Composition for forming resist underlayer film

Abstract

Provided is a composition for forming a resist underlayer film, containing a polybutadiene that has a carbon-carbon double bond and may be modified, and a solvent.

Description

Composition for forming a 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 manufacturing a semiconductor device, and a method for forming a pattern.

[0002] Conventionally, microfabrication using lithography with resist compositions has been performed in the manufacturing of semiconductor devices. This microfabrication method involves forming a thin film of a photoresist composition on a semiconductor substrate such as a silicon wafer, irradiating it with an active light such as ultraviolet light through a mask pattern on which the device pattern is drawn, developing the film, and then 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, semiconductor devices have become more highly integrated, 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 application of EUV light (wavelength 13.5 nm) or EB (electron beam) is being considered for cutting-edge microfabrication. Consequently, poor resist pattern formation has become a major problem. Therefore, in order to solve this problem, methods of providing a resist underlayer film between the resist and the semiconductor substrate are being widely investigated.

[0003] A composition for forming a resist underlayer has been proposed, comprising a polymer (A) having one or more polymerizable multiple bonds selected from the group consisting of carbon-carbon double bonds, carbon-carbon triple bonds, carbon-nitrogen double bonds, and carbon-nitrogen triple bonds in its side chain, and a solvent (see Patent Document 1).

[0004] International Publication No. 2024 / 029548 brochure

[0005] The properties required of a resist underlayer include, for example, that it does not intermix with the resist film formed on top (i.e., it is insoluble in the resist solvent), and that it can form a good resist pattern by improving the sensitivity and adhesion of the resist pattern. The present invention has been made in view of the above circumstances, and aims to provide a resist underlayer film formation composition that can form a good resist pattern while improving sensitivity, as well as a method for manufacturing a resist underlayer film, a laminate, a semiconductor device, and a pattern formation method using the resist underlayer film formation composition.

[0006] The inventors of the present invention conducted diligent research to solve the above problems and, as a result, found that they could solve the above problems, and completed the present invention having the following gist.

[0007] In other words, the present invention encompasses the following embodiments: [1] A composition for forming a resist underlayer film, comprising a polybutadiene having a carbon-carbon double bond and which may be modified, and a solvent. [2] The resist underlayer film forming composition according to [1], wherein the polybutadiene has at least one selected from the structural units represented by the following formula (1-1) and the structural units represented by the following formula (1-2). [3] The resist underlayer film forming composition according to [1] or [2], wherein the polybutadiene has a hydroxyl group. [4] The resist underlayer film forming composition according to any one of [1] to [3], wherein the polybutadiene has at least one selected from the structural units represented by the following formula (2-1) and the structural units represented by the following formula (2-2). (In equations (2-1) and (2-2), L １(Each of these independently represents a monovalent group having polymerizable multiple bonds.) [5] The resist underlayer film forming composition according to any one of [1] to [4], wherein the solvent comprises at least one selected from the group consisting of alkylene glycol monoalkyl ethers and monocarboxylic acid esters of alkylene glycol monoalkyl ethers. [6] The resist underlayer film forming composition according to any one of [1] to [5], further comprising a crosslinking agent. [7] The resist underlayer film forming composition according to [6], wherein the crosslinking agent comprises at least one selected from the group consisting of aminoplast crosslinking agents and phenoplast crosslinking agents. [8] The resist underlayer film forming composition according to any one of [1] to [7], further comprising a curing catalyst. [9] The resist underlayer film forming composition according to any one of [1] to [8], used in EUV lithography.

[10] The resist underlayer film forming composition according to any one of [1] to [9], used for forming an underlayer film of a metal-containing resist.

[11] A resist underlayer film which is a cured product of a resist underlayer film forming composition according to any one of [1] to

[10] .

[12] A laminate comprising a semiconductor substrate and the resist underlayer film according to

[11] .

[13] A method for manufacturing a semiconductor device, comprising the steps of: forming a resist underlayer film on a semiconductor substrate using a resist underlayer film forming composition according to any one of [1] to

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

[14] A pattern forming method, comprising the steps of: forming a resist underlayer film on a semiconductor substrate using a resist underlayer film forming composition according to any one of [1] to

[10] ; forming a resist film on the resist underlayer film; irradiating the resist film with light or an electron beam, 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 resist underlayer film formation composition that can form a good resist pattern while improving sensitivity, as well as a method for manufacturing a resist underlayer film, a laminate, a semiconductor device, and a pattern formation method using the resist underlayer film formation composition.

[0009] (Composition for forming a resist underlayer film) The resist underlayer film formation composition of the present invention comprises polybutadiene having a carbon-carbon double bond and which may be modified, and a solvent. The resist underlayer film formation composition may also contain a crosslinking agent, a curing catalyst, a photoacid generator, etc. Polybutadiene has a carbon-carbon double bond. Polybutadiene may be modified as long as it has a carbon-carbon double bond. By using polybutadiene having a carbon-carbon double bond and which may be modified (hereinafter sometimes referred to as "the polybutadiene of the present invention") as the polymer contained in the resist underlayer film formation composition, a good resist pattern can be formed on the resist underlayer film formed from the resist underlayer film formation composition, while improving sensitivity and suppressing pattern collapse and bridging. The inventors believe that the carbon-carbon double bond, and optionally polymerizable multiple bond, of the polybutadiene of the present invention contribute to the improvement of sensitivity and resist pattern.

[0010] <Polybutadiene of the present invention> The polybutadiene of the present invention has a carbon-carbon double bond. The polybutadiene of the present invention may be modified as long as it has a carbon-carbon double bond. Preferably, the polybutadiene of the present invention is not hydrogenated polybutadiene.

[0011] The polybutadiene of the present invention may be unmodified polybutadiene or modified polybutadiene insofar as it has a carbon-carbon double bond.

[0012] The polybutadiene of the present invention preferably has a hydroxyl group in that it can impart good solvent resistance to the resist underlayer film that forms a crosslinked structure. The polybutadiene of the present invention may have the hydroxyl group at the terminal or in the side chain.

[0013] The polybutadiene of the present invention has, for example, at least one selected from the structural units represented by the following formula (1-1) and the structural units represented by the following formula (1-2).

[0014] The structural unit represented by formula (1-2) may be either the cis or trans isomer.

[0015] The molar ratio (X:Y) of the structural unit (X) represented by formula (1-1) and the structural unit (Y) represented by formula (1-2) in the polybutadiene of the present invention is not particularly limited, but may be 100:0 to 10:90, 95:5 to 10:90, 90:10 to 20:80, 90:10 to 50:50, or 90:10 to 80:20.

[0016] Examples of unmodified polybutadiene include polybutadiene whose terminals are not modified and which has at least one structural unit selected from the structural units represented by formula (1-1) and the structural units represented by formula (1-2). Unmodified polybutadiene may be a commercially available product. Examples of commercially available products include NISSO-PB B-1000, B-2000, and B-3000 (manufactured by Nippon Soda Co., Ltd.).

[0017] Examples of modified polybutadiene include polybutadiene with hydroxyl groups at both ends and epoxidized polybutadiene. Polybutadiene with hydroxyl groups at both ends may be commercially available. Examples of commercially available products include NISSO-PB G-1000, G-2000, G-3000 (manufactured by Nippon Soda Co., Ltd.) and Poly bd R-45HT, R-15HT (manufactured by Idemitsu Kosan Co., Ltd.). Epoxidized polybutadiene may also be commercially available. Examples of commercially available products include NISSO-PB JP-100, JP-200 (manufactured by Nippon Soda Co., Ltd.) and Epolid PB3600 (manufactured by Daicel Corporation).

[0018] The polybutadiene of the present invention preferably has at least one selected from the structural units represented by the following formula (2-1) and the structural units represented by the following formula (2-2). (In equations (2-1) and (2-2), L １ Each of these independently represents a monovalent group having polymerizable multiple bonds. * represents a bond.

