Resist underlayer film-forming composition using diarylmethane derivatives

Abstract

This invention provides a composition for forming a photoresist underlayer using a diarylmethane derivative, which can form a film exhibiting high etch resistance, good dry etch rate ratio and optical constants, good coverage even for so-called uneven substrates, small thickness variation after embedding, and flatness. Furthermore, it provides a method for manufacturing a polymer suitable for the photoresist underlayer forming composition, a photoresist underlayer using the photoresist underlayer forming composition, and a method for manufacturing a semiconductor device. The photoresist underlayer forming composition comprises an aromatic compound (A) having 6 to 120 carbon atoms, a reaction product of a compound represented by the following formula (1), and a solvent. In formula (1), Z represents -(C=O)- or -C(-OH)-, Ar1 and Ar2 each independently represent a substituted phenyl, naphthyl, anthraceneyl, or pyrene group, and ring Y represents a substituted aliphatic ring, a substituted aromatic ring, or a fused ring of substituted aliphatic and aromatic rings.

Description

Technical Field

[0001] The present invention relates to a composition for forming a photoresist underlayer film, the composition being capable of forming a film exhibiting high etch resistance and good optical constants, good coating even on so-called high-difference substrates, and high embedding capability for fine patterns, a method for manufacturing a polymer suitable for the composition for forming a photoresist underlayer film, a photoresist underlayer film using the composition for forming a photoresist underlayer film, and a method for manufacturing a semiconductor device. Background Technology

[0002] In recent years, for the lower layer film material of the resist used in multilayer resist processes, it is required that it function as an anti-reflective film, especially for short-wavelength exposure, and that it has appropriate optical constants while also having etch resistance in substrate processing. A polymer with repeating units containing benzene rings has been proposed (Patent Document 1).

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2004-354554 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] As resist patterns become increasingly miniaturized, the resist layer needs to be thinner. Known photolithography processes for this purpose involve forming at least two resist underlayers and using these resist underlayers as mask materials. This method involves forming at least one organic film (lower organic film) and at least one inorganic underlayer on a semiconductor substrate, using the resist pattern formed on the upper resist film as a mask to pattern the inorganic underlayer, and then using that pattern as a mask to pattern the lower organic film. This allows for the formation of patterns with high aspect ratios. Examples of materials for forming the aforementioned at least two layers include combinations of organic resins (e.g., acrylic resins, phenolic varnish resins) and inorganic materials (e.g., silicone resins (e.g., organopolysiloxanes), inorganic silicon compounds (e.g., SiON, SiO2)). Furthermore, in recent years, dual patterning techniques involving two photolithography and two etching processes to obtain a single pattern have been widely used, employing the aforementioned multilayer processes in each step. At this point, for organic films formed after the initial pattern is created, in addition to the property of flattening the height difference, the property of embedding fine patterns is also required.

[0008] However, for substrates with varying resist patterns on the substrate being processed, known as "high-low difference substrates," the coating properties produced by the resist underlayer film forming composition are low, and there is also the problem of difficulty in forming films with high embedding properties for fine patterns.

[0009] This invention addresses this problem and aims to provide a composition for forming a resist underlayer film, which can form a film exhibiting high etch resistance, good dry etch rate ratio and optical constants, good coverage even on substrates with significant differences in texture, and high embeddability for fine patterns. Furthermore, this invention also aims to provide a resist underlayer film using this composition and a method for manufacturing a semiconductor device.

[0010] Problem-solving methods

[0011] This invention includes the following:

[0012] [1] A composition for forming a resist underlayer film comprises an aromatic compound (A) having 6 to 120 carbon atoms, a reaction product of a compound represented by the following formula (1), and a solvent.

[0013]

[0014] In formula (1), Z represents -(C=O)- or -C(-OH)-, Ar1 and Ar2 each independently represent phenyl, naphthyl, anthracene or pyrene that can be substituted, and ring Y represents an aliphatic ring that can be substituted, an aromatic ring that can be substituted, or a fused ring of aliphatic and aromatic rings that can be substituted.

[0015] [2] According to the composition for forming a resist underlayer film as described in [1], in the reaction product, one carbon atom in ring Y is linked to one of the aromatic compounds (A), and one carbon atom in Ar1 or Ar2 is linked to the other of the aromatic compounds (A).

[0016] [3] The composition for forming a resist underlayer film according to [1] or [2], wherein the compound represented by formula (1) is represented by the following formula (1a).

[0017]

[0018] In formula (1a), Z represents -(C=O)-, Ar1 and Ar2 each independently represent phenyl, naphthyl, anthracene or pyrene that can be substituted, and ring Y represents an aliphatic ring that can be substituted, or a fused ring of aliphatic and aromatic rings that can be substituted.

[0019] [4] According to the composition for forming a resist underlayer film as described in [1], one carbon atom in ring Y of the reaction product is linked to two of the aromatic compounds (A).

[0020] [5] According to the composition for forming a resist underlayer film as described in [4], the ring Y in formula (1a) is a fused ring structure containing a cyclohexene ring.

[0021] [6] According to the composition for forming a resist underlayer film as described in [5], in the formula (1a), ring Y represents a fused ring of aliphatic ring and aromatic ring.

[0022] [7] The composition for forming a resist underlayer film according to any one of [1] to [3], wherein the compound represented by formula (1) is represented by the following formula (1b).

[0023]

[0024] In formula (1b), Z represents -C(-OH)-, Ar1 and Ar2 each independently represent substituted phenyl, naphthyl, anthracene or pyrene, and ring Y represents a substituted aliphatic ring, a substituted aromatic ring, or a fused ring of substituted aliphatic and aromatic rings.

[0025] [8] The composition for forming a resist underlayer film according to [7], wherein the formula (1b) is an aromatic compound.

[0026] [9] The composition for forming a resist underlayer film according to [8], wherein Y in formula (1b) comprises a naphthalene ring.

[0027]

[10] The composition for forming a resist underlayer film according to any one of [1] to [9], wherein in the formula (1), Ar1 and Ar2 each independently represent a phenyl or naphthyl group that can be substituted with a hydroxyl group.

[0028]

[11] The composition for forming a resist underlayer film according to any one of [1] to

[10] , wherein the aromatic compound (A) comprises one or more benzene rings, naphthalene rings, anthracene rings, pyrene rings or combinations thereof.

[0029]

[12] The composition for forming a resist underlayer film according to any one of [1] to

[10] , wherein the aromatic compound (A) comprises two or more benzene rings, naphthalene rings, anthracene rings, pyrene rings or combinations thereof.

[0030]

[13] The composition for forming a resist underlayer film according to any one of [1] to

[12] , wherein it further comprises a crosslinking agent.

[0031]

[14] The composition for forming a resist underlayer film according to any one of [1] to

[13] , wherein it further comprises an acid and / or an acid-generating agent.

[0032]

[15] The composition for forming a resist underlayer film according to any one of [1] to

[14] , wherein the solvent has a boiling point of 160°C or higher.

[0033]

[16] A resist underlayer film, characterized in that it is a sintered product of a coating film formed by any one of the resist underlayer film forming compositions described in any one of [1] to

[15] .

[0034]

[17] A method for manufacturing a semiconductor device includes a step of forming a photoresist underlayer film on a semiconductor substrate using a photoresist underlayer film forming composition as described in any one of [1] to

[15] , a step of forming a photoresist film thereon, a step of forming a photoresist pattern by irradiation and development using light or an electron beam, a step of etching the underlayer film using the photoresist pattern, and a step of processing the semiconductor substrate using the patterned underlayer film.

[0035]

[18] The method for manufacturing a semiconductor device described in

[17] above, wherein the process of forming a resist underlayer film is performed by nanoimprinting.

[0036] Invention Effects

[0037] The resist underlayer film formation composition of the present invention not only has high etch resistance and good optical constants, but also the resulting resist underlayer film has good coverage for so-called high-difference substrates, and can form a film with high embedding ability for fine patterns, thereby realizing finer substrate processing.

[0038] In particular, the composition for forming a resist underlayer film of the present invention is effective for photolithography processes that form at least two resist underlayer films for the purpose of reducing the thickness of the resist film and use the resist underlayer film as an etching mask. Detailed Implementation

[0039] [Composition for forming the lower layer film of the resist]

[0040] The composition for forming a resist underlayer film according to the present invention comprises an aromatic compound (A) having 6 to 120 carbon atoms, a reaction product of a compound represented by the following formula (1), and a solvent.

[0041]

[0042] In formula (1), Z represents -(C=O)- or -C(-OH)-, Ar1 and Ar2 each independently represent phenyl, naphthyl, anthracene or pyrene that can be substituted, and ring Y represents an aliphatic ring that can be substituted, an aromatic ring that can be substituted, or a fused ring of aliphatic and aromatic rings that can be substituted.

[0043] The following will explain in sequence.

[0044] [Aromatic compounds with 6 to 120 carbon atoms (A)]

[0045] Aromatic compounds (A) with 6 to 120 carbon atoms can be:

[0046] (a) Monocyclic compounds such as benzene, phenol, and phloroglucinol.

[0047] (b) Fused-ring compounds such as naphthalene, dihydroxynaphthalene, naphthol, 9,10-anthraquinone, and indenefluorenedione.

