Resist underlayer film forming composition

Abstract

Provided is a novel resist underlayer film-forming composition which: meets the requirements that self-curing is performed at a low temperature without containing an acid catalyst or a crosslinking agent, the amount of a sublimate can be reduced, and a high-hardness film having high bending resistance can be obtained; can also be used as a crosslinking agent; exhibits higher flattening and higher heat resistance than conventional crosslinking agents when used as a crosslinking agent; has embedding properties equivalent to those of conventional products; and has an optical constant or etching resistance that can be freely changed according to the selection of monomers. This resist underlayer film-forming composition contains a solvent and a polymer (X) containing a repeating structural unit which is obtained by alternately bonding, via a linking group -O-, an aromatic compound A having an ROCH2- group (R is a monovalent organic group, a hydrogen atom, or a mixture thereof) to an aromatic compound B having at most 120 carbon atoms and different from A, and in which one to six B's are bonded to one A.

Description

[Technical Field]

[0001] The present invention relates to a resist underlayer film forming composition, a resist underlayer film which is a fired product of a coated film made from the composition, and a method for manufacturing a semiconductor device using the composition. [Background technology]

[0002] Microfabrication is performed using lithography processes in the manufacturing of semiconductor devices. In these lithography processes, when the resist layer on a substrate is exposed with an ultraviolet laser such as a KrF excimer laser or an ArF excimer laser, a problem is known to occur where the resist pattern with the desired shape cannot be formed due to the influence of standing waves generated by the reflection of the ultraviolet laser from the substrate surface. To solve this problem, a resist underlayer film (anti-reflective film) is used between the substrate and the resist layer. It is known that novolac resin is used as the composition for forming the resist underlayer film.

[0003] Furthermore, in order to achieve the thinning of the resist layer required as resist patterns become finer, a lithography process is known in which at least two resist underlayer films are formed and these underlayer films are used as mask materials. Examples of materials for forming the at least two layers include organic resins (e.g., acrylic resins, novolac resins), silicon resins (e.g., organopolysiloxanes), and inorganic silicon compounds (e.g., SiON, SiO2). When dry etching using a pattern formed from the organic resin layer as a mask, it is necessary that the pattern has etching resistance to etching gases (e.g., fluorocarbons).

[0004] As a composition for forming such a resist underlayer film, for example, Patent Document 1 describes the following formula (1):

[0005] [ka]

[0006] (In the formula, X 1 X represents a divalent organic group having 6 to 20 carbon atoms and having at least one aromatic ring which may be substituted with a halogen group, a nitro group, an amino group, or a hydroxyl group. 2 (This represents an organic group having 6 to 20 carbon atoms, or a methoxy group, having at least one aromatic ring which may be substituted with a halogen group, a nitro group, an amino group, or a hydroxyl group.) A resist underlayer film forming composition is disclosed, comprising a polymer having a structural unit represented by and a solvent. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] WO2014 / 171326A1 [Overview of the project] [Problems that the invention aims to solve]

[0008] However, conventional resist underlayer film forming compositions were unsatisfactory in that they could not self-cure at low temperatures without acid catalysts or crosslinking agents, generated sublimation that contaminated the equipment, and could not produce high-hardness films with high bending resistance. Therefore, there was a need to improve these points while maintaining properties such as not eluting into resist solvents and obtaining desired optical constants and etching resistance. [Means for solving the problem]

[0009] This invention solves the above problems. In other words, this invention encompasses the following: [1] A polymer (X) comprising repeating structural units in which aromatic compound A having a ROCH2- group (where R is a monovalent organic group, a hydrogen atom, or a mixture thereof) and aromatic compound B having 120 or fewer carbon atoms different from A are alternately bonded via a linking group -O-, wherein 1 to 6 B are bonded to 1 A, and A resist lower layer film forming composition containing a solvent. [2] The resist lower layer film forming composition according to [1], wherein the polymer (X) contains a repeating structural unit represented by the formula (1). [Chemical formula] (In the formula (1), A1 represents an organic group derived from an aromatic compound A having a ROCH2-group (R is a monovalent organic group, a hydrogen atom, or a mixture thereof), and B1 represents an organic group derived from an aromatic compound B having 120 or less carbon atoms different from A1.) [3] The resist lower layer film forming composition according to [2], wherein R in the formula (1) may be substituted with a phenyl group, a naphthyl group, or an anthracenyl group, and may be interrupted by an oxygen atom, a nitrogen atom, or a carbonyl group, and is a saturated or unsaturated straight-chain or branched C2-C 20 aliphatic or C3-C 20 alicyclic hydrocarbon group, a hydrogen atom, or a mixture thereof. [4] The resist lower layer film forming composition according to [2], wherein B1 in the formula (1) is represented by the following formula 2. [Chemical formula] (In the formula (2), C1 and C2 each independently represent an aromatic ring having 6 to 48 carbon atoms which may contain a hetero atom, or a hydrocarbon group containing an aromatic ring having 6 to 48 carbon atoms which may contain a hetero atom, Y represents a single bond, a carbonyl group, a sulfonyl group, -CR 1 2-group, or -(CF3)C(CF3)-group, R 1 may be interrupted by an oxygen atom, a carbonyl group, a nitrogen atom, a carbon-carbon double bond, or a carbon-carbon triple bond, and may be a C1-C10 alkyl group, a hydroxy group, a hydrogen atom, a halogen, an aromatic hydrocarbon group having 6 to 20 carbon atoms, or -NR 2 2, R2 represents a linear or cyclic alkyl group having 1 to 10 carbon atoms, which may be interrupted by a carbon-carbon double bond or a carbon-carbon triple bond, and the carbon-carbon double bond or the carbon-carbon triple bond may be bonded to the terminal, i is 0 or 1, The dotted line represents a bond with an oxygen atom.) [5] The resist underlayer film forming composition according to [4], wherein i in the formula (2) is 1. [6] The resist underlayer film forming composition according to [4] or [5], wherein the polymer (X) further contains a repeating structural unit represented by the formula (3). [Chemical formula] (In the formula (3), B1 is represented by the above formula 2, and A2 represents an organic group derived from an aromatic compound A' having 120 or less carbon atoms different from B1.) [7] The resist underlayer film forming composition according to any one of [2] to [6], wherein A1 in the formula (1) does not have a phenolic hydroxyl group. [8] The resist underlayer film forming composition according to any one of [1] to [6], wherein the polymer (X) has a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms at at least one terminal. [9] The resist underlayer film forming composition according to any one of [1] to [8], further comprising a film material (Z) capable of crosslinking with the polymer (X).

[10] The resist underlayer film forming composition according to any one of [1] to [9], further comprising a crosslinking agent.

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

[10] , further comprising an acid and / or an acid generator.

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

[11] , further comprising a surfactant.

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

[12] , wherein the solvent contains a solvent having a boiling point of 160°C or higher.

[14] A resist underlayer film characterized by being a fired product of a coating film comprising the composition described in any one of the items [1] to

[13] .

[15] A step of forming a resist underlayer film on a semiconductor substrate using the composition described in any one of [1] to

[13] , A step of forming a resist film on the formed resist underlayer film, A process of forming a resist pattern by irradiating the formed resist film with light or an electron beam and developing it. A step of etching and patterning the resist underlayer film through the formed resist pattern, and Process of processing a semiconductor substrate via a patterned resist underlayer film. A method for manufacturing a semiconductor device containing [a specific component].

[16] A step of forming a resist underlayer film on a semiconductor substrate using the composition described in any one of [1] to

[13] , A step of forming a hard mask on the formed resist underlayer film, A step of forming a resist film on the formed hard mask, A process of forming a resist pattern by irradiating the formed resist film with light or an electron beam and developing it. A step of etching and patterning the hard mask through the formed resist pattern, and A step of etching and patterning the resist underlayer film through a patterned hard mask, and Process of processing a semiconductor substrate via a patterned resist underlayer film. A method for manufacturing a semiconductor device containing [a specific component].

[17] A method for manufacturing a semiconductor device according to

[15] or

[16] , wherein the step of forming a resist underlayer film is performed by nanoimprint

[15] or

[16] . [Effects of the Invention]

[0010] According to the present invention, a novel resist underlayer film forming composition is provided that meets the requirements for self-curing at low temperatures without the use of acid catalysts or crosslinking agents, for reducing the amount of sublimation, and for obtaining a highly hard film with high bending resistance. Furthermore, it can be used as a crosslinking agent, and when used as a crosslinking agent, it exhibits higher planarity and higher heat resistance than conventional crosslinking agents, while having the same embedding properties as conventional products, and allowing the optical constants and etching resistance to be freely changed by selecting monomers. [Modes for carrying out the invention]

[0011] The resist underlayer film forming composition according to the present invention comprises a polymer (X) containing repeating structural units in which aromatic compound A having a ROCH2- group (where R is a monovalent organic group, a hydrogen atom, or a mixture thereof) and aromatic compound B having 120 or fewer carbon atoms different from A are alternately bonded via a linking group -O-, wherein 1 to 6 B are bonded to 1 A, and a solvent.

[0012] [Polymer (X)] The polymer (X) is a repeating structural unit in which aromatic compound A having a ROCH2- group (where R is a monovalent organic group, a hydrogen atom, or a mixture thereof) and aromatic compound B having 120 or fewer carbon atoms different from A are alternately bonded via a linking group -O-, and each repeating structural unit contains 1 to 6, preferably 1 to 4, preferably 2 to 4, more preferably 2 to 3, and most preferably 2 B atoms bonded to one A atom.

[0013] Preferably, the polymer (X) contains repeating structural units represented by formula (1). [ka] (In formula (1), A1 represents an organic group derived from aromatic compound A having a ROCH2- group (where R is a monovalent organic group, a hydrogen atom, or a mixture thereof), and B1 represents an organic group derived from aromatic compound B having 120 or fewer carbon atoms, different from A1.)

[0014] Preferably, the polymer (X) further contains a repeating structural unit represented by the formula (3). [Chemical formula] (In the formula (3), B1 is represented by the above formula 2, and A2 represents an organic group derived from an aromatic compound A' having 120 or less carbon atoms different from B1.)

[0015] The monovalent organic group R is preferably a saturated or unsaturated straight-chain or branched C2-C which may be substituted with a phenyl group, a naphthyl group or an anthracenyl group and may be interrupted by an oxygen atom, a nitrogen atom or a carbonyl group. 20 aliphatic or C3-C 20 alicyclic hydrocarbon group, a hydrogen atom, or a mixture thereof. "Mixture" means that a plurality of ROCH2-groups present within a single structural unit may be different, and also means that the ROCH2-groups in each of two or more structural units may be different.

[0016] Typical saturated aliphatic hydrocarbon groups include linear or branched alkyl groups having 2 to 20 carbon atoms, such as ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, s-butyl group, t-butyl group, n-pentyl group, 1-methyl-n-butyl group, 2-methyl-n-butyl group, 3-methyl-n-butyl group, 1,1-dimethyl-n-propyl group, 1,2-dimethyl-n-propyl group, 2,2-dimethyl-n-propyl group, 1-ethyl-n-propyl group, n-hexyl, 1-methyl-n-pentyl group, 2-methyl-n-pentyl group, 3-methyl Examples include ethyl-n-pentyl group, 4-methyl-n-pentyl group, 1,1-dimethyl-n-butyl group, 1,2-dimethyl-n-butyl group, 1,3-dimethyl-n-butyl group, 2,2-dimethyl-n-butyl group, 2,3-dimethyl-n-butyl group, 3,3-dimethyl-n-butyl group, 1-ethyl-n-butyl group, 2-ethyl-n-butyl group, 1,1,2-trimethyl-n-propyl group, 1,2,2-trimethyl-n-propyl group, 1-ethyl-1-methyl-n-propyl group, 1-ethyl-2-methyl-n-propyl group, and 1-methoxy-2-propyl group.