[0019] L １ The number of carbon atoms of L is not particularly limited, and may be, for example, 1 to 20, or may be 1 to 10.

[0020] L １ As L, a monovalent group represented by the following formula (2A) is preferable. (In formula (2A), X represents an oxygen atom or -NH-. L ２ represents a monovalent group having a polymerizable multiple bond.)

[0021] L ２ The number of carbon atoms of L is not particularly limited, and may be, for example, 1 to 20, or may be 1 to 10. L １ When the number of carbon atoms of L is 1 to 20, the number of carbon atoms of L ２ is 1 to 19. L １ When the number of carbon atoms of L is 1 to 10, the number of carbon atoms of L ２ is 1 to 9.

[0022] L １ and L ２ Examples of the polymerizable multiple bond in L and L include a carbon-carbon double bond, a carbon-carbon triple bond, a carbon-nitrogen double bond, and a carbon-nitrogen triple bond.

[0023] L in formula (2A) ２ Examples of L include the following monovalent groups (L2-1) to (L2-33). (In the formula, * represents a bond.)

[0024] An example of the structural unit represented by formula (2-1) can be obtained, for example, by the following reaction using epoxidized polybutadiene. (In the formula, X and L ２ are the same as X and L in formula (2A), respectively.) ２ )

[0025] An example of the structural unit represented by formula (2-2) can be obtained, for example, by the following reaction using epoxidized polybutadiene. (In the formula, X and L ２ are the same as X and L in formula (2A), respectively.)２ These are the same as above.

[0026] The above reaction can be carried out in the presence of a catalyst, for example, tetrabutylphosphonium bromide.

[0027] During the above reaction, polymerization inhibitors may be used to suppress the polymerization of polymerizable multiple bonds. Examples of polymerization inhibitors include hydroquinone, methoquinone, 2,2,6,6-tetramethylpiperidine 1-oxyl free radical, and 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl free radical.

[0028] The polybutadiene of the present invention may have at least one selected from the structural units represented by the following formula (3-1) and the structural units represented by the following formula (3-2). (In equations (3-1) and (3-2), L １１ Each of these independently represents a monovalent group that does not possess polymerizable multiple bonds. * represents a bond.

[0029] L １１ The number of carbon atoms is not particularly limited, but for example, it may be 1 to 20 or 1 to 10.

[0030] L １１ Examples include monovalent groups represented by the following formula (3A). (In formula (3A), Y represents an oxygen atom or -NH-. １２ (This represents a monovalent group that does not possess polymerizable multiple bonds.)

[0031] L １２ The number of carbon atoms is not particularly limited, but for example, it may be 1 to 20 or 1 to 10. １１ When the number of carbon atoms is between 1 and 20, L １２ The number of carbon atoms in L is between 1 and 19. １１ When the number of carbon atoms is between 1 and 10, L １２ The number of carbon atoms is between 1 and 9.

[0032] L １２The compound may or may not have heteroatoms. Examples of heteroatoms include oxygen atoms, nitrogen atoms, sulfur atoms, and halogen atoms. Examples of halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms.

[0033] L １２ It may or may not have a ring structure. １２ It may or may not have an aromatic ring. Examples of aromatic rings include aromatic hydrocarbon rings and aromatic heterocycles. Examples of aromatic hydrocarbon rings include benzene rings, naphthalene rings, and anthracene rings. １２ It may or may not have an aliphatic hydrocarbon ring.

[0034] An example of a structural unit represented by formula (3-1) can be obtained, for example, by the following reaction using epoxidized polybutadiene. (wherein Y and L) １２ Y and L in equation (3A) １２ These are the same as above.

[0035] An example of a structural unit represented by formula (3-2) can be obtained, for example, by the following reaction using epoxidized polybutadiene. (wherein Y and L) １２ Y and L in equation (3A) １２ These are the same as above.

[0036] The lower limit of the weight-average molecular weight of the polybutadiene of the present invention is, for example, 500, 1,000, 2,000, or 3,000. The upper limit of the weight-average molecular weight of the polybutadiene of the present invention is, for example, 30,000, 20,000, or 10,000.

[0037] The content of polybutadiene in the resist underlayer film forming composition is not particularly limited, but from the viewpoint of suitably obtaining the effects of the present invention, it is preferably, for example, 50 to 100% by mass, and more preferably 70 to 95% by mass, relative to the film constituent components. In this invention, film constituent components refer to components other than the solvent contained in the resist underlayer film forming composition.

[0038] <Solvent> The solvent is not particularly limited and may be water or an organic solvent. Examples of organic solvents include alkylene glycol monoalkyl ethers and monocarboxylic acid esters of alkylene glycol monoalkyl ethers.

[0039] Examples of alkylene groups in alkylene glycol monoalkyl ethers include alkylene groups having 2 to 4 carbon atoms. Examples of alkyl groups in alkylene glycol monoalkyl ethers include alkyl groups having 1 to 4 carbon atoms. Examples of the number of carbon atoms in alkylene glycol monoalkyl ethers include 3 to 8. Examples of alkylene glycol monoalkyl ethers include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, and propylene glycol monoethyl ether.

[0040] Examples of alkylene groups in the monocarboxylic acid esters of alkylene glycol monoalkyl ethers include alkylene groups having 2 to 4 carbon atoms. Examples of alkyl groups in the monocarboxylic acid esters of alkylene glycol monoalkyl ethers include alkyl groups having 1 to 4 carbon atoms. Examples of monocarboxylic acids in the monocarboxylic acid esters of alkylene glycol monoalkyl ethers include saturated monocarboxylic acids having 2 to 4 carbon atoms. Examples of saturated monocarboxylic acids having 2 to 4 carbon atoms include acetic acid, propionic acid, and butyric acid. Examples of the number of carbon atoms in the monocarboxylic acid esters of alkylene glycol monoalkyl ethers include 5 to 10. Examples of monocarboxylic acid esters of alkylene glycol monoalkyl ethers include methyl cellosolve acetate, ethyl cellosolve acetate, propylene glycol monomethyl ether acetate, and propylene glycol propyl ether acetate.

[0041] Other organic solvents include, for example, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol, toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, cycloheptanone, 4-methyl-2-pentanol, methyl 2-hydroxyisobutyrate, ethyl 2-hydroxyisobutyrate, ethyl ethoxyacetate, 2-hydroxyethyl acetate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl 3-ethoxypropionate, methyl pyruvate, ethyl pyruvate, ethyl acetate, butyl acetate, ethyl lactate, butyl lactate, 2-heptanone, methoxycyclopentane, anisole, γ-butyrolactone, N-methylpyrrolidone, N,N-dimethylformamide, and N,N-dimethylacetamide.

[0042] Among these solvents, alkylene glycol monoalkyl ethers and monocarboxylic acid esters of alkylene glycol monoalkyl ethers are preferred.

[0043] These solvents can be used individually or in combination of two or more.

[0044] The mass percentage of the organic solvent in the solvent is not particularly limited, but 50% to 100% by mass is preferred.

[0045] The solvent content in the resist underlayer film forming composition is not particularly limited, but is preferably 50% to 99.99% by mass, more preferably 75% to 99.95% by mass, and particularly preferably 90% to 99.9% by mass.

[0046] <Crosslinking agent> The crosslinking agent is not particularly limited. The crosslinking agent is different from the polybutadiene of the present invention.

[0047] As crosslinking agents, aminoplast crosslinking agents and phenoplast crosslinking agents are preferred. Aminoplast crosslinking agents are addition condensates of compounds having amino groups, such as melamine and guanamine, with formaldehyde. Phenoplast crosslinking agents are addition condensates of compounds having phenolic hydroxyl groups with formaldehyde.

[0048] Examples of crosslinking agents 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, for example, attached to a nitrogen atom or a carbon atom constituting an aromatic hydrocarbon ring.

[0049] R １０１ Preferably, the group is 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 bonding bond.

[0050] Preferred crosslinking agents include melamine compounds, guanamine compounds, glycoluryl compounds, urea compounds, and compounds having a phenolic hydroxyl group. These can be used individually or in combination of two or more.

