Composition for forming resist underlayer film

Abstract

The purpose of the present invention is to provide: a resist underlayer film that requires the characteristics of a resist underlayer film that has high density and hardness after etching and does not bend; a composition for forming a resist underlayer film, which enables the formation of the resist underlayer film; a method for forming a resist pattern; and a method for manufacturing a semiconductor device. [Solution] A composition for forming a resist underlayer film, which contains a solvent and a polymer obtained by reacting a glycoluril compound with an aromatic compound having at least one phenolic hydroxyl group, and which has a nitrogen content of less than 10% by mass.

Description

Technical Field

[0001] The present invention relates to a composition for forming a photoresist underlayer film suitable for photolithography in semiconductor substrate processing, a photoresist underlayer film obtained from the composition for forming a photoresist underlayer film, a method for forming a photoresist pattern using the composition for forming a photoresist underlayer film, and a method for manufacturing a semiconductor device using the composition. Background Technology

[0002] In recent years, semiconductor manufacturing processes have advanced rapidly. In hybrid processes, material bending occurs after etching spin-coated carbon (SOC). Therefore, materials that do not bend even after SOC etching are required. This also necessitates a high-hardness resist underlayer film. This invention advances the development of high-hardness film materials.

[0003] Increasing the film density is accompanied by an increase in film hardness. Higher film density and hardness result in greater pressure resistance during etching and a more flexible film material. To improve film density, the inventors of this application discovered that by polymerizing monomers with a rigid and linear framework in a two-dimensional direction (planar structure), and further... Polymers can be synthesized by stacking and hydrogen bonding in three dimensions, as well as by synthesizing polymers containing hydroxyl groups with thermally crosslinkable sites, thereby achieving high film density / high hardness.

[0004] Specifically, it was discovered that polymers of glycourea compounds with substituents and reactive comonomers with phenolic hydroxyl groups produce high film density / high hardness.

[0005] A composition for forming an antireflective film in a photolithography process for semiconductor device manufacturing is reported, which contains a glycourea compound. The antireflective film formed by this composition has the following characteristics: it effectively absorbs reflected light from the substrate when irradiation light of wavelengths such as 248 nm, 193 nm, and 157 nm is used for micro-processing, does not mix with the photoresist layer, obtains excellent photoresist patterns, and has a large dry etching speed compared to photoresist (see Patent Document 1).

[0006] Furthermore, it has been reported that an antireflective film formed from a coating composition comprising a polymer that can be obtained by reacting a glycourea compound with at least one reactive compound comprising at least one hydroxyl group and / or at least one acid group has the following characteristics: even under short wavelength exposure, it suppresses reflection from the substrate and protects the photolithographic properties of the photoresist (see Patent Document 2).

[0007] However, although patent documents 1 and 2 mention the formation of high-density / high-hardness films, there is no evidence to support this claim.

[0008] Existing technical documents

[0009] Patent documents

[0010] Patent Document 1: Japanese Patent Application Publication No. 2004-126161

[0011] Patent Document 2: Japanese Patent No. 5613950 Summary of the Invention

[0012] The problem that the invention aims to solve

[0013] With the rapid advancements in semiconductor manufacturing processes, there is a strong demand for high-quality and improved properties of the underlayer resist. This includes a requirement for an underlayer resist with high density and hardness after etching, and the ability to resist without bending. This invention provides a composition for forming an underlayer resist having these properties, an underlayer resist obtained from the composition, a method for forming a resist pattern using the composition, and a method for manufacturing a semiconductor device using the composition.

[0014] Methods for solving problems

[0015] This invention addresses the aforementioned problems. Specifically, this invention includes the following solutions.

[0016] The first aspect of the present invention relates to a composition for forming a resist underlayer film, comprising a polymer obtained by reacting a glycourea compound with an aromatic compound having at least one phenolic hydroxyl group, and a solvent, wherein the polymer has a nitrogen content of less than 10% by mass.

[0017] The second aspect of the present invention relates to the composition for forming a resist underlayer film as described in the first aspect, wherein the carbon content of the polymer is 80% or less.

[0018] The third aspect of the present invention relates to the composition for forming a photoresist underlayer film as described in the first aspect, wherein the glycourea compound is a glycourea compound substituted with at least one substituent, wherein the substituent is at least one substituent selected from hydroxyalkyl with 1 to 12 carbon atoms, alkoxyalkyl with 2 to 12 carbon atoms, and alkenyloxyalkyl with 3 to 12 carbon atoms.

[0019] The fourth aspect of the present invention relates to the composition for forming a resist underlayer film as described in the first aspect, wherein the glycoure compound is selected from tetrahydroxymethylglycourea, tetrabutoxymethylglycourea, tetramethoxymethylglycourea, partially hydroxymethylated glycourea, dimethoxymethylglycourea, monomethyl ether of dihydroxymethylglycourea or dimethyl ether of dihydroxymethylglycourea, trimethyl ether of tetrahydroxymethylglycourea, tetramethyl ether of tetrahydroxymethylglycourea, tetraethoxymethylglycourea, tetrapropoxymethylglycourea, tetrapentyloxymethylglycourea, tetrahexyloxymethylglycourea, and mixtures thereof.

[0020] The fifth aspect of the present invention relates to the composition for forming a resist underlayer film as described in the first aspect, wherein the glycourea compound is a glycourea compound that is at least substituted with methoxymethyl.

[0021] The sixth aspect of the present invention relates to the composition for forming a resist underlayer film as described in the first aspect, wherein the aromatic compound having a phenolic hydroxyl group is selected from the following compounds.

[0022]

[0023]

[0024]

[0025] The seventh aspect of the present invention relates to the composition for forming a resist underlayer film as described in the first aspect, wherein the solvent is a solvent with a boiling point of 160°C or higher.

[0026] The eighth aspect of the present invention relates to the composition for forming a resist underlayer film as described in the first aspect, which further comprises a crosslinking agent.

[0027] The ninth aspect of the present invention relates to the composition for forming a resist underlayer film as described in the eighth aspect, wherein the crosslinking agent is an amino plastic crosslinking agent, or an amino plastic crosslinking agent and a phenolic plastic crosslinking agent.

[0028] The tenth aspect of the present invention relates to the composition for forming a resist underlayer film as described in the first aspect, which further comprises a surfactant.

[0029] The eleventh aspect of the present invention relates to the composition for forming a resist underlayer film as described in the first aspect, which further comprises an acid and / or its salt and / or an acid-generating agent.

[0030] The 12th aspect of the present invention relates to a resist underlayer film, which is a sintered product of a coated film formed from any one of the compositions of the 1st to 11th aspects.

[0031] The 13th aspect of the present invention relates to a method for forming a resist pattern for manufacturing a semiconductor, comprising the steps of: coating a resist underlayer film forming composition as described in any one of the first to eleventh aspects onto a semiconductor substrate and firing it to form a resist underlayer film; forming a resist film on the resist underlayer film; and forming a resist pattern on the resist film by irradiation and development with light or an electron beam.

[0032] The 14th aspect of the present invention relates to a method for manufacturing a semiconductor device, comprising the following steps: coating a resist underlayer film forming composition as described in any one of the first to eleventh aspects onto a semiconductor substrate and firing it to form a resist underlayer film; forming a resist film on the resist underlayer film; forming a resist pattern on the resist film; etching the resist underlayer film using the resist pattern; and processing the semiconductor substrate using the patterned resist underlayer film.

[0033] The 15th aspect of the present invention relates to a method for manufacturing a semiconductor device as described in the 14th aspect, wherein a resist pattern is formed on the resist film by irradiation and development with light or an electron beam.

[0034] The 16th aspect of the present invention relates to a method for manufacturing a semiconductor device as described in the 14th aspect, wherein a resist pattern is formed on the resist film by nanoimprinting or a self-assembled film.

