Resist underlayer film-forming composition

Abstract

A resist underlayer film forming composition comprising a compound P and a solvent, the compound P comprising a fluorene skeleton, and comprising a partial structure having a total of 2 groups selected from a phenolic hydroxyl group and a hydroxyl hydrogen atom of a hydroxymethyl group and a hydroxymethyl group substituted with a substituent on 1 aromatic hydrocarbon ring.

Description

Technical Field

[0001] The present invention relates to a resist underlayer film forming composition, a resist underlayer film as a sintered product comprising a coating film containing the composition, and a method for manufacturing a semiconductor device using the composition. Background Technology

[0002] In the manufacture of semiconductor devices, microfabrication based on photolithography is performed. In this photolithography process, a known problem is that when exposing a resist layer on a substrate using ultraviolet lasers such as KrF excimer lasers or ArF excimer lasers, the standing waves generated by the reflection of the ultraviolet laser on the substrate surface prevent the formation of a resist pattern with the desired shape. To solve this problem, a resist underlayer film (anti-reflective film) is provided between the substrate and the resist layer. Furthermore, phenolic varnish resin is known to be used as the composition for forming the resist underlayer film.

[0003] Furthermore, to achieve the thinning of the resist layer required for miniaturizing the resist pattern, a photolithography process is known in which at least two resist underlayer films are formed, and these resist underlayer films are used as mask materials. Examples of materials forming the at least two layers include organic resins (e.g., acrylic resins, phenolic varnish resins), silicone resins (e.g., organopolysiloxanes), and inorganic silicon compounds (e.g., SiON, SiO2). When a pattern formed from the aforementioned organic resin layer is used as a mask for dry etching, the pattern needs to be etch-resistant to etching gases (e.g., fluorocarbons).

[0004] As a composition for forming such a resist underlayer film, for example, Patent Document 1 discloses a resist underlayer film forming composition, which contains a phenolic varnish resin and a compound having phenolic hydroxyl and hydroxymethyl groups on a benzene ring as a crosslinking agent.

[0005] Existing technical documents Patent documents Patent Document 1: International Publication No. 2014 / 208542 Summary of the Invention The technical problem that the invention aims to solve However, conventional resist underlayer film forming compositions have unsatisfactory aspects regarding requirements such as reducing the amount of sublimation in contaminated devices, etch resistance during substrate processing, and especially bulge suppression (suppressing the formation of lumpy protrusions).

[0006] Technical solutions for solving technical problems The present invention solves the above-mentioned problems. That is, the present invention includes the following:

[0007] [1] A resist underlayer film forming composition comprising compound P and a solvent, said compound P comprising a fluorene skeleton and comprising a local structure of two groups comprising a total of two groups having a phenolic hydroxyl group on an aromatic hydrocarbon ring and a group having a hydroxyl hydrogen atom selected from hydroxymethyl and hydroxymethyl replaced by a substituent.

[0008] [2] The resist underlayer film forming composition according to [1], wherein the compound P is a compound represented by the following formula (1).

[0009] [Chemistry 1] (In formula (1), Ar) 1 Each can be independently represented as a benzene ring, naphthalene ring, or biphenyl ring that may have substituents. Ar 2 Each of these can independently represent either a benzene ring or a naphthalene ring, and R can independently represent a hydrogen atom, an alkyl group with 1 to 4 carbon atoms, or an alkoxyalkyl group with 2 to 6 carbon atoms. [3] A composition for forming a resist underlayer film according to [1] or [2], wherein the content of compound P is 90% by mass or more based on the total solids content in the composition.

[0010] [4] The resist underlayer film forming composition according to [2], wherein in the formula (1), R is all hydrogen atoms.

[0011] [5] A resist underlayer film forming composition according to any one of [1] to [4], wherein the resist underlayer film forming composition further comprises at least one of an acid and an acid-generating agent.

[0012] [6] A resist underlayer film forming composition according to any one of [1] to [5], wherein the resist underlayer film forming composition further comprises a surfactant.

[0013] [7] A resist underlayer film forming composition according to any one of [1] to [6], wherein the solvent comprises a solvent having a boiling point of 160°C or higher.

[0014] [8] A resist underlayer film, which is a sintered product of a coated film comprising any one of [1] to [7] resist underlayer film forming composition.

[0015] [9] A method for manufacturing a semiconductor device includes the following steps: The process of forming a photoresist underlayer film on a semiconductor substrate using any one of [1] to [7]; The process of forming a resist film on the formed resist underlayer film; The process of forming a resist pattern by irradiating and developing the formed resist film with light or electron beams; The process of etching the underlying resist film through the formed resist pattern to form a patterned underlying resist film; and The process of processing a semiconductor substrate using a patterned resist underlayer film.

[0016]

[10] A method for manufacturing a semiconductor device includes the following steps: The process of forming a photoresist underlayer film on a semiconductor substrate using any one of [1] to [7]; The process of forming a hard mask on the formed resist underlayer film; The process of forming a resist film on the hard mask; The process of forming a resist pattern by irradiating and developing the formed resist film with light or electron beams; The process of etching the hard mask using the formed resist pattern to form a patterned hard mask; and The process of etching the resist underlayer film using a patterned hard mask to form a patterned resist underlayer film; and The process of processing a semiconductor substrate using a patterned resist underlayer film.

[0017] Invention Effects According to the present invention, a novel resist underlayer film forming composition is provided, which can meet the requirements of reducing the amount of sublimation in contaminated devices, etch resistance in substrate processing, and especially bulge suppression, while maintaining other good properties. Detailed Implementation

[0018] [Resist Underlayer Film Formation Composition] The resist underlayer film forming composition of the present invention comprises compound P and a solvent, wherein compound P comprises a fluorene skeleton and comprises a partial structure of two groups, namely, a group having a phenolic hydroxyl group on an aromatic hydrocarbon ring and a group having a hydroxyl hydrogen atom selected from hydroxymethyl and hydroxymethyl replaced by a substituent.

[0019] From the viewpoint of obtaining a resist underlayer film that can reduce the amount of sublimation and has excellent bulging inhibition, based on the total solids content in the composition, it is preferable to contain 90% by mass or more of compound P, more preferably 95% by mass or more of compound P, and most preferably 100% by mass of compound P.

[0020] [Compound P] Compound P contains a fluorene skeleton and includes local structures.

[0021] This local structure has a phenolic hydroxyl group and two functional groups on one aromatic hydrocarbon ring.