[0051] Examples of melamine compounds include hexamethylmelamine, hexamethoxymethylmelamine, compounds in which one to six methylol groups of hexamethylmelamine are methoxymethylated or mixtures thereof, hexamethoxyethylmelamine, hexaacyloxymethylmelamine, compounds in which one to six methylol groups of hexamethylmelamine are acyloxymethylated or mixtures thereof.

[0052] Examples of guanamine compounds include tetramethylolguanamine, tetramethoxymethylguanamine, compounds in which one to four methylol groups of tetramethylolguanamine are methoxymethylated or mixtures thereof, tetramethoxyethylguanamine, tetraacyloxyguanamine, compounds in which one to four methylol groups of tetramethylolguanamine are acyloxymethylated or mixtures thereof.

[0053] Examples of glycoluryl compounds include tetramethylol glycoluryl, tetramethoxy glycoluryl, tetramethoxymethyl glycoluryl, compounds in which one to four methylol groups of tetramethylol glycoluryl are methoxymethylated or mixtures thereof, and compounds in which one to four methylol groups of tetramethylol glycoluryl are acyloxymethylated or mixtures thereof.

[0054] Furthermore, the glycoluryl compound may also be, for example, a glycoluryl derivative represented by the following formula (1E). (In equation (1E), four R １ Each of these independently represents either a methyl group or an ethyl group, R ２ and R ３ Each of these independently represents a hydrogen atom, an alkyl group with 1 to 4 carbon atoms, or a phenyl group.

[0055] Examples of glycoluryl derivatives represented by formula (1E) include compounds represented by the following formulas (1E-1) to (1E-6).

[0056] A glycoluryl derivative represented by formula (1E) can be obtained, for example, by reacting a glycoluryl derivative represented by the following formula (2E) with at least one compound represented by the following formula (3d).

[0057] (In formula (2E), R ２ and R ３ Each of these independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a phenyl group, R ４ Each of these independently represents an alkyl group having 1 to 4 carbon atoms.

[0058] (In formula (3d), R １ (This represents a methyl group or an ethyl group.)

[0059] Examples of glycoluryl derivatives represented by formula (2E) include the compounds represented by formulas (2E-1) to (2E-4) below. Furthermore, examples of compounds represented by formula (3d) include the compounds represented by formulas (3d-1) and (3d-2) below.

[0060] Examples of urea compounds include tetramethylolurea, tetramethoxymethylurea, compounds in which one to four methylol groups of tetramethylolurea are methoxymethylated or mixtures thereof, and tetramethoxyethylurea.

[0061] Examples of compounds having a phenolic hydroxyl group include compounds represented by the following formulas (G-1) or (G-2). (In equations (G-1) and (G-2), Q １ R indicates a single bond or an m1-valent organic group. １ and R ４ Each of these represents an alkyl group having 2 to 10 carbon atoms, or an alkyl group having 2 to 10 carbon atoms having an alkoxy group having 1 to 10 carbon atoms. ２ and R ５ Each represents either a hydrogen atom or a methyl group. ３ and R ６Each of these 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 n is an integer ≤ 3. ２ is 2 ≤ n ２ An integer n ≤ 5 ３ is 0 ≤ n ３ n is an integer ≤ 3. ４ is 0 ≤ n ４ integers ≤ 3, 3 ≤ (n １ +n ２ +n ３ +n ４ This shows integers n ≤ 6. ５ is 1 ≤ n ５ n is an integer ≤ 3. ６ is 1 ≤ n ６ An integer n ≤ 4 ７ is 0 ≤ n ７ n is an integer ≤ 3. ８ is 0 ≤ n ８ integers ≤ 3, 2 ≤ (n ５ +n ６ +n ７ +n ８ (This represents an integer between 5 and 2. m1 represents an integer between 2 and 10.)

[0062] Furthermore, examples of compounds having a phenolic hydroxyl group include compounds represented by the following formulas (G-3) or (G-4). Compounds represented by formulas (G-1) or (G-2) may be obtained by reacting a compound represented by the following formula (G-3) or (G-4) with a hydroxyl group-containing ether compound or an alcohol having 2 to 10 carbon atoms. (In equations (G-3) and (G-4), Q ２ R indicates a single bond or an m2 valent organic group. ８ , R ９ , R １１ and R １２ Each represents either a hydrogen atom or a methyl group. ７ and R １０ Each of these 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 n is an integer ≤ 3. １０ is 2 ≤ n １０ An integer n ≤ 5１１ is an integer of 0 ≦ n １１ ≦ 3, n １２ is an integer of 0 ≦ n １２ ≦ 3, 3 ≦ (n ９ + n １０ + n １１ + n １２ ) ≦ 6. n １３ is an integer of 1 ≦ n １３ ≦ 3, n １４ is an integer of 1 ≦ n １４ ≦ 4, n １５ is an integer of 0 ≦ n １５ ≦ 3, n １６ is an integer of 0 ≦ n １６ ≦ 3, 2 ≦ (n １３ + n １４ + n １５ + n １６ ) ≦ 5. m2 represents an integer from 2 to 10.) Q ２ Examples of the m2-valent organic group in Q include m2-valent organic groups having 1 to 4 carbon atoms.

[0063] Examples of the compound represented by formula (G-1) or formula (G-2) include the following compounds.

[0064] Examples of the compound represented by formula (G-3) or formula (G-4) include the following compounds. The above compounds can be obtained as products of Asahi Organic Materials Industry Co., Ltd. and Honshu Chemical Industry Co., Ltd. Examples of the products include the trade name TMOM-BP of Asahi Organic Materials Industry Co., Ltd.

[0065] Among these, glycoluryl compounds are preferred, specifically tetramethylol glycoluryl, tetramethoxy glycoluryl, tetramethoxymethyl glycoluryl, compounds in which one to four methylol groups of tetramethylol glycoluryl are methoxymethylated or mixtures thereof, compounds in which one to four methylol groups of tetramethylol glycoluryl are acyloxymethylated or mixtures thereof, and tetramethoxymethyl glycoluryl is more preferred.

[0066] The molecular weight of the crosslinking agent is not particularly limited, but it is preferably 500 or less.

[0067] The crosslinking agent content in the resist underlayer film forming composition is not particularly limited, but is, for example, 1% to 70% by mass, preferably 5% to 60% by mass, relative to the total amount of polybutadiene of the present invention.

[0068] <Curing Catalyst> The curing catalyst included as an optional component in the resist underlayer film formation composition is preferably a thermal acid generator. Examples of thermal acid generators 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 salt of p-phenolsulfonic acid), 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.

[0069] Only one type of curing catalyst may be used, or two or more types may be used in combination.

[0070] When a curing catalyst is used, the content of the curing catalyst is, for example, 0.1% to 50% by mass relative to the crosslinking agent, preferably 1% to 30% by mass.

[0071] <Photoacid Generators> Examples of photoacid generators include onium salt compounds, sulfonimide compounds, and disulfonyldiazomethane compounds.

[0072] Examples of iodonium salt compounds include iodonium salt compounds such as diphenyliodonium hexafluorophosphate, diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoron-butanesulfonate, diphenyliodonium perfluoron-octanesulfonate, diphenyliodonium camphorsulfonate, bis(4-tert-butylphenyl)iodonium camphorsulfonate and bis(4-tert-butylphenyl)iodonium trifluoromethanesulfonate, as well as sulfonium salt compounds such as triphenylsulfonium hexafluoroantimonate, triphenylsulfonium nonafluoron-butanesulfonate, triphenylsulfonium camphorsulfonate, triphenylsulfonium trifluoromethanesulfonate, and triphenylsulfonium-4-(3-hydroxyadamantane-1-carbonyloxy)-1,1,2-trifluorobutane-1-sulfonate.