[0035] The 17th aspect of the present invention relates to a method for manufacturing a semiconductor device, comprising the following steps: coating a resist underlayer film forming composition as described in any one of the first to eleventh aspects onto a semiconductor substrate and firing it to form a resist underlayer film; forming a hard mask on the resist underlayer film; further forming a resist film on the hard mask; forming a resist pattern on the resist film; etching the hard mask using the resist pattern; etching the resist underlayer film using the patterned hard mask; and processing the semiconductor substrate using the patterned resist underlayer film.

[0036] The 18th aspect of the present invention relates to a method for manufacturing a semiconductor device as described in the 17th aspect, wherein the aforementioned hard mask is formed by coating a composition comprising an inorganic material or by vapor deposition of a composition comprising an inorganic material.

[0037] The 19th aspect of the present invention relates to a method for manufacturing a semiconductor device as described in the 17th aspect, wherein a resist pattern is formed on the resist film by irradiation and development with light or an electron beam.

[0038] The 20th aspect of the present invention relates to a method for manufacturing a semiconductor device as described in the 17th aspect, wherein a resist pattern is formed on the resist film by nanoimprinting or a self-assembled film.

[0039] The 21st aspect of the present invention relates to a method for manufacturing a semiconductor device, comprising the following steps: coating a resist underlayer film forming composition as described in any one of the first to eleventh aspects onto a semiconductor substrate and firing it to form a resist underlayer film; forming a hard mask on the resist underlayer film; further forming a resist film on the hard mask; forming a resist pattern on the resist film; etching the hard mask using the resist pattern; etching the resist underlayer film using the patterned hard mask; removing the hard mask; and processing the semiconductor substrate using the patterned resist underlayer film.

[0040] The 22nd aspect of the present invention relates to a method for manufacturing a semiconductor device as described in the 21st aspect, wherein the aforementioned hard mask is formed by coating a composition comprising an inorganic material or by vapor deposition of a composition comprising an inorganic material.

[0041] The 23rd aspect of the present invention relates to a method for manufacturing a semiconductor device as described in the 21st aspect, wherein a resist pattern is formed on the resist film by irradiation and development with light or an electron beam.

[0042] The 24th aspect of the present invention relates to a method for manufacturing a semiconductor device as described in the 21st aspect, wherein a resist pattern is formed on the resist film by nanoimprinting or a self-assembled film.

[0043] The 25th aspect of the present invention relates to a method for manufacturing a semiconductor device as described in the 21st aspect, wherein a hard mask is removed by either etching or an alkaline solution.

[0044] The 26th aspect of the present invention relates to a method for manufacturing a semiconductor device, comprising the following steps: coating a resist underlayer film forming composition as described in any one of the first to eleventh aspects onto a semiconductor substrate and firing it to form a resist underlayer film; forming a hard mask on the resist underlayer film; further forming a resist film on the hard mask; forming a resist pattern on the resist film; etching the hard mask using the resist pattern; etching the resist underlayer film using the patterned hard mask; removing the hard mask; forming a vapor-deposited film (spacer) on the resist underlayer film after removing the hard mask; processing the vapor-deposited film (spacer) by etching; removing the patterned resist underlayer film to leave the patterned vapor-deposited film (spacer); and processing the semiconductor substrate using the patterned vapor-deposited film (spacer).

[0045] The 27th aspect of the present invention relates to a method for manufacturing a semiconductor device as described in the 26th aspect, wherein the aforementioned hard mask is formed by coating a composition comprising inorganic material or by vapor deposition of a composition comprising inorganic material.

[0046] The 28th aspect of the present invention relates to a method for manufacturing a semiconductor device as described in the 26th aspect, wherein a resist pattern is formed on the resist film by irradiation and development with light or an electron beam.

[0047] The 29th aspect of the present invention relates to a method for manufacturing a semiconductor device as described in the 26th aspect, wherein a resist pattern is formed on the resist film by nanoimprinting or a self-assembled film.

[0048] The 30th aspect of the present invention relates to a method for manufacturing a semiconductor device as described in the 26th aspect, wherein a hard mask is removed by either etching or an alkaline solution.

[0049] The effects of the invention

[0050] The resist underlayer film forming composition of the present invention, by having a coplanar structure with a small free volume in the two-dimensional direction, and further synthesizing polymers through stacking in the three-dimensional direction via hydrogen bonding, can form a resist underlayer film with high film density. By further synthesizing a polymer containing hydroxyl groups with thermally crosslinking sites, a high-hardness resist underlayer film can be further achieved. Such a high-density and high-hardness resist underlayer film can be widely used in diverse semiconductor manufacturing processes. Detailed Implementation

[0051] The resist underlayer film forming composition of the present invention is characterized by comprising a polymer obtained by reacting a glycourea compound with an aromatic compound having at least one phenolic hydroxyl group, and a solvent. Further, it may optionally comprise a crosslinking agent, an acid-generating agent, or a surfactant.

[0052] The following is a detailed description of each ingredient.

[0053] <Glycourea compounds>

[0054] The glycourea compound of the present invention is preferably a glycourea compound substituted with at least one substituent. Furthermore, the glycourea compound of the present invention can be a single glycourea compound or can be used as a mixture.

[0055] Examples of substituents include hydroxyalkyl groups with 1 to 12 carbon atoms, alkoxyalkyl groups with 2 to 12 carbon atoms, and alkenyloxyalkyl groups with 3 to 12 carbon atoms.

[0056] The preferred hydroxyalkyl group has 1 to 12 carbon atoms, such as hydroxymethyl, hydroxybutyl, and hydroxyethyl.

[0057] Preferably, the alkoxyalkyl group has 2 to 12 carbon atoms, and examples include methoxymethyl, ethoxymethyl, propoxymethyl, butoxymethyl, pentyloxymethyl, hexoxymethyl, methoxyethyl, ethoxyethyl, propoxyethyl, butoxyethyl, methoxypropyl, ethoxypropyl, propoxypropyl, butoxypropyl, methoxybutyl, ethoxybutyl, propoxybutyl, butoxybutyl, etc.

[0058] Preferably, the alkenyloxyalkyl group has 3 to 12 carbon atoms, and examples include vinyloxymethyl, vinyloxyethyl, vinyloxypropyl, allyloxymethyl, allyloxyethyl, and allyloxypropyl.

[0059] Preferred are glycourea compounds substituted with these substituents, selected from tetrahydroxymethylglycourea, tetrabutoxymethylglycourea, tetramethoxymethylglycourea, partially hydroxymethylated glycourea, dimethoxymethylglycourea, monomethyl ether or dimethyl ether of dihydroxymethylglycourea, trimethyl ether of tetrahydroxymethylglycourea, tetramethyl ether of tetrahydroxymethylglycourea, tetraethoxymethylglycourea, tetrapropoxymethylglycourea, tetrapentyloxymethylglycourea, tetrahexyloxymethylglycourea, and mixtures thereof.

[0060] <Aromatic compounds with phenolic hydroxyl groups>

[0061] The aromatic compounds with phenolic hydroxyl groups mentioned above are selected from the following compounds.

[0062]

[0063]

[0064]

[0065] Preferably, the aromatic compounds having phenolic hydroxyl groups are selected from the following compositions.

[0066]

[0067] <Polymer Manufacturing>

[0068] Polymers obtained by reacting glycourea compounds with aromatic compounds having phenolic hydroxyl groups can be modulated using known methods. For example, they can be modulated by condensing glycourea compounds with aromatic compounds having phenolic hydroxyl groups.

[0069] One or more aromatic compounds with phenolic hydroxyl groups can be used, either glycourea or aromatic compounds. In this condensation reaction, aromatic compounds with phenolic hydroxyl groups can be used in a ratio of 0.1 to 10 moles, preferably 0.1 to 2 moles, relative to 1 mole of glycourea.