[0022] These two groups are selected from hydroxymethyl and groups formed by substituting the hydroxyl hydrogen atoms of hydroxymethyl with substituents.

[0023] The number of phenolic hydroxyl groups on an aromatic hydrocarbon ring is not particularly limited; it can be one or more, but one is preferred.

[0024] More specifically, compound P is the compound shown in formula (1) below.

[0025] [Chemistry 2] (In formula (1), Ar) 1 Each can be independently represented as a benzene ring, naphthalene ring, or biphenyl ring that may have substituents. Ar 2 Each of these can independently represent either a benzene ring or a naphthalene ring, and R can independently represent a hydrogen atom, an alkyl group with 1 to 4 carbon atoms, or an alkoxyalkyl group with 2 to 6 carbon atoms. The RO-CH2- group in formula (1) is an example of a group formed by substituting a hydroxymethyl or hydroxymethyl hydrogen atom with a substituent.

[0026] In equation (1), 1 Ar 2 It has one phenolic hydroxyl group.

[0027] In equation (1), 1 Ar 2 It has two RO-CH2- groups.

[0028] In equation (1), bonded to one Ar 2 At least one of the two RO-CH2- groups is bonded to a carbon atom adjacent to the carbon atom bonded to the phenolic hydroxyl group.

[0029] In equation (1), bonded to one Ar 2 One of the two RO-CH2- groups can be bonded to the carbon atom at the para position of the carbon atom bonded to the phenolic hydroxyl group.

[0030] In equation (1), it is preferred to bond to one Ar 2 The two RO-CH2- groups are both bonded to the carbon atom adjacent to the carbon atom bonded to the phenolic hydroxyl group.

[0031] Ar in equation (1) 1 It forms the skeleton of fluorescein.

[0032] Ar in equation (1) 1 It is a benzene ring, a naphthalene ring, or a biphenyl ring, represented by the following formula (2).

[0033] [Chemistry 3] Ar in equation (1) 1 Preferably, it is a benzene ring or a naphthalene ring, more preferably a benzene ring.

[0034] Ar in equation (1) 1 It can have substituents, for example, alkyl, phenyl, 1-naphthyl, 2-naphthyl, etc., having 1 to 4 carbon atoms.

[0035] Ar in equation (1) 2 Benzene rings are preferred.

[0036] Examples of alkyl groups having 1 to 4 carbon atoms include methyl, ethyl, n-propyl, isopropyl, cyclopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, cyclobutyl, 1-methyl-cyclopropyl, and 2-methyl-cyclopropyl.

[0037] As an alkoxyalkyl group with 2 to 6 carbon atoms, it can be straight-chain, branched, or cyclic, for example, ethoxy, isopropoxy, n-pentoxy, n-hexoxy, cyclohexoxy, etc.

[0038] As an example of an alkoxyalkyl group having 2 to 6 carbon atoms, the group shown in the following formula (3) can be cited.

[0039] [Chemistry 4] (In equation (3), R) 102 It indicates methyl or ethyl. (This represents a bonding bond.) In formula (1), R is preferably at least one hydrogen atom, and more preferably all of them are hydrogen atoms.

[0040] Compound P can be exemplified by the following compounds, but is not limited to these.

[0041] [Chemistry 5] (In the formula, R is synonymous with R in formula (1).) [Chemistry 6] For example, compound P can be synthesized by reacting a compound of formula (4) below with formaldehyde in an aqueous solution in the presence of a base. If necessary, a methoxymethyl group can be introduced by further reacting a compound that has reacted with a hydroxymethyl group to provide a methoxymethyl group.

[0042] [Chemistry 7] (In equation (4), Ar) 1 Ar 2Synonymous with equation (1). [solvent] The resist underlayer film forming composition of the present invention can be prepared by dissolving the above-mentioned compound P in a suitable solvent and can be used in a homogeneous solution state.

[0043] Examples of such solvents include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol, propylene glycol monomethyl ether, propylene glycol monopropyl ether, propylene glycol monomethyl ether acetate, propylene glycol propyl ether acetate, methyl cellosolve acetate, ethyl cellosolve acetate, 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, ethyl 3-ethoxypropionate, methyl 3-ethoxypropionate, methyl pyruvate, ethyl pyruvate, ethyl acetate, butyl acetate, ethyl lactate, butyl lactate, N,N-dimethylformamide, N,N-dimethylacetamide, and N-methylpyrrolidone.

[0044] Furthermore, high-boiling-point solvents with a boiling point above 180°C can also be used. Specific examples of high-boiling-point organic solvents include 1-octanol, 2-ethylhexanol, 1-nonanol, 1-decanol, 1-undecylol, ethylene glycol, 1,2-propanediol, 1,3-butanediol, 2,4-pentanediol, 2-methyl-2,4-pentanediol, 2,5-hexanediol, 2,4-heptanediol, 2-ethyl-1,3-hexanediol, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol, glycerol, n-nonyl acetate, etc. Ethylene glycol mono-2-ethylhexyl ether, ethylene glycol monophenyl ether, ethylene glycol monobenzyl ether, diethylene glycol monoethyl ether, diethylene glycol monoisopropyl ether, diethylene glycol mono-n-butyl ether, diethylene glycol monoisobutyl ether, diethylene glycol monohexyl ether, diethylene glycol monophenyl ether, diethylene glycol monobenzyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, diethylene glycol butyl methyl ether, triethylene glycol dimethyl ether, triethylene glycol monomethyl ether, triethylene glycol n-butyl ether, triethylene glycol monobutyl ether, triethylene glycol monobutyl ether, triethylene glycol monoethyl ... diethylene glycol monoethyl ether, diethylene glycol monoethyl ether, diethylene glycol monoethyl ether, diethylene glycol monoethyl ether, diethylene glycol monoethyl ether, diethylene glycol monoethyl ether, diethylene glycol monoethyl ether, diethylene glycol monoethyl ether, diethylene glycol monoethyl ether, diethylene glycol monoethyl ether, diethylene glycol monoethyl ether, diethylene glycol monoethyl ether, diethylene glycol monoethyl ether, di Diethylene glycol butyl methyl ether, triethylene glycol diacetate, tetraethylene glycol dimethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol mono-n-propyl ether, dipropylene glycol mono-n-butyl ether, tripropylene glycol dimethyl ether, tripropylene glycol monomethyl ether, tripropylene glycol mono-n-propyl ether, tripropylene glycol mono-n-butyl ether, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, triacetyl glycerol, propylene glycol monomethyl ether acetate, ethylene glycol monobutyl ether acetate, triacetyl glycerol, propylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, triacetyl glycerol, propylene glycol monomethyl ether acetate, di ... Diethylene glycol diacetate, dipropylene glycol monomethyl ether acetate, dipropylene glycol methyl n-propyl ether, dipropylene glycol methyl ether acetate, 1,4-butanediol diacetate, 1,3-butanediol diacetate, 1,6-hexanediol diacetate, triethylene glycol diacetate, γ-butyrolactone, dihexyl malonate, diethyl succinate, dipropyl succinate, dibutyl succinate, dihexyl succinate, dimethyl adipate, diethyl adipate, dibutyl adipate, etc.

