EB (electron beam) is used. The composition for forming a resist underlayer film of the present invention is preferably applied for EB (electron beam) or EUV (extreme ultraviolet: 13.5 nm) irradiation, more preferably for EUV (extreme ultraviolet) exposure. The irradiation energy of the electron beam is not particularly limited.

[0136] After irradiation with EB or EUV and before 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.

[0137] For example, an alkaline developer or an organic solvent is used for development. The development temperature is, for example, 5°C to 50°C. The development time is, 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 may 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 may 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.

[0138] An organic solvent can be used as a developer for the metal-containing resist, and development is carried out with the developer (solvent) after irradiation with light or electron beams. As a result, for example, when a negative metal-containing resist film is used, the metal-containing resist film in the unexposed areas is removed, and a pattern of the metal-containing resist film is formed. Examples of the developer (organic solvent) include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, isoamyl acetate, ethyl methoxyacetate, ethyl ethoxyacetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monophenyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monopropyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monophenyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, 2-methoxybutyl acetate, 3-methoxybutyl acetate, 4-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-ethyl-3-methyl ... -Methoxybutyl acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, 2-ethoxybutyl acetate, 4-ethoxybutyl acetate, 4-propoxybutyl acetate, 2-methoxypentyl acetate, 3-methoxypentyl acetate, 4-methoxypentyl acetate, 2-methyl-3-methoxypentyl acetate, 3-methyl-3 -methoxypentyl acetate, 3-methyl-4-methoxypentyl acetate, 4-methyl-4-methoxypentyl acetate, propylene glycol diacetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate, ethyl carbonate, propyl carbonate, butyl carbonate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, butyl pyruvate, methyl acetoacetate, ethyl acetoacetate, methyl propionate, ethyl propionate,Examples of the developer include propyl propionate, isopropyl propionate, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, and propyl 3-methoxypropionate. Furthermore, surfactants and the like can also be added to these developers.

[0139] 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.

[0140] The present invention will now be described in detail with reference to examples, but the present invention is not limited to these examples.

[0141] The weight-average molecular weights of the polymers shown in Synthesis Examples 1 and 2 and Comparative Synthesis Example 1 below in this specification are the results of measurement 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: GPC column: Asahipak (registered trademark) GF-310HQ, GF-510HQ, GF-710HQ Column temperature: 40°C Solvent: N,N-dimethylformamide (DMF) Flow rate: 0.6 ml / min Standard sample: polystyrene (manufactured by Tosoh Corporation)

[0142] [1] Polymer Synthesis <Synthesis Example 1> 7.33 g of 2-hydroxypropyl methacrylate (manufactured by Tokyo Chemical Industry Co., Ltd.), 5.00 g of methyl methacrylate (manufactured by Tokyo Chemical Industry Co., Ltd.), and 0.50 g of azobisisobutyronitrile (manufactured by Tokyo Chemical Industry Co., Ltd.) were dissolved in 29.94 g of propylene glycol monomethyl ether, and the solution was added to 21.39 g of PGME heated to reflux at 140°C and reacted for 24 hours to obtain a solution containing polymer 1. GPC analysis showed that the obtained polymer 1 had a weight average molecular weight of 7,900 and a dispersity of 2.2, calculated as standard polystyrene. The structure present in polymer 1 is shown in the following formula.

[0143] Synthesis Example 2 6.00 g of polyglycidyl methacrylate (manufactured by Maruzen Petrochemical Co., Ltd.), 4.88 g of sorbic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.02 g of hydroquinone (manufactured by Tokyo Chemical Industry Co., Ltd.), and 0.46 g of tetrabutylphosphonium bromide (manufactured by Hokko Chemical Industry Co., Ltd.) were added to 16.7 g of propylene glycol monomethyl ether acetate and 16.7 g of propylene glycol monomethyl ether in a reaction vessel and dissolved. The atmosphere in the reaction vessel was replaced with nitrogen, and the reaction was carried out at 100°C for 24 hours to obtain a polymer solution. The polymer solution did not become cloudy even when cooled to room temperature, and the solubility in a propylene glycol monomethyl ether / propylene glycol monomethyl ether acetate mixed solvent was good. After cooling the polymer solution to room temperature, a propylene glycol monomethyl ether / propylene glycol monomethyl ether acetate mixed solvent was added to make a 10% by mass solution. GPC analysis revealed that the resulting polymer 2 had a weight average molecular weight of 18,700 and a polydispersity of 2.0, calculated in terms of standard polystyrene. The structure present in polymer 2 is shown in the following formula.