[0048] (c) Heterocyclic compounds such as furan, thiophene, pyridine, carbazole, phenothiazine, phenothiazine, and indolecarbazole.

[0049] (d) Compounds formed by the bonding of aromatic rings (a) to (c) through single bonds, such as biphenyl, phenylindole, 9,9-bis(4-hydroxyphenyl)fluorene, α,α,α',α'-tetra(4-hydroxyphenyl)-p-xylene, and 9,9-fluorene-bisnaphthol.

[0050] (e) Like phenylnaphthylamine, use -(CH2) n Compounds formed by linking aromatic rings of (a) to (d) with spacer groups exemplified by -(n=1~20), -CH=CH-, -C≡C-, -N=N-, -NH-, -NR-, -NHCO-, -NRCO-, -S-, -COO-, -OCO-, -O-, -CO- and -CH=N-.

[0051] As aromatic compounds, examples include benzene, thiophene, furan, pyridine, pyrimidine, pyrazine, pyrrole, oxazole, thiazole, imidazole, naphthalene, anthracene, quinoline, carbazole, fluorene, quinazoline, purine, indazine, benzothiophene, benzofuran, indole, phenylindole, acridine, etc.

[0052] Furthermore, the aforementioned aromatic compound (A) may be an aromatic compound containing an amino group, a hydroxyl group, or both. Alternatively, the aforementioned aromatic compound (A) may be an arylamine compound, a phenolic compound, or an aromatic compound containing both.

[0053] Preferably, it is an aromatic amine or a compound containing a phenolic hydroxyl group.

[0054] Examples of aromatic amines include aniline, diphenylamine, phenylnaphthylamine, hydroxydiphenylamine, phenylnaphthylamine, N,N'-diphenylethylenediamine, and N,N'-diphenyl-1,4-phenylenediamine.

[0055] Examples of compounds containing phenolic hydroxyl groups include phenol, dihydroxybenzene, trihydroxybenzene, hydroxynaphthalene, dihydroxynaphthalene, trihydroxynaphthalene, tri(4-hydroxyphenyl)methane, tri(4-hydroxyphenyl)ethane, 1,1,2,2-tetra(4-hydroxyphenyl)ethane, and polynuclear phenols.

[0056] Examples of polynuclear phenols include dihydroxybenzene, trihydroxybenzene, hydroxynaphthalene, dihydroxynaphthalene, trihydroxynaphthalene, tri(4-hydroxyphenyl)methane, tri(4-hydroxyphenyl)ethane, 2,2'-biphenyl, or 1,1,2,2-tetra(4-hydroxyphenyl)ethane.

[0057] The hydrogen atoms of the aromatic compound (A) having 6 to 120 carbon atoms can be substituted by alkyl groups having 1 to 20 carbon atoms, alkenyl groups having 2 to 10 carbon atoms, alkynyl groups having 2 to 10 carbon atoms, fused ring groups, heterocyclic groups, hydroxyl groups, formyl groups, amino groups, nitro groups, ether groups, alkoxy groups, cyano groups, and carboxyl groups.

[0058] Examples of alkyl groups having 1 to 20 carbon atoms include straight-chain or branched alkyl groups with or without 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.

[0059] Alkenyl and alkynyl groups having 2 to 10 carbon atoms can be categorized as straight-chain or branched alkenyl and alkynyl groups with or without substituents, such as vinyl, ethynyl, 2-propynyl, 2-propynyl, 2-butenyl, 2-butynyl, 3-butenyl, 3-butynyl, etc.

[0060] Alkyl groups having 1 to 20 carbon atoms whose number is interrupted by oxygen, sulfur, or amide bonds can be exemplified by, 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 aforementioned alkyl groups. 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., and further include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl, or octadecyl, each of which is substituted with methoxy, ethoxy, propoxy, butoxy, methylthio, ethylthio, propylthio, butylthio, methylcarbonylamino, ethylcarbonylamino, methylaminocarbonyl, ethylaminocarbonyl, etc. Preferably, methoxy, ethoxy, or methylthio, more preferably methoxy or ethoxy.

[0061] Examples of alkenyl groups with 2 to 10 carbon atoms that can be interrupted by oxygen atoms include 2-propenoxy, 2-propynoxy, 3-butenoxy, 3-butynoxy, and 2-(ethynoxy)ethoxy.

[0062] Fused ring groups refer to substituents derived from fused ring compounds. Specifically, examples include phenyl, naphthyl, anthraceneyl, phenanthrene, tetraphenyl, triphenylene, pyrene, and... The groups are preferably phenyl, naphthyl, anthraceneyl, and pyrene.

[0063] Heterocyclic groups refer to substituents derived from heterocyclic compounds. Specifically, examples include thiophene, furanyl, pyridinyl, pyrimidinyl, pyrazinyl, pyrroleyl, oxazolyl, thiazolyl, imidazolyl, quinolinyl, carbazoleyl, quinazolinyl, purineyl, indazine, benzothiophene, benzofuranyl, indoleyl, acridineyl, isoydinoleyl, benzimidazolyl, isoquinolinyl, quinoxalinyl, terpineyl, pteridineyl, chromenyl (benzopyranyl), and isochrynyl. (benzopyranyl), xanthonyl, thiazolyl, pyrazolyl, imidazolinyl, azazinyl, preferably thienyl, furanyl, pyridinyl, pyrimidinyl, pyrazinyl, pyrroleyl, oxazolyl, thiazolyl, imidazolyl, quinolinyl, carbazoleyl, quinazolinyl, purinyl, inzazinyl, benzothienyl, benzofuranyl, indoleyl, and azazinyl, most preferably thienyl, furanyl, pyridinyl, pyrimidinyl, pyrroleyl, oxazolyl, thiazolyl, imidazolyl, and carbazoleyl.

[0064] The nitrogen atoms on these heterocycles can be replaced by alkenyl groups with 2 to 10 carbon atoms or alkynyl groups with 2 to 10 carbon atoms.

[0065] It should be noted that the above aromatic compounds can be linked by single bonds or spacer groups.

[0066] Examples of spacer groups include -(CH2). n One or more of the following spacer groups are selected: -(n=1~20), -CH=CH-, -C≡C-, -N=N-, -NH-, -NR-, -NHCO-, -NRCO-, -S-, -COO-, -OCO-, -O-, -CO-, -Ph-, -Ph-Ph-, -Ph-O-Ph- (Ph=C6H4), and -CH=N-. These spacer groups can be two or more connected together.

[0067] Examples of substituent R on the nitrogen atom include straight-chain or branched alkyl groups having 1 to 20 carbon atoms, which may or may not have the aforementioned substituents.

[0068] The aromatic compound (A) mentioned above preferably contains one or more benzene rings, naphthalene rings, anthracene rings, pyrene rings or combinations thereof, and more preferably contains two or more benzene rings, naphthalene rings, anthracene rings, pyrene rings or combinations thereof.

[0069] Furthermore, for the aforementioned aromatic compound (A), two or more aromatic compounds (A) can be fused within a range of no more than 120 carbon atoms.

[0070] As examples of the aromatic compound (A) mentioned above, other compounds as described below can also be listed.

[0071]

[0072]

[0073]

[0074]

[0075] Examples of preferred aromatic compounds (A) include 1-naphthoaldehyde, 1-pyrenealdehyde, 9-fluorenone, carbazole, N-phenyl-1-naphthylamine, 2-phenylindole, 2,2'-biphenyl, 1,5-dihydroxynaphthalene, and 9,9-bis(4-hydroxyphenyl)fluorene, but are not limited to these.

[0076] The aromatic compound (A) mentioned above can be one or more, preferably one or two.

[0077] [The compound represented by formula (1)]

[0078] In the above formula (1), Ar1 and Ar2 each independently represent phenyl, naphthyl, anthraceneyl or pyrene that can be substituted.

[0079] Examples of substituents include hydroxyl groups, alkyl groups with 1 to 20 carbon atoms that can be substituted with carbonyl groups and whose carbonyl groups can be interrupted by oxygen or sulfur atoms, hydroxyl groups, oxo groups, carboxyl groups, cyano groups, nitro groups, sulfonyl groups, acyl groups with 1 to 6 carbon atoms, alkoxy groups with 1 to 6 carbon atoms, alkoxycarbonyl groups with 1 to 6 carbon atoms, amino groups, glycidyl groups, aryl groups with 6 to 20 carbon atoms, alkenyl groups with 2 to 10 carbon atoms, and alkynyl groups with 2 to 10 carbon atoms. These substituents can be bonded to Ar1 and / or Ar2 via oxygen atoms.

[0080] The alkyl groups having 1 to 20 carbon atoms are as exemplified with respect to the aromatic compounds (A) having 6 to 120 carbon atoms. Examples of acyl groups having 1 to 6 carbon atoms include formyl and acetyl. Examples of alkoxy groups having 1 to 6 carbon atoms include methoxy, ethoxy, n-propoxy, and isopropoxy. Examples of alkoxycarbonyl groups having 1 to 6 carbon atoms include methoxycarbonyl, ethoxycarbonyl, n-propoxycarbonyl, and isopropoxycarbonyl. Examples of aryl groups having 6 to 20 carbon atoms include phenyl, o-methylphenyl, m-methylphenyl, p-methylphenyl, o-methoxyphenyl, p-methoxyphenyl, α-naphthyl, β-naphthyl, o-biphenyl, m-biphenyl, p-biphenyl, 1-anthrayl, 2-anthrayl, 9-anthrayl, 1-phenanthyl, 2-phenanthyl, 3-phenanthyl, 4-phenanthyl, 9-phenanthyl, and fluorene. Examples of alkenyl groups with 2 to 10 carbon atoms include vinyl and allyl. Examples of alkynyl groups with 2 to 10 carbon atoms include ethynyl. Regarding heteroatoms, cyclic compounds, linked rings, and fused rings, the above applies.