[0045] These solvents can be used alone or in combination of two or more. The proportion of solids remaining after removing the organic solvent from the composition is, for example, 0.5% to 30% by mass, preferably 0.8% to 15% by mass.

[0046] Alternatively, the following compounds described in WO2018 / 131562A1 may also be used.

[0047] [Chemistry 8] (R in equation (i)) 1 R 2 and R 3 Each alkyl group represents an alkyl group with 1 to 20 carbon atoms that can be interrupted by hydrogen, oxygen, sulfur, or amide bonds. These groups can be the same or different and can bond together to form a ring structure. Examples of alkyl groups having 1 to 20 carbon atoms include straight-chain or branched alkyl groups that may or may not have substituents, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl, n-hexyl, isohexyl, n-heptyl, n-octyl, cyclohexyl, 2-ethylhexyl, n-nonyl, isononyl, p-tert-butylcyclohexyl, n-decyl, n-dodecylnonyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecanyl, octadecyl, nonadecanyl, and eicosyl. Alkyl groups having 1 to 12 carbon atoms are preferred, alkyl groups having 1 to 8 carbon atoms are more preferred, and alkyl groups having 1 to 4 carbon atoms are even more preferred.

[0048] Alkyl groups having 1 to 20 carbon atoms whose number is interrupted by oxygen, sulfur, or amide bonds include, for example, alkyl groups containing the structural units -CH2-O-, -CH2-S-, -CH2-NHCO-, or -CH2-CONH-. -O-, -S-, -NHCO-, or -CONH- can be one or more units in the alkyl group. Specific examples of alkyl groups with 1 to 20 carbon atoms interrupted by -O-, -S-, -NHCO-, or -CONH- units include methoxy, ethoxy, propoxy, butoxy, methylthio, ethylthio, propylthio, butylthio, methylcarbonylamino, ethylcarbonylamino, propylcarbonylamino, butylcarbonylamino, methylaminocarbonyl, ethylaminocarbonyl, propylaminocarbonyl, butylaminocarbonyl, etc.; further examples include groups formed by substituting methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl, or octadecyl groups with methoxy, ethoxy, propoxy, butoxy, methylthio, ethylthio, propylthio, butylthio, methylcarbonylamino, ethylcarbonylamino, methylaminocarbonyl, ethylaminocarbonyl, etc. Preferably, methoxy, ethoxy, or methylthio, more preferably methoxy or ethoxy.

[0049] Because of their high boiling points, these solvents are also effective in imparting high embedding and high planarization properties to the resist underlayer film forming composition.

[0050] Specific examples of the preferred compounds shown in formula (i) are shown below.

[0051] [Chemistry 9] Preferably, 3-methoxy-N,N-dimethylpropionamide, N,N-dimethylisobutyramide, and compounds represented by the following formulas are used: [Chemistry 10] The compounds represented by formula (i) are particularly preferred as 3-methoxy-N,N-dimethylpropionamide and N,N-dimethylisobutyramide.

[0052] These solvents can be used alone or in combination of two or more. Preferred solvents include propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, ethyl lactate, butyl lactate, cyclohexanone, 3-methoxy-N,N-dimethylpropionamide, N,N-dimethylisobutyramide, 2,5-dimethylhexane-1,6-dimethyldiacetate (DAH; CAS, 89182-68-3), and 1,6-diacetoxyhexane (CAS, 6222-17-9). Propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, and N,N-dimethylisobutyramide are particularly preferred.

[0053] Among these solvents, those with a boiling point of 160°C or higher are preferred.

[0054] [Any ingredients] The resist underlayer film forming composition of the present invention may further contain at least one of an acid and / or an acid-generating agent, a thermal acid-generating agent, and a surfactant as an optional component.

[0055] (Acid and / or acid-producing agent) The resist underlayer film forming composition of the present invention can contain acid and / or acid-generating agent.

[0056] Examples of acids include p-toluenesulfonic acid, trifluoromethanesulfonic acid, pyridinium p-toluenesulfonic acid, pyridinium phenolsulfonic 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, naphtholic acid, and other carboxylic acid compounds, as well as inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, and phosphoric acid.

[0057] One acid may be used alone, or two or more may be used in combination. The amount of acid used relative to the total solids content is typically from 0.0001% to 20% by mass, preferably from 0.0005% to 10% by mass, and more preferably from 0.01% to 5% by mass.

[0058] Examples of acid-producing agents include thermal acid-producing agents and photo-producing acid-producing agents.

[0059] 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 quaternary ammonium salts of trifluoroacetic acid and alkyl esters of organic sulfonic acids.

[0060] Examples of photoacid-generating agents include onium salt compounds, sulfonylimide compounds, and disulfonyldiazomethane compounds. Examples of onium salt compounds include 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, and triphenylsulfonium trifluoromethanesulfonate.

[0061] Examples of sulfonylimide compounds include: N-(trifluoromethanesulfonyloxy)succinimide, N-(nonafluoron-butanesulfonyloxy)succinimide, N-(camphorsulfonyloxy)succinimide, and N-(trifluoromethanesulfonyloxy)naphthalenediformimide.

[0062] Examples of disulfonyl diazonium compounds include bis(trifluoromethylsulfonyl)diazomethane, bis(cyclohexylsulfonyl)diazomethane, bis(phenylsulfonyl)diazomethane, bis(p-toluenesulfonyl)diazomethane, bis(2,4-dimethylbenzenesulfonyl)diazomethane, and methylsulfonyl-p-toluenesulfonyl diazonium.

[0063] Acid-producing agents can be used in isolation or in combination of two or more.