[0144] Comparative Synthesis Example 1 In a reaction vessel, 100.00 g of monoallyl diglycidyl isocyanurate (manufactured by Shikoku Chemicals Corporation), 66.4 g of 5,5-diethylbarbituric acid, and 4.1 g of benzyltriethylammonium chloride were added to 682.00 g of propylene glycol monomethyl ether and dissolved. After replacing the atmosphere in the reaction vessel with nitrogen, the reaction was carried out at 130°C for 24 hours to obtain a solution containing Comparative Polymer 1. GPC analysis showed that the obtained Comparative Polymer 1 had a weight average molecular weight of 10,800 and a polydispersity of 5.2, calculated as standard polystyrene. The structure present in Comparative Polymer 1 is shown in the following formula.

[0145]

[0146] [2] Preparation of Compositions for Forming Resist Underlayer Films (Examples and Comparative Examples) A ​​cyclodextrin compound (CAVASOL (registered trademark) series manufactured by CycloChem Corporation), the polymers obtained in Synthesis Examples 1 and 2 and Comparative Synthesis Example 1, a crosslinking agent, a curing catalyst, and a solvent were mixed in the proportions shown in Tables 1 and 2, and the mixture was filtered through a 0.1 μm fluororesin filter to prepare solutions of compositions for forming resist underlayer films.

[0147] The meanings of the abbreviations in Tables 1 and 2 are as follows: M-β-CD: Methyl-β-cyclodextrin HP-β-CD: Hydroxypropyl-β-cyclodextrin MA-β-CD: Monoacetyl-β-cyclodextrin PL-LI: Tetramethoxymethylglycoluril PGME-PL: Imidazo[4,5-d]imidazole-2,5(1H,3H)-dione,tetrahydro-1,3,4,6-tetrakis[(2-methoxy-1-methylethoxy)methyl]- PyPSA: Pyridinium-p-hydroxybenzenesulfonic acid Nikalac Mw390: Hexamethoxymethylmelamine PGMEA: Propylene glycol monomethyl ether acetate PGME: Propylene glycol monomethyl ether

[0148]

[0149]

[0150] [3] Elution Test into Photoresist Solvent Each of the resist underlayer film-forming compositions of Examples 1 to 6 and Comparative Examples 1 and 2 was applied to a silicon wafer using a spinner. The silicon wafer was baked on a hot plate at 205°C for 60 seconds to obtain a film with a thickness of 5 nm. Each of the resist underlayer film-forming compositions of Examples 7 to 9 and Comparative Example 3 was applied to a silicon wafer using a spinner. The silicon wafer was baked on a hot plate at 205°C for 60 seconds to obtain a film with a thickness of 10 nm. These resist underlayer films were immersed in a mixed solution of propylene glycol monomethyl ether / propylene glycol monomethyl ether = 70 / 30, which is a solvent used in photoresists. A change in film thickness of 5 Å or less was rated as good, and a change in film thickness of more than 5 Å was rated as bad. The results are shown in Table 3.

[0151]

[0152] [4] Resist Patterning Evaluation [Resist Pattern Formation Test Using an EUV Exposure Apparatus] The resist underlayer film-forming compositions of Examples 1 and 2 and Comparative Example 1 were each applied to a silicon wafer using a spinner. The silicon wafer was baked on a hot plate at 205°C for 60 seconds to obtain a 5 nm-thick resist underlayer film. A negative EUV resist solution was spin-coated onto the resist underlayer film and heated at 100°C for 60 seconds to form an EUV resist film. The resist film was exposed under specified conditions using an EUV exposure apparatus (NXE3400B). After exposure, the resist was baked at 170°C for 60 seconds (PEB), cooled to room temperature on a cooling plate, and developed with a negative photoresist developer. After development, the resist was baked at 250°C for 60 seconds (HB), cooled to room temperature on a cooling plate, and formed a resist pattern with pillar sizes of 17 nm to 26 nm. A scanning electron microscope (CG6300, manufactured by Hitachi High-Technologies Corporation) was used to measure the length of the resist pattern. The photoresist patterns thus obtained were evaluated for the possibility of forming 23 nm pillars (PL). Formation of 23 nm PL patterns was confirmed in all cases of Examples 1 and 2 and Comparative Example 1. The EUV irradiation dose that formed 23 nm pillars was defined as the optimal irradiation energy, and the irradiation energy (mJ / cm) at that time was ２ ) are shown in Table 4. In Examples 1 and 2, an improvement in sensitivity was confirmed compared to Comparative Example 1, and in Examples 1 and 2, an improvement in minimum CD size and LCDU was confirmed compared to Comparative Example 1.

