Composition for forming resist underlayer film

Abstract

This composition for forming a resist underlayer film comprises a resin (A) and a solvent (B). The resin (A) is a polymer containing a structural unit represented by formula (1) or a structural unit represented by formula (2). In formula (1), R1 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R2 represents a hydrogen atom, a methyl group or an ethyl group, and p is an average addition mole number and is 2 to 20.　In formula (2), Q represents a divalent group having no sulfur atom, and q represents an average addition mole number and is 1-20.

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] In the manufacture of semiconductor devices, microfabrication by lithography using a resist composition has traditionally been performed. This microfabrication process involves forming a thin film of a photoresist composition on a semiconductor substrate, such as a silicon wafer, irradiating the substrate with active light such as ultraviolet light through a mask pattern bearing a device pattern, developing the film, and etching the substrate using the resulting photoresist pattern as a protective film, thereby forming fine irregularities on the substrate surface corresponding to the photoresist pattern. In recent years, the integration density of semiconductor devices has increased, and in addition to the conventionally used i-line (wavelength 365 nm), KrF excimer laser (wavelength 248 nm), and ArF excimer laser (wavelength 193 nm), the practical use of EUV light (wavelength 13.5 nm) or EB (electron beam) is being considered for cutting-edge microfabrication. As a result, poor resist pattern formation due to influences from the semiconductor substrate, etc., has become a major problem. To address this issue, methods of providing a resist underlayer film between the resist and the semiconductor substrate have been widely investigated.

[0003] A resist underlayer film-forming composition has been proposed, which comprises a reaction product of a compound (A) represented by formula (1) (in formula (1), A represents an organic group containing an aliphatic ring, an aromatic ring, or a heterocycle) dissolved in a solvent, a compound (B) having two functional groups reactive with an epoxy group, and a compound (C) having one functional group reactive with an epoxy group (see Patent Document 1).

[0004] International Publication No. 2022 / 075339

[0005] Properties required for a resist underlayer film include, for example, no intermixing with a resist film formed on top (being insoluble in a resist solvent), the ability to improve resist sensitivity, etc. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a composition for forming a resist underlayer film that can improve resist sensitivity, as well as methods for producing a resist underlayer film, a laminate, and a semiconductor device, and a pattern formation method, all of which use the composition for forming a resist underlayer film.

[0006] 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.

[0007] That is, the present invention includes the following aspects: [1] A composition for forming a resist underlayer film, comprising a resin (A) and a solvent (B), wherein the resin (A) is a polymer containing a structural unit represented by the following formula (1) or a structural unit represented by the following formula (2): (In formula (1), R １ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R ２ represents a hydrogen atom, a methyl group, or an ethyl group, and p represents the average number of moles added and is 2 to 20. In formula (2), Q represents a divalent group having no sulfur atom, and q represents the average number of moles added and is 1 to 20. [2] The composition for forming a resist underlayer film according to [1], wherein Q in formula (2) is represented by the following formula (2-1) or formula (2-2): (In formula (2-1), Q １ represents an alkylene group, an alkenylene group, an alkynylene group, a phenylene group, a naphthylene group, or an anthrylene group, and the phenylene group, the naphthylene group, and the anthrylene group may each independently be substituted with a group selected from the group consisting of an alkyl group having 1 to 6 carbon atoms, a halo group, an alkoxy group having 1 to 6 carbon atoms, a nitro group, a cyano group, and a hydroxy group. n1 and n2 each independently represent 0 or 1. In formula (2-2), X １ represents a group represented by any one of the following formulas (2-2-1) to (2-2-3).１ and Z ２ each independently represents a single bond or a group represented by the following formula (2-2-4). * represents a bond. (In formulas (2-2-1) to (2-2-3), R １１ and R １２ each independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, a benzyl group, or a phenyl group, and the benzyl group and the phenyl group may be substituted with a group selected from the group consisting of an alkyl group having 1 to 6 carbon atoms, a halo group, an alkoxy group having 1 to 6 carbon atoms, a nitro group, a cyano group, a hydroxy group, and an alkylthio group having 1 to 6 carbon atoms; and R １１ and R １２ may be bonded to each other to form a ring having 3 to 6 carbon atoms. １３ represents an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, a benzyl group, or a phenyl group, and the benzyl group and the phenyl group may each independently be substituted with a group selected from the group consisting of an alkyl group having 1 to 6 carbon atoms, a halo group, an alkoxy group having 1 to 6 carbon atoms, a nitro group, a cyano group, and a hydroxy group. * represents a bond. *1 represents a bond bonding to a carbon atom in formula (2-2). *2 represents a bond bonding to a nitrogen atom in formula (2-2). (In formula (2-2-4), m represents an integer of 1 to 4. n represents an integer of 0 to 4. p1 and p2 each independently represent 0 or 1. *3 represents a bond bonding to the nitrogen atom in formula (2-2). *4 represents a bond.) [3] The composition for forming a resist underlayer film according to [1], wherein the resin (A) is a polymer (1) containing a structural unit represented by formula (1), and the mass proportion of the structural unit represented by formula (1) in the polymer (1) is 50 mass% or more. [4] The composition for forming a resist underlayer film according to [1] or [2], wherein the resin (A) is a polymer (2) containing a structural unit represented by formula (2), and the mass proportion of the structural unit represented by formula (2) in the polymer (2) is 50 mass% or more. [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 (C). [7] The composition for forming a resist underlayer film according to [6], wherein the crosslinking agent (C) 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 containing a curing catalyst (D). [9] 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 [8].