[0017] Cyclic alkyl groups can also be used. For example, cyclic alkyl groups having 3 to 20 carbon atoms include cyclopropyl group, cyclobutyl group, 1-methyl-cyclopropyl group, 2-methyl-cyclopropyl group, cyclopentyl group, 1-methyl-cyclobutyl group, 2-methyl-cyclobutyl group, 3-methyl-cyclobutyl group, 1,2-dimethyl-cyclopropyl group, 2,3-dimethyl-cyclopropyl group, 1-ethyl-cyclopropyl group, 2-ethyl-cyclopropyl group, cyclohexyl group, 1-methyl-cyclopentyl group, 2-methyl-cyclopentyl group, 3-methyl-cyclopentyl group, 1-ethyl-cyclobutyl group, 2-ethyl-cyclobutyl group, 3-ethyl-cyclobutyl group, and 1,2-dimethyl-cyclobutyl group. Examples include tyl group, 1,3-dimethylcyclobutyl group, 2,2-dimethylcyclobutyl group, 2,3-dimethylcyclobutyl group, 2,4-dimethylcyclobutyl group, 3,3-dimethylcyclobutyl group, 1-n-propylcyclopropyl group, 2-n-propylcyclopropyl group, 1-i-propylcyclopropyl group, 2-i-propylcyclopropyl group, 1,2,2-trimethylcyclopropyl group, 1,2,3-trimethylcyclopropyl group, 2,2,3-trimethylcyclopropyl group, 1-ethyl-2-methylcyclopropyl group, 2-ethyl-1-methylcyclopropyl group, 2-ethyl-2-methylcyclopropyl group, and 2-ethyl-3-methylcyclopropyl group.

[0018] Typical unsaturated aliphatic hydrocarbon groups include alkenyl groups having 2 to 20 carbon atoms, such as ethenyl group, 1-propenyl group, 2-propenyl group, 1-methyl-1-ethenyl group, 1-butenyl group, 2-butenyl group, 3-butenyl group, 2-methyl-1-propenyl group, 2-methyl-2-propenyl group, 1-ethylethenyl group, 1-methyl-1-propenyl group, 1-methyl-2-propenyl group, 1-pentenyl group, 2-pentenyl group, 3-pentenyl group, 4-pentenyl group, 1-n-propylethenyl group, 1-methyl-1-butenyl group, and 1-methyl-2 -Butenyl group, 1-methyl-3-butenyl group, 2-ethyl-2-propenyl group, 2-methyl-1-butenyl group, 2-methyl-2-butenyl group, 2-methyl-3-butenyl group, 3-methyl-1-butenyl group, 3-methyl-2-butenyl group, 3-methyl-3-butenyl group, 1,1-dimethyl-2-propenyl group, 1-i-propylethenyl group, 1,2-dimethyl-1-propenyl group, 1,2-dimethyl-2-propenyl group, 1-cyclopentenyl group, 2-cyclopentenyl group, 3-cyclopentenyl group, 1-hexenyl group, 2-hexenyl group, 3-hex Cenyl group, 4-hexenyl group, 5-hexenyl group, 1-methyl-1-pentenyl group, 1-methyl-2-pentenyl group, 1-methyl-3-pentenyl group, 1-methyl-4-pentenyl group, 1-n-butylethenyl group, 2-methyl-1-pentenyl group, 2-methyl-2-pentenyl group, 2-methyl-3-pentenyl group, 2-methyl-4-pentenyl group, 2-n-propyl-2-propenyl group, 3-methyl-1-pentenyl group, 3-methyl-2-pentenyl group, 3-methyl-3-pentenyl group, 3-methyl-4-pentenyl group, 3-ethyl-3-butenyl group, 4-methyl-1-pentenyl group, 4-methyl-2-pentenyl group, 4-methyl-3-pentenyl group, 4-methyl-4-pentenyl group, 1,1-dimethyl-2-butenyl group, 1,1-dimethyl-3-butenyl group, 1,2-dimethyl-1-butenyl group, 1,2-dimethyl-2-butenyl group, 1,2-dimethyl-3-butenyl group, 1-methyl-2-ethyl-2-propenyl group, 1-s-butylethenyl group, 1,3-dimethyl-1-butenyl group, 1,3-dimethyl-2-butenyl group, 1,3-dimethyl-3-butenyl group, 1-i-butylethenyl group, 2,2-dimethyl-3-butenyl group, 2,3-dimethyl-1-butenyl group, 2,3-dimethyl-2-butenyl group, 2,3-dimethyl-3-butenyl group, 2-i-propyl-2-propenyl group, 3,3-dimethyl-1-butenyl group, 1-ethyl-1-butenyl group, 1-ethyl-2-butenyl group, 1-ethyl-3-butenyl group, 1-n-propyl-1-propenyl group, 1-n-propyl-2-propenyl group, 2-ethyl-1-butenyl group, 2-ethyl-2-butenyl group, 2-ethyl-3-butenyl group, 1,1,2-trimethyl-2-propenyl group, 1-t-butylethenyl group, 1-methyl-1-ethyl-2-propenyl group, 1-ethyl-2-methyl-1-propenyl group, 1-ethyl-2-methyl-2-propenyl group, 1-i-propyl Examples include propyl-1-propenyl group, 1-i-propyl-2-propenyl group, 1-methyl-2-cyclopentenyl group, 1-methyl-3-cyclopentenyl group, 2-methyl-1-cyclopentenyl group, 2-methyl-2-cyclopentenyl group, 2-methyl-3-cyclopentenyl group, 2-methyl-4-cyclopentenyl group, 2-methyl-5-cyclopentenyl group, 2-methylene-cyclopentyl group, 3-methyl-1-cyclopentenyl group, 3-methyl-2-cyclopentenyl group, 3-methyl-3-cyclopentenyl group, 3-methyl-4-cyclopentenyl group, 3-methyl-5-cyclopentenyl group, 3-methylene-cyclopentyl group, 1-cyclohexenyl group, 2-cyclohexenyl group, and 3-cyclohexenyl group.

[0019] Preferably, R is -H, -CH3 group, -CH2CH3 group, -CH2CH2CH3 group, -CH2CH2CH2CH3 group, cyclohexyl group, and -CH(CH3)CH2OCH3 group.

[0020] In formula (1), B1 is preferably represented by the following formula 2. [ka] (In formula (2), C1 and C2 each independently represent an aromatic ring having 6 to 48 carbon atoms, which may contain heteroatoms having 6 to 48 carbon atoms, or a hydrocarbon group containing an aromatic ring having 6 to 48 carbon atoms, which may contain heteroatoms. Y is a single bond, carbonyl group, sulfonyl group, -CR 1 Represents a 2-group or a -(CF3)C(CF3)-group, R 1 The carbon atoms may be interrupted by an oxygen atom, a carbonyl group, a nitrogen atom, a carbon-carbon double bond, or a carbon-carbon triple bond, and a carbon-carbon double bond or carbon-carbon triple bond may be bonded to the end of the alkyl group having 1 to 10 carbon atoms, a hydroxyl group, a hydrogen atom, a halogen, an aromatic hydrocarbon group having 6 to 20 carbon atoms, or -NR. 2 Represents 2, R 2 This represents a chain or cyclic alkyl group having 1 to 10 carbon atoms, which may be interrupted by carbon-carbon double bonds or carbon-carbon triple bonds, and which may have carbon-carbon double bonds or carbon-carbon triple bonds attached to its terminals. i is either 0 or 1. The dotted lines represent bonds with oxygen atoms.

[0021] Preferably, C1 and C2 each independently have an electron-withdrawing substituent on the aromatic ring. The electron-withdrawing substituent is not particularly limited, but examples include cyano groups, ketone groups, nitro groups, aldehyde groups, carboxyl groups, ester groups, and the like. Preferably, i in equation (2) is 1.

[0022] Polymer (X) can be synthesized by polymerizing aromatic compound A having a ROCH2- group (where R is a monovalent organic group, a hydrogen atom, or a mixture thereof), aromatic compound B having 120 or fewer carbon atoms different from A, a compound containing a functional group that acts as a linking group if necessary (e.g., aldehyde, ketone, ROCH2-Ar-CH2OR (where R is a monovalent organic group, a hydrogen atom, or a mixture thereof)), and further optionally, aromatic compound A' having 120 or fewer carbon atoms different from B1, in the presence of a base catalyst (e.g., sodium hydroxide, potassium hydroxide, potassium carbonate, trimethylamine, triethylamine, etc.).

[0023] The aromatic compound A used in the synthesis of polymer (X), which has a ROCH2- group (where R is a monovalent organic group, a hydrogen atom, or a mixture thereof), is preferably an aromatic compound with 120 or fewer carbon atoms. Aromatic compound A is provided that it has a ROCH2- group, (a) It may be a monocyclic compound such as benzene, (b) These may be condensed ring compounds such as naphthalene, anthracene, and pyrene. (c) These may be heterocyclic compounds such as furan, pyrrole, thiophene, pyridine, carbazole, iminostilbene, phenothiazine, indole, and indolocarbazole. (d) Compounds in which the aromatic rings of (a) to (c) are linked by single bonds or alkylene groups, such as biphenyl, phenylindole, α,α,α',α'-tetrakis(4-hydroxyphenyl)-p-xylene, and calixarene. (e) Like 2,2-diphenylpropane, -(CH2) n The compounds may also be those in which aromatic rings (a) to (d) are linked by spacers exemplified by -(n=1 to 20), -CH=CH-, -C≡C-, -N=N-, -NH-, -NR-, -NHCO-, -NRCO-, -S-, -COO-, -O-, -CO-, and -CH=N-, (f) Fluorenes such as 9,9-bis(4-hydroxyphenyl)fluorene, or compounds having a fluorene or fluorenone skeleton as described later, may also be used. The examples mentioned above are not limited to these.

[0024] Examples of aromatic compound A, though not limited to these, include benzene, biphenyl, 2,2-diphenylpropane, thiophene, furan, pyridine, pyrimidine, pyrazine, pyrrole, oxazole, thiazole, imidazole, naphthalene, anthracene, quinoline, carbazole, quinazoline, purine, indidine, benzothiophene, benzofuran, indole, phenylindole, acridine, fluorene, etc. More specifically, examples include 3,3',5,5'-tetramethoxymethyl-4,4'-dihydroxybiphenyl and 2,2-bis(4-hydroxy-3,5-dihydroxymethylphenyl)propane. Further examples of aromatic compound A include compounds having a fluorene or fluorenone skeleton, as illustrated below. [ka] [ka] [ka] [ka] [ka]

[0025] The aromatic compound A used as a starting material for polymer (X) may have phenolic hydroxyl groups, but it is preferable that A1 in formula (1) does not have phenolic hydroxyl groups. Here, "does not have phenolic hydroxyl groups" means that when measured by analytical means such as NMR, the amount of phenolic hydroxyl groups is below the detection limit, or if detected, it is at most a trace amount.