[0064] When using an acid-generating agent, the proportion thereof is from 0.01% to 10 parts by mass, or from 0.1% to 8 parts by mass, or from 0.5% to 5 parts by mass relative to 100 parts by mass of the solid component of the resist underlayer film-forming composition.

[0065] (surfactant) The resist underlayer film forming composition of the present invention may further contain a surfactant. 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 octylphenyl ether and polyoxyethylene nonylphenyl 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 nonionic surfactants such as polyoxyethylene sorbitan fatty acid esters such as polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, and polyoxyethylene sorbitan tristearate; EFTOP [registered trademark] EF301, EFTOP EF303, EFTOP EF352 (manufactured by Mitsubishi Materials Electronics & Chemicals Co., Ltd.), MEGAFACE [registered trademark] F171, MEGAFACE F173, MEGAFACE R-30, MEGAFACE R-30-N, MEGAFACE R-40, MEGAFACE R-40-LM (manufactured by DIC Corporation), FLUORAD FC430, FLUORAD FC431 (manufactured by Sumitomo 3M Corporation), AsahiGuard [registered trademark] AG710, Surflon [registered trademark] S-382, Surflon SC101, Surflon SC102, Surflon SC103, Surflon SC104, Surflon SC105, Surflon Fluoropolymer surfactants such as SC106 (manufactured by Asahi Glass Co., Ltd.) and organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.) can be added. One of these surfactants can be added, or two or more can be added in combination. The surfactant content is, for example, from 0.01% to 5% by mass relative to the solids content after removing the solvent described later from the resist underlayer film-forming composition of the present invention.

[0066] (Light absorber) Examples of light absorbers include commercially available light absorbers listed in "Technology and Markets of Industrial Pigments" (CMC publication) and "Dye Handbook" (edited by the Organic Synthetic Chemistry Society). Preferred examples include CIDisperse 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; CIDisperse Orange 1,5,13,25,29,30,31,44,57,72, and 73; CIDisperse Red 1,5,7,13,17,19,43,50,54,58,65,72,73,88,117,137,143,199, and 210; CIDisperse Violet 43; and CIDisperse Blue. 96; CIFluorescent Brightening Agent 112, 135 and 163; CISolvent Orange 2 and 45; CISolvent Red 1, 3, 8, 23, 24, 25, 27 and 49; CIPigmentGreen 10; CIPigment Brown 2, etc. The above-mentioned light absorbers are generally formulated in a proportion of 10% by mass or less, preferably 5% by mass or less, relative to the total solids content of the resist underlayer film-forming composition.

[0067] (Rheology modifier) Rheology modifiers are mainly added to improve the flowability of the resist underlayer film-forming composition, especially to improve the uniformity of the resist underlayer film thickness during the baking process, and to improve the filling ability of the resist underlayer film-forming composition into the pores. 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 formulated in proportions of less than 30% by mass relative to the total solids content of the resist underlayer film-forming composition.

[0068] (Adhesive aid) Adhesion aids are primarily added to improve the adhesion between the substrate or photoresist and the underlying photoresist film, especially to prevent the photoresist from peeling off during development. Specific examples include chlorosilanes such as trimethylchlorosilane, dimethylhydroxymethylchlorosilane, methyldiphenylchlorosilane, and chloromethyldimethylchlorosilane; alkoxysilanes such as trimethylmethoxysilane, dimethyldiethoxysilane, methyldimethoxysilane, dimethylhydroxymethylethoxysilane, diphenyldimethoxysilane, and phenyltriethoxysilane; and hexamethyldisilazane, N,N'-bis(trimethylsilyl)urea, dimethyltrimethylsilylamine, and trimethylsilyl... Imidazole and other silazane compounds; silane compounds such as hydroxymethyltrichlorosilane, γ-chloropropyltrimethoxysilane, γ-aminopropyltriethoxysilane, and γ-glycidoxypropyltrimethoxysilane; heterocyclic compounds such as benzotriazole, benzimidazole, indazole, imidazole, 2-mercaptobenzimidazole, 2-mercaptobenzothiazole, 2-mercaptobenzoxazole, urazole, thiouracil, mercaptoimidazole, and mercaptopyrimidine; ureas such as 1,1-dimethylurea and 1,3-dimethylurea; or thiourea compounds. These adhesive aids are typically formulated 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.

[0069] The solid content of the resist underlayer film forming composition of the present invention is typically from 0.1% to 70% by mass, preferably from 0.1% to 60% by mass. The solid content refers to the percentage of all components remaining after removing the solvent from the resist underlayer film forming composition. The preferred proportions of the polymer in the solid content are, sequentially, 1% to 100% by mass, 1% to 99.9% by mass, 50% to 99.9% by mass, 50% to 95% by mass, and 50% to 90% by mass.

[0070] One criterion for evaluating whether a resist underlayer film-forming composition is a homogeneous solution is to observe the permeability of a specific microfilter; however, the resist underlayer film-forming composition of this invention permeates through pores with a diameter of 0.1 mm. m The microfilter, with a diameter of m, produces a uniform solution.

[0071] Examples of materials that can be used for the aforementioned microfilters include: fluorinated resins such as PTFE (polytetrafluoroethylene) and PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer), PE (polyethylene), UPE (ultra-high molecular weight polyethylene), PP (polypropylene), PSF (polysulfone), PES (polyethersulfone), and nylon, with PTFE (polytetrafluoroethylene) being the preferred material.

[0072] [Resist underlayer film] The resist underlayer film can be formed using the resist underlayer film forming composition of the present invention as follows.

[0073] The resist underlayer film formation composition of the present invention is formed by coating a substrate used in the manufacture of semiconductor devices (e.g., silicon wafer substrate, silicon / silicon dioxide coated substrate, silicon nitride substrate, glass substrate, ITO substrate, polyimide substrate, and low-k material coated substrate, etc.) with a suitable coating method such as a spinner or coater, and then firing it using a heating device such as a heating plate. The firing conditions are appropriately selected from a firing temperature of 80°C to 600°C and a firing time of 0.3 minutes to 60 minutes. Preferably, the firing temperature is 150°C to 350°C and the firing time is 0.5 minutes to 2 minutes. Air, or inert gases such as nitrogen or argon, can be used as the atmosphere gas during firing. The firing can be performed by changing the temperature and firing time in the first and second stages, respectively. Here, the thickness of the underlying film is, for example, 10 nm to 1000 nm, or 20 nm to 500 nm, or 30 nm to 400 nm, or 50 nm to 300 nm. If a quartz substrate is used as the substrate, it is possible to manufacture a replica of the quartz embossing mold (mold replica).