[0070] Preferably, the polymer has a nitrogen content of less than 10% by mass. More preferably, the polymer has a carbon content of less than 80%.

[0071] The above condensation reactions can proceed even without a solvent, but are usually carried out using a solvent. There are no particular limitations on the solvent, as long as it can dissolve the reaction substrate and does not hinder the reaction. Examples include 1,2-dimethoxyethane, diethylene glycol dimethyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, tetrahydrofuran, and dimethyl ether. Alkane and other ethers. Furthermore, if the catalyst used is a liquid substance such as formic acid, it can also act as a solvent.

[0072] The condensation reaction temperature is typically 40℃ to 200℃, preferably 80℃ to 180℃. The reaction time varies depending on the reaction temperature, but is typically 5 minutes to 50 hours, preferably 5 minutes to 24 hours.

[0073] The polymer involved in one aspect of the present invention typically has a weight-average molecular weight of 500 to 100,000, preferably 600 to 50,000, 700 to 10,000, or 800 to 8,000.

[0074] <Solvent>

[0075] The composition for forming a resist underlayer film, as one aspect of the present invention, comprises a solvent.

[0076] The solvent is not particularly limited as long as it can dissolve the polymer obtained by reacting a glycourea compound with an aromatic compound having a phenolic hydroxyl group, and other optional components that may be added as needed.

[0077] Examples of solvents include, for instance, methyl cellosolve acetate, ethyl cellosolve acetate, propylene glycol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, methyl isobutyl methanol, propylene glycol monobutyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether acetate, toluene, xylene, methyl ethyl ketone, cyclopentanone, cyclohexanone, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxylate, ethyl hydroxyacetate, methyl 2-hydroxy-3-methylbutyrate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, 3... Ethyl ethoxypropionate, methyl 3-ethoxypropionate, methyl pyruvate, ethyl pyruvate, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl 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, propylene glycol dibutyl ether, ethyl lactate, propyl lactate, isopropyl lactate, lactic acid Butyl acetate, isobutyl lactate, 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, ethyl hydroxyacetate, methyl 2-hydroxy-2-methylpropionate, ethyl 2-hydroxy-2-methylpropionate, methyl 3-methoxy-2-methylpropionate, methyl 2-hydroxy-3-methylbutyrate, ethyl methoxyacetate Esters, ethyl ethoxylate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-methoxybutylacetate, 3-methoxypropylacetate, 3-methyl-3-methoxybutylacetate, 3-methyl-3-methoxybutylpropionate, 3-methyl-3-methoxybutylbutyrate, methyl acetoacetate, toluene, xylene, methyl ethyl ketone, methyl propyl ketone, methyl butyl ketone, 2-heptanone, 3-heptanone, 4-heptanone, N,N-dimethylformamide, N-methylacetamide, N,N-dimethylacetamide, N-methylpyrrolidone, 4-methyl-2-pentanol, and γ-butyrolactone, etc. These solvents can be used alone or in combination of two or more.

[0078] In addition, solvents with a boiling point above 160°C and solvents with a boiling point below 160°C can be combined.

[0079] As such a high-boiling-point solvent, the following compounds, for example, described in International Publication No. 2018 / 131562 (A1), may be preferred.

[0080]

[0081] [R in equation (i)] 1 R 2 and R 3 Each alkyl group represents a hydrogen atom, an alkyl group with 1 to 20 carbon atoms (which can be interrupted by an oxygen atom, a sulfur atom, or an amide bond), and these groups can be the same or different, and can combine to form a ring structure.

[0082] Alternatively, 1,6-diacetoxyhexane (boiling point 260°C), tripropylene glycol monomethyl ether (boiling point 242°C), and various high-boiling solvents described in paragraph 0082 of Japanese Patent Application Publication No. 2021-84974 may be preferred.

[0083] Alternatively, the following materials may be preferred: dipropylene glycol monomethyl ether acetate (boiling point 213°C), diethylene glycol monoethyl ether acetate (boiling point 217°C), diethylene glycol monobutyl ether acetate (boiling point 247°C), dipropylene glycol dimethyl ether (boiling point 171°C), dipropylene glycol monomethyl ether (boiling point 187°C), dipropylene glycol monobutyl ether (boiling point 231°C), and tripropylene glycol monomethyl ether (…). The following are examples of high-boiling solvents: γ-butyrolactone (boiling point 242°C), benzyl alcohol (boiling point 204°C), propylene carbonate (boiling point 205°C), tetraethylene glycol dimethyl ether (boiling point 275°C), 1,6-diacetoxyhexane (boiling point 260°C), dipropylene glycol (boiling point 230°C), 1,3-butanediol diacetate (boiling point 232°C), and various high-boiling solvents described in paragraphs 0023 to 0031 of this publication.

[0084] <Acids and / or their salts and / or acid-producing agents>

[0085] As one aspect of the invention, the composition for forming a resist underlayer film may contain an acid and / or its salt and / or an acid-generating agent.

[0086] Examples of acids include p-toluenesulfonic acid, trifluoromethanesulfonic acid, salicylic acid, 5-sulfosalicylic acid, 4-phenolsulfonic acid, camphorsulfonic acid, 4-chlorobenzenesulfonic acid, benzenedisulfonic acid, 1-naphthalenesulfonic acid, citric acid, benzoic acid, hydroxybenzoic acid, and naphthoic acid.

[0087] Salts of the aforementioned acids can also be used as salts. There are no limitations on the salt composition; salts of ammonia derivatives such as trimethylamine salts and triethylamine salts, pyridine derivatives, and morpholine derivatives can be used appropriately.

[0088] Acids and / or their salts may be used alone, or two or more may be used in combination. The mixing amount relative to the total solid content is typically 0.0001 to 20% by mass, preferably 0.0005 to 10% by mass, and more preferably 0.01 to 5% by mass.

[0089] Examples of acid-producing agents include thermal acid-producing agents and photo-producing acid-producing agents.

[0090] Examples of heat-generating acid agents include 2,4,4,6-tetrabromocyclohexadienone, benzoin toluene sulfonate, 2-nitrobenzyl toluene sulfonate, K-PURE (registered trademark) CXC-1612, K-PURE CXC-1614, K-PURE TAG-2172, K-PURE TAG-2179, K-PURE TAG-2678, K-PURE TAG2689, K-PURE TAG2700 (manufactured by King Industries), and SI-45, SI-60, SI-80, SI-100, SI-110, SI-150 (manufactured by Sanshin Chemical Industry Co., Ltd.), as well as alkyl sulfonic acid esters.

[0091] Photoacid-generating agents produce acid during the exposure of the photoresist. Therefore, the acidity of the underlying film can be adjusted. This is one method for matching the acidity of the underlying film with that of the upper photoresist. Furthermore, the pattern shape of the photoresist formed on the upper layer can be adjusted by adjusting the acidity of the underlying film.

[0092] Examples of photoacid-generating agents included in the resist lower layer film forming composition of the present invention include: Salt compounds, sulfonylimide compounds, and disulfonyldiazomethane compounds, etc.

[0093] As Salt compounds, such as diphenyliodine, can be cited as an example. Hexafluorophosphate, diphenyliodine Trifluoromethanesulfonate, diphenyliodine Nonafluoro-n-butane sulfonate, diphenyl iodide Perfluorooctane sulfonate, diphenyl iodide Camphor sulfonate, bis(4-tert-butylphenyl)iodine Camphor sulfonate and bis(4-tert-butylphenyl)iodine Iodine, such as trifluoromethanesulfonate Salt compounds, as well as sulfonium salt compounds such as triphenylsulfonium hexafluoroantimonate, triphenylsulfonium nonafluoro n-butane sulfonate, triphenylsulfonium camphor sulfonate, and triphenylsulfonium trifluoromethane sulfonate.