[0073] Examples of sulfonimide compounds include N-(trifluoromethanesulfonyloxy)succinimide, N-(nonafluoron-butanesulfonyloxy)succinimide, N-(camphorsulfonyloxy)succinimide, and N-(trifluoromethanesulfonyloxy)naphthalimide.

[0074] Examples of disulfonyl diazomethane compounds include bis(trifluoromethylsulfonyl)diazomethane, bis(cyclohexylsulfonyl)diazomethane, bis(phenylsulfonyl)diazomethane, bis(p-toluenesulfonyl)diazomethane, bis(2,4-dimethylbenzenesulfonyl)diazomethane, and methylsulfonyl-p-toluenesulfonyldiazomethane.

[0075] Only one type of photoacid generator may be used, or two or more types may be used in combination.

[0076] When a photoacid generator is used, the content of the photoacid generator is, for example, 0.1% to 30% by mass, preferably 1% to 20% by mass, relative to the polybutadiene of the present invention.

[0077] <Other components> The resist underlayer film forming composition does not produce pinholes or striations, and surfactants can be added to further improve the coatability against surface unevenness.

[0078] Examples of surfactants include linear or branched alkylbenzenesulfonic acids (e.g., dodecylbenzenesulfonic acid), 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. Examples include nonionic surfactants such as polyoxyethylene sorbitan fatty acid esters like polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, and polyoxyethylene sorbitan tristearate; fluorinated surfactants such as F-Top EF301, EF303, EF352 (manufactured by Tochem Products Co., Ltd., product name), Megafac F171, F173, R-30 (manufactured by DIC Corporation, product name), Florard FC430, FC431 (manufactured by Sumitomo 3M Co., Ltd., product name), Asahi Guard AG710, Surflon S-382, SC101, SC102, SC103, SC104, SC105, SC106 (manufactured by AGC Inc., product name); and organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.). The amount of these surfactants added is usually 2.0% by mass or less, preferably 1.0% by mass or less, relative to the total solid content of the resist underlayer film forming composition. These surfactants may be added individually or in combination of two or more types.

[0079] The resist underlayer film forming composition may optionally contain a polymerization inhibitor (radical trapping agent). Examples of polymerization inhibitors 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 resist underlayer film forming composition is not particularly limited, but is preferably 1% by mass or less relative to the solid content.

[0080] The solid content of the resist underlayer film forming composition of the present invention, i.e., the components excluding the solvent, is, for example, 0.01% to 10% by mass.

[0081] The resist underlayer formation composition is preferably used in EUV lithography. The resist underlayer formation composition is preferably used to form an underlayer of a metal-containing resist.

[0082] (Resist Underlayer Film) The resist underlayer film of the present invention is a cured product of the resist underlayer film forming composition described above. The resist underlayer film can be manufactured, for example, by coating the resist underlayer film forming composition described above onto a semiconductor substrate and firing it.

[0083] Examples of semiconductor substrates to which the resist underlayer film formation composition is applied include silicon wafers, germanium wafers, and compound semiconductor wafers such as gallium arsenide, indium phosphide, gallium nitride, indium nitride, and aluminum nitride.

[0084] When a semiconductor substrate with an inorganic film formed on its surface is used, the inorganic film is 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 polysilicon films, silicon oxide films, silicon nitride films, BPSG (Boro-Phosphoric Acid Glass) films, titanium nitride films, titanium oxide nitride films, tungsten films, gallium nitride films, and gallium arsenide films.

[0085] The resist underlayer film forming composition of the present invention is applied to such a semiconductor substrate by an appropriate coating method such as a spinner or coater. Subsequently, the resist underlayer film is formed by baking using a heating means such as a hot plate. The baking conditions are appropriately selected from a bake temperature of 100°C to 400°C and a bake time of 0.3 minutes to 60 minutes. Preferably, the bake temperature is 120°C to 350°C and the bake time is 0.5 minutes to 30 minutes, and more preferably, the bake temperature is 150°C to 300°C and the bake time is 0.8 minutes to 10 minutes.

[0086] The thickness of the resist underlayer film can 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 ( The wavelengths are 5 nm to 0.05 μm (50 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), 0.003 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).

[0087] The method for measuring the film thickness of the resist underlayer in this specification is as follows: • Measurement device name: Ellipsometer-type film thickness measuring device RE-3100 (SCREEN Corporation) • SWE (single-wavelength ellipsometer) mode • Arithmetic mean of 8 points (for example, 8 points measured at 1 cm intervals in the wafer X direction)

[0088] (Laminate) The laminate of the present invention comprises a semiconductor substrate and a resist underlayer film of the present invention. Examples of the semiconductor substrate include the semiconductor substrate described above. The resist underlayer film is disposed on top of the semiconductor substrate, for example.

[0089] (Method for manufacturing semiconductor devices, method for forming patterns) The method for manufacturing semiconductor devices of the present invention includes at least the following steps: - A step of forming a resist underlayer film on a semiconductor substrate using the resist underlayer film forming composition of the present invention; and - A step of forming a resist film on the resist underlayer film.

[0090] The pattern formation method of the present invention includes at least the following steps: • A step of forming a resist underlayer film on a semiconductor substrate using the resist underlayer film formation composition of the present invention; • 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, 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.

[0091] Typically, a resist film is formed on top of a resist underlayer. The thickness of the resist film can be, 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 limits are 100 nm, 80 nm, 50 nm, 30 nm, 20 nm, and 10 nm.

[0092] The resist film formed on the resist underlayer by a known method (e.g., coating and firing of a resist composition) is not particularly limited as long as it responds to light or electron beam (EB) used for irradiation. Both negative-type and positive-type photoresists can be used. In this specification, resists that respond to EB are also referred to as photoresists. Examples of photoresists include positive-type photoresists consisting of a novolac resin and 1,2-naphthoquinone diazide sulfonic acid ester, chemically amplified photoresists consisting of a binder having a group that decomposes with acid to increase the alkali dissolution rate and a photoacid generator, chemically amplified photoresists consisting of a low-molecular-weight compound that decomposes with acid to increase the alkali dissolution rate of the photoresist, an alkali-soluble binder and a photoacid generator, and chemically amplified photoresists consisting of a binder having a group that decomposes with acid to increase the alkali dissolution rate and a low-molecular-weight compound that decomposes with acid to increase the alkali dissolution rate of the photoresist and a photoacid generator, and resists containing metal elements. Examples include V146G (manufactured by JSR Corporation), APEX-E (manufactured by Cyprey Corporation), PAR710 (manufactured by Sumitomo Chemical Co., Ltd.), and AR2772 and SEPR430 (manufactured by Shin-Etsu Chemical Co., Ltd.). Additionally, 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).

[0093] 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 While so-called resist compositions and metal-containing resist compositions such as resist compositions, radiation-sensitive resin compositions, and high-resolution patterning compositions based on organometallic solutions described in JP 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., can be used, they are not limited to these.

[0094] Examples of resist compositions include the following compositions.

[0095] A photosensitive or radiation-sensitive resin composition comprising resin A having repeating units with acid-degradable groups whose polar groups are protected by protecting groups that are removed by the action of an acid, and a compound represented by the following general formula (121).

[0096] In general formula (121), m represents an integer from 1 to 6. １ and R ２ Each of these independently represents either a fluorine atom or a perfluoroalkyl group. １ is -O-, -S-, -COO-, -SO ２ -, or -SO ３ Represents -. L ２ W represents an alkylene group or single bond which may have substituents. １ This represents a cyclic organic group which may have substituents. ＋ This represents a cation.

[0097] 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 the third to seventh period of groups 3 to 15 of the periodic table.

[0098] 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) that includes an acid-dissociable group, and an acid generator.

[0099] (In formula (31), Ar is a group obtained by removing (n+1) hydrogen atoms from an arene having 6 to 20 carbon atoms. １ R is a hydroxyl group, a sulfanyl group, or a monovalent organic group having 1 to 20 carbon atoms. n is an integer from 0 to 11. If n is 2 or greater, multiple R １ They are the same or different. R ２ R is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. In formula (32), ３ R is a monovalent group having 1 to 20 carbon atoms and containing the above-mentioned acid-dissociable group. Z is a single bond, an oxygen atom, or a sulfur atom. ４(These are a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.)