[0153]

[0154] [5] Resist Patterning Evaluation - 2 [Resist Pattern Formation Test Using an EUV Exposure Apparatus] The resist underlayer film forming compositions of Examples 4 to 6 and Comparative Examples 1 and 2 were each applied to a silicon wafer using a spinner. The silicon wafer was baked on a hot plate at 205°C for 60 seconds to obtain a 5 nm-thick resist underlayer film. A negative EUV resist solution was spin-coated onto the resist underlayer film and heated at 100°C for 60 seconds to form an EUV resist film. The resist film was exposed under specified conditions using an EUV exposure apparatus (NXE3400B). After exposure, the resist was baked at 170°C for 60 seconds (PEB), cooled to room temperature on a cooling plate, and developed with a negative photoresist developer. After development, the resist was baked at 250°C for 60 seconds (HB), cooled to room temperature on a cooling plate, and formed a resist pattern with a pillar size of 21 nm to 25 nm. A scanning electron microscope (CG6300, manufactured by Hitachi High-Technologies Corporation) was used to measure the length of the resist pattern. The photoresist patterns thus obtained were evaluated for the possibility of forming 22 nm pillars (PL). Formation of 22 nm PL patterns was confirmed in all cases of Examples 4 to 6. Formation of 22 nm PL patterns was not confirmed in Comparative Examples 1 and 2. The EUV irradiation dose that formed 22 nm pillars was defined as the optimal irradiation energy, and the irradiation energy (mJ / cm) at that time was used as the optimal irradiation energy. ２ ) are shown in Table 5. It was confirmed that Examples 4 to 6 exhibited good irradiation energy, minimum CD size, and LCDU.

[0155]

[0156] [6] Resist Patterning Evaluation - 3 [Resist Pattern Formation Test Using an EUV Exposure Apparatus] The resist underlayer film forming compositions of Examples 7 to 9 and Comparative Example 3 were each applied to a silicon wafer using a spinner. The silicon wafer was baked on a hot plate at 205°C for 60 seconds to obtain a resist underlayer film with a thickness of 10 nm. A negative EUV resist solution was spin-coated onto the resist underlayer film and heated at 100°C for 60 seconds to form an EUV resist film. The resist film was exposed under specified conditions using an EUV exposure apparatus (NXE3400B). After exposure, the resist film was baked at 170°C for 60 seconds (PEB), cooled to room temperature on a cooling plate, and developed with a negative photoresist developer. After development, the resist film was baked at 250°C for 60 seconds (HB), cooled to room temperature on a cooling plate, and formed a resist pattern with pillar sizes of 17 nm to 23 nm. A scanning electron microscope (CG6300, manufactured by Hitachi High-Technologies Corporation) was used to measure the length of the resist pattern. The photoresist patterns thus obtained were evaluated for the possibility of forming 21 nm pillars (PL). Formation of 21 nm PL patterns was confirmed in all cases of Examples 7 to 9 and Comparative Example 3. The EUV irradiation dose that formed 21 nm pillars was defined as the optimal irradiation energy, and the irradiation energy (mJ / cm) at that time was determined as the optimum irradiation energy. ２ ) are shown in Table 6. It was confirmed that Examples 7 to 9 exhibited good irradiation energy and minimum CD size.