[0081] Preferably, in the above formula (1), Ar1 and Ar2 each independently represent a phenyl or naphthyl group that can be substituted with a hydroxyl group.

[0082] In the above formula (1), ring Y represents a substituted aliphatic ring, a substituted aromatic ring, or a fused ring of substituted aliphatic and aromatic rings.

[0083] Examples of aliphatic rings include monocyclic rings such as cyclohexane and cyclohexene, polycyclic rings such as bicyclic [3.2.1]octane and bicyclic [2.2.1]hept-2-ene, and spirocyclic rings such as spirobicyclopentane, but they are not limited to these.

[0084] Examples of aromatic rings include benzene, indene, naphthalene, azurite, anthracene, phenanthrene, tetraphenylene, triphenylene, pyrene, etc. And so on, but not limited to these.

[0085] Examples of fused rings that are aliphatic and aromatic rings include, but are not limited to, benzo[a]cyclohexene, benzo[b]cyclohexene, 1,2,3,4-tetrahydronaphthalene, fluorene, etc.

[0086] Substituents are as illustrated for Ar1 and Ar2 above.

[0087] For the compound represented by formula (1), preferably, through a reaction with the above-mentioned aromatic compound (A), one carbon atom in ring Y is linked to one of the above-mentioned aromatic compounds (A), one carbon atom in Ar1 or Ar2 is linked to another of the above-mentioned aromatic compounds (A), or one carbon atom in ring Y is linked to two of the above-mentioned aromatic compounds (A).

[0088] The compound represented by preferred formula (1) is represented by the following formula (1a).

[0089]

[0090] In formula (1a), Z represents -(C=O)-, Ar1 and Ar2 each independently represent phenyl, naphthyl, anthracene or pyrene that can be substituted, and ring Y represents an aliphatic ring that can be substituted, or a fused ring of aliphatic and aromatic rings that can be substituted.

[0091] Ar1, Ar2, Y and their substituents are illustrated in connection with the above formula (1).

[0092] Preferably, ring Y in formula (1a) is a fused ring structure containing a cyclohexene ring. More preferably, in formula (1a), ring Y represents a fused ring of an aliphatic ring and an aromatic ring. More preferably, ring Y in formula (1a) represents a fused ring of a cyclohexene ring and an aromatic ring. Most preferably, ring Y in formula (1a) represents a fused ring of a cyclohexene ring and a benzene ring.

[0093] The compound represented by preferred formula (1) is represented by the following formula (1b).

[0094]

[0095] In formula (1b), Z represents -C(-OH)-, Ar1 and Ar2 each independently represent a substituted phenyl, naphthyl, anthraceneyl, or pyrene group, and ring Y represents a substituted aliphatic ring, a substituted aromatic ring, or a fused ring of substituted aliphatic and aromatic rings.

[0096] Ar1, Ar2, Y and their substituents are illustrated in connection with the above formula (1).

[0097] Preferably, the above formula (1b) is an aromatic compound. More preferably, in the above formula (1b), Y comprises a naphthalene ring. Most preferably, in the above formula (1b), Y is a naphthalene ring.

[0098] Among the compounds represented by the above formula (1), several particularly preferred compounds are p-naphthoquinone phenylmethane and α-naphthoquinone phenylmethane.

[0099] The compound represented by formula (1) can be one or more, preferably one or two. Alternatively, for example, it can be a combination of one or more compounds represented by formula (1a) and one or more compounds represented by formula (1b).

[0100] [Reaction Products]

[0101] By reacting the aromatic compound (A) with the carbonyl or hydroxymethylene group of the compound represented by formula (1), a reaction product (polymer) can be obtained in which one carbon atom in ring Y of the compound represented by formula (1) is linked to one of the aromatic compounds (A), one carbon atom in Ar1 or Ar2 is linked to another of the aromatic compounds (A), or one carbon atom in ring Y of the compound represented by formula (1) is linked to two of the aromatic compounds (A).

[0102] As the acid catalyst used in the reaction, inorganic acids such as sulfuric acid, phosphoric acid, and perchloric acid, organic sulfonic acids such as p-toluenesulfonic acid, p-toluenesulfonic acid monohydrate, and methanesulfonic acid, and carboxylic acids such as formic acid and oxalic acid can be used. The amount of acid catalyst used is selected according to the type of acid used. Generally, it is 0.001 to 10,000 parts by mass relative to 100 parts by mass of aromatic compound (A), preferably 0.01 to 1,000 parts by mass, and more preferably 0.1 to 100 parts by mass.

[0103] The condensation and addition reactions described above can be carried out without a solvent, but are usually carried out using a solvent. Any solvent that does not hinder the reaction can be used. Examples include ethers such as 1,2-dimethoxyethane, diethylene glycol dimethyl ether, propylene glycol monomethyl ether, tetrahydrofuran, and dioxane; esters such as propylene glycol monomethyl ether acetate; and ketones such as N-methylpyrrolidone.

[0104] The reaction temperature is typically the reflux temperature of the reaction mixture, preferably 40°C to 200°C. The reaction time is selected according to the reaction temperature, and is usually around 30 minutes to 50 hours.

[0105] The weight-average molecular weight (Mw) of the polymer obtained in the manner described above is typically 200–10,000, preferably 300–5,000 or 400–4,000.

[0106] The preferred reaction products used in this invention are described in the examples.

[0107] [solvent]

[0108] As a solvent for the resist underlayer film forming composition of the present invention, any solvent capable of dissolving the above-mentioned reaction products can be used without particular limitation. In particular, since the resist underlayer film forming composition of the present invention is used in a uniform solution state, considering its coating performance, it is recommended to use solvents commonly used in photolithography processes simultaneously.

[0109] Examples of such solvents include methyl cellolytic acetate, ethyl cellolytic acetate, propylene glycol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, methyl isobutyl carbitol, 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, and 3-methoxypropionic acid. Ethyl ester, ethyl 3-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 dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether, diethylene glycol dibutyl ether, propylene glycol monomethyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether, propylene glycol dipropyl ether, propylene glycol dibutyl ether, ethyl lactate, propyl lactate, isopropyl lactate, butyl lactate, isobutyl lactate, methyl formate Ester, 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 hydroxyethyl acetate, ethyl 2-hydroxy-2-methylpropionate, methyl 3-methoxy-2-methylpropionate, methyl 2-hydroxy-3-methylbutyrate, ethyl methoxyethyl acetate, ethyl ethoxyethyl acetate, 3-methyl Methyl propionate, ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-methoxybutyl acetate, 3-methoxypropyl acetate, 3-methyl-3-methoxybutyl acetate, 3-methyl-3-methoxybutyl propionate, 3-methyl-3-methoxybutyl butyrate, methyl acetoacetate, toluene, xylene, methyl ethyl ketone, methyl propyl ketone, methyl butyl ketone, 2-heptanone, 3-heptanone, 4-heptanone, cyclohexanone, 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.

[0110] Alternatively, the following compounds described in WO2018 / 131562A1 may also be used.

[0111]

[0112] R in equation (i) 1 R 2 and R 3These can be hydrogen atoms, alkyl groups with 1 to 20 carbon atoms that can be interrupted by oxygen atoms, sulfur atoms or amide bonds, and can be the same or different from each other, and can bond together to form a ring structure.

[0113] Examples of alkyl groups having 1 to 20 carbon atoms include straight-chain or branched alkyl groups with or without 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.

[0114] Alkyl groups having 1 to 20 carbon atoms whose carbon atoms are interrupted by oxygen, sulfur, or amide bonds can be exemplified by 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 aforementioned alkyl groups. 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., and more preferably methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl, or octadecyl groups, each substituted with methoxy, ethoxy, propoxy, butoxy, methylthio, ethylthio, propylthio, butylthio, methylcarbonylamino, ethylcarbonylamino, methylaminocarbonyl, ethylamino, etc. Preferably methoxy, ethoxy, or methylthio, more preferably methoxy or ethoxy.

[0115] Because these solvents have relatively high boiling points, they are also effective in imparting high embedding and high planarization properties to compositions used for forming etchant-based underlayer films.

[0116] The following shows specific examples of the preferred compounds represented by formula (i).

[0117]

[0118] Among the above compounds, 3-methoxy-N,N-dimethylpropionamide, N,N-dimethylisobutyramide, and the following formula are preferred.

[0119]

[0120] The compounds represented by formula (i) are particularly preferred, including 3-methoxy-N,N-dimethylpropionamide and N,N-dimethylisobutyramide.

[0121] These solvents can be used alone or in combination of two or more. Among these solvents, those with a boiling point above 160°C are preferred, including 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.