[0026] Aromatic compound B is an aromatic compound having 120 or fewer carbon atoms, provided that it is different from aromatic compound A. The description of aromatic compound B is the same as that for aromatic compound A above. Aromatic compound B preferably has a halogen on its aromatic ring, more preferably two or more halogens, and fluorine is preferred as the halogen. Examples of aromatic compound B include, but are not limited to, 2,5-difluorotoluene, 2,5-difluoroaniline, 2,5-difluorophenol, 1,2,3-trifluorobenzene, 2,5-difluorobenzonitrile, 2,5-difluorobenzaldehyde, 2,5-difluorobenzylamine, 2,5-difluorobenzyl alcohol, 2,5-difluoroanisole, 2,3,6-trifluorophenol, 2,5-difluorobenzylcyanide, 4-amino-2,5-difluorobenzonitrile, 2,5-difluorophenyl isocyanate, 2,5-difluoroacetophenone, 2,3,5-trifluorobenzonitrile, 2,4,5-trifluorobenzonitrile, 2,5-difluorobenzoic acid, 2,5-difluoronitrobenzene, 2,4,5-trifluorobenzyl alcohol, 2,5-difluorobenzyl chloride, 2,3,5,6-tetrafluorophenol, and 1,2-difluorobenzyl Zen, 2,3-difluorotoluene, 3,4-difluorotoluene, 3,4-difluoroaniline, 2,3-difluoroaniline, 2,3-difluorophenol, 3,4-difluorophenol, 4-ethynyl-1,2-difluorobenzene, 3,4-difluorobenzonitrile, 2,3-difluorobenzonitrile, 2,3-difluorobenzaldehyde, 3,4-difluorobenzaldehyde, 2,3-difluorobenzylamine, 3,4-difluorobenz Dial alcohol, 3,4-difluoroanisole, 2,3-difluoroanisole, 2,3-difluorobenzyl alcohol, 3,4-difluorothiol, 2,3,4-trifluorophenol, 2,3,6-trifluorophenol, 2,3-difluoroacetonitrile, 3,4-difluorophenyl isocyanate, 5-ethynyl-1,2,3-trifluorobenzene, 3,4-difluoroacetophenone, 2,3,4-trifluorobenzonitrile, 3,4,5-trifluorobenzonitrile, 2,3-difluorobenzoic acid, 3,4-difluorobenzoic acid, 3,4-difluoronitrobenzene, 4,5-difluorodironitrile, 2,3,4-trifluorobenzaldehyde, 3,4,5-trifluorobenzaldehyde, 2,3,6-trifluorobenzaldehyde, 1,3-difluorobenzene, 2,4-difluorotoluene, 2,6-difluorotoluene, 3,5-difluoroaniline, 2,6-difluoroaniline, 3,5-difluorophenol, 2,4-difluorophenol, 2,6-difluoro Enol, 1,3,5-trifluorobenzaldehyde, 1-ethynyl-2,4-difluorobenzene, 1-ethynyl-3,5-difluorobenzene, 2,6-difluorobenzonitrile, 3,5-difluorobenzonitrile, 2,4-difluorobenzonitrile, 3,5-difluorobenzaldehyde, 2,6-difluorobenzaldehyde, 2,4-difluorobenzaldehyde, 1-ethyl-3,5-difluorobenzaldehyde, 3,5-difluorobenzylaniline, 2,6-difluorobenzylaniline, 2,4-difluorobenzyl alcohol 2,4-difluoroanisole, 3,5-difluorobenzyl alcohol, 3,5-difluoroanisole, 2,6-difluorobenzyl alcohol, 2,6-difluoroanisole, 2,4-difluorothiol, 2,6-difluorobenzyl cyanide, 3,5-difluorobenzyl cyanide, 2,4-difluorobenzyl cyanide, 2,4-difluorophenyl isocyanate, 2,6-difluoro-4-hydroxybenzonitrile, 1,3-difluoro-5-propylbenzene, 2,4,6-trifluorobenzonitrile, 2,6-difluorobenzonitrile Difluorobenzoic acid, 2,4-difluorobenzoic acid, 3,5-difluorobenzoic acid, 2,6-difluoronitrobenzene, 3,5-difluoronitrobenzene, 2,4,6-trifluorobenzaldehyde, 2,4,5-trifluorobenzyl alcohol, 2,6-difluorobenzyl chloride, 2,6-difluoronaphthalene, 3,6-difluoronaphthalene, 1,5-difluoronaphthalene, 2,7-difluoronaphthalene, 1,6-difluoronaphthalene, 1,2-difluoronaphthalene, 1,7-difluoronaphthalene, 1,3-difluoronaphthalene, 1,Examples include 4-difluoronaphthalene, 2,2-difluorobiphenyl, 4,4-difluorobiphenyl, 9,9-bis(fluorophenyl)fluorene, bis(fluoronaphthyl)fluorene, 9,9-bis(4-fluorophenyl)fluorene, 1,4-difluorobenzene, 4,4'-difluorodiphenylmethane, and 4,4-difluorobenzophenone, but 1,4-difluorobenzene, 4,4'-difluorodiphenylmethane, and 4,4-difluorobenzophenone are preferred.

[0027] Aromatic compound A' is an aromatic compound with 120 or fewer carbon atoms, provided that it induces an organic group different from that of B1. The description of aromatic compounds is the same as that for aromatic compound A above. Examples of aromatic compound A' include, but are not limited to, hydroquinone, resorcinol, catechol, phloroglucinol, 2,6-dihydroxynaphthalene, 3,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 1,2-dihydroxynaphthalene, 1,7-dihydroxynaphthalene, 1,3-dihydroxynaphthalene, 1,4-dihydroxynaphthalene, 4,4-biphenol, 4,4',4''-trihydroxytriphenylmethane, calixalene, bisphenol A, bisphenol AP, bisphenol AF, bisphenol B, bisphenol BP, bisphenol C, bisphenol E, bisphenol F, and bi Examples include sphenol G, bisphenol M, bisphenol S, bisphenol P, bisphenol PH, bisphenol TMC, bisphenol Z, dihydroxycarbazole, dihydroxyphenylamine, α,α,α',α'-tetrakis(4-hydroxyphenyl)-p-xylene, 9,9-bis(hydroxyphenyl)fluorene, bis(hydroxynaphthyl)fluorene, 1,5-dihydroxynaphthalene, 2,2-biphenol, and 1,1,1-tris(4-hydroxyphenyl)ethane, but 9,9-bis(4-hydroxyphenyl)fluorene, 1,5-dihydroxynaphthalene, 2,2-biphenol, and 1,1,1-tris(4-hydroxyphenyl)ethane are preferred.

[0028] The compounds used in the synthesis of polymer (X) are not limited to one compound, but two or more compounds may be used in combination. Therefore, the repeating structural units formed by the alternating bonding of aromatic compound A having a ROCH2- group and aromatic compound B having 120 or fewer carbon atoms, which is different from A, via the linking group -O-, may be the same or different.

[0029] Polymer (X) may have at least one terminal aromatic hydrocarbon group having 6 to 30 carbon atoms, which may be substituted. Examples of such aromatic hydrocarbon groups include phenyl groups and naphthyl groups, which may be substituted with vinyl groups, etc.

[0030] The present invention is characterized in that it constitutes a repeating structural unit in which aromatic compound A, aromatic compound B, and optionally aromatic compound A' are alternately bonded via a linking group -O-.

[0031] The weight-average molecular weight of the polymer (X) contained in the resist underlayer film-forming composition of the present invention is not particularly limited. In terms of standard polystyrene equivalent, it may be, for example, 500 or more, for example, 1,000 or more, for example, 2,000 or more, for example, 500,000 or less, for example, 100,000 or less.

[0032] [solvent] The resist underlayer film forming composition of the present invention can be prepared by dissolving each of the above components in a suitable solvent and is used in a homogeneous solution state.

[0033] 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 ethoxyacetate, ethyl hydroxyacetate, methyl 2-hydroxy-3-methylbutanoate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl 3-ethoxypropionate, methyl pyruvate, ethyl pyruvate, ethyl ethyl acetate, butyl acetate, ethyl lactate, butyl lactate, N,N-dimethylformamide, N,N-dimethylacetamide, and N-methylpyrrolidone.

[0034] Furthermore, high-boiling point solvents with a boiling point of 180°C or higher can also be used. Specific examples of high-boiling point organic solvents include 1-octanol, 2-ethylhexanol, 1-nonanol, 1-decanol, 1-undecanol, ethylene glycol, 1,2-propylene glycol, 1,3-butylene glycol, 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, glycerin, n-nonyl acetate, ethylene glycol monohexyl ether, 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 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, triacetin, propylene glycol diacetate, dipropylene glycol monomethyl ether acetate, dipropylene glycol methyl-n-propyl ether, dipropylene glycol methyl ether acetate, 1,4-butanediol diacetate, 1,3-butylene glycol diacetate, 1,Examples include 6-hexanediol diacetate, triethylene glycol diacetate, γ-butyrolactone, dihexyl malonate, diethyl succinate, dipropyl succinate, dibutyl succinate, dihexyl succinate, dimethyl adipate, diethyl adipate, and dibutyl adipate.

[0035] These solvents can be used individually or in combination of two or more. The proportion of solids remaining in the composition after removing the organic solvent is, for example, 0.5% to 30% by mass, preferably 0.8% to 15% by mass.

[0036] Additionally, the following compounds described in WO2018 / 131562A1 can also be used. [ka] (R in equation (i)) 1 , R 2 and R 3 Each of these represents a hydrogen atom, an oxygen atom, a sulfur atom, or an alkyl group having 1 to 20 carbon atoms, which may be interrupted by an amide bond. These groups may be identical or different, and may be bonded to each other to form a ring structure.

[0037] Examples of alkyl groups having 1 to 20 carbon atoms include linear or branched alkyl groups that may or may not have substituents, such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, isopentyl group, neopentyl group, n-hexyl group, isohexyl group, n-heptyl group, n-octyl group, cyclohexyl group, 2-ethylhexyl group, n-nonyl group, isononyl group, p-tert-butylcyclohexyl group, n-decyl group, n-dodecylnonyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, and eicosyl group. Preferably, it is an alkyl group having 1 to 12 carbon atoms, more preferably an alkyl group having 1 to 8 carbon atoms, and even more preferably an alkyl group having 1 to 4 carbon atoms.

[0038] Examples of alkyl groups having 1 to 20 carbon atoms interrupted by an oxygen atom, a sulfur atom, or an amide bond include those containing the structural units -CH2-O-, -CH2-S-, -CH2-NHCO-, or -CH2-CONH-. -O-, -S-, -NHCO-, or -CONH- may be present in one or more units within the alkyl group. Specific examples of alkyl groups having 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, and butylaminocarbonyl groups. The group is a methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, dodecyl group, or octadecyl group, each of which is substituted with a methoxy group, ethoxy group, propoxy group, butoxy group, methylthio group, ethylthio group, propylthio group, butylthio group, methylcarbonylamino group, ethylcarbonylamino group, methylaminocarbonyl group, ethylaminocarbonyl group, etc. Preferably, it is a methoxy group, ethoxy group, methylthio group, or ethylthio group, and more preferably, it is a methoxy group or ethoxy group.

[0039] Because these solvents have relatively high boiling points, they are also effective in imparting high embedding and high planarity properties to resist underlayer film forming compositions.

[0040] The following are specific examples of preferred compounds represented by formula (i). [ka]

[0041] Among the above, 3-methoxy-N,N-dimethylpropionamide, N,N-dimethylisobutylamide, and The following formula: [ka] Compounds represented by formula (i) are preferred, and particularly preferred compounds represented by formula (i) are 3-methoxy-N,N-dimethylpropionamide and N,N-dimethylisobutylamide.