[10] A laminate comprising: a semiconductor substrate; and the resist underlayer film according to [9].

[11] 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 [8]; and forming a resist film on the resist underlayer film.

[12] 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 [8]; forming a resist film on the resist underlayer film; irradiating the resist film with light or an electron beam and then developing the resist film to obtain a resist pattern; and etching the resist underlayer film using the resist pattern as a mask.

[0008] According to the present invention, it is possible to provide a composition for forming a resist underlayer film that can improve resist sensitivity, as well as a method for producing a resist underlayer film, a laminate, and a semiconductor element, and a method for forming a pattern, all of which use the composition for forming a resist underlayer film.

[0009] (Composition for forming a resist underlayer film) The composition for forming a resist underlayer film of the present invention contains a resin (A) and a solvent (B). The composition for forming a resist underlayer film may also contain a crosslinking agent (C), a curing catalyst (D), and the like. The resin (A) has an ethylene glycol group. When the composition for forming a resist underlayer film contains the resin (A) having an ethylene glycol group, a resist pattern with improved sensitivity can be formed on the resist underlayer film formed from the composition for forming a resist underlayer film.

[0010] <Resin (A)> Resin (A) is a polymer containing a structural unit represented by the following formula (1) or a structural unit represented by the following formula (2). (In formula (1), R １ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R ２ represents a hydrogen atom, a methyl group, or an ethyl group, and p represents the average number of moles added, which is 2 to 20. In formula (2), Q represents a divalent group having no sulfur atom, and q represents the average number of moles added, which is 1 to 20.

[0011] p is 2 to 20, and may be 2 to 10, or 2 to 7. q is 1 to 20, and may be 1 to 15, or 1 to 10. R １ is preferably a hydrogen atom or a methyl group. Q will be described later.

[0012] <<Polymer Containing a Structural Unit Represented by Formula (1)>> A polymer containing a structural unit represented by formula (1) (hereinafter, may be referred to as "polymer (1)") is, for example, a vinyl polymer. A vinyl polymer is a polymer formed by polymerizing the polymerizable unsaturated bond of a compound having a group having a polymerizable unsaturated bond. The vinyl polymer may be a homopolymer or a copolymer. Examples of the group having a polymerizable unsaturated bond include a (meth)acryloyl group, a (meth)acrylamide group, a vinylaryl group (e.g., a styryl group), a vinyloxy group, and an allyl group.

[0013] Examples of the monomer that provides the structural unit represented by formula (1) include the monomer represented by the following formula (1A). (In formula (1A), R １ , R ２ , and p are R in formula (1), respectively. １ , R ２ , and p.)

[0014] An example of the monomer represented by formula (1A) is polyethylene glycol mono(meth)acrylate. The monomer represented by formula (1A) may be a commercially available product. Examples of commercially available products include Blemmer PE90, PE-200, and PE-350 (manufactured by NOF Corp.).

[0015] The polymer (1) may have a structural unit other than the structural unit represented by formula (1). Examples of such a structural unit include a structural unit represented by formula (B-10) below, a structural unit represented by formula (B-11) below, a structural unit represented by formula (B-12) below, and a structural unit represented by formula (B-13) below. The structural unit represented by formula (B-11), the structural unit represented by formula (B-12), and the structural unit represented by formula (B-13) are structural units different from the structural unit represented by formula (1) and the structural unit represented by formula (B-10).

[0016] (In formula (B-10), R ２ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. １represents a single bond or a linking group. ２ represents a monovalent group having a polymerizable multiple bond. (In formula (B-11), R ２ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms; L ５３ represents a monovalent group having 1 to 20 carbon atoms. ２ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, Ar represents a benzene ring or a naphthalene ring, L ５４ is a hydroxy group, a cyano group, a nitro group, or an amino group (-NH ２ ) represents. ５５ 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 ５４ may be the same or different. When m2 is 2 to 5, multiple L ５５ may be the same or different. ２ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms; L ５６ 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.

[0017] R in formulas (B-10) to (B-13) ２ are each independently preferably a hydrogen atom or a methyl group.