[0100] A resist composition containing a resin (A1) comprising structural units having a cyclic carbonate ester structure, structural units represented by the following formula, and structural units having an acid-unstable group, and an acid generator.

[0101] [In the formula, R ２ X represents an alkyl group having 1 to 6 carbon atoms, a hydrogen atom, or a halogen atom, which may have a halogen atom. １ These are single bonds, -CO-O-* or -CO-NR ４ - represents *, where * represents a bond with -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 hydroxyl groups and carboxyl groups.

[0102] Examples of resist films include the following:

[0103] A resist film comprising a base resin containing repeating units represented by the following formula (a1) and / or repeating units represented by the following formula (a2), and repeating units that generate acid bonded to the polymer main chain upon exposure.

[0104] (In equations (a1) and (a2), R Ａ Each of these is independently either a hydrogen atom or a methyl group. １ and R ２ These are each independently tertiary alkyl groups having 4 to 6 carbon atoms. ３ Each of these is independently either a fluorine atom or a methyl group. m is an integer from 0 to 4. １ X is a linking group having 1 to 12 carbon atoms, containing a single bond, a phenylene group or a naphthylene group, or at least one selected from an ester bond, a lactone ring, a phenylene group, and a naphthylene group. ２ (These are single bonds, ester bonds, or amide bonds.)

[0105] Examples of resist materials include the following:

[0106] A resist material comprising a polymer having repeating units represented by the following formula (b1) or formula (b2).

[0107] (In equations (b1) and (b2), R Ａ X is a hydrogen atom or a methyl group. １ X is a single bond or an ester group. ２ X 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 a portion 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 in is replaced by 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 Each of these is independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group, but at least one is a fluorine atom or a trifluoromethyl group. Also, Rf １ and Rf ２ These may combine to form a carbonyl group. １ ~R ５ Each of these is 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, and some or all of the hydrogen atoms of these groups may be substituted with a hydroxyl group, a carboxyl 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 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 sulfonic acid ester group. １ and R ２These may combine to form a ring with the sulfur atom to which they are bonded.

[0108] A resist material comprising a base resin containing a polymer having repeating units represented by the following formula (a).

[0109] (In formula (a), R Ａ R is a hydrogen atom or a methyl group. １ R is a hydrogen atom or an acid-unstable group. ２ This is a linear, branched, or cyclic alkyl group having 1 to 6 carbon atoms, or a halogen atom other than bromine. １ This is a linear, branched, or cyclic alkylene group having 1 to 12 carbon atoms, which may contain a single bond or a phenylene group, or an ester group or a lactone ring. ２ is -O-, -O-CH ２ It is - or -NH-. m is an integer from 1 to 4. u is an integer from 0 to 3. However, m + u is an integer from 1 to 4.

[0110] A resist composition that generates 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) contains a fluororesin component (F1) having a constituent unit (f1) containing a base-dissociable group and a constituent unit (f2) containing a group represented by the following general formula (f2-r-1), the resist composition.

[0111] [In formula (f2-r-1), Rf ２１ Each of these is independently a hydrogen atom, an alkyl group, an alkoxy group, a hydroxyl group, a hydroxyalkyl group, or a cyano group. n'' is an integer from 0 to 2. * represents a bond.

[0112] The aforementioned constituent unit (f1) includes a constituent unit represented by the following general formula (f1-1) or a constituent unit represented by the following general formula (f1-2).

[0113] [In formulas (f1-1) and (f1-2), 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 X is a divalent aromatic cyclic group which may have substituents. ０１ R is a single bond or a divalent linking group. ２ These are, independently, organic groups that contain a fluorine atom.

[0114] The resist composition may be a metal-containing resist. Metal-containing resists are also called metal oxide resists (MORs), and a typical example is a tin oxide-based resist. Examples of metal oxide resist materials include a coating composition containing a metal oxo-hydroxo network having an organic ligand via a metal-carbon bond and / or metal-carboxylate bond, as described in Japanese Patent Application Publication No. 2019-113855. An example of a metal-containing resist uses a peroxo ligand as a radiosensitizing stabilizing ligand. Details of peroxo-based metal oxo-hydroxo compounds are described in the patent document described in paragraph

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

[0115] A coating comprising a metal oxo-hydroxo network having organic ligands via metal-carbon bonds and / or metal-carboxylate bonds.

[0116] Inorganic oxo / hydroxo-based compositions.

[0117] A coating solution comprising an organic solvent; a first organometallic composition comprising formula R ｚ SnO （２－（ｚ／２）－（ｘ／２）） (OH) ｘ (Here, 0 < z ≤ 2 and 0 < (z + x) ≤ 4), equation R'ｎ SnX ４－ｎ A first organometallic composition represented by (where n = 1 or 2), or a mixture thereof, where R and R' are independently hydrocarbyl groups having 1 to 31 carbon atoms, and X is a ligand or a combination thereof having a hydrolyzable bond to Sn; and a hydrolyzable metal compound of the formula MX' ｖ A coating solution comprising a hydrolyzable metal compound represented by (where M is a metal selected from groups 2 to 16 of the periodic table, v is a number from 2 to 6, and X' is a ligand or combination thereof having a hydrolyzable M-X bond).

[0118] Organic solvent and formula RSnO （３／２－ｘ／２） (OH) ｘ A coating solution comprising a first organometallic compound represented by the formula (wherein 0 < x < 3), wherein the solution contains about 0.0025 M to about 1.5 M of tin, and R is an alkyl group or cycloalkyl group having 3 to 31 carbon atoms, wherein the alkyl group or cycloalkyl group is bonded to tin at a secondary or tertiary carbon atom.

[0119] An aqueous solution of an inorganic pattern-forming precursor comprising a mixture of water, a metal oxide cation, a polyatomic inorganic anion, and a radiation-sensitive ligand containing a peroxide group.

[0120] Other examples of metal-containing resists include the compositions described in Japanese Patent Publication No. 2011-253185, WO2015 / 026482, WO2016 / 065120, WO2017 / 066319, WO2017 / 156388, WO2018 / 031896, Japanese Patent Publication No. 2020-122959, Japanese Patent Publication No. 2020-122960, WO2019 / 099981, WO2019 / 199467, WO2019 / 195522, WO2019 / 195522, WO2020 / 210660, WO2021 / 011367, and WO2021 / 016229. These contents are incorporated into this specification to the same extent as if they were all explicitly stated.

[0121] The method for forming a metal-containing resist film from a metal-containing resist is not particularly limited, and includes a method of applying a coating-type resist material (a composition for forming a metal-containing resist film), which is a metal-containing resist, and firing it.

[0122] Furthermore, the metal-containing resist film may be formed by vapor deposition. An example of a method for forming a metal-containing resist film by vapor deposition is the method described in Japanese Patent Application Publication No. 2017-116923. The contents of Japanese Patent Application Publication No. 2017-116923 are incorporated herein to the same extent as if they were fully disclosed. In Japanese Patent Application Publication No. 2017-116923, the metal-containing resist film in the present invention is referred to as a metal oxide-containing film.

[0123] Irradiation with light or an electron beam is performed, for example, through a mask (reticle) for forming a predetermined pattern. For example, i-rays, KrF excimer lasers, ArF excimer lasers, EUV (extreme ultraviolet) or EB (electron beams) are used. The resist underlayer film forming composition of the present invention is preferably applied for EB (electron beam) or EUV (extreme ultraviolet: 13.5 nm) irradiation, and more preferably for EUV (extreme ultraviolet) exposure. The electron beam irradiation energy and the amount of light exposure are not particularly limited.

[0124] A bake (PEB: Post Exposure Bake) may be performed after irradiation with light or electron beam and before development. The bake 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 bake 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.