[0042] These solvents can be used individually or in combination of two or more. Among these solvents, those with a boiling point of 160°C or higher are preferred, and propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, ethyl lactate, butyl lactate, cyclohexanone, 3-methoxy-N,N-dimethylpropionamide, N,N-dimethylisobutylamide, 2,5-dimethylhexane-1,6-diyldiacetate (DAH; cas, 89182-68-3), and 1,6-diacetoxyhexane (cas, 6222-17-9) are particularly preferred. Propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, and N,N-dimethylisobutylamide are especially preferred.

[0043] [Optional ingredients] The resist underlayer film forming composition of the present invention may further contain at least one of the following as optional components: a crosslinking agent, an acid and / or an acid generator, a thermal acid generator, and a surfactant.

[0044] (Crosslinking agent) The resist underlayer film forming composition of the present invention may further contain a crosslinking agent. Preferably, the crosslinking agent is a crosslinkable compound having at least two crosslinking substituents. Examples include melamine compounds, substituted urea compounds, and phenolic compounds or polymers thereof, having crosslinking substituents such as methylol groups and methoxymethyl groups. Specifically, examples include compounds such as methoxymethylated glycoluryl, butoxymethylated glycoluryl, methoxymethylated melamine, butoxymethylated melamine, methoxymethylated benzoguanamine, and butoxymethylated benzoguanamine. Examples include tetramethoxymethylglycoluryl, tetrabutoxymethylglycoluryl, and hexamethoxymethylmelamine. Furthermore, substituted urea compounds include compounds such as methoxymethylated urea, butoxymethylated urea, or methoxymethylated thiourea. Examples include tetramethoxymethylurea and tetrabutoxymethylurea. Condensed forms of these compounds can also be used. Examples of phenolic compounds include tetrahydroxymethylbiphenol, tetramethoxymethylbiphenol, tetrahydroxymethylbisphenol, tetramethoxymethylbisphenol, and compounds represented by the following formula. [ka] [ka]

[0045] As the crosslinking agent, a compound having at least two epoxy groups can also be used. Examples of such compounds include tris(2,3-epoxypropyl) isocyanurate, 1,4-butanediol diglycidyl ether, 1,2-epoxy-4-(epoxyethyl)cyclohexane, glycerol triglycidyl ether, diethylene glycol diglycidyl ether, 2,6-diglycidylphenyl glycidyl ether, 1,1,3-tris[p-(2,3-epoxypropoxy)phenyl]propane, 1,2-cyclohexanedicarboxylic acid diglycidyl ester, 4,4'-methylenebis(N,N-diglycidylaniline), 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, trimethylolethane triglycidyl ether, bisphenol-A-diglycidyl ether, and Daicel Corporation's Epolleed® GT-401, GT-403, GT-301, and GT-30 2. Celoxide® 2021, 3000, 1001, 1002, 1003, 1004, 1007, 1009, 1010, 828, 807, 152, 154, 180S75, 871, 872 manufactured by Mitsubishi Chemical Corporation, EPPN201, EPPN202, EPPN102, EPPN103S, EPPN104S, EPPN1020, EPPN1025, EPPN1027 manufactured by Nippon Kayaku Co., Ltd., and Denacol® EX-25 manufactured by Nagase ChemteX Corporation. 2. Examples include EX-611, EX-612, EX-614, EX-622, EX-411, EX-512, EX-522, EX-421, EX-313, EX-314, EX-321, CY175, CY177, CY179, CY182, CY184, CY192 from BASF Japan Ltd., and Epiclon 200, 400, 7015, 835LV, and 850CRP from DIC Corporation. As the compound having at least two epoxy groups, an epoxy resin having an amino group can also be used. Examples of such epoxy resins include YH-434 and YH-434L (manufactured by Shin-Nippon Chemical Epoxy Manufacturing Co., Ltd.).

[0046] The crosslinking agent may also be a compound having at least two blocked isocyanate groups. Examples of such compounds include Takenate® B-830 and B-870N manufactured by Mitsui Chemicals, Inc., and Vestanat® B1358 / 100 manufactured by Evonik Degussa.

[0047] The crosslinking agent may also be a compound having at least two vinyl ether groups. Examples of such compounds include bis(4-(vinyloxymethyl)cyclohexylmethyl)glutarate, tri(ethylene glycol) divinyl ether, divinyl adipate ester, diethylene glycol divinyl ether, 1,2,4-tris(4-vinyloxybutyl) trimellitate, 1,3,5-tris(4-vinyloxybutyl) trimellitate, bis(4-(vinyloxy)butyl) terephthalate, bis(4-(vinyloxy)butyl) isophthalate, ethylene glycol divinyl ether, 1,4-butanediol divinyl ether, tetramethylene glycol divinyl ether, tetraethylene glycol divinyl ether, neopentyl glycol divinyl ether, trimethylolpropane trivinyl ether, trimethylolethane trivinyl ether, hexanediol divinyl ether, 1,4-cyclohexanediol divinyl ether, tetraethylene glycol divinyl ether, pentaerythritol divinyl ether, pentaerythritol trivinyl ether, and cyclohexanedimethanol divinyl ether.

[0048] Furthermore, a crosslinking agent with high heat resistance can be used as the crosslinking agent. Preferably, a crosslinking agent with high heat resistance is a compound containing a crosslinking substituent having an aromatic ring (e.g., a benzene ring, a naphthalene ring) in its molecule.

[0049] Examples of this compound include compounds having the substructure of formula (4) below, or polymers or oligomers having the repeating unit of formula (5) below. [ka] The above R 11 , R 12 , R 13 , and R 14 This is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and the examples given above can be used for these alkyl groups.

[0050] Examples of compounds, polymers, and oligomers of formulas (4) and (5) are given below. [ka] [ka] [ka]

[0051] The above compounds can be obtained as products of Asahi Organic Chemicals Co., Ltd. and Honshu Chemical Industry Co., Ltd. For example, among the above crosslinking agents, compound (4-23) can be obtained from Honshu Chemical Industry Co., Ltd. under the trade name TMOM-BP, and compound (4-24) can be obtained from Asahi Organic Chemicals Co., Ltd. under the trade name TM-BIP-A. 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., but is 0.001% by mass or more, 0.01% by mass or more, 0.05% by mass or more, 0.5% by mass or more, or 1.0% by mass or more relative to the total solids, and is 80% by mass or less, 50% by mass or less, 40% by mass or less, 20% by mass or less, or 10% by mass or less. These crosslinking agents may undergo crosslinking reactions by self-condensation, but if crosslinkable substituents are present in the polymer of the present invention, they can undergo crosslinking reactions with those crosslinkable substituents.

[0052] You may add one of these crosslinking agents, or you may add two or more in combination.

[0053] (Acids and / or their salts and / or acid generators) The resist underlayer film forming composition according to the present invention may contain an acid and / or a salt thereof and / or an acid generator.

[0054] Examples of acids include carboxylic acid compounds such as methanesulfonic acid, p-toluenesulfonic acid, trifluoromethanesulfonic acid, salicylic acid, 5-sulfosalicylic acid, 4-phenolsulfonic acid, camphorsulfonic acid, 4-chlorobenzenesulfonic acid, benzenedisulfonic acid, 1-naphthalenesulfonic acid, citric acid, benzoic acid, hydroxybenzoic acid, and naphthalenecarboxylic acid, as well as inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, and phosphoric acid. As the salt, the aforementioned acid salts can also be used. While the salt is not limited, ammonia derivative salts such as trimethylamine salt and triethylamine salt, pyridine derivative salts, morpholine derivative salts, etc., can be suitably used. Only one type of acid and / or its salt may be used, or two or more types may be used in combination. The amount added is usually 0.0001 to 20% by mass, preferably 0.0005 to 10% by mass, and more preferably 0.01 to 5% by mass, relative to the total solids.

[0055] Examples of acid generators include thermal acid generators and photoacid generators. Examples of thermal acid generators include 2,4,4,6-tetrabromocyclohexadienone, benzoin tosylate, 2-nitrobenzyl tosylate, K-PURE® CXC-1612, CXC-1614, TAG-2172, TAG-2179, TAG-2678, TAG-2689, TAG-2700 (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, alkyl organic sulfonates, and the like.

[0056] The photoacid generator produces acid when the resist is exposed to light. Therefore, the acidity of the underlying film can be adjusted. This is one method for matching the acidity of the underlying film to that of the upper resist. Furthermore, adjusting the acidity of the underlying film allows for adjustment of the pattern shape of the resist formed on the upper layer. Examples of photoacid generators included in the resist underlayer film forming composition of the present invention include onium salt compounds, sulfonimide compounds, and disulfonyl diazomethane compounds.

[0057] Examples of iodonium salt compounds include iodonium salt compounds such as diphenyliodonium hexafluorophosphonate, 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.

[0058] Examples of sulfonimide compounds include N-(trifluoromethanesulfonyloxy)succinimide, N-(nonafluoron-butanesulfonyloxy)succinimide, N-(camphorsulfonyloxy)succinimide, and N-(trifluoromethanesulfonyloxy)naphthalimide.

[0059] Examples of disulfonyl diazomethane compounds include bis(trifluoromethylsulfonyl)diazomethane, bis(cyclohexylsulfonyl)diazomethane, bis(phenylsulfonyl)diazomethane, bis(p-toluenesulfonyl)diazomethane, bis(2,4-dimethylbenzenesulfonyl)diazomethane, and methylsulfonyl-p-toluenesulfonyldiazomethane.

[0060] Only one type of acid generator may be used, or two or more types may be used in combination. When an acid generator is used, the ratio is 0.01 to 10 parts by mass, or 0.1 to 8 parts by mass, or 0.5 to 5 parts by mass, per 100 parts by mass of solid content of the resist underlayer film forming composition.

[0061] (Surfactants) The resist underlayer film forming composition of the present invention may further contain a surfactant. Examples of the surfactant include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, and polyoxyethylene oleyl ether; polyoxyethylene alkylaryl 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; polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, and polyoxyethylene sorbitan monosodium Nonionic surfactants such as thearate, polyoxyethylene sorbitan trioleate, polyoxyethylene sorbitan tristearate, and other polyoxyethylene sorbitan fatty acid esters; F-Top® EF301, EF303, EF352 (manufactured by Mitsubishi Materials Electronic Chemicals Co., Ltd.); Megafac® F171, F173, R-30, R-30-N, R-40, R-4 Examples of fluorine-based surfactants include 0-LM (manufactured by DIC Corporation), Florard FC430, FC431 (manufactured by Sumitomo 3M Co., Ltd.), Asahi Guard® AG710, Surflon® S-382, SC101, SC102, SC103, SC104, SC105, and SC106 (manufactured by Asahi Glass Co., Ltd.), and organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.). One of these surfactants may be added, or two or more may be added in combination. The content ratio of the surfactant is, for example, 0.01% to 5% by mass relative to the solid content of the resist underlayer film forming composition of the present invention excluding the solvent described later.

[0062] [Membrane material (Z)] The polymer (X) according to the present invention can also be used as a crosslinking agent for the film material (Z). That is, the resist underlayer film-forming composition according to the present invention further comprises a film material (Z) that can crosslink with the polymer (X). The film material (Z) can be said to be a film material that can crosslink with the polymer (X).