[0018] L １ When L is a linking group, the number of carbon atoms in the linking group is not particularly limited, but may be, for example, 1 to 10. １ is a linking group, examples of the linking group include a linking group having a structure obtained by reacting an epoxy group with a nucleophilic functional group, and a linking group having a structure obtained by reacting an isocyanate group with a nucleophilic functional group.

[0019] L １Examples of the linking groups include the following linking groups (L1-1) to (L1-11). (wherein *1 represents R in formula (B-10) ２ *2 represents a bond bonded to the carbon atom bonded to L in formula (B-10). ２ represents a bond bonded to

[0020] 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, and may be, for example, 1 to 20 or 1 to 10. The polymerizable multiple bond is, for example, one or more types of 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.

[0021] L ２ Examples of the monovalent group having a polymerizable multiple bond in L include a (meth)acryloyl group, a (meth)acrylamide group, a vinylaryl group (for example, a styryl group), a vinyloxy group, and an allyl group. ２ Examples of the group include monovalent groups represented by the following formulae (L2-1) to (L2-81). (* represents a bond.)

[0022] -L in formula (B-10) １ -L ２ Examples of the group include groups represented by the following formulas. (In the formula, R ａ represents a hydrogen atom or a methyl group. * represents a bond.

[0023] L in formula (B-11) ５３The 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 ５３ Examples of the monovalent group having 1 to 20 carbon atoms include groups represented by the following formula (B-11-1). (In formula (B-11-1), L ３ａ represents an optionally substituted alkyl group having 1 to 6 carbon atoms, or an optionally substituted aromatic hydrocarbon group. X represents a single bond or a carbonyl group. * represents a bond.

[0024] L 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. ３ａ When X is an optionally substituted alkyl group having 1 to 6 carbon atoms, for example, X represents a carbonyl group.

[0025] L ５５ Examples of the halogen atom in L include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. ５５ 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.５５ Examples 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.

[0026] L ５３ and L ５６ 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. ５６ 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.

[0027] Examples of the monomer used to derive the formula (B-11) include the following compounds:

[0028] Examples of the monomer used to derive the formula (B-12) include the following compounds: Me represents a methyl group.

[0029] Examples of the monomer used to derive the formula (B-13) include the following compounds:

[0030] The mass proportion of the structural unit represented by formula (1) in polymer (1) is not particularly limited, but is preferably 50 mass % or more from the viewpoint of more suitably achieving the effects of the present invention.

[0031] Polymer (1) can be obtained, for example, by radical polymerization. Furthermore, a method for obtaining polymer (1) having a polymerizable multiple bond can be, for example, a method in which a monomer represented by formula (1A) is copolymerized with a monomer having an epoxy group and a polymerizable unsaturated bond (e.g., glycidyl methacrylate), and then the resulting polymer is reacted with (meth)acrylic acid. In the reaction between the polymer and (meth)acrylic acid, the epoxy group in the polymer reacts with the carboxy group in the (meth)acrylic acid, thereby introducing a group containing a polymerizable multiple bond (a (meth)acryloyl group) into the side chain of the polymer.

[0032] <<Polymer containing a structural unit represented by formula (2)>> A polymer containing a structural unit represented by formula (2) (hereinafter, may be referred to as "polymer (2)") will be described. Polymer (2) contains a structural unit represented by the following formula (2). (In formula (2), Q represents a divalent group having no sulfur atom, and q represents the average number of moles added, which is 1 to 20.)

[0033] Q in formula (2) is not particularly limited as long as it does not have a sulfur atom, and examples thereof include divalent groups having 1 to 20 carbon atoms. From the viewpoint of suitably obtaining the effects of the present invention, Q in formula (2) is preferably represented by the following formula (2-1) or formula (2-2). (In formula (2-1), Q １ represents an alkylene group, an alkenylene group, an alkynylene group, a phenylene group, a naphthylene group, or an anthrylene group, and the phenylene group, the naphthylene group, and the anthrylene group may each independently be substituted with a group selected from the group consisting of an alkyl group having 1 to 6 carbon atoms, a halo group, an alkoxy group having 1 to 6 carbon atoms, a nitro group, a cyano group, and a hydroxy group. n1 and n2 each independently represent 0 or 1. In formula (2-2), X１ represents a group represented by any one of the following formulas (2-2-1) to (2-2-3). １ and Z ２ each independently represents a single bond or a group represented by the following formula (2-2-4). * represents a bond. (In formulas (2-2-1) to (2-2-3), R １１ and R １２ each independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, a benzyl group, or a phenyl group, and the benzyl group and the phenyl group may be substituted with a group selected from the group consisting of an alkyl group having 1 to 6 carbon atoms, a halo group, an alkoxy group having 1 to 6 carbon atoms, a nitro group, a cyano group, a hydroxy group, and an alkylthio group having 1 to 6 carbon atoms; and R １１ and R １２ may be bonded to each other to form a ring having 3 to 6 carbon atoms. １３ represents an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, a benzyl group, or a phenyl group, and the benzyl group and the phenyl group may each independently be substituted with a group selected from the group consisting of an alkyl group having 1 to 6 carbon atoms, a halo group, an alkoxy group having 1 to 6 carbon atoms, a nitro group, a cyano group, and a hydroxy group. * represents a bond. *1 represents a bond bonding to a carbon atom in formula (2-2). *2 represents a bond bonding to a nitrogen atom in formula (2-2). (In formula (2-2-4), m represents an integer of 1 to 4. n represents an integer of 0 to 4. p1 and p2 each independently represent 0 or 1. *3 represents a bond bonding to the nitrogen atom in formula (2-2). *4 represents a bond.)