[0122] [Cross-linking agent component]

[0123] The resist underlayer film forming composition of the present invention may include a crosslinking agent component. Examples of such crosslinking agents include melamine derivatives, substituted ureas, or polymers thereof. Preferably, the crosslinking agent has at least two crosslinking-forming substituents, such as compounds like methoxymethylated glycourea, butoxymethylated glycourea, methoxymethylated melamine, butoxymethylated melamine, methoxymethylated benzoguanamine, butoxymethylated benzoguanamine, methoxymethylated urea, butoxymethylated urea, or methoxymethylated thiourea. Condensates of these compounds may also be used.

[0124] Furthermore, a crosslinking agent with high heat resistance can be used as the aforementioned crosslinking agent. Preferably, a compound containing a crosslinking-forming substituent with an aromatic ring (e.g., benzene ring, naphthalene ring) is used as the crosslinking agent.

[0125] For this compound, examples include compounds having a partial structure of the following formula (4), polymers or oligomers having repeating units of the following formula (5).

[0126]

[0127] The above R 11 R 12 R 13 and R 14 It is an alkyl group having 1 to 10 hydrogen atoms or carbon atoms, and the examples above can be used for these alkyl groups.

[0128] 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. For oligomers and polymers, the number of repeating unit structures can be in the range of 2 to 100 or 2 to 50.

[0129] The following examples illustrate compounds, polymers, and oligomers of formulas (4) and (5).

[0130]

[0131]

[0132] The above-mentioned compounds can be obtained as products of Asahi Organic Materials Co., Ltd. and Honshu Chemical Co., Ltd. For example, among the above-mentioned crosslinking agents, the compound of formula (4-24) can be obtained as a product of Asahi Organic Materials Co., Ltd. under the trade name TM-BIP-A.

[0133] In addition to the compounds mentioned above, compounds with the following structures can also be used as crosslinking agents.

[0134]

[0135] The amount of crosslinking agent added varies depending on the coating solvent used, the substrate used, the required solution viscosity, the required film shape, etc., and is 0.001 to 80% by mass relative to the total solids, preferably 0.01 to 50% by mass, and more preferably 0.05 to 40% by mass. These crosslinking agents sometimes undergo crosslinking reactions based on self-condensation, but when crosslinking substituents are present in the reaction products of the present invention, they can undergo crosslinking reactions with these crosslinking substituents.

[0136] [Acids and / or their salts and / or acid-producing agents]

[0137] The composition for forming the resist underlayer film of the present invention may contain an acid and / or its salt and / or an acid-generating agent.

[0138] Examples of acids include, for example, 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, naphthoic acid and other carboxylic acid compounds, hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid and other inorganic acids, etc.

[0139] Salts of the aforementioned acids can also be used as salts. There are no restrictions on the salts used, but preferred salts include ammonia derivatives such as trimethylamine salts and triethylamine salts, pyridine derivatives such as p-toluenesulfonic acid pyridinium, and morpholine derivatives.

[0140] The acid or its salt may be used alone, or two or more may be used in combination. The amount used is typically 0.0001 to 20% by mass relative to the total solids, preferably 0.0005 to 10% by mass, and more preferably 0.01 to 5% by mass.

[0141] Examples of acid-producing agents include thermal acid-producing agents and photo-producing acid-producing agents. Examples of thermal acid-producing agents include 2,4,4,6-tetrabromocyclohexadienone, benzoin toluene sulfonate, 2-nitrobenzyl toluenesulfonic acid, 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.

[0142] Photoacid-generating agents produce acid during the exposure of the photoresist. Therefore, the acidity of the lower film can be adjusted. This is a method to match the acidity of the lower film with that of the upper photoresist. Furthermore, by adjusting the acidity of the lower film, the pattern shape of the photoresist formed on the upper layer can be adjusted.

[0143] Examples of photoacid-generating agents included in the resist lower film forming composition of the present invention include onium salt compounds, sulfonylimide compounds, and disulfonyldiazomethane compounds.

[0144] Examples of ononium 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.

[0145] Examples of sulfonylimide compounds include, for example, N-(trifluoromethanesulfonyloxy)succinimide, N-(nonafluorobutanyloxy)succinimide, N-(camphorsulfonyloxy)succinimide, and N-(trifluoromethanesulfonyloxy)naphthalenediformimide.

[0146] Examples of disulfonyl diazonium compounds include, for example, bis(trifluoromethylsulfonyl)diazomethane, bis(cyclohexylsulfonyl)diazomethane, bis(phenylsulfonyl)diazomethane, bis(p-toluenesulfonyl)diazomethane, bis(2,4-dimethylbenzenesulfonyl)diazomethane, and methylsulfonyl-p-toluenesulfonyl diazonium.

[0147] Acid-producing agents can be used in isolation or in combination of two or more.

[0148] When using an acid-generating agent, the proportion thereof is 0.01 to 5 parts by weight, or 0.1 to 3 parts by weight, or 0.5 to 1 part by weight, relative to 100 parts by weight of the solids of the composition for forming the lower layer of the resist film.

[0149] [Other ingredients]

[0150] In the resist lower film forming composition of the present invention, a surfactant may be incorporated to further improve the coating properties against surface unevenness in order to prevent the generation of pinholes, streaks, etc. Examples of surfactants include, for instance, 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; sorbitan fatty acid esters such as polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan monooleate, polyoxyethylene sorbitan trioleate, and polyoxyethylene sorbitan tristearate; and polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, and polyoxyethylene sorbitan tristearate. Non-ionic surfactants such as polyoxyethylene sorbitan fatty acid esters, Etotron EF301, EF303, and EF352 (manufactured by Todo Co., Ltd., commercial products) name), F171, F173, R-40, R-40N, R-40LM (trade name made by DIC Co., Ltd.), F171, F173, R-40, R-40LM (trade name made by DIC Co., Ltd.), F171, F173, R-40 Fluoropolymer surfactants such as 31 (manufactured by Sumitomo Silem Co., Ltd., trade name), Asahigard AG710, Servolon S-382, SC101, SC102, SC103, SC104, SC105, SC106 (manufactured by Asahi Glass Co., Ltd., trade name), and organosiloxane polymer-KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.) are used. The amount of these surfactants in the formulation is typically 2.0% by mass or less, preferably 1.0% by mass or less, relative to the total solids of the photoresist underlayer film material. These surfactants can be used alone or in combination of two or more. When using surfactants, the proportion is 0.0001 to 5 parts by mass, 0.001 to 1 part by mass, or 0.01 to 0.5 parts by mass relative to 100 parts by mass of the photoresist underlayer film forming composition.

[0151] In the resist underlayer film forming composition of the present invention, light absorbers, rheology modifiers, adhesive additives, etc., may be added. Rheology modifiers are effective in improving the flowability of the underlayer film forming composition. Adhesive additives are effective in improving the adhesion between the semiconductor substrate or the resist and the underlayer film.

[0152] As light absorbers, commercially available light absorbers listed in "Technology and Markets of Industrial Pigments" (CMC Publication) or "Dye Handbook" (Organic Synthetic Chemistry Society) are preferred, 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 CI Dispersible Red 1, 44, 57, 72 and 73; CI Dispersible Red 1, 5, 7, 13, 17, 19, 43, 50, 54, 58, 65, 72, 73, 88, 117, 137, 143, 199 and 210; CI Dispersible Violet 43; CI Dispersible Blue 96; CI Fluorescent Whitening Agent 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 formulated in a proportion of 10% by mass or less, preferably 5% by mass or less, relative to the total solids of the composition for forming the resist underlayer film.

[0153] Rheology modifiers are mainly added to improve the flowability of the composition for forming the lower resist film, especially to improve the uniformity of the film thickness of the lower resist film during the baking process, and to improve the filling ability of the composition for forming the lower resist film to 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 octyl decyl 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 of the composition used for forming the resist underlayer film.

[0154] Adhesive additives are primarily used to improve the adhesion between the substrate or photoresist and the composition used for forming the underlying film of the photoresist, 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; hexamethyldisilazane; N,N'-bis(trimethylsilyl)urea; dimethyltrimethylsilylamine; and trimethylsilyl... Silazane compounds such as silyl imidazole, hydroxymethyl trichlorosilane, γ-chloropropyltrimethoxysilane, γ-aminopropyltriethoxysilane, and γ-glycidoxypropyltrimethoxysilane, benzotriazole, benzimidazole, indazole, imidazole, 2-mercaptobenzimidazole, 2-mercaptobenzothiazole, 2-mercaptobenzoxazole, uracil, thiouracil, mercaptoimidazole, mercaptopyrimidine, urea, 1,1-dimethylurea, 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 of the composition for forming the resist underlayer.

[0155] The solids content of the resist underlayer film forming composition involved in this invention is typically set to 0.1–70% by mass, preferably 0.1–60% by mass. Solids content refers to the percentage of all components in the resist underlayer film forming composition after removing the solvent. The preferred proportions of the above-mentioned reaction products in the solids are 1–100% by mass, 1–99.9% by mass, 50–99.9% by mass, 50–95% by mass, and 50–90% by mass, respectively.