[0063] The membrane material (Z) used optionally in the present invention can be used without particular limitations as long as it is a material capable of crosslinking with the polymer (X) described above. The membrane material may be a polymer, an oligomer, or a low molecular weight compound with a molecular weight of 1,000 or less. Examples of crosslinking groups present in the membrane material include, but are not limited to, hydroxyl groups, carboxyl groups, amino groups, and alkoxy groups.

[0064] More specifically, examples include the film materials (a) through (z) disclosed in the section [Film Materials (Y)] of the specification WO2021 / 172295 (Japanese Patent Application No. 2020-033333).

[0065] The above crosslinkable film material (Z) is preferably, (Y1) A membrane material containing an aliphatic ring (e.g., (a) above), (Y2) Novolac film material (e.g., the above (b)(c)(d)(e)(f)(g)(h)(i)(j)(k)(l)), (Y3) Polyether film material (e.g., (z) above), (Y4) Polyester membrane material (e.g., (o)(p) above), (Y5) A compound different from the crosslinkable compound (A) (for example, the above (n)(r)(s)(t)(u)(v)(w)(x)(y)), (Y6) A film material containing an aromatic condensed ring (e.g., (q) above), (Y7) Acrylic resin, and (Y8) Methacrylic resin It includes at least one selected from the group consisting of the following.

[0066] When the resist underlayer film-forming composition according to the present invention contains a crosslinkable film material (Z) (film material or polymer), the content of the crosslinkable film material (Z) is usually 1 to 99.9% by mass, preferably 50 to 99.9% by mass, more preferably 50 to 95% by mass, and even more preferably 50 to 90% by mass, relative to the total solid content.

[0067] The resist underlayer film forming composition of the present invention may further contain absorbents, rheology modifiers, adhesion aids, and the like. Rheology modifiers are effective in improving the fluidity of the underlayer film forming composition. Adhesion aids are effective in improving the adhesion between the semiconductor substrate or resist and the underlayer film.

[0068] (Photo-absorbing agent) Examples of light absorbers include commercially available light absorbers listed in "Technology and Market of Industrial Dyes" (CMC Publishing) and "Dye Handbook" (edited by the Society of Synthetic Organic Chemistry), such as 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; CIDisperse Blue 96; and CIFluorescent Brightening Agent. 112, 135 and 163; CISolvent Orange 2 and 45; CISolvent Red 1, 3, 8, 23, 24, 25, 27 and 49; CIPigment Green 10; CIPigment Brown 2, etc., can be suitably used. The above light absorbers are usually blended in a proportion of 10% by mass or less, preferably 5% by mass or less, relative to the total solid content of the resist underlayer film forming composition.

[0069] (Rheological modifier) Rheology modifiers are primarily added to improve the fluidity of the resist underlayer film-forming composition, particularly in the baking process, to improve the uniformity of the resist underlayer film thickness and enhance the filling of holes by the resist underlayer film-forming composition. Specific examples include phthalate derivatives such as dimethyl phthalate, diethyl phthalate, diisobutyl phthalate, dihexyl phthalate, and butyl isodecyl phthalate; adipic acid derivatives such as din-normal butyl adipate, diisobutyl adipate, diisooctyl adipate, and octyldecyl adipate; maleic acid derivatives such as din-normal butyl malate, diethyl malate, and dinonyl malate; oleic acid derivatives such as methyl oleate, butyl oleate, and tetrahydrofurfuryl oleate; or stearic acid derivatives such as n-butyl stearate and glyceryl stearate. These rheology modifiers are typically blended in a proportion of less than 30% by mass relative to the total solid content of the resist underlayer film-forming composition.

[0070] (Adhesion aid) Adhesion aids are added primarily to improve the adhesion between the substrate or resist and the resist underlayer film-forming composition, and especially to prevent the resist from peeling off during development. Specific examples include chlorosilanes such as trimethylchlorosilane, dimethylmethylolchlorosilane, methyldiphenylchlorosilane, and chloromethyldimethylchlorosilane; alkoxysilanes such as trimethylmethoxysilane, dimethyldiethoxysilane, methyldimethoxysilane, dimethylmethylolethoxysilane, diphenyldimethoxysilane, and phenyltriethoxysilane; silazanes such as hexamethyldisilazane, N,N'-bis(trimethylsilyl)urea, dimethyltrimethylsilylamine, and trimethylsilylimidazole; and methyloltric Examples of adhesive aids include silanes such as lorosilane, 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; and ureas such as 1,1-dimethylurea and 1,3-dimethylurea, or thiourea compounds. These adhesive aids are usually blended in a proportion of less than 5% by mass, preferably less than 2% by mass, relative to the total solid content of the resist underlayer film forming composition.

[0071] The solid content of the resist underlayer film-forming composition according to the present invention is usually 0.1 to 70% by mass, preferably 0.1 to 60% by mass. The solid content is the percentage of all components in the resist underlayer film-forming composition excluding the solvent. The percentage of the polymer in the solid content is preferably in the following order: 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.

[0072] One way to evaluate whether a resist underlayer film-forming composition is in a uniform solution state is to observe its passability through a specific microfilter. The resist underlayer film-forming composition according to the present invention passes through a microfilter with a pore size of 0.1 μm and exhibits a uniform solution state.

[0073] Examples of microfilter materials include fluororesins 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, but PTFE (polytetrafluoroethylene) is preferred.

[0074] [Underlying resist film] The resist underlayer can be formed using the resist underlayer forming composition according to the present invention as follows. The resist underlayer forming composition of the present invention is applied to a substrate used in the manufacture of semiconductor devices (for example, silicon wafer substrates, silicon dioxide coated substrates (SiO2 substrates), silicon nitride substrates (SiN substrates), silicon oxide nitride substrates (SiON substrates), titanium nitride substrates (TiN substrates), tungsten substrates (W substrates), glass substrates, ITO substrates, polyimide substrates, and low-k material coated substrates, etc.) using an appropriate coating method such as a spinner or coater, and then fired using a heating means such as a hot plate to form a resist underlayer. The firing conditions are appropriately selected from a firing temperature of 80°C to 600°C and a firing time of 0.3 to 60 minutes. Preferably, the firing temperature is 150°C to 350°C and the firing time is 0.5 to 2 minutes. Air may be used as the atmospheric gas during firing, or an inert gas such as nitrogen or argon may be used. The thickness of the underlying film formed here can be, for example, 10 to 1000 nm, 20 to 500 nm, 30 to 400 nm, or 50 to 300 nm. Furthermore, if a quartz substrate is used as the substrate, a replica (mold replica) of the quartz imprint mold can be fabricated.

[0075] Furthermore, an adhesion layer and / or a silicone layer containing 99% by mass or less, or 50% by mass or less, of Si can be formed on the resist underlayer film according to the present invention by coating or vapor deposition. For example, in addition to the method of forming the adhesion layer described in Japanese Patent Application Publication No. 2013-202982 and Japanese Patent No. 5827180, and the silicon-containing resist underlayer film (inorganic resist underlayer film) forming composition described in WO2009 / 104552A1 by spin coating, a Si-based inorganic material film can be formed by CVD or the like.

[0076] Furthermore, by applying the resist underlayer film forming composition according to the present invention onto a semiconductor substrate having a stepped portion and a non-stepped portion (a so-called stepped substrate) and firing it, the step difference between the stepped portion and the non-stepped portion can be reduced.

[0077] [Manufacturing method for semiconductor devices] The method for manufacturing a semiconductor device according to the present invention is: A step of forming a resist underlayer film using the resist underlayer film forming composition according to the present invention, A step of forming a resist film on the formed resist underlayer film, A process of forming a resist pattern by irradiating the formed resist film with light or an electron beam and developing it. A step of etching and patterning the resist underlayer film through the formed resist pattern, and Process of processing a semiconductor substrate via a patterned resist underlayer film. Includes.

[0078] Furthermore, the method for manufacturing a semiconductor device according to the present invention is A step of forming a resist underlayer film using the resist underlayer film forming composition according to the present invention, A step of forming a hard mask on the formed resist underlayer film, A step of forming a resist film on the formed hard mask, A process of forming a resist pattern by irradiating the formed resist film with light or an electron beam and developing it. A step of etching and patterning the hard mask through the formed resist pattern, and A step of etching and patterning the resist underlayer film through a patterned hard mask, and Process of processing a semiconductor substrate via a patterned resist underlayer film. Includes.

[0079] The process of forming a resist underlayer film using the resist underlayer film forming composition according to the present invention is as described above.

[0080] An organopolysiloxane film may be formed as a second resist underlayer on the resist underlayer formed by the above process, and a resist pattern may be formed on it. This second resist underlayer may be a SiON film or SiN film formed by a vapor deposition method such as CVD or PVD. Furthermore, an anti-reflective coating (BARC) may be formed as a third resist underlayer on this second resist underlayer, and this third resist underlayer may be a resist shape correction film that does not have anti-reflective properties.

[0081] In the process of forming the resist pattern, exposure is performed either through a mask (reticle) for forming a predetermined pattern or by direct drawing. For example, g-line, i-line, KrF excimer laser, ArF excimer laser, EUV, or electron beam can be used as the exposure source. After exposure, post-exposure baking is performed as needed. Then, the resist is developed with a developer (e.g., a 2.38% by mass aqueous solution of tetramethylammonium hydroxide), and further rinsed with a rinse solution or pure water to remove the used developer. Finally, post-baking is performed to dry the resist pattern and improve its adhesion to the substrate.

[0082] The etching process performed after the formation of the resist pattern is carried out by dry etching. Examples of etching gases used for 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 having steps, recesses, and / or protrusions. Furthermore, argon, nitrogen, or carbon dioxide can be mixed with these gases and used.

[0083] [Formation of a resist underlayer by nanoimprint lithography] The process of forming the resist underlayer film described above can also be carried out by nanoimprint lithography. This method is as follows: A step of applying a curable composition onto the formed resist underlayer film, A step of bringing the curable composition into contact with the mold, A step of irradiating the curable composition with light or an electron beam to form a cured film, and A step of separating the cured film from the mold, Includes.

[0084] The polymer (X) according to the present invention is expected to exhibit good permeability to gases such as He, H2, N2, and air, and shows good embedding properties, hardness, and bending resistance. By changing the molecular framework, the optical constants and etching rate can be adjusted to suit the process. The details are disclosed, for example, in the section [Formation of resist underlayer film by nanoimprint method] of the specification WO2021 / 172295 (Japanese Patent Application No. 2020-033333). [Examples]

[0085] The following examples illustrate specific compositions according to the present invention, but this does not limit the present invention.

[0086] The equipment used to measure the weight-average molecular weight of the reaction products obtained in the following synthesis example is shown. Equipment: HLC-8320GPC manufactured by Tosoh Corporation GPC column: TSKgel Super-MultiporeHZ-N (2 tubes) Column temperature: 40℃ Flow rate: 0.35ml / min Eluent:THF Standard sample: Polystyrene

[0087] The chemical structures (examples) and abbreviations of the main raw materials used are as follows: [ka]

[0088] [ka]

[0089] [Synthesis Example 1] 12.00 g of TMOM-BP (Honshu Chemical Industry Co., Ltd.), 7.23 g of 4,4-difluorobenzophenone (Tokyo Chemical Industries, Ltd., hereafter referred to as DFBP), 4.78 g of potassium carbonate (Fujifilm Wako Pure Chemical Industries, Ltd.), and 56.01 g of N-methylpyrrolidone (hereafter referred to as NMP) were placed in a flask. The mixture was then heated to 150°C under nitrogen and reacted for approximately 4.5 hours. After the reaction stopped, potassium carbonate was removed by filtration. 1N-HCl was added to the resulting filtrate to neutralize it, and the mixture was stirred for a while. This diluted solution was added dropwise to a methanol / water = 90 / 10 (vol / vol) solution to reprecipitation, and the mixture was filtered by suction. The resulting precipitate was dried to obtain resin (1-1). The weight-average molecular weight Mw, measured in polystyrene equivalent by GPC, was approximately 7,300. The obtained resin was dissolved in propylene glycol monomethyl ether (hereinafter referred to as PGMEA), and ion exchange was carried out for 4 hours using a cation exchange resin and an anion exchange resin to obtain the target compound solution.