[0034] Q in formula (2-1) １ The alkylene group in formula (2-1) may be, for example, an alkylene group having 1 to 15 carbon atoms. The alkylene group may have a ring structure. Examples of the ring structure include a cyclohexane ring. １ When is an alkylene group, examples of the group represented by formula (2-1) include the following groups. (* represents a bond.)

[0035] Q in formula (2-1) １ Examples of the alkenylene group in formula (2-1) include alkenylene groups having 2 to 15 carbon atoms. The alkenylene group may have a ring structure. The number of carbon-carbon double bonds in the alkenylene group may be one or two or more. Q in formula (2-1) １ When is an alkenylene group, examples of the group represented by formula (2-1) include the following groups. (* represents a bond.)

[0036] Q in formula (2-1) １ Examples of the alkynylene group in the formula (I) include alkynylene groups having 2 to 15 carbon atoms. The alkynylene group may have a ring structure. The number of carbon-carbon triple bonds in the alkynylene group may be one or two or more.

[0037] Q in formula (2-1) １ When has a phenylene group or a naphthylene group, examples of the group represented by formula (2-1) include the following groups. (* represents a bond.)

[0038] Examples of the group represented by formula (2-2) include the following groups. (* represents a bond.)

[0039] The mass proportion of the structural unit represented by formula (2) in polymer (2) is not particularly limited, but is preferably 50 mass % or more from the viewpoint of more suitably achieving the effects of the present invention.

[0040] The method for synthesizing polymer (2) is not particularly limited, and examples thereof include the reaction shown in the following (I): (I): Reaction of a diepoxy compound represented by the following formula (2A) with a compound represented by the following formula (2-1A) or formula (2-2A). In reaction (I), a compound other than the above compound may be used in combination.

[0041] In the reaction (I), for example, a catalyst that activates the epoxy group is used. Examples of catalysts that activate the epoxy group 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 polymer raw materials used in the reaction. Optimal conditions for the temperature and time of the polymerization reaction can be selected, for example, from the ranges of 80 to 160°C and 2 to 50 hours. (In formula (2A), q has the same meaning as q in formula (2). In formula (2-1A), Q １ , n1, and n2 are respectively Q in formula (2-1). １ , n1, and n2. １ , Z １ , and Z ２ are X in formula (2-2), respectively. １ , Z １ , and Z ２ It is the same as Z. １ and a hydrogen atom bonded to Z ２ The hydrogen atom bonded to the alkyl group is usually an active hydrogen atom. Examples of the active hydrogen include a hydrogen atom of a carboxy group and a hydrogen atom bonded to a nitrogen atom.

[0042] The diepoxy compound represented by formula (2A) is, for example, polyethylene glycol diglycidyl ether. The polyethylene glycol diglycidyl ether may be a commercially available product. Examples of commercially available products include Epolite 40E, Epolite 100E, Epolite 200E, and Epolite 400E (manufactured by Kyoeisha Chemical Co., Ltd.).

[0043] The lower limit of the weight average molecular weight of the resin (A) is, for example, 500, 1,000, or 1,500. The upper limit of the weight average molecular weight of the resin (A) is, for example, 50,000, 30,000, or 20,000.

[0044] The content of the resin (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 95% by mass, more preferably 45% by mass to 90% by mass, and particularly preferably 50% by mass to 85% 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.

[0045] <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).

[0046] 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.

[0047] Examples of linear or cyclic alkyl ketones include methyl ethyl ketone, cyclopentanone, and cyclohexanone.

[0048] An example of the cyclic lactone is γ-butyrolactone.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] Among these solvents (B), alkylene glycol monoalkyl ethers and monocarboxylic acid esters of alkylene glycol monoalkyl ethers are preferred.

[0053] These solvents (B) may be used alone or in combination of two or more.

[0054] The mass proportion of the organic solvent in the solvent (B) is not particularly limited, but is preferably 50 mass % to 100 mass %.

[0055] 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.

[0056] <Crosslinking Agent (C)> The crosslinking agent (C) is not particularly limited. The crosslinking agent (C) has a structure different from that of the resin (A).

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] Examples of the glycoluril derivative represented by the formula (1E) include compounds represented by the following formulas (1E-1) to (1E-6).

[0066] 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).

[0067] (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.