[0156] One measure of whether a composition for forming a resist underlayer film is a homogeneous solution is to observe the permeability of a specific microfilter. However, the composition for forming a resist underlayer film of the present invention exhibits a homogeneous solution state when passing through a microfilter with a pore size of 0.1 μm.

[0157] As materials for the aforementioned microfilters, examples 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.

[0158] [Resist underlayer film and semiconductor device manufacturing method]

[0159] The following describes a method for manufacturing a photoresist underlayer film and a semiconductor device using the photoresist underlayer film formation composition of the present invention.

[0160] The resist underlayer film forming composition of the present invention is applied to a substrate used in the manufacture of semiconductor devices (e.g., silicon wafer substrate, silicon dioxide substrate (SiO2 substrate), silicon nitride substrate (SiN substrate), silicon oxynitride 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 a coating machine, and then formed by firing. The firing conditions are appropriately selected from a firing temperature of 80°C to 500°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. Here, the film thickness of the formed underlayer film is, for example, 10 to 1000 nm, or 20 to 500 nm, or 30 to 300 nm, or 50 to 200 nm.

[0161] As the firing atmosphere, either air or nitrogen atmosphere can be selected.

[0162] Alternatively, an inorganic photoresist underlayer film (hard mask) can also be formed on the organic photoresist underlayer film of the present invention. For example, in addition to the method for forming a silicon-containing photoresist underlayer film (inorganic photoresist underlayer film) composition by spin coating as described in WO2009 / 104552A1, Si-based inorganic material films can also be formed by CVD or the like.

[0163] Furthermore, by coating the resist underlayer film forming composition of the present invention onto a semiconductor substrate (so-called high-low difference substrate) having a high-low difference portion and a low-low difference portion, and then firing it, it is possible to form a resist underlayer film with a high-low difference portion and a low-low difference portion having a high-low difference portion in the range of 3 to 50 nm.

[0164] Next, a photoresist film, such as a photoresist layer, is formed on the lower photoresist film. The photoresist layer can be formed by a known method, namely, coating a photoresist composition solution onto the lower film and firing it. The thickness of the photoresist film is, for example, 50–10000 nm, 100–2000 nm, or 200–1000 nm.

[0165] As a photoresist formed on the underlying resist film, there are no particular restrictions as long as it is a photoresist that is photosensitive for use in exposure. Both negative and positive photoresists can be used. Examples include positive photoresists containing phenolic varnish resin and 1,2-naphthoquinone diazonyl sulfonate; chemically amplified photoresists containing binders and photoacid-generating agents that increase the rate of alkali dissolution by acid decomposition; chemically amplified photoresists containing low-molecular-weight compounds that increase the rate of alkali dissolution by acid decomposition; alkali-soluble binders and photoacid-generating agents; and chemically amplified photoresists containing binders, low-molecular-weight compounds, and photoacid-generating agents that increase the rate of alkali dissolution by acid decomposition. For example, examples include APEX-E manufactured by Sprint, PAR710 manufactured by Sumitomo Chemical Co., Ltd., and SEPR430 manufactured by Shin-Etsu Chemical Co., Ltd. Additionally, examples include fluorinated polymer photoresists such as those described in Proc.SPIE Vol. 3999 330-334 (2000), Proc.SPIE Vol. 3999 357-364 (2000), and Proc.SPIE Vol. 3999 365-374 (2000).

[0166] Next, a resist pattern is formed by irradiation and development with light or electron beams. First, exposure is performed through a prescribed mask. Near-ultraviolet, far-ultraviolet, or extreme ultraviolet light (e.g., EUV (wavelength 13.5 nm)) is used for exposure. Specifically, KrF excimer lasers (wavelength 248 nm), ArF excimer lasers (wavelength 193 nm), and F2 excimer lasers (wavelength 157 nm) can be used. Among these, ArF excimer lasers (wavelength 193 nm) and EUV (wavelength 13.5 nm) are preferred. After exposure, post-exposure baking may be performed as needed. Post-exposure baking is performed under conditions appropriately selected from a heating temperature of 70°C to 150°C and a heating time of 0.3 to 10 minutes.

[0167] Furthermore, in this invention, an electron beam lithography resist can be used instead of a photoresist as the resist. Both negative and positive electron beam resists can be used. Examples include chemically amplified resists containing an acid-generating agent and a binder having groups that change the rate of alkali dissolution by acid decomposition; chemically amplified resists containing an alkali-soluble binder, an acid-generating agent, and a low-molecular-weight compound that changes the rate of alkali dissolution by acid decomposition; chemically amplified resists containing an acid-generating agent, a binder having groups that change the rate of alkali dissolution by acid decomposition, and a low-molecular-weight compound that changes the rate of alkali dissolution by acid decomposition; non-chemically amplified resists containing a binder having groups that change the rate of alkali dissolution by electron beam decomposition; and non-chemically amplified resists containing a portion of the binder that changes the rate of alkali dissolution by electron beam cutting. When using these electron beam resists, the irradiation source can be set to an electron beam, and the resist pattern can be formed in the same way as when using a photoresist.

[0168] Next, development is performed using a developer. Thus, for example, when using a positive photoresist, the photoresist in the exposed areas is removed, forming a photoresist pattern.

[0169] Examples of suitable developing solutions include aqueous solutions of alkali metal hydroxides such as potassium hydroxide and sodium hydroxide, aqueous solutions of quaternary ammonium hydroxides such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, and choline, as well as alkaline aqueous solutions of amines such as ethanolamine, propylamine, and ethylenediamine. Furthermore, surfactants may be added to these developing solutions. Developing conditions can be appropriately selected from a temperature range of 5–50°C and a development time range of 10–600 seconds.

[0170] Then, using the patterned photoresist (upper layer) as a protective film, the inorganic lower layer (intermediate layer) is removed. Next, using the film composed of the patterned photoresist and the inorganic lower layer (intermediate layer) as a protective film, the organic lower layer (lower layer) is removed. Finally, using the patterned inorganic lower layer (intermediate layer) and organic lower layer (lower layer) as protective films, the semiconductor substrate is processed.

[0171] First, the inorganic lower layer (intermediate layer), to which the photoresist has been removed, is removed by dry etching, exposing the semiconductor substrate. Gases that can be used in the dry etching of the inorganic lower layer include tetrafluoromethane (CF4), perfluorocyclobutane (C4F8), perfluoropropane (C3F8), trifluoromethane, carbon monoxide, argon, oxygen, nitrogen, sulfur hexafluoride, difluoromethane, nitrogen trifluoride and chlorine trifluoride, chlorine, trichloroborane, and dichloroborane. Halogen gases are preferred for the dry etching of the inorganic lower layer, and fluorine gases are more preferably used. Examples of fluorine gases include tetrafluoromethane (CF4), perfluorocyclobutane (C4F8), perfluoropropane (C3F8), trifluoromethane, and difluoromethane (CH2F2).

[0172] Then, the organic underlayer is removed using a film consisting of patterned photoresist and an inorganic underlayer as a protective film. For the organic underlayer (underlayer), dry etching using an oxygen-based gas is preferred. This is because the inorganic underlayer, containing a large number of silicon atoms, is difficult to remove using dry etching with an oxygen-based gas.

[0173] Finally, the semiconductor substrate is processed. The semiconductor substrate is preferably processed by dry etching using fluorine-based gases.

[0174] Examples of fluorine gases include tetrafluoromethane (CF4), perfluorocyclobutane (C4F8), perfluoropropane (C3F8), trifluoromethane, and difluoromethane (CH2F2).

[0175] Furthermore, an organic antireflective film can be formed on top of the photoresist layer before the photoresist is formed. Therefore, there are no particular limitations on the antireflective film composition used, and any antireflective film composition conventionally used in photolithography processes can be selected. In addition, the antireflective film can be formed by conventional methods, such as coating and firing using a spin coater or a coating machine.

[0176] In this invention, an organic underlayer film can be formed on a substrate, followed by an inorganic underlayer film, and then a photoresist can be coated onto it. This narrows the pattern width of the photoresist, allowing substrate processing even when the photoresist is thinly coated to prevent pattern collapse, by selecting an appropriate etching gas. For example, a fluorine-based gas with a sufficiently fast etching rate for the photoresist can be used as the etching gas to process the underlayer film; similarly, a fluorine-based gas with a sufficiently fast etching rate for the inorganic underlayer film can be used as the etching gas; and an oxygen-based gas with a sufficiently fast etching rate for the organic underlayer film can also be used as the etching gas.

[0177] Furthermore, the photoresist underlayer film formed from the photoresist underlayer film forming composition sometimes absorbs light depending on the wavelength of the light used in the photolithography process. In such cases, it can function as an anti-reflective film that prevents reflected light from the substrate. Furthermore, the underlayer film formed from the photoresist underlayer film forming composition of the present invention can also function as a hard mask. The underlayer film of the present invention can also be used as a layer to prevent interaction between the substrate and the photoresist, a layer to prevent adverse effects on the substrate from materials used in the photoresist or substances generated during photoresist exposure, a layer to prevent the diffusion of substances generated from the substrate during heating and firing onto the upper photoresist, and a barrier layer to reduce the poisoning effect of the photoresist layer caused by the dielectric layer of the semiconductor substrate.