[0090] [ka]

[0091] [Synthesis Example 2] 15.00 g of TMOM-BP, 4.52 g of DFBP, 4.23 g of 4,4'-difluorodiphenylmethane, 2.99 g of potassium carbonate, and 2.51 g of NMP were placed in a flask. The mixture was then heated to 150°C under nitrogen and reacted for approximately 4.5 hours. After the reaction stopped, potassium carbonate was removed by filtration. 1N-HCl was added to the resulting filtrate to neutralize it, and the mixture was stirred for a while. This diluted solution was added dropwise to a methanol / water = 90 / 10 (vol / vol) solution to reprecipitation, and the mixture was filtered by suction. The resulting precipitate was dried to obtain resin (1-2). The weight-average molecular weight Mw, measured in polystyrene equivalent by GPC, was approximately 5,100. The obtained resin was dissolved in PGMEA, and ion exchange was carried out for 4 hours using a cation exchange resin and anion exchange resin to obtain the target compound solution.

[0092] [ka]

[0093] [Synthesis Example 3] 12.00 g of TMOM-BP, 11.60 g of 9,9-bis(4-hydroxyphenyl)fluorene (Tokyo Chemical Industries, Ltd.), 14.45 g of DFBP, 9.55 g of potassium carbonate, and 111.06 g of NMP were placed in a flask. The mixture was then heated to 150°C under nitrogen and reacted for approximately 3.5 hours. After the reaction stopped, potassium carbonate was removed by filtration. 1N-HCl was added to the resulting filtrate to neutralize it, and the mixture was stirred for a while. This diluted solution was added dropwise to a methanol / water = 90 / 10 (vol / vol) solution to reprecipitation, and the mixture was filtered by suction. The resulting precipitate was dried to obtain resin (1-3). The weight-average molecular weight Mw, measured in polystyrene equivalent by GPC, was approximately 6,500. The obtained resin was dissolved in PGMEA, and ion exchange was carried out for 4 hours using a cation exchange resin and anion exchange resin to obtain the target compound solution.

[0094] [ka]

[0095] [Synthesis Example 4] 15.00 g of TMOM-BP, 6.63 g of 1,5-dihydroxynaphthalene (Tokyo Chemical Industries, Ltd.), 18.06 g of DFBP, 11.93 g of potassium carbonate, and 120.45 g of NMP were placed in a flask. The mixture was then heated to 150°C under nitrogen and reacted for approximately 1.5 hours. After the reaction stopped, potassium carbonate was removed by filtration. 1N-HCl was added to the resulting filtrate to neutralize it, and the mixture was stirred for a while. This diluted solution was added dropwise to a methanol / water = 90 / 10 (vol / vol) solution to reprecipitation, and the mixture was filtered by suction. The resulting precipitate was dried to obtain resin (1-4). The weight-average molecular weight Mw, measured in polystyrene equivalent by GPC, was approximately 7,600. The obtained resin was dissolved in propylene glycol monomethyl ether (hereinafter referred to as PGME), and ion exchange was carried out for 4 hours using a cation exchange resin and anion exchange resin to obtain the target compound solution.

[0096] [ka]

[0097] [Synthesis Example 5] 15.00 g of TMOM-BP, 2.36 g of 1,4-difluorobenzene (Tokyo Chemical Industries, Ltd., hereafter referred to as DFB), 4.52 g of DFB, 5.97 g of potassium carbonate, and 25.49 g of NMP were placed in a flask. The mixture was then heated to 150°C under nitrogen and reacted for approximately 3 hours. After the reaction stopped, potassium carbonate was removed by filtration. 1N-HCl was added to the resulting filtrate to neutralize it, and the mixture was stirred for a while. This diluted solution was added dropwise to a methanol / water = 90 / 10 (vol / vol) solution to reprecipitation, and the mixture was filtered by suction. The resulting precipitate was dried to obtain resin (1-5). The weight-average molecular weight Mw, measured in polystyrene equivalent by GPC, was approximately 15,200. The obtained resin was dissolved in cyclohexanone (hereafter referred to as CYH), and ion exchange was carried out for 4 hours using a cation exchange resin and anion exchange resin to obtain the target compound solution.

[0098] [ka]

[0099] [Synthesis Example 6] 10.00 g of TMOM-BP, 1.10 g of 1-naphthol, 7.53 g of DFBP, 4.97 g of potassium carbonate, and 55.07 g of NMP were placed in a flask. The mixture was then heated to 150°C under nitrogen and reacted for approximately 4.5 hours. After the reaction stopped, potassium carbonate was removed by filtration. 1N-HCl was added to the resulting filtrate to neutralize it, and the mixture was stirred for a while. This diluted solution was added dropwise to a methanol / water = 90 / 10 (vol / vol) solution to reprecipitation, and the mixture was filtered by suction. The resulting precipitate was dried to obtain resin (1-6). The weight-average molecular weight Mw, measured in polystyrene equivalent by GPC, was approximately 5,700. The obtained resin was dissolved in PGMEA, and ion exchange was carried out for 4 hours using a cation exchange resin and anion exchange resin to obtain the target compound solution.

[0100] [ka]

[0101] [Synthesis Example 7] 12.00 g of TMOM-BP, 0.81 g of 4-fluorostyrene (Tokyo Chemical Industries, Ltd.), 5.78 g of DFBP, 4.77 g of potassium carbonate, and 4.51 g of NMP were placed in a flask. The mixture was then heated to 150°C under nitrogen and reacted for approximately 4.5 hours. After the reaction stopped, potassium carbonate was removed by filtration. 1N-HCl was added to the resulting filtrate to neutralize it, and the mixture was stirred for a while. This diluted solution was added dropwise to a methanol / water = 90 / 10 (vol / vol) solution to reprecipitate, and the mixture was filtered by suction. The resulting precipitate was dried to obtain resin (1-8). The weight-average molecular weight Mw, measured in polystyrene equivalent by GPC, was approximately 14,400. The obtained resin was dissolved in PGMEA, and ion exchange was carried out for 4 hours using a cation exchange resin and anion exchange resin to obtain the target compound solution.

[0102] [ka]

[0103] [Synthesis Example 8] 12.00 g of TMOM-BP, 2.64 g of 2,2-biphenol (Tokyo Chemical Industries, Ltd.), 5.78 g of DFBP, 10.32 g of potassium carbonate, and 78.93 g of NMP were placed in a flask. The mixture was then heated to 150°C under nitrogen and reacted for approximately 4 hours. After the reaction stopped, potassium carbonate was removed by filtration. 1N-HCl was added to the resulting filtrate to neutralize it, and the mixture was stirred for a while. This diluted solution was added dropwise to a methanol / water = 90 / 10 (vol / vol) solution to reprecipitation, and the mixture was filtered by suction. The resulting precipitate was dried to obtain resin (1-9). The weight-average molecular weight Mw, measured in polystyrene equivalent by GPC, was approximately 5,000. The obtained resin was dissolved in PGMEA, and ion exchange was carried out for 4 hours using a cation exchange resin and anion exchange resin to obtain the target compound solution.

[0104] [ka]

[0105] [Synthesis Example 9] 12.00 g of TMOM-BP, 4.30 g of 1,1,1-tris(4-hydroxyphenyl)ethane (Tokyo Chemical Industries, Ltd.), 10.32 g of DFBP, 8.86 g of potassium carbonate, and 82.80 g of NMP were placed in a flask. The mixture was then heated to 150°C under nitrogen and reacted for approximately 1.5 hours. After the reaction stopped, potassium carbonate was removed by filtration. 1N-HCl was added to the resulting filtrate to neutralize it, and the mixture was stirred for a while. This diluted solution was added dropwise to a methanol / water = 90 / 10 (vol / vol) solution to reprecipitation, and then filtered by suction. The resulting precipitate was dried to obtain resin (1-10). The weight-average molecular weight Mw, measured in polystyrene equivalent by GPC, was approximately 7,500. The obtained resin was dissolved in PGMEA, and ion exchange was carried out for 4 hours using cation exchange resin and anion exchange resin to obtain the target compound solution.

[0106] [ka]

[0107] [Synthesis Example 10] 8.00 g of TMOM-BP, 1.92 g of TM-BIP-A, 6.02 g of DFBP, 3.98 g of potassium carbonate, and 6.48 g of NMP were placed in a flask. The mixture was then heated to 100°C under nitrogen and reacted for approximately 5 hours. After the reaction stopped, potassium carbonate was removed by filtration. 1N-HCl was added to the resulting filtrate to neutralize it, and the mixture was stirred for a while. This diluted solution was added dropwise to a methanol / water = 70 / 30 (vol / vol) solution to reprecipitation, and the mixture was filtered by suction. The resulting precipitate was dried to obtain resin (1-11). The weight-average molecular weight Mw, measured in polystyrene equivalent by GPC, was approximately 4,400. The obtained resin was dissolved in PGMEA, and ion exchange was carried out for 4 hours using a cation exchange resin and anion exchange resin to obtain the target compound solution.

[0108] [ka]

[0109] [Synthesis Example 11] 8.00 g of carbazole (manufactured by Tokyo Chemical Industry Co., Ltd.), 8.63 g of 9-fluorenone (manufactured by Tokyo Chemical Industry Co., Ltd.), 2.30 g of methanesulfonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), and 18.93 g of PGMEA were placed in a 100 mL flask. The mixture was then heated under nitrogen until reflux was achieved, and after approximately 1.5 hours, it was precipitated with methanol and dried to obtain polymer (1-12). The weight-average molecular weight Mw, measured in polystyrene equivalent by GPC, was approximately 2,600. The obtained resin was dissolved in PGMEA, and ion exchange was carried out for 4 hours using a cation exchange resin and anion exchange resin to obtain the target polymer solution.

[0110] [ka]

[0111] [Comparative Synthesis Example 1] 5.00 g of 4,4'-dihydroxy3,3',5,5'-tetramethylbiphenyl, 4.50 g of DFBP, 2.97 g of potassium carbonate, and 29.11 g of NMP were placed in a flask. The mixture was then heated to 150°C under nitrogen and reacted for approximately 4.5 hours. After the reaction stopped, potassium carbonate was removed by filtration. 1N HCl was added to the resulting filtrate to neutralize it, and the mixture was stirred for a while. This diluted solution was added dropwise to a methanol / water = 90 / 10 (vol / vol) solution to reprecipitation, and the mixture was filtered by suction. The resulting precipitate was dried to obtain resin (2-1). The weight-average molecular weight Mw, measured in polystyrene equivalent by GPC, was approximately 1,500. The obtained resin was dissolved in PGMEA, and ion exchange was carried out for 4 hours using a cation exchange resin and anion exchange resin to obtain the target compound solution.