[0068] (In formula (3d), R １ represents a methyl group or an ethyl group.)

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] Examples of the compound represented by formula (G-1) or formula (G-2) include the following compounds:

[0074] 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.

[0075] 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.

[0076] The molecular weight of the crosslinking agent (C) is not particularly limited, but is preferably 1,000 or less.

[0077] 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 resin (A).

[0078] <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.

[0079] Examples of the photoacid generator include an onium salt compound, a sulfonimide compound, and a disulfonyldiazomethane compound.

[0080] 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.

[0081] Examples of the sulfonimide compound include N-(trifluoromethanesulfonyloxy)succinimide, N-(nonafluoronormalbutanesulfonyloxy)succinimide, N-(camphorsulfonyloxy)succinimide, and N-(trifluoromethanesulfonyloxy)naphthalimide.

[0082] 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.

[0083] The curing catalyst (D) may be used alone or in combination of two or more.

[0084] 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.

[0085] <Other Components> A surfactant may be further added to the composition for forming a resist underlayer film in order to prevent pinholes, striations, and the like from occurring and to further improve the coatability against surface irregularities.

[0086] 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.

[0087] 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.

[0088] 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.

[0089] The resist underlayer film-forming composition is preferably used in an EUV (extreme ultraviolet) exposure process, and is preferably used to form an underlayer film of a metal-containing resist.

[0090] (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.

[0091] 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.

[0092] 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.

[0093] 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.

[0094] 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).

[0095] 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)

[0096] (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.

[0097] (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.

[0098] 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 or an electron beam and then developing the resist film to obtain a resist pattern, and etching the resist underlayer film using the resist pattern as a mask.

[0099] Typically, a resist film is formed on the resist underlayer film. The film 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.

[0100] 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 light or electron beam (EB) 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 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, 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).

[0101] 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.

[0102] Examples of the resist composition include the following compositions.

[0103] 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):

[0104] 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.

[0105] 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.

[0106] 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.

[0107] 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.

[0108] 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.

[0109] [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 carboxy group.]

[0110] Examples of the resist film include the following.

[0111] 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:

[0112] (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.

[0113] Examples of resist materials include the following:

[0114] A resist material comprising a polymer having a repeating unit represented by the following formula (b1) or (b2):

[0115] (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.

[0116] A resist material comprising a base resin containing a polymer containing a repeating unit represented by the following formula (a):

[0117] (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.

[0118] 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):

[0119] [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.

[0120] 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).

[0121] [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.

[0122] 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.

[0123] A coating comprising a metal oxo-hydroxo network having organic ligands with metal carbon and / or metal carboxylate bonds.

[0124] Inorganic oxo / hydroxo-based compositions.

[0125] 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′ｎ SnX 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.

[0126] 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.

[0127] An aqueous inorganic patterning precursor solution comprising a mixture of water, metal suboxide cations, polyatomic inorganic anions, and radiation-sensitive ligands comprising peroxide groups.

[0128] 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.

[0129] 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.

[0130] 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.

[0131] Irradiation with light or electron beams is carried out, for example, through a mask (reticle) for forming a predetermined pattern. For example, i-line, KrF excimer laser, ArF excimer laser, EUV (extreme ultraviolet), or EB (electron beam) can be 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 and the exposure dose of light are not particularly limited.

[0132] After irradiation with light or electron beams 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.

[0133] 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.

[0134] 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.

[0135] 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.

[0136] The present invention will now be described in detail with reference to examples, but the present invention is not limited to these examples.

[0137] The weight-average molecular weights of the polymers shown in the following Synthesis Examples 1 to 8 and Comparative Synthesis Examples 1 and 2 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: TSKgel Super-Multipore HZ-N (2 columns) Column temperature: 40°C Solvent: tetrahydrofuran (THF) Flow rate: 0.35 ml / min Standard sample: polystyrene (manufactured by Tosoh Corporation)

[0138] Synthesis Example 1 A solution of 20.00 g of polyethylene glycol monomethacrylate (NOF Corporation, product name: Blemmer PE90), 1.36 g of azobisisobutyronitrile (Tokyo Chemical Industry Co., Ltd.), and 32.00 g of propylene glycol monomethyl ether was added to a dropping funnel, and the mixture was added dropwise at 100°C under a nitrogen atmosphere to a reaction flask containing 15.48 g of propylene glycol monomethyl ether. The mixture was heated and stirred for 24 hours to obtain a polymer solution. The polymer solution did not become cloudy even when cooled to room temperature, and had good solubility in propylene glycol monomethyl ether. GPC analysis revealed that the polymer in the obtained solution had a weight average molecular weight of 4000 in terms of standard polystyrene. The polymer obtained in this synthesis example has a structural unit represented by the following formula (1a):

[0139]