[0178] Furthermore, the lower layer film formed from the resist lower layer film formation composition is suitable for substrates with through-holes used in dual damascene processes, and can be used as an embedding material capable of filling holes without gaps. Additionally, it can also be used as a planarization material for planarizing the surface of semiconductor substrates with uneven surfaces.

[0179] Example

[0180] The present invention will now be described in more detail with reference to embodiments, etc., but the present invention is not limited in any way by the following embodiments, etc.

[0181] List the apparatus used to determine the weight-average molecular weight of the compounds obtained in the following synthetic examples.

[0182] Device: HLC-8320GPC manufactured by Higashikata Co., Ltd.

[0183] GPC column: TSKgel Super-MultiporeHZ-N (2 columns)

[0184] Column temperature: 40℃

[0185] Flow rate: 0.35 mL / min

[0186] Elution buffer: THF

[0187] Standard sample: Polystyrene

[0188] <Synthesis example 1>

[0189] In a flask, 10.00 g of p-naphtholquinone phenylmethane (manufactured by Fujifilm Wako Pure Chemicals Co., Ltd.), 4.17 g of 1-naphthal (manufactured by Tokyo Chemical Industry Co., Ltd.), 1.28 g of methanesulfonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), and 23.18 g of propylene glycol monomethyl ether acetate (hereinafter referred to as PGMEA) were added. The mixture was then heated to reflux under nitrogen and allowed to react for approximately 15 hours. After the reaction was stopped, the precipitate was precipitated with methanol and dried to obtain compound (1-1). The weight-average molecular weight (Mw) determined by GPC and converted to polystyrene was 450. The obtained compound was dissolved in PGMEA, and ion exchange was performed using a cation exchange resin and an anion exchange resin for 4 hours to obtain a solution of the target compound.

[0190]

[0191] <Synthesis example 2>

[0192] 8.00 g of α-naphtholquinone phenylmethane (manufactured by Fujifilm Wako Pure Chemicals Co., Ltd.), 3.18 g of 1-naphthal (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.98 g of methanesulfonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 4.00 g of NMP, and 18.24 g of PGMEA were added. The mixture was then heated to reflux under nitrogen for approximately 15 hours. After the reaction was stopped, the precipitate was precipitated with methanol and dried to obtain compounds (1-2). The weight-average molecular weight (Mw) determined by GPC and converted from polystyrene was 450. The obtained compounds were dissolved in PGMEA, and ion exchange was performed using cation exchange resin and anion exchange resin for 4 hours to obtain a solution of the target compound.

[0193]

[0194] <Synthesis example 3>

[0195] In a flask, 5.00 g of p-naphtholquinone phenylmethane (manufactured by Fujifilm Wako Pure Chemicals Co., Ltd.), 3.07 g of 1-pyrenecarboxaldehyde, 0.64 g of methanesulfonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), and 13.07 g of PGMEA were added. The mixture was then heated to reflux under nitrogen and allowed to react for approximately 15 hours. After the reaction was stopped, the precipitate was precipitated with methanol and dried to obtain compounds (1-3). The weight-average molecular weight (Mw) determined by GPC and conversion to polystyrene was 520. The obtained compounds were dissolved in cyclohexanone, and ion exchange was performed using cation exchange resin and anion exchange resin for 4 hours to obtain a solution of the target compounds.

[0196]

[0197] <Synthesis example 4>

[0198] 5.00 g of p-naphtholquinone phenylmethane (manufactured by Fujifilm Wako Pure Chemicals Co., Ltd.), 2.41 g of 9-fluorenone (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.64 g of methanesulfonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), and 12.07 g of PGMEA were added to a flask. The mixture was then heated to reflux under nitrogen and allowed to react for approximately 15 hours. After the reaction was stopped, the precipitate was precipitated with methanol and dried to obtain compounds (1-4). The weight-average molecular weight (Mw) determined by GPC and converted from polystyrene was 800. The obtained compounds were dissolved in PGMEA, and ion exchange was performed using cation exchange resin and anion exchange resin for 4 hours to obtain a solution of the target compounds.

[0199]

[0200] <Synthesis example 5>

[0201] In a flask, 8.00 g of α-naphtholquinone phenylmethane (manufactured by Fujifilm Wako Pure Chemicals Co., Ltd.), 3.67 g of 9-fluorenone (manufactured by Tokyo Chemical Industry Co., Ltd.), 1.96 g of methanesulfonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 1.36 g of NMP, and 12.27 g of PGMEA were added. The mixture was then heated to reflux under nitrogen and allowed to react for approximately 15 hours. After the reaction was stopped, the precipitate was precipitated with methanol and dried to obtain compounds (1-5). The weight-average molecular weight (Mw) determined by GPC and converted from polystyrene was 470. The obtained compounds were dissolved in PGMEA, and ion exchange was performed using cation exchange resin and anion exchange resin for 4 hours to obtain a solution of the target compounds.

[0202]

[0203] <Synthesis example 6>

[0204] 4.67 g of p-naphtholquinone phenylmethane (manufactured by Fujifilm Wako Pure Chemicals Co., Ltd.), 5.00 g of carbazole (manufactured by Tokyo Chemical Industry Co., Ltd.), 1.44 g of methanesulfonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), and 16.66 g of PGMEA were added to a flask. The mixture was then heated to reflux under nitrogen for approximately 9 hours. After the reaction was stopped, the precipitate was precipitated with methanol and dried to obtain compounds (1-6). The weight-average molecular weight (Mw) determined by GPC and converted to polystyrene was 3550. The obtained compounds were dissolved in PGMEA, and ion exchange was performed using cation exchange resin and anion exchange resin for 4 hours to obtain a solution of the target compounds.

[0205]

[0206] <Synthesis Example 7>

[0207] In a flask, 3.56 g of p-naphtholquinone phenylmethane (manufactured by Fujifilm Wako Pure Chemicals Co., Ltd.), 5.00 g of N-phenyl-1-naphthylamine (manufactured by Tokyo Chemical Industry Co., Ltd.), 1.10 g of methanesulfonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), and 14.48 g of PGMEA were added. The mixture was then heated to reflux under nitrogen and allowed to react for 22 hours. After the reaction was stopped, the precipitate was precipitated with methanol and dried to obtain compounds (1-7). The weight-average molecular weight (Mw) determined by GPC and converted to polystyrene was 1,450. The obtained compounds were dissolved in PGMEA, and ion exchange was performed using cation exchange resin and anion exchange resin for 4 hours to obtain a solution of the target compounds.

[0208]

[0209] <Synthesis example 8>

[0210] 9.69 g of p-naphtholquinone phenylmethane (manufactured by Fujifilm Wako Pure Chemicals Co., Ltd.), 5.00 g of 2-phenylindole (manufactured by Tokyo Chemical Industry Co., Ltd.), 1.24 g of methanesulfonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), and 23.90 g of PGMEA were added to a flask. The mixture was then heated to reflux under nitrogen and allowed to react for 21 hours. After the reaction was stopped, the precipitate was precipitated with methanol and water and dried to obtain compounds (1-8). The weight-average molecular weight (Mw) determined by GPC and converted to polystyrene was 1000. The obtained compounds were dissolved in PGMEA, and ion exchange was performed using cation exchange resin and anion exchange resin for 4 hours to obtain a solution of the target compounds.

[0211]

[0212] <Synthesis Example 9>

[0213] In a flask, 9.05 g of p-naphtholquinone phenylmethane (manufactured by Fujifilm Wako Pure Chemicals Co., Ltd.), 4.50 g of 2,2'-biphenyl, 1.16 g of methanesulfonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), and 22.07 g of PGMEA were added. The mixture was then heated to reflux under nitrogen and allowed to react for 21 hours. After the reaction was stopped, the precipitate was precipitated with methanol and water and dried to obtain compounds (1-9). The weight-average molecular weight (Mw) determined by GPC and converted to polystyrene was 900. The obtained compounds were dissolved in PGMEA, and ion exchange was performed using cation exchange resin and anion exchange resin for 4 hours to obtain a solution of the target compounds.

[0214]

[0215] <Synthesis example 10>

[0216] 10.52 g of p-naphtholquinone phenylmethane (manufactured by Fuji Fuji Wako Pure Chemicals Co., Ltd.), 4.50 g of 1-5-dihydroxynaphthalene (manufactured by Tokyo Chemical Industry Co., Ltd.), 1.35 g of methanesulfonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), and 24.55 g of PGMEA were added to a flask. The mixture was then heated to reflux under nitrogen and allowed to react for 21 hours. After the reaction was stopped, the precipitate was precipitated with methanol and water and dried to obtain compound (1-10). The weight-average molecular weight (Mw) determined by GPC and converted to polystyrene was 600. The obtained compound was dissolved in propylene glycol monomethyl ether (hereinafter referred to as PGME), and ion exchange was performed using a cation exchange resin and anion exchange resin for 4 hours to obtain a solution of the target compound.

[0217]

[0218] <Synthesis Example 11>

[0219] In a flask, 7.48 g of p-naphtholquinone phenylmethane (manufactured by Fujifilm Wako Pure Chemicals Co., Ltd.), 7.00 g of 9-9-bis(4-hydroxyphenyl)fluorene (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.96 g of methanesulfonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), and 23.16 g of PGMEA were added. The mixture was then heated to reflux under nitrogen and allowed to react for 21 hours. After the reaction was stopped, the precipitate was precipitated with methanol and water and dried to obtain compound (1-11). The weight-average molecular weight (Mw) determined by GPC and converted to polystyrene was 800. The obtained compound was dissolved in PGMEA, and ion exchange was performed using a cation exchange resin and anion exchange resin for 4 hours to obtain a solution of the target compound.