[0125] For development, for example, alkaline developers and organic solvents are used. The development temperature can be, for example, 5°C to 50°C. The development time can be, for example, 10 seconds to 300 seconds. As alkaline developers, aqueous solutions of the following alkalis can be used: inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia; primary amines such as ethylamine and n-propylamine; secondary amines such as diethylamine and di-n-butylamine; tertiary amines such as triethylamine and methyldiethylamine; alcohol amines such as dimethylethanolamine and triethanolamine; quaternary ammonium salts such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, and choline; and cyclic amines such as pyrrole and piperidine. Furthermore, appropriate amounts of alcohols such as isopropyl alcohol and nonionic surfactants can be added to the aqueous solutions of the above alkalis. Among these, preferred developers are aqueous solutions of quaternary ammonium salts, and more preferably aqueous solutions of tetramethylammonium hydroxide and choline. Furthermore, surfactants can also be added to these developers. Alternatively, instead of using an alkaline developer, development can be performed with an organic solvent such as butyl acetate, and the areas of the photoresist where the alkaline dissolution rate has not improved can be developed.

[0126] Organic solvents can be used as the developer for metal-containing resists, and development is performed with the developer (solvent) after irradiation with light or electron beam. As a result, for example, when a negative-type metal-containing resist film is used, the unexposed areas of the metal-containing resist film are removed, and a pattern of the metal-containing resist film is formed. Examples of developers (organic solvents) include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, isoamyl acetate, ethyl methoxyethyl acetate, ethoxyethyl acetate, 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 - 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 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 can be added to these developers.

[0127] 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. After that, the semiconductor substrate is processed by a known method (such as dry etching) to manufacture a semiconductor device.

[0128] The present invention will now be specifically described with reference to examples, but the present invention is not limited to these examples.

[0129] The weight-average molecular weight of the polymers shown in the synthesis examples below was measured by gel permeation chromatography (hereinafter abbreviated as GPC). A GPC instrument manufactured by Tosoh Corporation was used for the measurement.

[0130] The measurement conditions for the polymers shown in Synthesis Examples 1-4 below are as follows: GPC column: Shodex KF803L, Shodex KF802, Shodex KF801 [registered trademark] (Showa Denko K.K.) Column temperature: 40°C Solvent: N,N-dimethylformamide (DMF) Flow rate: 0.6 ml / min Standard sample: Polystyrene (manufactured by Tosoh Corporation)

[0131] Furthermore, the measurement conditions for the polymers shown in Synthesis Examples 5 to 14 below are as follows: GPC column: Shodex KF803L, Shodex KF802, Shodex KF801 [registered trademark] (Showa Denko K.K.) Column temperature: 40°C Solvent: Tetrahydrofuran (THF) Flow rate: 1.0 ml / min Standard sample: Polystyrene (manufactured by Tosoh Corporation)

[0132] <Synthesis Example 1> 8.00 g of monoallyl diglycidyl isocyanuric acid (manufactured by Shikoku Chemicals, Inc.), 5.45 g of diethyl barbituric acid (manufactured by Tokyo Chemical Industries, Inc.), and 0.48 g of tetrabutylphosphonium bromide (manufactured by Hokko Chemical Co., Ltd.) were added to 56.00 g of propylene glycol monomethyl ether in a reaction vessel and dissolved. After purging the reaction vessel with nitrogen, the reaction was carried out under reflux heating for 10 hours to obtain a solution containing polymer 1. The polymer solution did not become cloudy or otherwise discolored when cooled to room temperature, and its solubility in propylene glycol monomethyl ether was good. GPC analysis revealed that the polymer in the obtained solution had a weight-average molecular weight of 10,000 on a standard polystyrene basis. The polymer obtained in this synthesis example has structural units represented by the following formulas (1a) and (1b).

[0133]

[0134] <Synthesis Example 2> 20.00 g of polyglycidyl methacrylate (manufactured by Maruzen Petrochemical Co., Ltd.), 4.88 g of sorbic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.46 g of tetrabutylphosphonium bromide (manufactured by Tokyo Chemical Industry Co., Ltd.), and 0.02 g of hydroquinone (manufactured by Tokyo Chemical Industry Co., Ltd.) were added to 16.77 g of propylene glycol monomethyl ether and 2.58 g of propylene glycol monomethyl ether acetate in a reaction vessel and dissolved. After purging the reaction vessel with nitrogen, the reaction was carried out at 85°C for 24 hours to obtain a solution containing polymer 2. The polymer solution did not become cloudy or otherwise discolored when cooled to room temperature, and its solubility in the propylene glycol monomethyl ether / propylene glycol monomethyl ether acetate mixed solvent was good. GPC analysis revealed that the polymer in the obtained solution had a weight-average molecular weight of 21,000 on a standard polystyrene basis. The polymer obtained in this synthesis example has a structural unit represented by the following formula (1c).

[0135]

[0136] <Synthesis Example 3> 20.00 g of polyglycidyl methacrylate (manufactured by Maruzen Petrochemical Co., Ltd.), 3.75 g of methacrylic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.46 g of tetrabutylphosphonium bromide (manufactured by Tokyo Chemical Industry Co., Ltd.), and 0.02 g of hydroquinone (manufactured by Tokyo Chemical Industry Co., Ltd.) were added to 15.07 g of propylene glycol monomethyl ether and 0.88 g of propylene glycol monomethyl ether acetate 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 solution containing polymer 3. The polymer solution did not become cloudy or otherwise discolored when cooled to room temperature, and its solubility in the propylene glycol monomethyl ether / propylene glycol monomethyl ether acetate mixed solvent was good. GPC analysis revealed that the polymer in the obtained solution had a weight-average molecular weight of 21,000 on a standard polystyrene basis. The polymer obtained in this synthesis example has a structural unit represented by the following formula (1d).

[0137]

[0138] <Synthesis Example 4> 7.47 g of NISSO-PB® JP-200 (manufactured by Nippon Soda Co., Ltd.), 3.30 g of methacrylic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 1.77 g of tetrabutylphosphonium bromide (manufactured by Tokyo Chemical Industry Co., Ltd.), and 0.03 g of 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl free radical (manufactured by Tokyo Chemical Industry Co., Ltd.) were added to 29.32 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 solution containing polymer 4. The polymer solution did not become cloudy or otherwise discolored when cooled to room temperature, and its solubility in the propylene glycol monomethyl ether / propylene glycol monomethyl ether acetate mixed solvent was good. GPC analysis revealed that the polymer in the obtained solution had a weight-average molecular weight of 6,900 on a standard polystyrene basis. The polymer obtained in this synthesis example has structural units represented by the following formulas (1e) and (1f).

[0139]

[0140] <Synthesis Example 5> 12.00 g of a 60% PGME (propylene glycol monomethyl ether) solution of NISSO-PB® JP-200 (manufactured by Nippon Soda Co., Ltd.), 1.58 g of methacrylic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 2.72 g of 4-vinylbenzoic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 2.67 g of tetrabutylphosphonium bromide (manufactured by Tokyo Chemical Industry Co., Ltd.), and 6.02 g of a 1% PGMEA (propylene glycol monomethyl ether acetate) solution of 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl free radical (manufactured by Tokyo Chemical Industry Co., Ltd.) were added to 6.44 g of propylene glycol monomethyl ether and 0.40 g of propylene glycol monomethyl ether acetate in a reaction vessel and dissolved. After purging the reaction vessel with nitrogen, the reaction was carried out at 120°C for 24 hours to obtain a solution containing polymer 5. The polymer solution did not become cloudy or otherwise discolored when cooled to room temperature, and showed good solubility in a propylene glycol monomethyl ether / propylene glycol monomethyl ether acetate mixed solvent. GPC analysis revealed that the polymer in the obtained solution had a weight-average molecular weight of 7,300 on a standard polystyrene basis. The polymer obtained in this synthesis example has structural units represented by the following formulas (1e), (1f), and (1g).