[0140] Synthesis Example 2 A solution of 20.00 g of polyethylene glycol monomethacrylate (NOF Corporation, product name: Blemmer PE200, average number of moles added: 4.5), 1.46 g of azobisisobutyronitrile (Tokyo Chemical Industry Co., Ltd.), and 33.29 g of propylene glycol monomethyl ether was added to a dropping funnel, and the mixture was added dropwise at 100°C under a nitrogen atmosphere to a reaction flask containing 15.72 g of propylene glycol monomethyl ether. The mixture was heated and stirred for 24 hours to obtain a polymer solution. The polymer solution did not become cloudy even when cooled to room temperature, and had good solubility in propylene glycol monomethyl ether. GPC analysis revealed that the polymer in the obtained solution had a weight-average molecular weight of 4000 in terms of standard polystyrene. The polymer obtained in this synthesis example has a structural unit represented by the following formula (1b):

[0141] n is 4.5.

[0142] Synthesis Example 3 A solution of 10.00 g of polyethylene glycol monomethacrylate (NOF Corporation, product name: Blemmer PE90), 3.64 g of glycidyl methacrylate (Tokyo Chemical Industry Co., Ltd.), 0.72 g of azobisisobutyronitrile (Tokyo Chemical Industry Co., Ltd.), and 29.03 g of propylene glycol monomethyl ether was added to a dropping funnel, and the mixture was added dropwise at 100°C under a nitrogen atmosphere to a reaction flask containing 14.41 g of propylene glycol monomethyl ether. The mixture was heated and stirred for 24 hours to obtain a polymer solution. The polymer solution did not become cloudy even when cooled to room temperature, and had good solubility in propylene glycol monomethyl ether. GPC analysis revealed that the polymer in the obtained solution had a weight average molecular weight of 4000 in terms of standard polystyrene. The polymer obtained in this synthesis example has structural units represented by the following formulas (1a) and (1c).

[0143]

[0144] Synthesis Example 4 20.00 g of the polymer solution obtained in Synthesis Example 3, 1.89 g of methacrylic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.34 g of tetrabutylphosphonium bromide (manufactured by ACROSS), and 0.28 g of hydroquinone (manufactured by Tokyo Chemical Industry Co., Ltd.) were added to 25.02 g of propylene glycol monomethyl ether in a reaction vessel and dissolved. After replacing the atmosphere in the reaction vessel with nitrogen, the reaction was carried out at 120°C for 24 hours to obtain a polymer solution. The polymer solution did not become cloudy even when cooled to room temperature, and had good solubility in propylene glycol monomethyl ether. GPC analysis revealed that the polymer in the obtained solution had a weight average molecular weight of 5,000 in terms of standard polystyrene. The polymer obtained in this Synthesis Example has structural units represented by the following formulas (1a) and (1d).

[0145]

[0146] Comparative Synthesis Example 1 A solution of 20.00 g of 2-hydroxyethyl methacrylate (Tokyo Chemical Industry Co., Ltd.), 1.26 g of azobisisobutyronitrile (Tokyo Chemical Industry Co., Ltd.), and 47.53 g of propylene glycol monomethyl ether was added to a dropping funnel, and the mixture was added dropwise at 100°C under a nitrogen atmosphere to a reaction flask containing 28.71 g of propylene glycol monomethyl ether. The mixture was heated and stirred for 24 hours to obtain a polymer solution. The polymer solution did not become cloudy even when cooled to room temperature, and exhibited good solubility in propylene glycol monomethyl ether. GPC analysis revealed that the polymer in the obtained solution had a weight-average molecular weight of 6,000 in terms of standard polystyrene. The polymer obtained in this synthesis example has a structural unit represented by the following formula (2a):

[0147]

[0148] Synthesis Example 5 10.00 g of ethylene glycol diglycidyl ether (manufactured by Kyoeisha Chemical Co., Ltd., product name: Epolite 40E), 4.66 g of fumaric acid (manufactured by Tokyo Chemical Industry Co., Ltd.), and 0.65 g of tetrabutylphosphonium bromide (manufactured by ACROSS) were added to 23.34 g of propylene glycol monomethyl ether in a reaction vessel and dissolved. After replacing the atmosphere in the reaction vessel with nitrogen, the reaction was carried out at 90°C for 24 hours to obtain a polymer solution. The polymer solution did not become cloudy even when cooled to room temperature, and had good solubility in propylene glycol monomethyl ether. GPC analysis showed that the polymer in the obtained solution had a weight average molecular weight of 3,000 in terms of standard polystyrene. The polymer obtained in this synthesis example has a structure represented by the following formulas (11a) and (12a).