[0074] Alternatively, an adhesive layer and / or an organosilicon layer containing 99% by mass or less or 50% by mass or less of Si can be formed on the resist underlayer film of the present invention by coating or vapor deposition. For example, in addition to the method of forming a composition of a silicon-containing resist underlayer film (inorganic resist underlayer film) described in Japanese Patent Application Publication No. 2013-202982, Japanese Patent No. 5827180, and WO2009 / 104552A1 by spin coating, a Si-based inorganic material film can also be formed by CVD or the like.

[0075] Furthermore, by coating the resist underlayer film forming composition of the present invention onto a semiconductor substrate (so-called stepped difference substrate) having a stepped difference portion and a stepped difference non-stepped portion and then firing it, a resist underlayer film with a stepped difference portion and a stepped difference non-stepped portion having a stepped difference portion in the range of 3 to 70 nm can be formed.

[0076] [Semiconductor device manufacturing method] The method for manufacturing the semiconductor device of the present invention includes the following steps: The process of forming a resist underlayer film using the resist underlayer film forming composition of the present invention; The process of forming a resist film on the formed resist underlayer film; The process of forming a resist pattern by irradiating and developing the formed resist film with light or electron beams; The process of etching the underlying resist film through the formed resist pattern to form a patterned underlying resist film; and The process of processing a semiconductor substrate using a patterned resist underlayer film.

[0077] Furthermore, the method for manufacturing the semiconductor device of the present invention includes the following steps: The process of forming a resist underlayer film using the resist underlayer film forming composition of the present invention; The process of forming a hard mask on the formed resist underlayer film; The process of forming a resist film on the hard mask; The process of forming a resist pattern by irradiating and developing the formed resist film with light or electron beams; The process of etching the hard mask using the formed resist pattern to form a patterned hard mask; and The process of etching the resist underlayer film using a patterned hard mask to form a patterned resist underlayer film; and The process of processing a semiconductor substrate using a patterned resist underlayer film.

[0078] The process of forming a resist underlayer film using the resist underlayer film forming composition of the present invention is as described above.

[0079] Alternatively, an organopolysiloxane film can be formed as a second photoresist underlayer film on the photoresist underlayer film formed through the above-described process, and a photoresist pattern can be formed on it. This second photoresist underlayer film can also be a SiON film or a SiN film formed using vapor deposition methods such as CVD or PVD. Furthermore, an anti-reflective film (BARC) can be formed on this second photoresist underlayer film as a third photoresist underlayer film. This third photoresist underlayer film can be a photoresist shape correction film without anti-reflective capabilities.

[0080] In the process of forming the resist pattern, exposure is performed using a mask (reticle) for forming the specified pattern or by direct drawing. Exposure light 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. Subsequently, development is carried out using 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.

[0081] The etching process following the formation of the resist pattern is performed by dry etching. Examples of etching gases used in dry etching include CHF3, CF4, and C2F6 for the second resist underlayer film (organopolysiloxane film), O2, N2O, and NO2 for the first resist underlayer film formed from the resist underlayer film forming composition of the present invention, and CHF3, CF4, and C2F6 for surfaces with stepped differences or recesses and / or protrusions. Furthermore, argon, nitrogen, or carbon dioxide can be mixed in these gases.

[0082] [Forming a resist underlayer using nanoimprinting] The above-mentioned process of forming the resist underlayer film can also be performed using nanoimprint lithography. This method includes the following steps: The process of applying a curable composition onto the formed resist underlayer film; The process of bringing the curable composition into contact with the mold; The process of forming a cured film by irradiating the curable composition with light or an electron beam; and The process of separating the cured film from the mold.

[0083] In the demolding process of photo-nanoimaging technology, the adhesion between the resist composition and the substrate is crucial. This is because if the adhesion between the resist composition and the substrate is low, during the demolding process, a portion of the photocured material obtained by curing the resist composition may adhere to the mold and peel off directly, resulting in pattern peeling defects. As a technique to improve the adhesion between the resist composition and the substrate, a bonding layer, or adhesive layer, has been proposed to form between the resist composition and the substrate to ensure a tight bond.

[0084] Furthermore, highly etch-resistant layers are sometimes used in the pattern formation of nanoimprinting. Organic or silicone-based materials are commonly used as materials for these highly etch-resistant layers. Furthermore, a bonding layer or a Si-containing silicone layer can be formed on the lower layer of the nanoimprinting resist by coating or vapor deposition. When these bonding layers or Si-containing silicone layers are hydrophobic and exhibit a high-purity water contact angle, and the lower layer is also hydrophobic and exhibits a high-purity water contact angle, improved adhesion between the films is expected, making peeling difficult. Conversely, when the bonding layers or silicone layers are hydrophilic and exhibit a low-purity water contact angle, and the lower layer is also hydrophilic and exhibits a low-purity water contact angle, improved adhesion between the films is expected, making peeling difficult.

[0085] In addition, based on the characteristics of the aforementioned sealing film, silicone layer, and lower film, He, H2, N2, air, etc., can be used.

[0086] The compound P involved in this invention exhibits the desired pure water contact angle not only during low-temperature calcination but also during high-temperature calcination. Furthermore, when the material is prepared by mixing a crosslinking agent, an acid catalyst, and a surfactant, it also exhibits the desired pure water contact angle. This improves adhesion to the upper film and also promises good permeability to gases such as He, H2, N2, and air. Moreover, compound P of this invention exhibits good planarization properties, and by modifying the molecular framework, the optical constants and etching rates can be adjusted to suit the process.

[0087] (Curing composition) As a photoresist formed on the underlayer of the resist film, there are no particular limitations as long as it is a photoresist used for photosensitive exposure. Both negative and positive photoresists can be used. Photoresists include: positive photoresists containing phenolic varnish resin and 1,2-naphthoquinone diazidosulfonate; chemically amplified photoresists containing binders and photoacid generators that accelerate alkali dissolution due to acid decomposition; chemically amplified photoresists containing low-molecular-weight compounds that accelerate alkali dissolution due to acid decomposition, alkali-soluble binders, and photoacid generators; and chemically amplified photoresists containing binders that accelerate alkali dissolution due to acid decomposition, low-molecular-weight compounds that accelerate alkali dissolution due to acid decomposition, and photoacid generators, etc. For example, examples include APEX-E manufactured by SHIPLEY Corporation, PAR710 manufactured by Sumitomo Chemical Co., Ltd., and SEPR430 manufactured by Shin-Etsu Chemical Co., Ltd. Additionally, examples include fluorinated polymer photoresists described in Proc. SPIE, Vol. 3999, 330-334 (2000), Proc. SPIE, Vol. 3999, 357-364 (2000), and Proc. SPIE, Vol. 3999, 365-374 (2000).