[0094] Examples of sulfonylimide compounds include N-(trifluoromethanesulfonyloxy)succinimide, N-(nonafluoron-butanesulfonyloxy)succinimide, N-(camphorsulfonyloxy)succinimide, and N-(trifluoromethanesulfonyloxy)naphthalenediformimide.

[0095] Examples of disulfonyldiazomethane compounds include bis(trifluoromethylsulfonyl)diazomethane, bis(cyclohexylsulfonyl)diazomethane, bis(phenylsulfonyl)diazomethane, bis(p-toluenesulfonyl)diazomethane, bis(2,4-dimethylbenzenesulfonyl)diazomethane, and methylsulfonyl-p-toluenesulfonyldiazomethane.

[0096] Acid-producing agents can be used alone, or two or more can be used in combination.

[0097] When using an acid-generating agent, the proportion of the acid-generating agent is 0.01 to 10 parts by weight, 0.1 to 8 parts by weight, or 0.5 to 5 parts by weight relative to 100 parts by weight of the solid component of the composition for forming the lower layer of the resist film.

[0098] <Other optional ingredients>

[0099] In addition to the above-mentioned components, the composition for forming the resist underlayer film, as one aspect of the present invention, may also include, as needed, a crosslinking agent, a surfactant, a light absorber, a rheology modifier, an adhesive aid, a curing catalyst, etc.

[0100] <Cross-linking agent>

[0101] Representative crosslinking agents include amino plastic crosslinking agents and phenolic plastic crosslinking agents.

[0102] As the aforementioned crosslinking agent, a crosslinking agent with high heat resistance can be used. As a crosslinking agent with high heat resistance, a compound containing crosslinking-forming substituents with aromatic rings (e.g., benzene rings, naphthalene rings) within the molecule is preferred.

[0103] Examples of crosslinking agents for amino plastics include highly alkylated, alkoxylated, or alkoxyalkylated melamine, benzoguanidine, glycourea, urea, and their polymers. Preferably, crosslinking agents have at least two crosslinking-forming substituents, such as compounds like methoxymethylated glycourea, butoxymethylated glycourea, methoxymethylated melamine, butoxymethylated melamine, methoxymethylated benzoguanidine, butoxymethylated benzoguanidine, methoxymethylated urea, butoxymethylated urea, methoxymethylated thiourea, or methoxymethylated thiourea. Condensates of these compounds can also be used.

[0104] Preferably, it is selected from at least one of tetramethoxymethyl glycourea and hexamethoxymethyl melamine.

[0105] If we give some specific examples, they are as follows.

[0106]

[0107] Examples of crosslinking agents for phenolic plastics include highly alkylated, alkoxylated, or alkoxyalkylated aromatic compounds and their polymers. Preferably, crosslinking agents have at least two crosslinking-forming substituents in one molecule, such as 2,6-dihydroxymethyl-4-methylphenol, 2,4-dihydroxymethyl-6-methylphenol, bis(2-hydroxy-3-hydroxymethyl-5-methylphenyl)methane, bis(4-hydroxy-3-hydroxymethyl-5-methylphenyl)methane, 2,2-bis(4-hydroxy-3,5-dihydroxymethylphenyl)propane, bis(3-formyl-4-hydroxyphenyl)methane, bis(4-hydroxy-2,5-dimethylphenyl)formylmethane, and α,α-bis(4-hydroxy-2,5-dimethylphenyl)-4-formyltoluene. Condensates of these compounds can also be used.

[0108] In addition to the compounds mentioned above, other examples of such compounds include compounds having a partial structure of the following formula (4), polymers or oligomers having repeating units of the following formula (5).

[0109]

[0110] The above R 11 R 12 R 13 and R 14 Alkyl groups having 1 to 10 hydrogen or carbon atoms can be used as illustrated above. n1 is an integer from 1 to 4, n2 is an integer from 1 to (5-n1), and (n1+n2) represents an integer from 2 to 5. n3 is an integer from 1 to 4, n4 is an integer from 0 to (4-n3), and (n3+n4) represents an integer from 1 to 4. Oligomers and polymers can be used in the range of 2 to 100 or 2 to 50 repeating unit structures.

[0111] If we give some specific examples, they are as follows.

[0112]

[0113]

[0114] R: -H or -CH(CH3)CH2OCH3

[0115] Crosslinking agents such as amino plastic crosslinking agents and phenolic plastic crosslinking agents can be used alone or in combination of two or more. For example, only amino plastic crosslinking agents can be used, or both amino plastic crosslinking agents and phenolic plastic crosslinking agents can be used. Amino plastic crosslinking agents can be manufactured by methods known to them or methods based thereon; in addition, commercially available products can be used.

[0116] Furthermore, the amount of crosslinking agents such as amino plastic crosslinking agents and phenolic plastic crosslinking agents used varies depending on the coating solvent used, the substrate used, the required solution viscosity, and the required film shape, but the total solid content of the composition for forming the resist underlayer film involved in this invention is 0.001% by mass or more, 0.01% by mass or more, 0.05% by mass or more, 0.5% by mass or more, or 1.0% by mass or more, and is 80% by mass or less, 50% by mass or less, 40% by mass or less, 20% by mass or less, or 10% by mass or less.

[0117] <surfactants>

[0118] In the resist underlayer film forming composition of the present invention, in order to avoid the generation of pinholes, streaks, etc., and to further improve the coating performance on uneven surfaces, a surfactant can be mixed in.

[0119] Examples of surfactants include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, and polyoxyethylene oil-based ether; polyoxyethylene alkyl aryl ethers such as polyoxyethylene octylphenol ether and polyoxyethylene nonylphenol ether; polyoxyethylene / polyoxypropylene block copolymers; sorbitol fatty acid esters such as sorbitol monolaurate, sorbitol monopalmitate, sorbitol monostearate, sorbitol monooleate, sorbitol trioleate, and sorbitol tristearate; and polyoxyethylene sorbitol fatty acid esters such as polyoxyethylene sorbitol monolaurate, polyoxyethylene sorbitol monopalmitate, polyoxyethylene sorbitol monostearate, polyoxyethylene sorbitol trioleate, and polyoxyethylene sorbitol tristearate. These are examples of nonionic surfactants.

[0120] Fluorinated surfactants include Ftop EF301, EF303, EF352 (manufactured by Tochem Products Co., Ltd., trade name), Mega fac F171, F173, R-30, R-40 (manufactured by Dainippon Ink Co., Ltd., trade name), Fluorad FC430, FC431 (manufactured by Sumitomo 3M Co., Ltd., trade name), Asahi Guard AG710, Surflon S-382, SC101, SC102, SC103, SC104, SC105, SC106 (manufactured by Asahi Glass Co., Ltd., trade name), etc.

[0121] Organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.), etc.

[0122] The amount of these surfactants mixed in relation to the total solids content of the resist underlayer film forming composition of the present invention is typically 2.0% by mass or less, preferably 1.0% by mass or less. These surfactants can be added individually or in combination of two or more.

[0123] <Other Additives>

[0124] As a light absorber, it can be suitable for use in, for example, " (Technology and Market of Industrial Pigments) (Published by CMC), Commercially available light absorbers listed in "(Dye Handbook)" (edited by the Organic Synthetic Chemistry Society), such as CI Disperse Yellow 1, 3, 4, 5, 7, 8, 13, 23, 31, 49, 50, 51, 54, 60, 64, 66, 68, 79, 82, 88, 90, 93, 102, 114, and 124; CI Disperse Orange 1, 5, 13, 25, 29, 30, 31, 44, 57, 72, and 73; CI Disperse Red 1, 5, 7, 13, 17, 19, 43, 50, 54, 58, and 6... 5, 72, 73, 88, 117, 137, 143, 199, and 210; CI Disperse Violet 43; CI Disperse Blue 96; CI Fluorescent Whitening Agents 112, 135, and 163; CI Solvent Orange 2 and 45; CI Solvent Red 1, 3, 8, 23, 24, 25, 27, and 49; CI Pigment Green 10; CI Pigment Brown 2, etc. The above-mentioned light absorbers are generally blended in a ratio of 10% by mass or less, preferably 5% by mass or less, relative to the total solid components of the resist underlayer film forming composition involved in this invention.