[0112] [ka]

[0113] [Example 1] A resin solution (solid content 17.17% by mass) was obtained in Synthesis Example 1. To 4.97 g of this resin solution, 0.17 g of TMOM-BP (Honshu Chemical Co., Ltd.), 1.95 g of PGME containing 2% by mass pyridinium p-hydroxybenzene sulfonate, 0.09 g of PGMEA containing 1% by mass surfactant (DIC Corporation, Megafac R-40), 5.57 g of PGMEA, and 2.93 g of PGME were added and dissolved. The solution was then filtered through a polytetrafluoroethylene microfilter with a pore size of 0.1 μm to prepare a solution of the resist underlayer film forming composition.

[0114] [Example 2] A resin solution (solid content 17.17% by mass) was obtained in Synthesis Example 1. 5.93 g of this resin solution was mixed with 1.53 g of PGME containing 2% by mass pyridinium p-hydroxybenzene sulfonate, 0.10 g of PGMEA containing 1% by mass surfactant (DIC Corporation, Megafac R-40), 4.75 g of PGMEA, and 2.69 g of PGME, and dissolved. The mixture was then filtered through a polytetrafluoroethylene microfilter with a pore size of 0.1 μm to prepare a solution of the resist underlayer film forming composition.

[0115] [Example 3] A resin solution (solid content 17.17% by mass) was obtained in Synthesis Example 1. 0.24 g of PGMEA containing 1% by mass surfactant (DIC Corporation, Megafac R-40), 0.52 g of PGMEA, and 5.28 g of PGME were added to 13.96 g of this resin solution and dissolved. The solution was then filtered through a polytetrafluoroethylene microfilter with a pore size of 0.1 μm to prepare a solution of the resist underlayer film forming composition.

[0116] [Example 4] In Synthesis Example 2, a resin solution (solid content 14.96% by mass) was obtained. To 5.70 g of this resin solution, 0.17 g of TMOM-BP, 1.28 g of PGME containing 2% by mass pyridinium p-hydroxybenzene sulfonate, 0.09 g of PGMEA containing 1% by mass surfactant (DIC Corporation, Megafac R-40), 4.83 g of PGMEA, and 2.93 g of PGME were added and dissolved. The solution was then filtered through a polytetrafluoroethylene microfilter with a pore size of 0.1 μm to prepare a solution of the resist underlayer film forming composition.

[0117] [Example 5] In Synthesis Example 3, a resin solution (solid content 17.90% by mass) was obtained. To 4.77 g of this resin solution, 0.17 g of TMOM-BP, 1.28 g of PGME containing 2% by mass pyridinium p-hydroxybenzene sulfonate, 0.09 g of PGMEA containing 1% by mass surfactant (DIC Corporation, Megafac R-40), 5.77 g of PGMEA, and 2.91 g of PGME were added and dissolved. The solution was then filtered through a polytetrafluoroethylene microfilter with a pore size of 0.1 μm to prepare a solution of the resist underlayer film forming composition.

[0118] [Example 6] A resin solution (solid content 17.39% by mass) was obtained in Synthesis Example 4. To 4.90 g of this resin solution, 0.17 g of TMOM-BP, 1.28 g of PGME containing 2% by mass pyridinium p-hydroxybenzene sulfonate, 0.09 g of PGMEA containing 1% by mass surfactant (DIC Corporation, Megafac R-40), 4.10 g of PGMEA, and 4.46 g of PGME were added and dissolved. The solution was then filtered through a polytetrafluoroethylene microfilter with a pore size of 0.1 μm to prepare a solution of the resist underlayer film forming composition.

[0119] [Example 7] In Synthesis Example 5, a resin solution (solid content 17.40% by mass) was obtained. To 4.90 g of this resin solution, 0.17 g of TMOM-BP, 1.28 g of PGME containing 2% by mass pyridinium p-hydroxybenzene sulfonate, 0.09 g of PGMEA containing 1% by mass surfactant (DIC Corporation, Megafac R-40), 4.10 g of PGMEA, 1.54 g of PGME, and 2.93 g of CYH were added and dissolved. The solution was then filtered through a polytetrafluoroethylene microfilter with a pore size of 0.1 μm to prepare a solution of the resist underlayer film forming composition.

[0120] [Example 8] A resin solution (solid content 21.61% by mass) was obtained in Synthesis Example 6. To 3.76 g of this resin solution, 0.16 g of TMOM-BP, 1.22 g of PGME containing 2% by mass pyridinium p-hydroxybenzene sulfonate, 0.08 g of PGMEA containing 1% by mass surfactant (DIC Corporation, Megafac R-40), 3.27 g of PGMEA, and 1.51 g of PGME were added and dissolved. The solution was then filtered through a polytetrafluoroethylene microfilter with a pore size of 0.1 μm to prepare a solution of the resist underlayer film forming composition.

[0121] [Example 9] A resin solution (solid content 19.85% by mass) was obtained in Synthesis Example 7. To 4.09 g of this resin solution, 0.16 g of TMOM-BP, 1.22 g of PGME containing 2% by mass pyridinium p-hydroxybenzene sulfonate, 0.08 g of PGMEA containing 1% by mass surfactant (DIC Corporation, Megafac R-40), 2.94 g of PGMEA, and 1.51 g of PGME were added and dissolved. The solution was then filtered through a polytetrafluoroethylene microfilter with a pore size of 0.1 μm to prepare a solution of the resist underlayer film forming composition.

[0122] [Example 10] A resin solution (solid content 20.06% by mass) was obtained in Synthesis Example 8. To 4.05 g of this resin solution, 0.16 g of TMOM-BP, 1.22 g of PGME containing 2% by mass pyridinium p-hydroxybenzene sulfonate, 0.08 g of PGMEA containing 1% by mass surfactant (DIC Corporation, Megafac R-40), 2.98 g of PGMEA, and 1.51 g of PGME were added and dissolved. The solution was then filtered through a polytetrafluoroethylene microfilter with a pore size of 0.1 μm to prepare a solution of the resist underlayer film forming composition.

[0123] [Example 11] A resin solution (solid content 19.38% by mass) was obtained in Synthesis Example 9. To 4.19 g of this resin solution, 0.16 g of TMOM-BP, 1.22 g of PGME containing 2% by mass pyridinium p-hydroxybenzene sulfonate, 0.08 g of PGMEA containing 1% by mass surfactant (DIC Corporation, Megafac R-40), 2.84 g of PGMEA, and 1.51 g of PGME were added and dissolved. The solution was then filtered through a polytetrafluoroethylene microfilter with a pore size of 0.1 μm to prepare a solution of the resist underlayer film forming composition.

[0124] [Example 12] A resin solution (solid content 17.52% by mass) was obtained in Synthesis Example 10. To 4.87 g of this resin solution, 0.17 g of TMOM-BP, 1.28 g of PGME containing 2% by mass pyridinium p-hydroxybenzene sulfonate, 0.09 g of PGMEA containing 1% by mass surfactant (DIC Corporation, Megafac R-40), 5.66 g of PGMEA, and 2.91 g of PGME were added and dissolved. The solution was then filtered through a polytetrafluoroethylene microfilter with a pore size of 0.1 μm to prepare a solution of the resist underlayer film forming composition.

[0125] [Example 13] A resin solution (solid content 30.00% by mass) was obtained in Synthesis Example 11. To 4.33 g of this resin solution, 1.51 g of the resin solution obtained in Synthesis Example 1 (solid content 17.17% by mass), 1.95 g of PGME containing 2% by mass pyridinium p-hydroxybenzene sulfonate, 0.13 g of PGMEA containing 1% by mass surfactant (DIC Corporation, Megafac R-40), 10.31 g of PGMEA, and 1.77 g of PGME were added and dissolved. The mixture was then filtered through a polytetrafluoroethylene microfilter with a pore size of 0.1 μm to prepare a solution of the resist underlayer film forming composition.

[0126] [Comparative Example 1] A resin solution (solid content 18.37% by mass) was obtained in Comparative Synthesis Example 1. To 5.31 g of this resin solution, 0.19 g of TMOM-BP, 1.46 g of PGME containing 2% by mass pyridinium p-hydroxybenzene sulfonate, 0.10 g of PGMEA containing 1% by mass surfactant (DIC Corporation, Megafac R-40), 5.21 g of PGMEA, and 2.71 g of PGME were added and dissolved. The solution was then filtered through a polytetrafluoroethylene microfilter with a pore size of 0.1 μm to prepare a solution of the resist underlayer film forming composition.

[0127] [Comparative Example 2] A resin solution (solid content 30.00% by mass) was obtained in Synthesis Example 11. To 4.33 g of this resin solution, 0.26 g of TMOM-BP, 1.95 g of PGME containing 2% by mass pyridinium p-hydroxybenzene sulfonate, 0.13 g of PGMEA containing 1% by mass surfactant (DIC Corporation, Megafac R-40), 11.56 g of PGMEA, and 1.77 g of PGME were added and dissolved. The solution was then filtered through a polytetrafluoroethylene microfilter with a pore size of 0.1 μm to prepare a solution of the resist underlayer film forming composition.

[0128] (Leaching test into resist solvent) Solutions of the resist underlayer-forming compositions prepared in Comparative Example 1 and Examples 1-12 were applied onto silicon wafers using a spin coater, and baked on a hot plate at 240°C, 350°C, or 400°C for 60 seconds to form a resist underlayer (thickness 200 nm). These resist underlayers were immersed in a common thinner, PGME / PGMEA=7 / 3, to confirm their solvent resistance (Table 1). A reduction in film thickness of less than 1% after immersion was indicated with ○, and a reduction in film thickness of 1% or more after immersion was indicated with ×.

[0129] [Table 1]

[0130] When firing at 240°C, a comparison of Example 1 and Comparative Example 1 shows that Example 1 exhibits good curability, while Comparative Example 1 exhibits insufficient curability. Therefore, introducing specific crosslinking groups into the polymer provides a significant advantage in terms of curability. Furthermore, generally, solvent resistance cannot be obtained with low-temperature firing except when firing in combination with a crosslinking agent and a catalyst. However, as shown in Examples 1-12, by having specific crosslinking groups in the polymer, sufficient curability can be obtained in all cases: when using a crosslinking agent and an acid catalyst, when using only an acid catalyst, and when neither a crosslinking agent nor an acid catalyst is used.

[0131] (Optical constant measurement) Solutions of the resist underlayer-forming compositions prepared in Comparative Example 1 and Examples 1-12 were applied onto silicon wafers using a spin coater. A resist underlayer (thickness 50 nm) was formed by baking on a hot plate at 240°C, 350°C, or 400°C for 60 seconds. The refractive index (n value) and optical absorption coefficient (k value, also called the attenuation coefficient) of these resist underlayers were measured at a wavelength of 193 nm using a spectroscopic ellipsometer (Table 2).

[0132] [Table 2]

[0133] As shown in the examples, the optical constant can be changed by changing the type of compound used in the combination.

[0134] (Measurement of dry etching rate) The etcher and etching gas used to measure the dry etching rate are as follows: RIE-200NL (Samco): CF4

[0135] Solutions of the resist underlayer-forming compositions prepared in Comparative Example 1 and Examples 1-12 were applied onto silicon wafers using a spin coater. A resist underlayer (200 nm thick) was formed by baking on a hot plate at 240°C, 350°C, or 400°C for 60 seconds. The dry etching rate was measured using CF4 gas as the etching gas, and the dry etching rate ratio for Comparative Example 1 and Examples 1-12 was determined. The dry etching rate ratio is the dry etching rate ratio of (resist underlayer) / (KrF photoresist) (Table 3).