[0088] (Process of applying curable composition) This step involves applying a curable composition to a photoresist underlayer film formed by the method for manufacturing the photoresist underlayer film of the present invention. Methods for applying the curable composition include, for example, inkjet printing, dip coating, air knife coating, curtain coating, wire rod coating, gravure coating, extrusion coating, spin coating, and slot scanning. Inkjet printing is suitable for applying the curable composition as droplets, while spin coating is suitable for coating the curable composition. In this step, a bonding layer and / or an organosilicon layer containing 99% by mass or less or 50% by mass or less of Si can also be formed on the photoresist underlayer film by coating or vapor deposition, and the curable composition can then be applied thereon.

[0089] (The process of bringing the curable composition into contact with the mold) In this process, the curable composition is brought into contact with the mold. For example, if the curable composition, which is a liquid, is brought into contact with a mold having a prototype pattern for transferring the pattern shape, a liquid film is formed in which the curable composition fills the recesses of the fine pattern on the surface of the mold.

[0090] Considering the subsequent processes involving irradiation light or electron beams, it is recommended to use molds with a light-transmitting material as the substrate. Specifically, the mold substrate is preferably made of light-transmitting resins such as glass, quartz, PMMA, and polycarbonate resin, transparent metal vapor-deposited films, flexible films such as polydimethylsiloxane, UV-curable films, and metal films. Considering the low coefficient of thermal expansion and the reduction of pattern deformation, quartz is more preferred as the mold substrate.

[0091] The fine patterns on the surface of the mold preferably have a pattern height of 4 nm or more and 200 nm or less. While a certain pattern height is necessary to improve the processing accuracy of the substrate, a lower pattern height results in less force required to peel the mold from the cured film during the process of separating the cured film from the mold (described later). Furthermore, fewer defects remain on the mask side due to torn resist patterns. Therefore, it is recommended to select and employ a appropriately balanced pattern height.

[0092] Furthermore, due to the elastic deformation of the resist pattern caused by the impact during mold removal, adjacent resist patterns may come into contact with each other, resulting in adhesion or damage. This can be avoided by keeping the pattern height to be approximately twice the pattern width or less (an aspect ratio of less than 2).

[0093] To improve the peelability of the cured composition from the mold surface, the mold can be pre-treated. One method of surface treatment is to apply a release agent to the mold surface to form a release agent layer. Examples of release agents include silicone-based, fluorine-based, hydrocarbon-based, polyethylene-based, polypropylene-based, paraffin-based, lignite-based, and carnauba wax-based release agents. Fluorine-based and hydrocarbon-based release agents are preferred. Commercially available examples include Optool (registered trademark) DSX manufactured by Daikin Industries, Ltd. A single release agent or two or more can be used together.

[0094] In this process, there is no particular limitation on the pressure applied to the curing composition when the mold comes into contact with it. A pressure of 0 MPa or more and 100 MPa or less is recommended. Preferably, the pressure is 0 MPa or more and 50 MPa or less, 30 MPa or less, or 20 MPa or less.

[0095] In the case where the droplets of the curing composition are pre-spread in the preceding process (the process of applying the curing composition), the spreading of the curing composition in this process is completed rapidly. As a result, the contact time between the mold and the curing composition can be shortened. The contact time is not particularly limited, but is preferably 0.1 seconds or more, and 600 seconds or less, 3 seconds or less, or 1 second or less. If the contact time is too short, the spreading and filling become insufficient, and defects known as unfilled defects may occur.

[0096] This process can be carried out under any conditions, including atmospheric atmosphere, reduced pressure atmosphere, and inert gas atmosphere, but is preferably carried out at a pressure of 0.0001 atmospheres or higher and 10 atmospheres or lower. To prevent the influence of oxygen and moisture on the curing reaction, it is recommended to carry out the process under reduced pressure atmosphere or inert gas atmosphere. Specific examples of inert gases that can be used to form an inert gas atmosphere include nitrogen, carbon dioxide, helium, argon, CFCs, HCFCs, HFCs, or mixtures thereof.

[0097] This process can be performed in an atmosphere containing condensable gases (hereinafter referred to as a "condensable gas atmosphere"). In this specification, condensable gas refers to a gas that condenses and liquefies due to capillary pressure generated during filling when it is filled, together with the curable composition, into the recesses of the micro-pattern formed on the mold and into the gap between the mold and the substrate. It should be noted that the condensable gas is present as a gas in the atmosphere before the curable composition comes into contact with the mold in this process. If this process is performed in a condensable gas atmosphere, the gas filled into the recesses of the micro-pattern is liquefied by the capillary pressure generated by the curable composition, thereby eliminating air bubbles and resulting in excellent filling performance. The condensable gas can dissolve in the curable composition.

[0098] The boiling point of the condensable gas is not limited, as long as it is below the atmosphere temperature of this process, but preferably above -10°C or above +10°C and below +23°C.

[0099] There are no particular restrictions on the vapor pressure of the condensable gas at the atmosphere temperature in this process, as long as it is below the mold pressure. Preferably, it is in the range of 0.1 MPa to 0.4 MPa.

[0100] Examples of condensable gases include: chlorofluorocarbons (CFCs) such as trichlorofluoromethane; fluorocarbons (FCs); hydrochlorofluorocarbons (HCFCs); hydrofluorocarbons (HFCs) such as 1,1,1,3,3-pentafluoropropane (CHF2CH2CF3, HFC-245fa, PFP); and hydrofluoroethers (HFEs) such as pentafluoroethyl methyl ether (CF3CF2OCH3, HFE-245mc).

[0101] Condensing gases can be used alone or in mixtures of two or more. Furthermore, these condensing gases can also be mixed with non-condensing gases such as air, nitrogen, carbon dioxide, helium, and argon. Air or helium is preferred as the non-condensing gas to be mixed with the condensing gas.