[0220]

[0221] <Comparative Synthesis Example 1>

[0222] 15.00 g of 2,2'-biphenol (manufactured by Tokyo Chemical Industry Co., Ltd.), 12.58 g of 1-naphthal (manufactured by Tokyo Chemical Industry Co., Ltd.), 1.94 g of methanesulfonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), and 29.58 g of PGMEA were added to a flask. The mixture was then heated to reflux under nitrogen and reacted for approximately 14 hours. After the reaction was stopped, the precipitate was precipitated with methanol and dried to obtain compound (2-1). The weight-average molecular weight (Mw) determined by GPC and converted to polystyrene was 5500. The obtained compound was dissolved in PGME, and ion exchange was performed using cation exchange resin and anion exchange resin for 4 hours to obtain a solution of the target compound.

[0223]

[0224] <Comparative Synthesis Example 2>

[0225] 10.00 g of 2,2'-biphenol (manufactured by Tokyo Chemical Industry Co., Ltd.), 9.68 g of 9-fluorenone (manufactured by Tokyo Chemical Industry Co., Ltd.), 2.58 g of methanesulfonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), and 33.39 g of PGMEA were added to a flask. The mixture was then heated to reflux under nitrogen and allowed to react for approximately 12.5 hours. After the reaction was stopped, the precipitate was precipitated with methanol and water and dried to obtain compound (2-2). The weight-average molecular weight (Mw) determined by GPC and converted to polystyrene was 1700. The obtained compound was dissolved in PGMEA, and ion exchange was performed using cation exchange resin and anion exchange resin for 4 hours to obtain a solution of the target compound.

[0226]

[0227] <Example 1>

[0228] In Synthesis Example 1, a compound solution (20.96% by mass of solids) was obtained. 0.26g of TMOM-BP (manufactured by Honshu Chemical Co., Ltd.), 1.95g of PGME containing 2% by mass of pyridinium p-hydroxybenzenesulfonate, 0.13g of PGMEA containing 1% by mass of surfactant (manufactured by DIC Co., Ltd., Megafack R-40), 7.85g of PGMEA, and 3.61g of PGME were added to 6.20g of this compound solution and dissolved. The solution was then filtered through a polytetrafluoroethylene microfilter with a pore size of 0.1μm to prepare a solution of a composition for forming a resist lower film.

[0229] <Example 2>

[0230] In Synthesis Example 2, a compound solution (13.88% by mass of solids) was obtained. 0.24g of TMOM-BP (manufactured by Honshu Chemical Co., Ltd.), 1.83g of PGME containing 2% by mass of pyridinium p-hydroxybenzenesulfonate, 0.12g of PGMEA (manufactured by DIC Co., Ltd., Megfack R-40), 0.42g of PGMEA, 0.91g of PGME, and 2.70g of cyclohexanone (containing 1% by mass of surfactant) were added to this compound solution and dissolved. The solution was then filtered through a polytetrafluoroethylene microfilter with a pore size of 0.1μm to prepare a solution of a composition for forming a photoresist lower film.

[0231] <Example 3>

[0232] In Synthesis Example 3, a compound solution (15.50% by mass of solids) was obtained. 0.26g of TMOM-BP (manufactured by Honshu Chemical Co., Ltd.), 1.95g of PGME containing 2% by mass of pyridinium p-hydroxybenzenesulfonate, 0.13g of PGMEA containing 1% by mass of surfactant (manufactured by DIC Co., Ltd., Megfack R-40), 7.23g of PGMEA, 1.77g of PGME, and 0.27g of cyclohexanone were added to this compound solution and dissolved. The solution was then filtered through a polytetrafluoroethylene microfilter with a pore size of 0.1μm to prepare a solution of a composition for forming a resist lower film.

[0233] <Example 4>

[0234] In Synthesis Example 4, a compound solution (13.82% by mass of solids) was obtained. 0.26g of TMOM-BP (manufactured by Honshu Chemical Co., Ltd.), 1.95g of PGME containing 2% by mass of pyridinium p-hydroxybenzenesulfonate, 0.13g of PGMEA containing 1% by mass of surfactant (manufactured by DIC Co., Ltd., Megafak R-40), 4.65g of PGMEA, and 3.61g of PGME were added to this compound solution and dissolved. The solution was then filtered through a polytetrafluoroethylene microfilter with a pore size of 0.1μm to prepare a composition for forming the lower layer of the resist film.

[0235] <Example 5>

[0236] In Synthesis Example 5, a compound solution (16.39% by mass of solids) was obtained. 0.24g of TMOM-BP (manufactured by Honshu Chemical Co., Ltd.), 1.83g of PGME containing 2% by mass of pyridinium p-hydroxybenzenesulfonate, 0.12g of PGMEA (manufactured by DIC Co., Ltd., Megfack R-40), 0.41g of PGMEA, 0.91g of PGME, and 4.05g of cyclohexanone (containing 1% by mass of surfactant) were added to this compound solution and dissolved. The solution was then filtered through a polytetrafluoroethylene microfilter with a pore size of 0.1μm to prepare a solution of a composition for forming a resist lower film.

[0237] <Example 6>

[0238] In Synthesis Example 6, a compound solution (14.09% by mass of solids) was obtained. 0.26g of TMOM-BP (manufactured by Honshu Chemical Co., Ltd.), 1.95g of PGME containing 2% by mass of pyridinium p-hydroxybenzenesulfonate, 0.13g of PGMEA containing 1% by mass of surfactant (manufactured by DIC Co., Ltd., Megfack R-40), 4.83g of PGMEA, and 3.61g of PGME were added to this compound solution and dissolved. The solution was then filtered through a polytetrafluoroethylene microfilter with a pore size of 0.1μm to prepare a solution of a composition for forming a resist lower film.

[0239] <Example 7>

[0240] In Synthesis Example 7, a compound solution (12.37% by mass of solids) was obtained. 0.23g of TMOM-BP (manufactured by Honshu Chemical Co., Ltd.), 1.71g of PGME containing 2% by mass of pyridinium p-hydroxybenzenesulfonate, 0.11g of PGMEA containing 1% by mass of surfactant (manufactured by DIC Co., Ltd., Megafack R-40), 4.85g of PGMEA, and 3.91g of PGME were added to 9.19g of this compound solution and dissolved. The solution was then filtered through a polytetrafluoroethylene microfilter with a pore size of 0.1μm to prepare a solution of a composition for forming a resist lower film.

[0241] <Example 8>

[0242] In Synthesis Example 8, a compound solution (17.46% by mass of solids) was obtained. 0.26g of TMOM-BP (manufactured by Honshu Chemical Co., Ltd.), 1.95g of PGME containing 2% by mass of pyridinium p-hydroxybenzenesulfonate, 0.13g of PGMEA (manufactured by DIC Co., Ltd., Megafak R-40), 6.61g of PGMEA, and 3.61g of PGME were added to 7.44g of this compound solution and dissolved. The solution was then filtered through a polytetrafluoroethylene microfilter with a pore size of 0.1μm to prepare a solution of a composition for forming a resist lower film.

[0243] <Example 9>

[0244] In Synthesis Example 9, a compound solution (18.75% by mass of solids) was obtained. 0.26g of TMOM-BP (manufactured by Honshu Chemical Co., Ltd.), 1.95g of PGME containing 2% by mass of pyridinium p-hydroxybenzenesulfonate, 0.13g of PGMEA containing 1% by mass of surfactant (manufactured by DIC Co., Ltd., Megafack R-40), 7.12g of PGMEA, and 3.61g of PGME were added to 6.93g of this compound solution and dissolved. The solution was then filtered through a polytetrafluoroethylene microfilter with a pore size of 0.1μm to prepare a solution of a composition for forming a resist lower film.

[0245] <Example 10>

[0246] In Synthesis Example 10, a compound solution (18.01% by mass of solids) was obtained. 0.26g of TMOM-BP (manufactured by Honshu Chemical Co., Ltd.), 1.95g of PGME containing 2% by mass of pyridinium p-hydroxybenzenesulfonate, 0.13g of PGMEA containing 1% by mass of surfactant (manufactured by DIC Co., Ltd., Megfack R-40), 5.39g of PGMEA, and 5.05g of PGME were added to 7.22g of this compound solution and dissolved. The solution was then filtered through a polytetrafluoroethylene microfilter with a pore size of 0.1μm to prepare a solution of a composition for forming a resist lower film.

[0247] <Example 11>

[0248] In Synthesis Example 11, a compound solution (18.50% by mass of solids) was obtained. 0.26g of TMOM-BP (manufactured by Honshu Chemical Co., Ltd.), 1.95g of PGME containing 2% by mass of pyridinium p-hydroxybenzenesulfonate, 0.13g of PGMEA containing 1% by mass of surfactant (manufactured by DIC Co., Ltd., Megafak R-40), 7.03g of PGMEA, and 3.61g of PGME were added to this compound solution and dissolved. The solution was then filtered through a polytetrafluoroethylene microfilter with a pore size of 0.1μm to prepare a solution of a composition for forming a resist lower film.