[0125] Rheology modifiers are mainly added to improve the flowability of the composition for forming the lower resist film, especially during the baking process, to improve the uniformity of the film thickness of the lower resist film and to improve the filling ability of the composition for forming the lower resist film into the cavities. Specific examples include phthalic acid derivatives such as dimethyl phthalate, diethyl phthalate, diisobutyl phthalate, dihexyl phthalate, and butyl isodecyl phthalate; adipic acid derivatives such as di-n-butyl adipate, diisobutyl adipate, diisooctyl adipate, and octyldecyl adipate; maleic acid derivatives such as di(n-butyl) maleate, diethyl maleate, and dinonyl maleate; oleic acid derivatives such as methyl oleate, butyl oleate, and tetrahydrofurfuryl oleate; or stearic acid derivatives such as n-butyl stearate and glyceryl stearate. These rheology modifiers are typically blended in proportions of less than 30% by mass relative to the total solid components of the resist underlayer film forming composition involved in this invention.

[0126] Adhesive aids are mainly added to improve the adhesion between the substrate or resist and the composition for forming the underlying film of the resist, especially to prevent the resist from peeling off during development. Specific examples include chlorosilanes such as trimethylchlorosilane, dimethylvinylchlorosilane, methyldiphenylchlorosilane, and chloromethyldimethylchlorosilane; alkoxysilanes such as trimethylmethoxysilane, dimethyldiethoxysilane, methyldimethoxysilane, dimethylvinylethoxysilane, diphenyldimethoxysilane, and phenyltriethoxysilane; silazanes such as hexamethyldisilazane, N,N'-bis(trimethylsilyl)urea, dimethyltrimethylsilylamine, and trimethylsilylimidazolium; silanes such as vinyltrichlorosilane, γ-chloropropyltrimethoxysilane, γ-aminopropyltriethoxysilane, and γ-epoxypropoxypropyltrimethoxysilane; and silanes such as benzotriazole, benzimidazole, indazole, imidazole, 2-mercaptobenzimidazole, 2-mercaptobenzothiazole, and 2-mercaptobenzo[]. Heterocyclic compounds such as azoles, urazoles, thiouracil, mercaptoimidazoles, and mercaptopyrimidines, as well as urea or thiourea compounds such as 1,1-dimethylurea and 1,3-dimethylurea. These adhesive aids are typically blended in proportions of less than 5% by mass, preferably less than 2% by mass, relative to the total solids content of the resist underlayer film forming composition involved in this invention.

[0127] Curing catalysts are effective for curing membranes. Specific examples include, but are not limited to, sulfonium salt compounds such as triphenylsulfonium nitrate, triphenylsulfonium maleate, triphenylsulfonium trifluoroacetate, triphenylsulfonium hydrochloride, and triphenylsulfonium acetate.

[0128] The solid content of the resist underlayer film forming composition of the present invention is 0.1 to 70% by mass or 0.1 to 60% by mass. The solid content refers to the proportion of all components in the resist underlayer film forming composition after the solvent has been removed. A crosslinkable resin may be contained in the solid content at a proportion of 1 to 99.9% by mass, 50 to 99.9% by mass, 50 to 95% by mass, or 50 to 90% by mass.

[0129] <Resist Underlayer>

[0130] The resist underlayer film can be formed using the resist underlayer film forming composition of the present invention, for example, as follows.

[0131] A resist underlayer film formation composition, as described in one aspect of the present invention, is coated onto a substrate used in the manufacture of semiconductor devices (e.g., silicon wafer substrate, silicon dioxide coated substrate (SiO2 substrate), silicon nitride substrate (SiN substrate), silicon oxide nitride substrate (SiON substrate), titanium nitride substrate (TiN substrate), tungsten substrate (W substrate), glass substrate, ITO substrate, polyimide substrate, and low-k material coated substrate, etc.) using a suitable coating method such as a spin coater or coating machine. Then, the resist underlayer film is formed by firing using a heating means such as a hot plate. The firing conditions are appropriately selected from a firing temperature of 80°C to 800°C and a firing time of 0.3 to 60 minutes. Preferably, the firing temperature is 150°C to 400°C and the firing time is 0.5 to 2 minutes. Air, or inactive gases such as nitrogen or argon, can be used as the atmosphere gas during firing. In one aspect, an oxygen concentration of 1% or less is particularly preferred. Here, the thickness of the underlying film formed is, for example, 10–1000 nm, or 20–500 nm, or 30–400 nm, or 50–300 nm. Furthermore, if a quartz substrate is used as the substrate, a replica of the quartz embossing mold (mold replica) can be fabricated.

[0132] Furthermore, an adhesive layer and / or a silicon-containing layer containing 99% by mass or less or 50% by mass or less of Si can also be formed on the resist underlayer film as an aspect of the present invention by coating or vapor deposition. For example, in addition to the method of forming the adhesive layer described in Japanese Patent Application Publication No. 2013-202982, Japanese Patent No. 5827180, and the silicon-containing resist underlayer film (inorganic resist underlayer film) forming composition described in International Publication No. 2009 / 104552 (A1) by spin coating, Si-based inorganic material films can also be formed by CVD or the like.

[0133] Furthermore, by coating a resist lower layer film forming composition, which is one aspect of the present invention, onto a semiconductor substrate (so-called high-low difference substrate) having portions with high-low differences and portions without high-low differences, and then firing it, the high-low difference between the portions with high-low differences and the portions without high-low differences can be reduced.

[0134] <Methods for forming resist patterns>

[0135] The method for forming a resist pattern used in semiconductor manufacturing includes the following steps: applying the resist underlayer film forming composition of the present invention onto a substrate used in the manufacture of the semiconductor device and firing it to form a resist underlayer film; forming a resist film on the resist underlayer film; and forming a resist pattern on the resist film by irradiation and development with light or an electron beam.

[0136] <Methods for Manufacturing Semiconductor Devices>

[0137] (i)

[0138] A method for manufacturing a semiconductor device, as one aspect of the present invention, includes the following steps:

[0139] The process of forming a photoresist underlayer film by coating a photoresist underlayer film composition, which is one aspect of the present invention, onto a semiconductor substrate and firing it to form a photoresist underlayer film;

[0140] The process of forming a resist film on the resist underlayer film;

[0141] The process of forming a resist pattern on a resist film by irradiation and development with light or electron beams;

[0142] The process of etching the underlying resist film using the resist pattern, and patterning the resist; and

[0143] The process of processing a semiconductor substrate using the patterned resist underlayer film described above.

[0144] (ii)

[0145] Furthermore, the method for manufacturing a semiconductor device as an aspect of the present invention includes the following steps:

[0146] The process of forming a photoresist underlayer film by coating a photoresist underlayer film composition, which is one aspect of the present invention, onto a semiconductor substrate and firing it to form a photoresist underlayer film;

[0147] The process of forming a hard mask on the underlying resist film;

[0148] The next step is to form a resist film on the hard mask.

[0149] The process of forming a resist pattern on a resist film by irradiation and development with light or electron beams;

[0150] The process of etching a hard mask using a resist pattern is called patterning.

[0151] The process of etching the resist underlayer using the patterned hard mask, and the patterning process; and

[0152] The process of processing a semiconductor substrate using the patterned resist underlayer film described above.