[0157]

[0158] [7] Resist Patterning Evaluation - 4 [Resist Pattern Formation Test Using an EUV Exposure Apparatus] The resist underlayer film forming compositions of Examples 8 and 9 and Comparative Example 3 were each applied to a silicon wafer using a spinner. The silicon wafer was baked on a hot plate at 205°C for 60 seconds to obtain a resist underlayer film with a film thickness of 10 nm. A negative EUV resist solution was spin-coated onto the resist underlayer film and heated at 100°C for 60 seconds to form an EUV resist film. The resist film was exposed under specified conditions using an EUV exposure apparatus (NXE3400B). After exposure, the resist film was baked at 170°C for 60 seconds (PEB), cooled to room temperature on a cooling plate, and developed with a negative photoresist developer. After development, the resist film was baked at 250°C for 60 seconds (HB), cooled to room temperature on a cooling plate, and formed a resist pattern with a line size of 11 nm to 17 nm. A scanning electron microscope (CG6300, manufactured by Hitachi High-Technologies Corporation) was used to measure the length of the resist pattern. The photoresist patterns thus obtained were evaluated for the possibility of forming 14 nm lines and spaces (L / S). Formation of 14 nm L / S patterns was confirmed in all cases of Examples 8 to 9 and Comparative Example 3. The EUV irradiation dose that formed 14 nm lines / 28 nm pitch (line and space (L / S = 1 / 1)) was defined as the optimal irradiation energy, and the irradiation energy (mJ / cm ２ ), and the minimum CD size at which no collapse was observed within the resist pattern shot are shown in Table 7. In Examples 8 to 9, an improvement in sensitivity was confirmed compared to Comparative Example 3, and an improvement in the minimum CD size was also confirmed in Examples 8 and 9.

[0159]

[0160] The resist underlayer film-forming composition according to the present invention can provide a composition for forming a resist underlayer film capable of forming a desired resist pattern, as well as a method for producing a substrate having a resist pattern and a method for producing a semiconductor device using the resist underlayer film-forming composition.

Claims

1. A composition for forming a resist underlayer film, comprising: a polysaccharide (A) having a hydroxy group; and a solvent (B).

2. The composition for forming a resist underlayer film according to claim 1, wherein the polysaccharide (A) is cyclodextrin.

3. The composition for forming a resist underlayer film according to claim 1, further comprising a polymer (C), wherein the polymer (C) comprises a unit structure represented by the following formula (C-1): (In formula (C-1), R １ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. １ represents an oxygen atom or an optionally substituted amino group. １ represents a monovalent group having 1 to 20 carbon atoms.

4. The composition for forming a resist underlayer film according to claim 3, wherein the mass ratio (A:C) of the polysaccharide (A) to the polymer (C) in the composition is 70:30 to 5:

95.

5. The composition for forming a resist underlayer film according to any one of claims 1 to 4, wherein the solvent (B) comprises at least one selected from the group consisting of a carboxylic acid having a hydroxy group, a linear or cyclic alkyl ketone, a cyclic lactone, an alkylene glycol monoalkyl ether, a monocarboxylic acid ester of an alkylene glycol monoalkyl ether, and an alkoxycarboxylic acid ester of an alkylene glycol monoalkyl ether.

6. The composition for forming a resist underlayer film according to any one of claims 1 to 4, further comprising a crosslinking agent (D).

7. The composition for forming a resist underlayer film according to claim 6, wherein the crosslinking agent (D) is at least one selected from the group consisting of aminoplast crosslinking agents and phenoplast crosslinking agents.

8. The composition for forming a resist underlayer film according to any one of claims 1 to 4, further comprising a curing catalyst (E).

9. The composition for forming a resist underlayer film according to any one of claims 1 to 4, which is used in an EB or EUV exposure process.

10. 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 4.

11. A laminate comprising: a semiconductor substrate; and the resist underlayer film according to claim 10.

12. A method for manufacturing a semiconductor device, comprising: a step of forming a resist underlayer film on a semiconductor substrate using a composition for forming a resist underlayer film according to any one of claims 1 to 4; and a step of forming a resist film on the resist underlayer film.

13. A pattern formation method comprising: a step of forming a resist underlayer film on a semiconductor substrate using a composition for forming a resist underlayer film according to any one of claims 1 to 4; a step of forming a resist film on the resist underlayer film; a step of irradiating the resist film with EB or EUV and then developing the resist film to obtain a resist pattern; and a step of etching the resist underlayer film using the resist pattern as a mask.

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