[0102] (The process of forming a cured film by irradiating a curable composition with light or an electron beam) In this process, a curable film is formed by irradiating the curable composition with light or an electron beam. That is, the curable composition with a fine pattern filled in the mold is irradiated with light or an electron beam through a mold, so that the curable composition with the fine pattern filled in the mold is cured in this state, thereby forming a curable film with a patterned shape.

[0103] The wavelength of light or electron beam is selected based on the sensitivity of the curable composition. Specifically, ultraviolet light, X-rays, electron beams, etc., with wavelengths above 150 nm and below 400 nm can be appropriately selected. Examples of light or electron beam light sources include high-pressure mercury lamps, ultra-high-pressure mercury lamps, low-pressure mercury lamps, deep ultraviolet lamps, carbon arc lamps, chemical lamps, metal halide lamps, xenon lamps, KrF excimer lasers, ArF excimer lasers, and F2 excimer lasers. There can be one or more light sources. Irradiation can be performed on the entire curable composition filling the fine pattern in the mold, or only on a portion of the area. Light irradiation can be performed intermittently multiple times on the entire area of ​​the substrate, or continuously on the entire area. Alternatively, it is possible to first irradiate a portion of the substrate and then irradiate a different area a second time.

[0104] The cured film obtained in this way preferably has a thickness of 1 nm or more, or 10 nm or more, and a thickness of 10 mm or less, or 100 mm or more. m Patterns with dimensions less than m.

[0105] (The process of separating the cured film from the mold) In this process, the cured film is separated from the mold. The cured film with a patterned shape is separated from the mold, and a cured film with a patterned shape that becomes a reversed pattern of the fine pattern formed on the mold is obtained in an independent state.

[0106] As a method for separating a patterned cured film from a mold, there are no particular limitations as long as the means of moving the cured film and the mold in opposite directions, and as long as a portion of the patterned cured film does not suffer physical damage. There are also no particular limitations on various conditions. For example, peeling can be performed by fixing the substrate and moving the mold away from the substrate, or by fixing the mold and moving the substrate away from the mold. Alternatively, peeling can be performed by pulling the substrate and the mold in opposite directions to move them.

[0107] It should be noted that when the aforementioned process of contacting the cured composition with the mold is performed in a condensing gas atmosphere, the condensing gas vaporizes as the pressure at the interface between the cured film and the mold decreases during the separation of the cured film from the mold in this process. This reduces the demolding force required to separate the cured film from the mold.

[0108] Through the above process, a cured film with a desired convex-concave pattern shape derived from the mold at the desired location can be prepared.

[0109] Example The following examples illustrate the content of the present invention, but the present invention is not limited to these examples.

[0110] <Comparative Synthesis Example 1> Under nitrogen atmosphere, 25.00 g of 2,2'-biphenol (manufactured by Tokyo Chemical Industry Co., Ltd.), 10.5 g of 1-naphthaldehyde (manufactured by Tokyo Chemical Industry Co., Ltd.), 15.5 g of 1-pyrenealdehyde (manufactured by Aldrich), and 3.87 g of methanesulfonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) were added to a 100 mL two-necked flask. The mixture was then heated to 120 °C and allowed to cool naturally to room temperature for approximately 24 hours. Methanol was used to precipitate the polymer, and the precipitate was dried. The weight-average molecular weight (Mw) was determined to be 5000 by GPC using a polystyrene conversion. The resulting polymer (A) was diluted to a solids concentration of 30% with propylene glycol monomethyl ether acetate (PGMEA), and equal volumes of cation exchange resin and anion exchange resin were added, respectively. The mixture was stirred for 4 hours. The ion exchange resin was filtered to obtain the polymer solution.

[0111] [Chemistry 11] <Example 1> 2.45 g of BPF tetrahydroxymethyl form (manufactured by Osaka Gas Chemical Co., Ltd., (B)) was mixed with 0.98 g of a propylene glycol monomethyl ether acetate solution containing 1% by mass of a surfactant (manufactured by DIC Co., Ltd., trade name: MEGAFACE [trade name] R-40, a fluorinated surfactant), 21.38 g of propylene glycol monomethyl ether (PGME), and 0.19 g of propylene glycol monomethyl ether acetate. Subsequently, using a 0.1 mm diameter nozzle... m A microfilter made of polytetrafluoroethylene (PTFE) was used for filtration to prepare a resist lower film formation composition.

[0112] [Chemistry 12] <Comparative Example 1> In Comparative Synthesis Example 1, 3.02 g of the resin solution (solid content 29.9% by mass) was dissolved by adding 0.10 g of propylene glycol monomethyl ether acetate, 3.68 g of propylene glycol monomethyl ether acetate, and 2.68 g of propylene glycol monomethyl ether, all containing 1% by mass of surfactant (manufactured by DIC Corporation, MEGAFACE R-40). The solution was then purified using a pore size of 0.1 mm. m A microfilter made of polytetrafluoroethylene (PTFE) was used to prepare a resist lower film forming composition.

[0113] <Comparative Example 2> 2.70 g of BCF dimethylolpropionate (manufactured by Osaka Gas Chemical Co., Ltd., (B)) was mixed with 1.06 g of a propylene glycol monomethyl ether acetate solution containing 5% by mass of a surfactant (manufactured by DIC Co., Ltd., trade name: MEGAFACE [trade name] R-40, a fluorinated surfactant), 25.94 g of propylene glycol monomethyl ether, and 0.36 g of propylene glycol monomethyl ether acetate. Subsequently, a 0.1 mm diameter tube was used. m A microfilter made of polytetrafluoroethylene (PTFE) was used for filtration to prepare a resist lower film formation composition.

[0114] [Chemistry 13] (Dissolution test of photoresist solvent) The photoresist underlayer film forming compositions prepared in Example 1 and Comparative Examples 1 and 2 were respectively coated onto silicon wafers using a spin coater. The underlayer films were then heated at 400°C for 90 seconds on a hot plate to form a photoresist underlayer film (film thickness 170 nm). These photoresist underlayer films were then immersed in a PGME / PGMEA mixed solvent (mass mixing ratio 70 / 30) used as the solvent for the photoresist solution. Cases insoluble in this solvent are marked "○" and are shown in Table 1.

[0115] [Table 1] (Optical constant determination) The resist underlayer film forming compositions prepared in Examples 1 and Comparative Examples 1 and 2 were respectively coated onto silicon wafers using a spin coater. The films were then heated at 400°C for 90 seconds on a hot plate to form resist underlayer films (50 nm thick). The refractive index (n-value) and optical absorption coefficient (also known as k-value or attenuation coefficient) at a wavelength of 193 nm were measured for these resist underlayer films using a spectroscopic ellipsometry. The results are shown in Table 2.