[0153] (iii)

[0154] Furthermore, the method for manufacturing a semiconductor device as an aspect of the present invention includes the following steps:

[0155] The process of forming a photoresist underlayer film by coating a photoresist underlayer film composition, which is one aspect of the present invention, onto a semiconductor substrate and firing it to form a photoresist underlayer film;

[0156] The process of forming a hard mask on the underlying resist film;

[0157] The next step is to form a resist film on the hard mask.

[0158] The process of forming a resist pattern on a resist film by irradiation and development with light or electron beams;

[0159] The process of etching a hard mask using a resist pattern is called patterning.

[0160] The process of etching the resist underlayer film using the patterned hard mask is called patterning.

[0161] The process of removing the aforementioned hard mask; and

[0162] The process of processing a semiconductor substrate using the patterned resist underlayer film described above.

[0163] (iv)

[0164] Furthermore, the method for manufacturing a semiconductor device as an aspect of the present invention includes the following steps:

[0165] The process of forming a photoresist underlayer film by coating a photoresist underlayer film composition, which is one aspect of the present invention, onto a semiconductor substrate and firing it to form a photoresist underlayer film;

[0166] The process of forming a hard mask on the underlying resist film;

[0167] The next step is to form a resist film on the hard mask.

[0168] The process of forming a resist pattern on a resist film by irradiation and development with light or electron beams;

[0169] The process of etching a hard mask using a resist pattern is called patterning.

[0170] The process of etching the underlying resist film using the etched hard mask is to perform a patterning process.

[0171] The process of removing the aforementioned hard mask;

[0172] The process of forming a vapor-deposited film (spacer) on the resist underlayer after the hard mask has been removed;

[0173] The process of processing the vapor-deposited film (spacer) by etching;

[0174] The process of removing the patterned resist underlayer to leave the patterned vapor-deposited film (spacer); and

[0175] The process of processing a semiconductor substrate using the patterned vapor-deposited film (spacer) described above.

[0176] The semiconductor substrate can be processed using the manufacturing methods described in (i) to (iv) above.

[0177] The process of forming a photoresist underlayer film using the photoresist underlayer film forming composition as an aspect of the present invention is as described in the above-mentioned <Photoresist Underlayer Film> section.

[0178] Alternatively, a hard mask containing silicon or the like can be formed as a second resist lower layer film on the resist lower layer film formed through the above process, and a resist pattern can be formed thereon [as described in (ii) to (iv)].

[0179] Hard masks can be coating films containing inorganic materials or vapor-deposited films of inorganic materials formed by vapor deposition methods such as CVD and PVD. Examples include SiON films, SiN films, or SiO2 films.

[0180] An anti-reflective film (BARC) can also be formed on the hard mask, or a resist shape correction film without anti-reflective capability can be formed.

[0181] In the above-described process of forming the resist pattern, exposure is performed either by using a mask (photomask) to form the specified pattern or by direct drawing. Exposure sources can include, for example, gamma rays, i-rays, KrF excimer lasers, ArF excimer lasers, EUV, and electron beams. After exposure, post-exposure baking is performed as needed. Then, development is carried out with a developer (e.g., a 2.38% by mass tetramethylammonium hydroxide aqueous solution), followed by rinsing with a rinsing solution or pure water to remove the developer. Finally, post-baking is performed to dry the resist pattern and improve adhesion to the substrate.

[0182] The etching process performed after the above-mentioned resist pattern is formed is carried out by dry etching.

[0183] The aforementioned resist film can also be patterned using nanoimprinting or self-assembly film methods.

[0184] For nanoimprinting, a resist composition is formed using a mold (mold) that is transparent to light and has been patterned. Furthermore, for self-assembled film methods, patterning is achieved using self-assembled films with naturally formed nanoscale regular structures, such as diblock polymers (polystyrene-polymethyl methacrylate, etc.).

[0185] In nanoimprint lithography, a silicon-containing layer (hard mask layer) can be selectively formed on a photoresist underlayer by coating or vapor deposition before applying a curable composition that becomes a photoresist film. A bonding layer is then formed on the photoresist underlayer or the silicon-containing layer (hard mask layer) by coating or vapor deposition, and the curable composition that becomes a photoresist film is applied on the bonding layer.

[0186] It should be noted that the following gases can be used in the processing of the hard mask (containing silicon layer) / resist underlayer / substrate: CF4, CHF3, CH2F2, CH3F, C4F6, C4F8, O2, N2O, NO2, He, and H2. These gases can be used alone or in mixtures of two or more. Furthermore, argon, nitrogen, carbon dioxide, carbonyl sulfide, sulfur dioxide, neon, or nitrogen trifluoride can be mixed with these gases.

[0187] It should be noted that wet etching is sometimes performed to simplify the process and reduce damage to the substrate. This results in reduced dimensional variations, lower pattern roughness, and improved substrate yield. Therefore, in steps (iii) to (iv) above, hard masks can be removed using either etching or an alkaline solution. In particular, when using an alkaline solution, there are no restrictions on the composition; however, the following substances are preferred as the alkaline component.

[0188] Examples of alkaline components include, for example, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, methyltripropylammonium hydroxide, methyltributylammonium hydroxide, ethyltrimethylammonium hydroxide, dimethyldiethylammonium hydroxide, benzyltrimethylammonium hydroxide, hexadecyltrimethylammonium hydroxide, and (2-hydroxyethyl)trimethylammonium hydroxide, monoethanolamine, diethanolamine, triethanolamine, 2-(2-aminoethoxy)ethanol, N,N-dimethylethanolamine, N,N-diethylethanolamine, N,N-dibutylethanolamine, and N- Methylethanolamine, N-ethylethanolamine, N-butylethanolamine, N-methyldiethanolamine, monoisopropanolamine, diisopropanolamine, triisopropanolamine, tetrahydrofurfurylamine, N-(2-aminoethyl)piperazine, 1,8-diazabicyclo[5.4.0]undecene-7, 1,4-diazabicyclo[2.2.2]octane, hydroxyethylpiperazine, piperazine, 2-methylpiperazine, trans-2,5-dimethylpiperazine, cis-2,6-dimethylpiperazine, 2-piperidinemethanol, cyclohexylamine, 1,5-diazabicyclo[4,3,0]nonene-5, etc.

[0189] Furthermore, especially from an operational point of view, tetramethylammonium hydroxide and tetraethylammonium hydroxide are particularly preferred, and inorganic bases can also be used in combination with quaternary ammonium hydroxides. As inorganic bases, hydroxides of alkali metals such as potassium hydroxide, sodium hydroxide, and rubidium hydroxide are preferred, with potassium hydroxide being more preferred.

[0190] Example

[0191] The present invention will be described in more detail below with examples of synthesis, embodiments and comparative examples, but the present invention is not limited to the following embodiments.

[0192] [Polymer Synthesis]

[0193] The weight-average molecular weights shown in the following synthetic examples in this specification are the results obtained by gel permeation chromatography (hereinafter referred to as GPC). A Tosoh Corporation-manufactured GPC apparatus (HLC-8320GPC) was used in the determination, and the determination conditions are as follows.

[0194] GPC column: TSKgelSuperH-RC, TSKgelSuperMultipore HZ-N, TSKgelSuperMultiporeHZ-N (Tosoh Co., Ltd.)