[0249] <Comparative Example 1>

[0250] In Comparative Synthesis Example 1, a compound solution (22.44% by mass of solids) was obtained. 0.26g of TMOM-BP (manufactured by Honshu Chemical Co., Ltd.), 1.95g of PGME containing 2% by mass of pyridinium p-hydroxybenzenesulfonate, 0.13g of PGMEA containing 1% by mass of surfactant (manufactured by DIC Co., Ltd., Megafak R-40), 5.39g of PGMEA, and 6.48g of PGME were added to this compound solution and dissolved. The solution was then filtered through a polytetrafluoroethylene microfilter with a pore size of 0.1μm to prepare a solution of a composition for forming a resist lower film.

[0251] <Comparative Example 2>

[0252] In Comparative Synthesis Example 1, a compound solution (19.00% by mass of solids) was obtained. 0.26g of TMOM-BP (manufactured by Honshu Chemical Co., Ltd.), 1.95g of PGME containing 2% by mass of pyridinium p-hydroxybenzenesulfonate, 0.13g of PGMEA (manufactured by DIC Co., Ltd., Megafack R-40), 7.21g of PGMEA, and 3.61g of PGME were added to 6.84g of this compound solution and dissolved. The solution was then filtered through a polytetrafluoroethylene microfilter with a pore size of 0.1μm to prepare a solution of a composition for forming a resist lower film.

[0253] (Eluting test of the corrosion inhibitor solvent)

[0254] Solutions of the resist underlayer film forming compositions prepared in Comparative Examples 1-2 and Examples 1-11 were respectively spin-coated onto silicon wafers and fired at 350°C for 60 seconds on a hot plate to form resist underlayer films (film thickness 150 nm). These resist underlayer films were impregnated with PGME / PGMEA = 7 / 3 as a general-purpose diluent. It was confirmed that the resist underlayer films were insoluble and had sufficient curability.

[0255] (Optical constant measurement)

[0256] Solutions of the resist underlayer film forming compositions prepared in Comparative Examples 1-2 and Examples 1-11 were respectively spin-coated onto silicon wafers. The wafers were then heated at 350°C for 60 seconds on a hot plate to form a resist underlayer film (50 nm thick). The refractive index (n-value) and optical absorptivity (k-value, also known as attenuation coefficient) at a wavelength of 193 nm were measured using a spectroellipsometer for these resist underlayer films (Table 1).

[0257] Table 1 Refractive index n and optical absorption coefficient k

[0258]

[0259] Comparing Comparative Example 1 with Example 1, and Comparative Example 2 with Examples 4 and 9, it can be seen that the examples can improve the n value. Furthermore, as in the other examples, by changing the types of compounds combined, the optical constants can be significantly changed.

[0260] [Determination of dry etching rate]

[0261] The etcher and etching gas used in the determination of dry etching rate are described below.

[0262] RIE-10NR (Made by Samco): CF4

[0263] Solutions of the resist underlayer film formation compositions prepared in Comparative Examples 1-2 and Examples 1-11 were respectively coated onto silicon wafers using a spin coater. The wafers were then heated at 350°C for 60 seconds on a hot plate to form a resist underlayer film (film thickness 150 nm). The dry etching rate was measured using CF4 gas as the etching gas, and the dry etching rate ratios for Comparative Examples 1-2 and Examples 1-11 were determined. The dry etching rate ratio is the dry etching rate ratio of (resist underlayer film) / (KrF photoresist) (Table 2).

[0264] Table 2 Dry Etching Rate Ratio

[0265]

[0266] Comparing Comparative Example 1 with Example 1, and Comparative Example 2 with Examples 4 and 9, it can be seen that the examples exhibit higher etching rates. Furthermore, as in the other examples, the etching resistance can be significantly varied by changing the types of compounds used in the combination.

[0267] (Embedded evaluation)

[0268] The embedding property was confirmed in a dense patterned region with a SiO2 substrate of 200 nm thickness, a trench width of 50 nm, and a spacing of 100 nm. The resist underlayer film forming compositions prepared in Comparative Examples 1-2 and Examples 1-11 were coated onto the above substrate and then fired at 350°C for 60 seconds to form a resist underlayer film of approximately 150 nm. The planarization of the substrate was observed using a Hitachi Hightech Noroges S-4800 scanning electron microscope to confirm whether the resist underlayer film forming composition had filled the pattern (Table 3).

[0269] Table 3 Embedding Performance Evaluation

[0270]

[0271] The examples demonstrate the same high embeddability as conventional materials.

[0272] Industrial availability

[0273] According to the present invention, a composition for forming a photoresist underlayer film can be provided, which can form a film exhibiting high etch resistance, good dry etch rate ratio and optical constants, good coverage even for so-called uneven substrates, small thickness variation after embedding, and flatness. Furthermore, according to the present invention, a method for manufacturing a polymer suitable for the photoresist underlayer film forming composition, a photoresist underlayer film using the photoresist underlayer film forming composition, and a method for manufacturing a semiconductor device can be provided.

Claims

1. A composition for forming a resist underlayer film, comprising an aromatic compound (A) having 6 to 120 carbon atoms, a reaction product of a compound represented by the following formula (1), and a solvent; In formula (1), Z represents -(C=O)- or -C(-OH)-, Ar1 and Ar2 each independently represent substituted phenyl, naphthyl, anthraceneyl or pyrene, and ring Y represents a substituted aliphatic ring, a substituted aromatic ring, or a fused ring of substituted aliphatic and aromatic rings. In the reaction product, one carbon atom in ring Y is linked to one of the aromatic compounds (A), and one carbon atom in Ar1 or Ar2 is linked to another of the aromatic compounds (A).

2. The composition for forming a resist underlayer film according to claim 1, wherein the compound represented by formula (1) is represented by the following formula (1a); In formula (1a), Z represents -(C=O)-, Ar1 and Ar2 each independently represent phenyl, naphthyl, anthracene or pyrene that can be substituted, and ring Y represents an aliphatic ring that can be substituted, or a fused ring of aliphatic and aromatic rings that can be substituted.

3. A composition for forming a resist underlayer film, comprising an aromatic compound (A) having 6 to 120 carbon atoms, a reaction product of a compound represented by the following formula (1), and a solvent; In formula (1), Z represents -(C=O)- or -C(-OH)-, Ar1 and Ar2 each independently represent substituted phenyl, naphthyl, anthraceneyl or pyrene, and ring Y represents a substituted aliphatic ring, a substituted aromatic ring, or a fused ring of substituted aliphatic and aromatic rings. One carbon atom in ring Y of the reaction product is linked to two of the aromatic compounds (A).

4. The composition for forming a resist underlayer film according to claim 3, wherein the ring Y in formula (1a) is a fused ring structure containing a cyclohexene ring.

5. The composition for forming a resist underlayer film according to claim 4, wherein in formula (1a), ring Y represents a fused ring of aliphatic and aromatic rings.

6. The composition for forming a resist underlayer film according to claim 1, wherein the compound represented by formula (1) is represented by the following formula (1b); In formula (1b), Z represents -C(-OH)-, Ar1 and Ar2 each independently represent substituted phenyl, naphthyl, anthracene or pyrene, and ring Y represents a substituted aliphatic ring, a substituted aromatic ring, or a fused ring of substituted aliphatic and aromatic rings.

7. The composition for forming a resist underlayer film according to claim 6, wherein formula (1b) is an aromatic compound.

8. The composition for forming a resist underlayer film according to claim 7, wherein in formula (1b), Y comprises a naphthalene ring.

9. The composition for forming a resist underlayer film according to any one of claims 1 to 8, wherein in formula (1), Ar1 and Ar2 each independently represent a phenyl or naphthyl group that can be substituted with a hydroxyl group.

10. The composition for forming a resist underlayer film according to any one of claims 1 to 8, wherein the aromatic compound (A) comprises one or more benzene rings, naphthalene rings, anthracene rings, pyrene rings, or combinations thereof.

11. The composition for forming a resist underlayer film according to any one of claims 1 to 8, wherein the aromatic compound (A) comprises two or more benzene rings, naphthalene rings, anthracene rings, pyrene rings, or combinations thereof.

12. The composition for forming a resist underlayer film according to any one of claims 1 to 8, further comprising a crosslinking agent.

13. The composition for forming a resist underlayer film according to any one of claims 1 to 8, further comprising an acid and / or an acid-generating agent.

14. The composition for forming a resist underlayer film according to any one of claims 1 to 8, wherein the solvent has a boiling point of 160°C or higher.

15. A resist underlayer film characterized by comprising: It is a sintered product of a coating film formed by the composition for forming a resist underlayer film according to any one of claims 1 to 14.

16. A method for manufacturing a semiconductor device, comprising the steps 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 14, forming a photoresist film thereon, forming a photoresist pattern by irradiation and development using light or an electron beam, etching the underlayer film using the photoresist pattern, and processing the semiconductor substrate using the patterned underlayer film.

17. The method for manufacturing a semiconductor device according to claim 16, wherein the step of forming a resist underlayer film is performed by nanoimprint lithography.

Images