[0116] [Table 2] Using the resist underlayer film formation compositions prepared in Example 1 and Comparative Examples 1 and 2, resist underlayer films (100 nm thick) were formed on a silicon wafer by the same method described above. Then, the dry etching rates of these resist underlayer films were measured using a RIE-10NR (manufactured by Samco Corporation) under conditions using CF4 or O2 / N2 as etching gases. The dry etching rates of each resist underlayer film were calculated when the dry etching rate of Comparative Example 1 was set to 1.00. The results are shown in Table 3 as “Relative Dry Etching Rates”.

[0117] [Table 3] (Determination of sublimation content in the lower layer of the resist film) The amount of sublimation was determined using the sublimation measuring apparatus described in International Publication No. 2007 / 111147. The resist underlayer film forming compositions prepared in Example 1 and Comparative Examples 1 and 2 were coated onto silicon wafers, and after firing at 400°C for 90 seconds, the amount of sublimation was measured when the film thickness reached 50 nm. The results are shown in Table 4. It should be noted that the values ​​recorded in the table are (sublimation amount of Example 1 or Comparative Example 2) / (sublimation amount of Comparative Example 1). Additionally, "-" in the table indicates a high amount of sublimation that was not evaluated.

[0118] [Table 4] Using the compositions prepared above, wafer edge removal and bulge suppression properties were evaluated according to the following method. The evaluation results are shown in Table 5 below. In the table, "-" indicates a high amount of sublimate, and no evaluation was conducted.

[0119] (Formation of a substrate with a resist underlayer after EBR treatment) Using a spin coater (Tokyo Gyokko Co., Ltd.) with the "CLEAN TRACK LITHIUS ProAP", the above-prepared composition was coated onto a silicon wafer (substrate) by spin coating. While rotating at 1000 rpm, a removal liquid nozzle was simultaneously sprayed at a speed of 1 mm per second towards a position 3 mm from the outer periphery of the substrate towards the center, spraying a removal liquid (propylene glycol monomethyl ether acetate / propylene glycol monoethyl ether = 30 / 70, mass ratio). After spraying the removal liquid at the 3 mm position for 2 seconds, spraying was stopped, and the substrate was rotated at 2000 rpm for 5 seconds. Next, the substrate was heated at 400°C for 90 seconds, thereby obtaining a substrate with a resist underlayer film having an average thickness of 170 nm.

[0120] (Wafer edge removal) Regarding wafer edge removal performance, the outer periphery of the wafer on the substrate with the resist underlayer film was observed using an optical microscope (10x magnification). Cases where no uneven removal was observed were rated as "A" (good), and cases where uneven removal was observed were rated as "B" (bad).

[0121] (Evaluation method for bulges) Regarding bulge suppression, the height variation was measured using a stylus-type surface roughness meter (Dektak XT-A) from the outer peripheral end of the substrate with the resist underlayer film to a length of 1 mm towards the center of the substrate. With the height of the substrate with the resist underlayer film set to 0, cases with a height less than 1 nm were rated "A" (good), cases with a height of 1 nm or more but less than 50 nm were rated "B" (slightly poor), and cases with a height of 50 nm or more were rated "C" (poor). As shown in Table 5, the composition of the examples and the resist underlayer film formed from the compositions exhibit excellent bulge suppression properties.

[0122] [Table 5] Industrial availability According to the present invention, a novel resist underlayer film forming composition is provided, which can meet the requirements of reducing the amount of sublimation in contaminated devices, etch resistance in substrate processing, and especially bulge suppression, while maintaining other good properties.

Claims

1. A resist underlayer film forming composition, characterized in that, The compound P comprises a fluorene skeleton and a partial structure comprising a total of two groups, namely a group having a phenolic hydroxyl group on an aromatic hydrocarbon ring and a group having a hydroxyl hydrogen atom selected from hydroxymethyl and hydroxymethyl replaced by a substituent.

2. The resist underlayer film forming composition according to claim 1, wherein, The compound P is a compound represented by the following formula (1). In equation (1), Ar 1 Each independently represents a benzene ring, naphthalene ring, or biphenyl ring with or without substituents. Ar 2 Each of the following can independently represent a benzene ring or a naphthalene ring, and R can independently represent a hydrogen atom, an alkyl group with 1 to 4 carbon atoms, or an alkoxyalkyl group with 2 to 6 carbon atoms.

3. The resist underlayer film forming composition according to claim 1, wherein, Based on the total solids content in the composition, the content of compound P is 90% by mass or more.

4. The resist underlayer film forming composition according to claim 2, wherein, In the formula (1), R consists entirely of hydrogen atoms.

5. The resist underlayer film forming composition according to claim 1, wherein, The resist underlayer film forming composition further comprises at least one of an acid and an acid-generating agent.

6. The resist underlayer film forming composition according to claim 1, wherein, The resist underlayer film forming composition further comprises a surfactant.

7. The resist underlayer film forming composition according to claim 1, wherein, The solvent contains solvents having a boiling point of 160°C or higher.

8. A resist underlayer film, characterized in that, The resist underlayer film is a sintered product of a coated film comprising the resist underlayer film forming composition according to any one of claims 1 to 7.

9. A method for manufacturing a semiconductor device, characterized in that, The process includes the following steps: The process of forming a photoresist underlayer film on a semiconductor substrate using the photoresist underlayer film forming composition according to any one of claims 1 to 7; The process of forming a resist film on the formed resist underlayer film; The process of forming a resist pattern by irradiating and developing the formed resist film with light or electron beams; The process of etching the underlying resist film through the formed resist pattern to form a patterned underlying resist film; and The process of processing a semiconductor substrate using a patterned resist underlayer film.

10. A method for manufacturing a semiconductor device, characterized in that, The process includes the following steps: The process of forming a photoresist underlayer film on a semiconductor substrate using the photoresist underlayer film forming composition according to any one of claims 1 to 7; The process of forming a hard mask on the formed resist underlayer film; The process of forming a resist film on the hard mask; The process of forming a resist pattern by irradiating and developing the formed resist film with light or electron beams; The process of etching the hard mask through the formed resist pattern to form a patterned hard mask; as well as The process of etching the resist underlayer film using a patterned hard mask to form a patterned resist underlayer film; and The process of processing a semiconductor substrate using a patterned resist underlayer film.

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