[0195] Column temperature: 40℃

[0196] Solvent: Tetrahydrofuran (Kanto Chemical, for high performance liquid chromatography)

[0197] Standard sample: Polystyrene (Shodex)

[0198] <Synthetic Example 1> Synthesis of polymer (1) (PL-LI / PGA = 100 / 100)

[0199] In a 200 mL three-necked flask equipped with a stirrer and a cooling tube, 15.00 g (47.12 mmol) of tetramethoxymethyl glycourea (POWDERLINK 1174, manufactured by Mitsui Cytec Co., Ltd.), 5.94 g (47.12 mmol) of phloroglucinol (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.02 g (0.24 mmol) of methanesulfonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), and 83.75 g of propylene glycol monomethyl ether were added. The mixture was heated to 50 °C and stirred at 50 °C for 9 hours. After the reaction was stopped, 732 g of water was added dropwise to precipitate the polymer. The precipitate was filtered and separated, and the filter was washed three times with 183 mL of water. The precipitate was then vacuum dried to obtain the polymer. The molecular weight of the polymer was determined by GPC (standard polystyrene conversion), and the weight-average molecular weight (Mw) was 1413, with a yield of 58.4%. The polymer has a repeating unit structure as shown in formula (1). The obtained polymer was diluted with propylene glycol monomethyl ether to a solids concentration of 30%, and equal amounts of cation exchange resin and anion exchange resin were added separately, and the mixture was stirred for 4 hours. The polymer solution was obtained by filtering the ion exchange resin.

[0200]

[0201] <Synthetic Example 2> Synthesis of polymer (2) (PL-LI / THPE = 100 / 100)

[0202] In a 100 mL three-necked flask equipped with a stirrer and cooling tube, 5.00 g (15.71 mmol) of tetramethoxymethyl glycourea (POWDERLINK 1174, manufactured by Mitsui Cytec Co., Ltd.), 4.81 g (15.71 mmol) of 1,1,1-tris(4-hydroxyphenyl)ethane (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.0075 g (0.08 mmol) of methanesulfonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), and 39.24 g of propylene glycol monomethyl ether were added. The mixture was heated to 50 °C and stirred at 50 °C for 6 hours. After the reaction was stopped, the polymer was precipitated by adding dropwise 392 g of a methanol (Kanto Chemical, premium grade) / water (5 / 5) mixed solvent. The precipitate was filtered and separated, and the filter was washed three times with 98 mL of methanol / water (5 / 5) mixed solvent. The precipitate was then dried under vacuum to obtain the polymer. The molecular weight of the polymer was determined using GPC (standard polystyrene conversion), and the weight-average molecular weight (Mw) was 850, with a yield of 50.9%. The polymer has a repeating unit structure as shown in formula (2). The obtained polymer was diluted with propylene glycol monomethyl ether to a solids concentration of 30%, and cation exchange resin and anion exchange resin of equal amounts to the solids were added, respectively, and stirred for 4 hours. The polymer solution was obtained by filtering the ion exchange resin.

[0203]

[0204] <Synthetic Example 3> Synthesis of polymer (3) (PL-LI / BHPF = 100 / 100)

[0205] In a 100 mL three-necked flask equipped with a stirrer and cooling tube, 5.00 g (15.71 mmol) of tetramethoxymethyl glycourea (POWDERLINK 1174, manufactured by Mitsui Cytec Co., Ltd.), 5.50 g (15.71 mmol) of 9,9-bis(4-hydroxyphenyl)fluorene (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.0075 g (0.08 mmol) of methanesulfonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), and 42.01 g of propylene glycol monomethyl ether were added. The mixture was heated to 50 °C and stirred at 50 °C for 6 hours. After the reaction was stopped, the polymer was precipitated by adding dropwise 410 g of a methanol (Kanto Chemical, premium grade) / water (5 / 5) mixed solvent. The precipitate was filtered and separated, and the filter was washed three times with 105 mL of methanol / water (5 / 5) mixed solvent. The precipitate was then dried under vacuum to obtain the polymer. The molecular weight of the polymer was determined using GPC (standard polystyrene conversion), and the weight-average molecular weight (Mw) was 2125, with a yield of 64.4%. The polymer has a repeating unit structure as shown in formula (3). The obtained polymer was diluted with propylene glycol monomethyl ether to a solids concentration of 30%, and cation exchange resin and anion exchange resin of equal amounts to the solids were added, respectively, and stirred for 4 hours. The polymer solution was obtained by filtering the ion exchange resin.

[0206]

[0207] <Comparative Synthesis Example 1> Synthesis of Polymer (S1) (PL-LI / phenylethylene glycol = 100 / 100)

[0208] In a 100 mL three-necked flask equipped with a stirrer and cooling tube, 5.00 g (15.71 mmol) of tetramethoxymethyl glycourea (POWDERLINK 1174, manufactured by Mitsui Cytec Co., Ltd.), 2.17 g (15.71 mmol) of phenylethylene glycol (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.0299 g (0.16 mmol) of p-toluenesulfonic acid monohydrate (manufactured by Tokyo Chemical Industry Co., Ltd.), and 28.65 g of propylene glycol monomethyl ether acetate were added. The mixture was heated to 85 °C and stirred at 85 °C for 4 hours. After the reaction was stopped, cation exchange resin and anion exchange resin in equal amounts to the solid components were added to the resulting reaction solution, and the mixture was stirred for 4 hours. The ion exchange resin was filtered to obtain a polymer solution. The weight-average molecular weight (Mw) determined by GPC to standard polystyrene was 3489. The molecular weight of the polymer was determined using GPC (standard polystyrene conversion), and the weight-average molecular weight (Mw) was 1218, with a repeating unit structure as shown in the following formula (6).

[0209]

[0210] <Comparative Synthesis Example 2> Synthesis of Polymer (S2) (PL-LI / 1,4-Butanediol = 100 / 100)

[0211] In a 100 mL three-necked flask equipped with a stirrer and cooling tube, 5.00 g (15.71 mmol) of tetramethoxymethyl glycourea (POWDERLINK 1174, manufactured by Mitsui Cytec Co., Ltd.), 1.41 g (15.71 mmol) of 1,4-butanediol (manufactured by Tokyo Chemical Industry Co., Ltd.), 1.49 g (7.85 mmol) of p-toluenesulfonic acid monohydrate (manufactured by Tokyo Chemical Industry Co., Ltd.), and 24.17 g of propylene glycol monomethyl ether acetate were added. The mixture was heated to 85 °C and stirred at 70 °C for 5 hours. After the reaction was stopped, cation exchange resin and anion exchange resin of equal amounts to the solid components were added to the resulting reaction solution, and the mixture was stirred for 4 hours. The ion exchange resin was filtered to obtain a polymer solution. The molecular weight of the polymer was determined by GPC (standard polystyrene conversion), and the weight-average molecular weight (Mw) was 995, exhibiting a repeating unit structure as shown in formula (7).

[0212]

[0213] <Preparation of the Underlayer Film for Resist>

[0214] Polymers (1) to (3) and (S1) to (S2), crosslinking agent [tetramethoxymethyl glycosuria], acid catalyst [p-toluenesulfonic acid], solvent [propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), and surfactant Mega facR-40 (manufactured by DIC Corporation)] were mixed in the following weight ratios (as shown in Table 4 below; the weight ratios of crosslinking agent, acid-producing agent and surfactant are shown when the weight of polymer is set to 100; regarding solvents, the weight ratios of each solvent are shown when the total weight of solvent is set to 100) and filtered using a 0.1 μm polytetrafluoroethylene microfilter to prepare a photoresist lower layer film material (Examples 1 to 3, Comparative Examples 1 to 2).

[0215] [Determination of Hardness]

[0216] The resist underlayer film forming compositions prepared in Examples 1-3 and Comparative Examples 1 and 2 were respectively coated onto silicon wafers using a spin coater. Then, they were baked on a hot plate at 400°C for 90 seconds to form a resist underlayer film (film thickness 0.2 μm). Nanoindentation tests were performed using a nanoindenter manufactured by TOYO Corporation to determine the hardness of the above-mentioned resist underlayer film. The results are shown in Table 1. The resist underlayer film formed by the resist underlayer film forming compositions prepared in Examples 1-3 has higher hardness than the resist underlayer film formed by the resist underlayer film forming compositions prepared in Comparative Examples 1 and 2.