[0141]

[0142] <Synthesis Example 6> 10.00 g of a 60% PGMEA solution of NISSO-PB® JP-200 (manufactured by Nippon Soda Co., Ltd.), 4.61 g of 4-vinylbenzoic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.96 g of tetrabutylphosphonium bromide (manufactured by Tokyo Chemical Industry Co., Ltd.), and 0.49 g of a 1% PGMEA solution of 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl free radical (manufactured by Tokyo Chemical Industry Co., Ltd.) were added to 7.05 g of propylene glycol monomethyl ether acetate in a reaction vessel and dissolved. After purging the reaction vessel with nitrogen, the reaction was carried out at 120°C for 24 hours to obtain a solution containing polymer 6. The polymer solution did not become cloudy or otherwise discolored even when cooled to room temperature, and its solubility in the propylene glycol monomethyl ether / propylene glycol monomethyl ether acetate mixed solvent was good. GPC analysis revealed that the polymer in the obtained solution had a weight-average molecular weight of 9,300 on a standard polystyrene basis. The polymer obtained in this synthesis example has structural units represented by the following formulas (1e) and (1g).

[0143]

[0144] <Synthesis Example 7> 8.00 g of a 40% PGMEA solution of NISSO-PB® JP-200 (manufactured by Nippon Soda Co., Ltd.), 2.82 g of 3,6,9-trioxadecanoic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 1.15 g of tetrabutylphosphonium bromide (manufactured by Tokyo Chemical Industry Co., Ltd.), and 2.60 g of a 1% PGMEA solution of 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl free radical (manufactured by Tokyo Chemical Industry Co., Ltd.) were added to 1.26 g of propylene glycol monomethyl ether and 0.14 g of propylene glycol monomethyl ether acetate in a reaction vessel and dissolved. After purging the reaction vessel with nitrogen, the reaction was carried out at 120°C for 24 hours to obtain a solution containing polymer 7. The polymer solution did not become cloudy or otherwise discolored when cooled to room temperature, and its solubility in a propylene glycol monomethyl ether / propylene glycol monomethyl ether acetate mixed solvent was good. GPC analysis revealed that the polymer in the obtained solution had a weight-average molecular weight of 8,100 on a standard polystyrene basis. The polymer obtained in this synthesis example has structural units represented by the following formulas (1e) and (1h).

[0145]

[0146] <Synthesis Example 8> 10.00 g of a 40% PGME solution of NISSO-PB® JP-200 (manufactured by Nippon Soda Co., Ltd.), 3.74 g of 1-adamantanecarboxylic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 1.44 g of tetrabutylphosphonium bromide (manufactured by Tokyo Chemical Industry Co., Ltd.), and 3.25 g of a 1% PGMEA solution of 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl free radical (manufactured by Tokyo Chemical Industry Co., Ltd.) were added to 0.18 g of propylene glycol monomethyl ether and 0.16 g of propylene glycol monomethyl ether acetate in a reaction vessel and dissolved. After purging the reaction vessel with nitrogen, the reaction was carried out at 120°C for 24 hours to obtain a solution containing polymer 8. The polymer solution did not become cloudy or otherwise discolored when cooled to room temperature, and its solubility in a propylene glycol monomethyl ether / propylene glycol monomethyl ether acetate mixed solvent was good. GPC analysis revealed that the polymer in the obtained solution had a weight-average molecular weight of 7,200 on a standard polystyrene basis. The polymer obtained in this synthesis example has structural units represented by the following formulas (1e) and (1i).

[0147]

[0148] <Synthesis Example 9> 10.00 g of a 40% PGME solution of NISSO-PB® JP-200 (manufactured by Nippon Soda Co., Ltd.), 2.87 g of 5-norbornene-2-carboxylic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 1.44 g of tetrabutylphosphonium bromide (manufactured by Tokyo Chemical Industry Co., Ltd.), and 3.25 g of a 1% PGMEA solution of 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl free radical (manufactured by Tokyo Chemical Industry Co., Ltd.) were added to 0.50 g of propylene glycol monomethyl ether and 0.04 g of propylene glycol monomethyl ether acetate in a reaction vessel and dissolved. After purging the reaction vessel with nitrogen, the reaction was carried out at 120°C for 24 hours to obtain a solution containing polymer 9. The polymer solution did not become cloudy or otherwise discolored when cooled to room temperature, and showed good solubility in a propylene glycol monomethyl ether / propylene glycol monomethyl ether acetate mixed solvent. GPC analysis revealed that the polymer in the obtained solution had a weight-average molecular weight of 7,300 on a standard polystyrene basis. The polymer obtained in this synthesis example has structural units represented by the following formulas (1e) and (1j).

[0149]

[0150] <Synthesis Example 10> 6.50 g of a 40% PGME solution of NISSO-PB® JP-200 (manufactured by Nippon Soda Co., Ltd.), 3.94 g of M6BA (manufactured by Midori Chemical Co., Ltd.), 0.94 g of tetrabutylphosphonium bromide (manufactured by Tokyo Chemical Industry Co., Ltd.), and 2.11 g of a 1% PGMEA solution of 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl free radical (manufactured by Tokyo Chemical Industry Co., Ltd.) were added to 11.48 g of propylene glycol monomethyl ether acetate in a reaction vessel and dissolved. After purging the reaction vessel with nitrogen, the reaction was carried out at 120°C for 24 hours to obtain a solution containing polymer 10. The polymer solution did not become cloudy or otherwise discolored even when cooled to room temperature, and its solubility in the propylene glycol monomethyl ether / propylene glycol monomethyl ether acetate mixed solvent was good. GPC analysis revealed that the polymer in the obtained solution had a weight-average molecular weight of 8,500 on a standard polystyrene basis. The polymer obtained in this synthesis example has structural units represented by the following formulas (1e) and (1k).

[0151]

[0152] <Synthesis Example 11> 10.00 g of a 40% PGME solution of NISSO-PB® JP-200 (manufactured by Nippon Soda Co., Ltd.), 2.43 g of N-acetylglycine (manufactured by Tokyo Chemical Industry Co., Ltd.), 1.44 g of tetrabutylphosphonium bromide (manufactured by Tokyo Chemical Industry Co., Ltd.), and 3.25 g of a 1% PGMEA solution of 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl free radical (manufactured by Tokyo Chemical Industry Co., Ltd.) were added to 0.30 g of propylene glycol monomethyl ether and 0.12 g of propylene glycol monomethyl ether acetate in a reaction vessel and dissolved. After purging the reaction vessel with nitrogen, the reaction was carried out at 120°C for 24 hours to obtain a solution containing polymer 11. The polymer solution did not become cloudy or otherwise discolored when cooled to room temperature, and showed good solubility in a propylene glycol monomethyl ether / propylene glycol monomethyl ether acetate mixed solvent. GPC analysis revealed that the polymer in the obtained solution had a weight-average molecular weight of 7,300 on a standard polystyrene basis. The polymer obtained in this synthesis example has structural units represented by the following formulas (1e) and (1l).

[0153]

[0154] <Synthesis Example 12> 21.12 g of a 50% PGMEA solution of NISSO-PB® JP-200 (manufactured by Nippon Soda Co., Ltd.), 9.91 g of perfluorobenzoic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.72 g of tetrabutylphosphonium bromide (manufactured by Tokyo Chemical Industry Co., Ltd.), and 0.18 g of 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl free radical (manufactured by Tokyo Chemical Industry Co., Ltd.) were added to 16.06 g of propylene glycol monomethyl ether acetate 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 solution containing polymer 12. The polymer solution did not become cloudy or otherwise discolored when cooled to room temperature, and its solubility in the propylene glycol monomethyl ether / propylene glycol monomethyl ether acetate mixed solvent was good. GPC analysis revealed that the polymer in the obtained solution had a weight-average molecular weight of 7,500 on a standard polystyrene basis. The polymer obtained in this synthesis example has structural units represented by the following formulas (1e) and (1m).