[0149]

[0150] Synthesis Example 6 10.00 g of diethylene glycol diglycidyl ether (manufactured by Kyoeisha Chemical Co., Ltd., product name: Epolite 100E), 3.97 g of fumaric acid (manufactured by Tokyo Chemical Industry Co., Ltd.), and 0.55 g of tetrabutylphosphonium bromide (manufactured by ACROSS) were added to 22.11 g of propylene glycol monomethyl ether in a reaction vessel and dissolved. After replacing the atmosphere in the reaction vessel with nitrogen, the reaction was carried out at 90°C for 24 hours to obtain a polymer solution. The polymer solution did not become cloudy even when cooled to room temperature, and had good solubility in propylene glycol monomethyl ether. GPC analysis showed that the polymer in the obtained solution had a weight average molecular weight of 3,000 in terms of standard polystyrene. The polymer obtained in this synthesis example has a structure represented by the following formulas (11b) and (12a).

[0151]

[0152] Synthesis Example 7 10.00 g of polyethylene glycol diglycidyl ether (manufactured by Kyoeisha Chemical Co., Ltd., product name: Epolite 400E), 2.38 g of fumaric acid (manufactured by Tokyo Chemical Industry Co., Ltd.), and 0.33 g of tetrabutylphosphonium bromide (manufactured by ACROSS) were added to 19.27 g of propylene glycol monomethyl ether in a reaction vessel and dissolved. After replacing the atmosphere in the reaction vessel with nitrogen, the reaction was carried out at 90°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 propylene glycol monomethyl ether was good. GPC analysis showed that the polymer in the obtained solution had a weight average molecular weight of 3000 in terms of standard polystyrene. The polymer obtained in this synthesis example has a structure represented by the following formulas (11c) and (12a).

[0153] n: about 9

[0154] Synthesis Example 8 10.00 g of ethylene glycol diglycidyl ether (manufactured by Kyoeisha Chemical Co., Ltd., product name: Epolite 40E), 7.32 g of 5-hydroxyisophthalic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), and 1.30 g of tetrabutylphosphonium bromide (manufactured by ACROSS) were added to 27.99 g of propylene glycol monomethyl ether in a reaction vessel and dissolved. After purging the reaction vessel with nitrogen, the reaction was carried out at 105°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 propylene glycol monomethyl ether was good. GPC analysis showed that the polymer in the obtained solution had a weight average molecular weight of 4000 in terms of standard polystyrene. The polymer obtained in this synthesis example has a structure represented by the following formulas (11a) and (12b).

[0155]

[0156] Comparative Synthesis Example 2 7.00 g of monoallyl diglycidyl isocyanuric acid (manufactured by Shikoku Chemical Industry Co., Ltd.), 3.47 g of fumaric acid (manufactured by Tokyo Chemical Industry Co., Ltd.), and 0.42 g of tetrabutylphosphonium bromide (manufactured by ACROSS) were added to 16.59 g of propylene glycol monomethyl ether in a reaction vessel and dissolved. After replacing the atmosphere in the reaction vessel with nitrogen, the reaction was carried out at 90°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 propylene glycol monomethyl ether was good. GPC analysis showed that the polymer in the obtained solution had a weight average molecular weight of 4000 in terms of standard polystyrene. The polymer obtained in this synthesis example has a structure represented by the following formulas (11d) and (12a).

[0157]

[0158] (Preparation of Compositions for Forming Resist Underlayer Film) (Examples and Comparative Examples) The polymers, crosslinking agents, curing catalysts, and solvents obtained in Synthesis Examples 1 to 2, 4 to 8, and Comparative Synthesis Examples 1 and 2 above were mixed in the proportions shown in Tables 1-1 and 1-2, and filtered through a 0.1 μm fluororesin filter to prepare compositions for forming resist underlayer films.

[0159] The abbreviations in Tables 1-1 and 1-2 are as follows: PL-LI: tetramethoxymethylglycoluril Py-PSA: pyridinium-p-hydroxybenzenesulfonic acid PGMEA: propylene glycol monomethyl ether acetate PGME: propylene glycol monomethyl ether

[0160]

[0161]

[0162] [Elution Test in Photoresist Solvent] Each of the resist underlayer film-forming compositions of Examples 1 to 7 and Comparative Examples 1 and 2 was applied to a silicon wafer, which was a semiconductor substrate, using a spinner. The silicon wafer was placed on a hot plate and baked at 205°C for 1 minute to form a resist underlayer film (film thickness: 5 nm). These resist underlayer films were immersed in a mixed solvent of propylene glycol monomethyl ether (70 vol%) and propylene glycol monomethyl ether acetate (30 vol%), which was used as the solvent for the photoresist-forming composition, at room temperature for 1 minute, and then heated at 100°C for 30 seconds to remove the solvent, after which the film thickness was measured. The results of the solvent resistance test are shown in Tables 2-1 and 2-2. A film thickness reduction of 2% or less (1 Å or less) was evaluated as "good," and a film thickness reduction of more than 2% was evaluated as "poor."