[0217] [Table 1]

[0218] Table 1

[0219]

[0220] [Determination of membrane density]

[0221] The resist underlayer film forming compositions prepared in Examples 1-3 and Comparative Examples 1 and 2 were respectively coated onto silicon wafers using a spin coater. Then, they were baked on a hot plate at 400°C for 90 seconds to form a resist underlayer film (film thickness 0.2 μm). The film density of the resist underlayer film was measured using an XRR tester manufactured by Bruker AXS D8 DISCOVER. The results are shown in Table 2. The resist underlayer film formed by the resist underlayer film forming compositions prepared in Examples 1-3 has a higher film density than the resist underlayer film formed by the resist underlayer film forming compositions prepared in Comparative Examples 1 and 2.

[0222] [Table 2]

[0223] Table 2

[0224]

Claims

1. A composition for forming a resist underlayer film, comprising a polymer obtained by reacting a glycourea compound with an aromatic compound having at least one phenolic hydroxyl group, and a solvent, wherein the polymer has a nitrogen content of less than 10% by mass.

2. The composition for forming a resist underlayer film according to claim 1, wherein the polymer has a carbon content of 80% or less.

3. The composition for forming a lower layer of resist according to claim 1, wherein the glycourea compound is a glycourea compound substituted with at least one substituent, the substituent being at least one substituent selected from hydroxyalkyl with 1 to 12 carbon atoms, alkoxyalkyl with 2 to 12 carbon atoms, and alkenyloxyalkyl with 3 to 12 carbon atoms.

4. The composition for forming a resist underlayer film according to claim 1, wherein the glycourea compound is selected from tetrahydroxymethylglycourea, tetrabutoxymethylglycourea, tetramethoxymethylglycourea, partially hydroxymethylated glycourea, dimethoxymethylglycourea, monomethyl ether or dimethyl ether of dihydroxymethylglycourea, trimethyl ether of tetrahydroxymethylglycourea, tetramethyl ether of tetrahydroxymethylglycourea, tetraethoxymethylglycourea, tetrapropoxymethylglycourea, tetrapentyloxymethylglycourea, tetrahexyloxymethylglycourea, and mixtures thereof.

5. The composition for forming a resist underlayer film according to claim 1, wherein the glycourea compound is a glycourea compound at least substituted with methoxymethyl.

6. The composition for forming a resist underlayer film according to claim 1, wherein the aromatic compound having a phenolic hydroxyl group is selected from the following compounds: 。 7. The composition for forming a resist underlayer film according to claim 1, wherein the solvent is a solvent with a boiling point of 160°C or higher.

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

9. The composition for forming a resist underlayer film according to claim 8, wherein the crosslinking agent is an amino plastic crosslinking agent, or an amino plastic crosslinking agent and a phenolic plastic crosslinking agent.

10. The composition for forming a resist underlayer film according to claim 1, further comprising a surfactant.

11. The composition for forming a resist underlayer film according to claim 1, further comprising an acid and / or its salt and / or an acid-generating agent.

12. A resist underlayer film, which is a sintered product of a coated film formed from the composition of any one of claims 1 to 11.

13. A method for forming a resist pattern for manufacturing a semiconductor, comprising the steps of: coating a resist underlayer film forming composition according to any one of claims 1 to 11 onto a semiconductor substrate and firing it to form a resist underlayer film; forming a resist film on the resist underlayer film; and forming a resist pattern on the resist film by irradiation and development with light or an electron beam.

14. A method for manufacturing a semiconductor device, comprising the following steps: The process of forming a photoresist underlayer film by coating the composition for forming a photoresist underlayer film according to any one of claims 1 to 11 onto a semiconductor substrate and firing it; The process of forming a resist film on the lower layer of the resist film; The process of forming a resist pattern on the resist film; The process of etching the underlying resist film using the resist pattern; and A process of processing a semiconductor substrate using the patterned resist underlayer film.

15. The method for manufacturing a semiconductor device according to claim 14, wherein a resist pattern is formed on the resist film by irradiation and development with light or an electron beam.

16. The method for manufacturing a semiconductor device according to claim 14, wherein a resist pattern is formed on the resist film by nanoimprinting or a self-assembled film.

17. A method for manufacturing a semiconductor device, comprising the following steps: The process of forming a photoresist underlayer film by coating the composition for forming a photoresist underlayer film according to any one of claims 1 to 11 onto a semiconductor substrate and firing it; The process of forming a hard mask on the lower layer of the resist film; The next step is to form a resist film on the hard mask. The process of forming a resist pattern on the resist film; The process of etching a hard mask using this resist pattern; The process of etching the resist underlayer using the patterned hard mask; and A process of processing a semiconductor substrate using the patterned resist underlayer film.

18. The method of manufacturing a semiconductor device according to claim 17, wherein the hard mask is formed by coating a composition comprising an inorganic material or by vapor deposition of a composition comprising an inorganic material.

19. The method for manufacturing a semiconductor device according to claim 17, wherein a resist pattern is formed on the resist film by irradiation and development with light or an electron beam.

20. The method for manufacturing a semiconductor device according to claim 17, wherein a resist pattern is formed on the resist film by nanoimprinting or a self-assembled film.

21. A method for manufacturing a semiconductor device, comprising the following steps: The process of forming a photoresist underlayer film by coating the composition for forming a photoresist underlayer film according to any one of claims 1 to 11 onto a semiconductor substrate and firing it; The process of forming a hard mask on the lower layer of the resist film; The next step is to form a resist film on the hard mask. The process of forming a resist pattern on the resist film; The process of etching a hard mask using this resist pattern; The process of etching the resist underlayer using the patterned hard mask; The process of removing the hard mask; and A process of processing a semiconductor substrate using the patterned resist underlayer film.

22. The method of manufacturing a semiconductor device according to claim 21, wherein the hard mask is formed by coating a composition comprising an inorganic material or by vapor deposition of a composition comprising an inorganic material.

23. The method for manufacturing a semiconductor device according to claim 21, wherein a resist pattern is formed on the resist film by irradiation and development with light or an electron beam.

24. The method for manufacturing a semiconductor device according to claim 21, wherein a resist pattern is formed on the resist film by nanoimprinting or a self-assembled film.

25. The method of manufacturing a semiconductor device according to claim 21, wherein the hard mask is removed by either etching or an alkaline solution.

26. A method for manufacturing a semiconductor device, comprising the following steps: The process of forming a photoresist underlayer film by coating the composition for forming a photoresist underlayer film according to any one of claims 1 to 11 onto a semiconductor substrate and firing it; The process of forming a hard mask on the lower layer of the resist film; The next step is to form a resist film on the hard mask. The process of forming a resist pattern on the resist film; The process of etching a hard mask using this resist pattern; The process of etching the resist underlayer using the patterned hard mask; The process of removing the hard mask; The process of forming a spacer by vapor deposition of the resist underlayer after the hard mask has been removed; The process of etching the vapor-deposited film, i.e., the spacer, is a process; The process of removing the patterned resist underlayer film to leave the patterned vapor-deposited film, i.e., the spacer; as well as The process of processing a semiconductor substrate using the patterned vapor-deposited film, i.e., the spacer.

27. The method of manufacturing a semiconductor device according to claim 26, wherein the hard mask is formed by coating a composition comprising an inorganic material or by vapor deposition of a composition comprising an inorganic material.

28. The method for manufacturing a semiconductor device according to claim 26, wherein a resist pattern is formed on the resist film by irradiation and development with light or an electron beam.

29. The method for manufacturing a semiconductor device according to claim 26, wherein a resist pattern is formed on the resist film by nanoimprinting or a self-assembled film.

30. The method of manufacturing a semiconductor device according to claim 26, wherein the hard mask is removed by either etching or an alkaline solution.

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