[0155]

[0156] <Synthesis Example 13> 19.96 g of a 50% PGMEA solution of NISSO-PB® JP-200 (manufactured by Nippon Soda Co., Ltd.), 11.29 g of 3,5-dibromobenzoic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.62 g of tetrabutylphosphonium bromide (manufactured by Tokyo Chemical Industry Co., Ltd.), and 0.16 g of 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl free radical (manufactured by Tokyo Chemical Industry Co., Ltd.) were added to 17.97 g of propylene glycol monomethyl ether acetate 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 solution containing polymer 12. The polymer solution did not become cloudy or otherwise discolored even when cooled to room temperature, and its solubility in the propylene glycol monomethyl ether / propylene glycol monomethyl ether acetate mixed solvent was good. GPC analysis revealed that the polymer in the obtained solution had a weight-average molecular weight of 7,500 on a standard polystyrene basis. The polymer obtained in this synthesis example has structural units represented by the following formulas (1e) and (1n).

[0157]

[0158] <Synthesis Example 14> 13.83 g of a 50% PGMEA solution of NISSO-PB® JP-200 (manufactured by Nippon Soda Co., Ltd.), 13.96 g of 2,3,5-triiodobenzoic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.43 g of tetrabutylphosphonium bromide (manufactured by Tokyo Chemical Industry Co., Ltd.), and 0.11 g of 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl free radical (manufactured by Tokyo Chemical Industry Co., Ltd.) were added to 21.67 g of propylene glycol monomethyl ether acetate 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 solution containing polymer 12. The polymer solution did not become cloudy or otherwise discolored even when cooled to room temperature, and its solubility in the propylene glycol monomethyl ether / propylene glycol monomethyl ether acetate mixed solvent was good. GPC analysis revealed that the polymer in the obtained solution had a weight-average molecular weight of 7,500 on a standard polystyrene basis. The polymer obtained in this synthesis example has structural units represented by the following formulas (1e) and (1o).

[0159]

[0160] [Preparation of Compositions for Forming Underlayer Films of Resists] (Examples, Comparative Examples) The polymers obtained in Synthesis Examples 1 to 14, polybutadiene polymer (polymer 15, formula (1p), NISSO-PB® G-1000 (manufactured by Nippon Soda Co., Ltd.)), crosslinking agent, curing catalyst, and solvent were mixed in the proportions shown in Table 1, and the mixture was filtered through a fluororesin filter with a pore size of 0.1 μm to prepare the underlayer film formation compositions for EUV lithography resists of Examples 1 to 14 and Comparative Examples 1 to 3, respectively.

[0161] According to the catalog of Nippon Soda Co., Ltd., polymer 15 is represented by the following formula (1g).

[0162] The abbreviations in Table 1 are as follows: PL-LI: Tetramethoxymethylglycoluryl PGME-PL: Imidazo[4,5-d]imidazole-2,5(1H,3H)-dione,tetrahydro-1,3,4,6-tetrakis[(2-methyl-1-methylethylethoxy)methyl]-(see structural formula below)

[0163] TPS-HAdTF: Triphenylsulfonium = 4-(3-hydroxyadamantane-1-carbonyloxy)-1,1,2-trifluorobutane-1-sulfonate (structural formula below)

[0164] Py-PSA: Pyridinium-p-hydroxybenzenesulfonic acid Py-PTS: Pyridinium-p-toluenesulfonic acid PGMEA: Propylene glycol monomethyl ether acetate PGME: Propylene glycol monomethyl ether In the table, "-" indicates that it has not been added.

[0165]

[0166] [Elution Test in Photoresist Solvent] The resist underlayer film formation compositions of Examples 1 to 14 and Comparative Examples 1 to 3 were each applied onto a silicon wafer, which is 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 (thickness 10 nm). These resist underlayer films were immersed in a mixed solution of propylene glycol monomethyl ether / propylene glycol monomethyl ether acetate = 70 / 30 (volume ratio), which is the solvent used for photoresists. A change in film thickness of less than 10 Å was judged as "good," and a change of 10 Å or more was judged as "poor." The results are shown in Table 2.

[0167]

[0168] [Formation of Negative Resist Patterns by EUV Exposure] The resist underlayer formation compositions of Examples 1 and 4, and Comparative Examples 1 to 3, were applied to silicon wafers using a spinner. The silicon wafers were baked on a hot plate at 205°C for 60 seconds to obtain a resist underlayer with a thickness of 10 nm. An EUV resist solution (tin oxide-based resist) was spin-coated onto the resist underlayer and heated at 130°C for 1 minute to form an EUV resist layer. Subsequently, exposure was performed using an ASML EUV exposure apparatus (NXE3400) under the conditions of NA = 0.33, σ = 0.60 / 0.82 (outer / inner), and 50017. During exposure, exposure was performed through a mask set so that the line and space pattern (hereinafter referred to as L / S) of the EUV resist after development was 14 nm line / 28 nm pitch (L / S = 1 / 1). After exposure, post-exposure heating (PEB, 180°C for 1 minute) was performed, followed by cooling to room temperature on a cooling plate. Development was then performed for 60 seconds using an organic solvent (acetic acid-containing propylene glycol monomethyl ether acetate solution), followed by rinsing to form a resist pattern with a CD size of 14 nm. A scanning electron microscope (Hitachi High-Technologies Corporation, CG6100) was used to measure the length of the resist pattern. The photoresist patterns obtained in this manner were evaluated by observation from the top of the pattern. A pattern with a CD size of 10.5 nm L / S was considered "good," while a pattern collapse was considered "poor." A pattern with a CD size of 17 nm L / S was considered "good," while a pattern bridge was considered "poor." The exposure amount used to form a CD size of 14 nm L / S was defined as the optimal exposure amount, and the exposure amount at that time (mJ / cm²) was determined. ２ Table 3 shows the results.

[0169]

[0170] Examples 1 and 4 showed improved sensitivity and bridge margin in L / S at a CD size of 14 nm compared to Comparative Examples 1 to 3. These results demonstrate that resist underlayer films obtained from resist underlayer formation compositions containing polybutadiene or its modified products can improve sensitivity or bridge margin and have good pattern formation ability.

Claims

1. A composition for forming a resist underlayer film, comprising a polybutadiene having a carbon-carbon double bond and which may be modified, and a solvent.

2. The resist underlayer film forming composition according to claim 1, wherein the polybutadiene has at least one selected from the structural units represented by the following formula (1-1) and the structural units represented by the following formula (1-2).

3. The resist underlayer film forming composition according to claim 1, wherein the polybutadiene has a hydroxyl group.

4. The resist underlayer film forming composition according to claim 1, wherein the polybutadiene has at least one selected from the structural units represented by the following formula (2-1) and the structural units represented by the following formula (2-2). (In equations (2-1) and (2-2), L １ Each of these independently represents a monovalent group having polymerizable multiple bonds.

5. The resist underlayer film forming composition according to claim 1, wherein the solvent comprises at least one selected from the group consisting of alkylene glycol monoalkyl ethers and monocarboxylic acid esters of alkylene glycol monoalkyl ethers.

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

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

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

9. The resist underlayer film formation composition according to claim 1, used in EUV lithography.

10. The resist underlayer film forming composition according to claim 1, used for forming an underlayer film of a metal-containing resist.

11. A resist underlayer film, which is a cured product of a resist underlayer film forming composition according to any one of claims 1 to 10.

12. A laminate comprising a semiconductor substrate and a resist underlayer film according to claim 11.

13. A method for manufacturing a semiconductor device, comprising the steps of: forming a resist underlayer film on a semiconductor substrate using a resist underlayer film forming composition according to any one of claims 1 to 10; and forming a resist film on the resist underlayer film.

14. A pattern formation method comprising: forming a resist underlayer film on a semiconductor substrate using a resist underlayer film forming composition according to any one of claims 1 to 10; forming a resist film on the resist underlayer film; irradiating the resist film with light or an electron beam, then developing the resist film to obtain a resist pattern; and etching the resist underlayer film using the resist pattern as a mask.

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