[0163]

[0164]

[0165] (Formation of Resist Pattern by EUV Exposure: Negative Organic Solvent Development) The resist underlayer film forming compositions of Examples 1 and 2, Examples 4 and 5, 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. An EUV resist solution (tin oxide-based resist) was then spin-coated thereon and heated at 130°C for 1 minute to form an EUV resist layer. The resist layer was then exposed using an ASML EUV exposure system (NXE3300B) under conditions of NA = 0.33, σ = 0.67 / 0.90, and dipole. The exposure was performed through a mask configured so that the line width and the width between lines (space width) of the EUV resist after development described below would be 14 nm, i.e., so that dense lines with a line-and-space (L / S) ratio of 1 / 1 would be formed. After exposure, post-exposure baking (PEB, 170°C for 1 minute) was performed, followed by cooling to room temperature on a cooling plate, development using an organic solvent (propylene glycol monomethyl ether acetate) for 60 seconds, and rinsing to form a resist pattern. A scanning electron microscope (CG4100, manufactured by Hitachi High-Technologies Corporation) was used to measure the length of the resist pattern. In forming the above resist pattern, the exposure dose required to obtain a pattern with a CD size of 14 nm was determined and is shown in Tables 3-1 and 3-2. A lower number indicates that the desired pattern can be obtained with a lower exposure dose.

[0166]

[0167]

[0168] The evaluation results showed that the introduction of ethylene glycol groups into the polymer enabled patterning with a smaller exposure dose.

Claims

1. A composition for forming a resist underlayer film, comprising a resin (A) and a solvent (B), wherein the resin (A) is a polymer containing a structural unit represented by the following formula (1) or a structural unit represented by the following formula (2): (In formula (1), R １ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R ２ represents a hydrogen atom, a methyl group, or an ethyl group, and p represents the average number of moles added, which is 2 to 20. In formula (2), Q represents a divalent group having no sulfur atom, and q represents the average number of moles added, which is 1 to 20.

2. The composition for forming a resist underlayer film according to claim 1, wherein Q in the formula (2) is represented by the following formula (2-1) or formula (2-2): (In formula (2-1), Q １ represents an alkylene group, an alkenylene group, an alkynylene group, a phenylene group, a naphthylene group, or an anthrylene group, and the phenylene group, the naphthylene group, and the anthrylene group may each independently be substituted with a group selected from the group consisting of an alkyl group having 1 to 6 carbon atoms, a halo group, an alkoxy group having 1 to 6 carbon atoms, a nitro group, a cyano group, and a hydroxy group. n1 and n2 each independently represent 0 or 1. In formula (2-2), X １ represents a group represented by any one of the following formulas (2-2-1) to (2-2-3). １ and Z ２ each independently represents a single bond or a group represented by the following formula (2-2-4). * represents a bond. (In formulas (2-2-1) to (2-2-3), R １１ and R １２ each independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, a benzyl group, or a phenyl group, and the benzyl group and the phenyl group may be substituted with a group selected from the group consisting of an alkyl group having 1 to 6 carbon atoms, a halo group, an alkoxy group having 1 to 6 carbon atoms, a nitro group, a cyano group, a hydroxy group, and an alkylthio group having 1 to 6 carbon atoms; and R １１ and R １２ may be bonded to each other to form a ring having 3 to 6 carbon atoms. １３ represents an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, a benzyl group, or a phenyl group, and the benzyl group and the phenyl group may each independently be substituted with a group selected from the group consisting of an alkyl group having 1 to 6 carbon atoms, a halo group, an alkoxy group having 1 to 6 carbon atoms, a nitro group, a cyano group, and a hydroxy group. * represents a bond. *1 represents a bond bonding to a carbon atom in formula (2-2). *2 represents a bond bonding to a nitrogen atom in formula (2-2). (In formula (2-2-4), m represents an integer of 1 to 4. n represents an integer of 0 to 4. p1 and p2 each independently represent 0 or 1. *3 represents a bond bonding to the nitrogen atom in formula (2-2). *4 represents a bond.) 3. The composition for forming a resist underlayer film according to claim 1, wherein the resin (A) is a polymer (1) containing a structural unit represented by the formula (1), and the mass proportion of the structural unit represented by the formula (1) in the polymer (1) is 50 mass% or more.

4. The composition for forming a resist underlayer film according to claim 1, wherein the resin (A) is a polymer (2) containing a structural unit represented by the formula (2), and the mass proportion of the structural unit represented by the formula (2) in the polymer (2) is 50 mass% or more.

5. The composition for forming a resist underlayer film according to claim 1, 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 claim 1, further comprising a crosslinking agent (C).

7. The composition for forming a resist underlayer film according to claim 6, wherein the crosslinking agent (C) 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 claim 1, further comprising a curing catalyst (D).

9. 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 8.

10. A laminate comprising: a semiconductor substrate; and the resist underlayer film according to claim 9.

11. 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 8; and a step of forming a resist film on the resist underlayer film.

12. 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 8; a step of forming a resist film on the resist underlayer film; a step of irradiating the resist film with light or an electron beam 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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