[0136] [Table 3]

[0137] As shown in the examples, the etching rate can be changed by changing the type of compound used in the combination.

[0138] (Measurement of sublimation volume) The amount of sublimation was measured using the sublimation measurement device described in International Publication No. 2007 / 111147. The resist underlayer film forming compositions prepared in Comparative Example 1 and Examples 1-12 were applied to silicon wafers, and the amount of sublimation was measured when the film thickness reached 200 nm after firing at 240°C, 350°C, or 400°C for 60 seconds (Table 4). The values ​​listed in the table represent the sublimation amount of Example 1-12 / the sublimation amount of Comparative Example 1.

[0139] [Table 4] *In Table 4, measurements at 400°C could not be taken due to equipment limitations.

[0140] Comparing Comparative Example 1 with Examples 1-12, the presence of specific crosslinking groups in the polymer significantly reduces the amount of sublimation in all cases: when using a crosslinking agent and acid catalyst, when using only an acid catalyst, and when neither a crosslinking agent nor an acid catalyst is used. Similarly, the amount of sublimation can be kept low even when the reacting compound is changed. Therefore, concerns about equipment contamination can be reduced.

[0141] (hardness measurement) The resist underlayer-forming compositions prepared in Comparative Example 1 and Examples 1-12 were applied to the substrates, and then baked at 240°C, 350°C, or 400°C for 60 seconds to form a 200 nm resist underlayer film. The hardness of this cured resist film was evaluated using a Bruker TI-980 triboidentor. Comparative Example 1 was used as a control, and those with higher hardness than Comparative Example 1 were rated as ○ (Table 5).

[0142] [Table 5]

[0143] Comparing Comparative Example 1 with Examples 1-12, it is found that having specific crosslinking groups in the polymer increases hardness in all cases: when using a crosslinking agent and an acid catalyst, when using only an acid catalyst, and when neither a crosslinking agent nor an acid catalyst is used. Furthermore, hardness usually increases with higher firing temperatures. However, when the Examples were fired at a low temperature of 240°C, their hardness was higher than when the Comparative Examples were fired at a high temperature of 350°C. Therefore, it is considered that they have good bending resistance not only at high firing temperatures but also at low firing temperatures.

[0144] (Evaluation of implantability) The embedding properties were confirmed in a dense pattern area with a 200 nm thick SiO2 substrate, a trench width of 50 nm, and a pitch of 100 nm. The resist underlayer film forming compositions prepared in Comparative Example 1 and Examples 1-12 were applied to the above substrates, and then baked at 240°C, 350°C, or 400°C for 60 seconds to form a resist underlayer film of approximately 200 nm. The planarity of this substrate was observed using a scanning electron microscope (S-4800) manufactured by Hitachi High-Technologies Corporation to confirm whether or not the resist underlayer film forming composition filled the inside of the pattern (Table 6). Patterns in which the resist underlayer film-forming composition was filled into the interior were marked with ○, and patterns in which the resist underlayer film-forming composition was not filled into the interior were marked with ×.

[0145] [Table 6]

[0146] The example material exhibits high embedding properties, similar to the conventional material (=comparative example).

[0147] (Bending resistance evaluation) Solutions of the resist underlayer-forming compositions prepared in Comparative Example 1 and Example 12 were applied to silicon wafers coated with silicon oxide using a spin coater. A resist underlayer (thickness 200 nm) was formed by baking at 350°C for 60 seconds on a hot plate. A silicon hard mask-forming composition solution was applied to the resist underlayer and baked at 240°C for 1 minute to form a silicon hard mask layer (thickness 30 nm). A resist solution was applied on top of that and baked at 100°C for 1 minute to form a resist layer (thickness 150 nm). Exposure was performed at a wavelength of 193 nm using a mask, followed by heated PEB (105°C for 1 minute), and then development to obtain a resist pattern. Subsequently, dry etching was performed using a fluorine-based gas and an oxygen-based gas to transfer the resist pattern to a silicon wafer coated with silicon oxide, and the shape of each pattern was observed using a Hitachi High-Technologies Corporation CG-4100.

[0148] As the pattern width narrows, irregular pattern bending becomes more likely. This makes it difficult to accurately process the substrate. Therefore, the less bending occurs, the finer the substrate processing becomes possible (Table 7). Products with higher bending resistance compared to the comparative examples were rated with ○.

[0149] [Table 7]

[0150] Next, the evaluation of the material of the present invention when used as a crosslinking agent is as follows. Dissolution tests in resist solvents, optical constant measurements, dry etching rate measurements, and hardness and bending resistance tests were performed using the methods described above. In addition, coating tests on stepped substrates and heat resistance evaluations were carried out as described below.

[0151] (Coating test on stepped substrates) As a coating test on stepped substrates, the coating thickness was compared on a 200 nm thick SiO2 substrate in an open area (OPEN) where no pattern was formed and in a dense pattern area (DENSE) with a trench width of 50 nm and a pitch of 100 nm. The resist underlayer forming compositions prepared in Comparative Example 2 and Example 13 were applied to the substrate and then baked at 350°C for 60 seconds to form a resist underlayer of approximately 200 nm. The planarity of this substrate was observed using a scanning electron microscope (S-4800) manufactured by Hitachi High-Technologies Corporation, and the planarity was evaluated by measuring the difference in film thickness between the trench area (patterned area) and the open area (unpatterned area) of the stepped substrate (this is the coating step difference between the trench area and the open area, and is called the bias). Here, planarity means that the difference in film thickness of the coated material on top of the area where a pattern exists (trench area (patterned area)) and the area where a pattern does not exist (open area (unpatterned area)) is small (Iso-dense bias). We rated options with less bias than Comparative Example 2 as "○".

[0152] (Heat resistance evaluation) Solutions of the resist underlayer-forming compositions prepared in Comparative Example 2 and Example 13 were applied onto silicon wafers using a spin coater, and baked on a hot plate at 350°C for 60 seconds to form a 200 nm resist underlayer. The obtained films were scraped off, and thermogravimetric analysis was performed in air while heating from room temperature (approximately 20°C) at a rate of 10°C per minute to confirm the change in weight loss over time. In the heat resistance evaluation, samples with a smaller weight loss rate than Comparative Example 2 were evaluated as "○".

[0153] [Table 8]

[0154] Based on the above, when the material of the present invention is used as a crosslinking agent, it is possible to create a material with higher planarization properties, higher heat resistance, higher hardness, and better bending resistance than the crosslinking agent of the comparative example. [Industrial applicability]

[0155] According to the present invention, a novel resist underlayer film forming composition is provided that meets the requirements for self-curing at low temperatures without the use of acid catalysts or crosslinking agents, for reducing the amount of sublimation, and for obtaining a highly hard film with high bending resistance. Furthermore, it can be used as a crosslinking agent, and when used as a crosslinking agent, it exhibits higher planarity and higher heat resistance than conventional crosslinking agents, while having the same embedding properties as conventional products, and allowing the optical constants and etching resistance to be freely changed by selecting monomers.

Claims

1. ROCH ２ A polymer (X) comprising repeating structural units in which aromatic compound A, having a monovalent organic group (R is a monovalent organic group, a hydrogen atom, or a mixture thereof) directly bonded to an aromatic ring, and aromatic compound B, having 120 or fewer carbon atoms different from A, are alternately bonded to the aromatic ring of aromatic compound A and the aromatic ring of aromatic compound B only via a linking group -O-, wherein 1 to 6 B are bonded to 1 A, and solvent A resist underlayer film forming composition containing the above.

2. A polymer (X) comprising repeating structural units in which aromatic compound A, having a ROCH2- group (where R is a monovalent organic group, a hydrogen atom, or a mixture thereof) directly bonded to an aromatic ring, and aromatic compound B, having 120 or fewer carbon atoms different from A and having a skeleton in which a benzene ring is bonded via a single carbon atom, are alternately bonded via a linking group -O-, wherein 1 to 6 B are bonded to 1 A, and solvent A resist underlayer film forming composition containing the above.

3. The resist underlayer forming composition according to claim 1, wherein the polymer (X) comprises a repeating structural unit represented by formula (1). 【Transformation 36】 (In formula (1), A1 represents an organic group derived from aromatic compound A in which a ROCH2- group (where R is a monovalent organic group, a hydrogen atom, or a mixture thereof) is directly bonded to an aromatic ring, and B1 represents an organic group derived from aromatic compound B, which has 120 or fewer carbon atoms and is different from A1.)

4. The resist underlayer forming composition according to claim 3, wherein R in formula (1) may be substituted with a phenyl group, a naphthyl group or anthracenyl group, and may be interrupted with an oxygen atom, a nitrogen atom or a carbonyl group, a saturated or unsaturated linear or branched C2-C20 aliphatic or C3-C20 alicyclic hydrocarbon group, a hydrogen atom, or a mixture thereof.

5. The resist underlayer film forming composition according to claim 3, wherein B1 in formula (1) is represented by the following formula (2). 【Chemistry 37】 (In formula (2), C1 and C2 each independently represent an aromatic ring having 6 to 48 carbon atoms, which may contain heteroatoms having 6 to 48 carbon atoms. Y represents a single bond, a carbonyl group, a sulfonyl group, a -CR12- group, or a -(CF3)C(CF3)- group. R1 represents an oxygen atom, a carbonyl group, a nitrogen atom, a carbon-carbon double bond, or a carbon-carbon triple bond which may be interrupted, and a carbon-carbon double bond or carbon-carbon triple bond which may be bonded to the end, an alkyl group having 1 to 10 carbon atoms, a hydroxyl group, a hydrogen atom, a halogen, an aromatic hydrocarbon group having 6 to 20 carbon atoms, or -NR22. R2 represents a chain or cyclic alkyl group having 1 to 10 carbon atoms. i is either 0 or 1, The dotted lines represent bonds with oxygen atoms.

6. The resist underlayer film forming composition according to claim 5, wherein i in formula (2) is 1.

7. The resist underlayer forming composition according to claim 5 or 6, wherein the polymer (X) further comprises a repeating structural unit represented by formula (3). 【Transformation 38】 (In formula (3), B1 is represented by formula (2), and A2 represents an organic group derived from aromatic compound A' having 120 or fewer carbon atoms, which is different from B1.)

8. The resist underlayer film forming composition according to any one of claims 1 to 7, wherein A1 in formula (1) does not have a phenolic hydroxyl group.

9. The resist underlayer forming composition according to any one of claims 1 to 8, wherein the polymer (X) has at least one terminal aromatic hydrocarbon group having 6 to 30 carbon atoms, which may be substituted.

10. The resist underlayer film forming composition according to any one of claims 1 to 9, further comprising a polymer (X) and a crosslinkable film material (Z).

11. The resist underlayer film forming composition according to any one of claims 1 to 10, further comprising a crosslinking agent.

12. The resist underlayer film forming composition according to any one of claims 1 to 11, further comprising an acid and / or an acid generator.

13. The resist underlayer film forming composition according to any one of claims 1 to 12, further comprising a surfactant.

14. The resist underlayer film forming composition according to any one of claims 1 to 13, wherein the solvent comprises a solvent having a boiling point of 160°C or higher.

15. A resist underlayer film characterized by being a fired product of a coated film made from the composition described in any one of Claims 1 to 14.

16. A step of forming a resist underlayer film on a semiconductor substrate using the composition described in any one of claims 1 to 14, A step of forming a resist film on the formed resist underlayer film, A process of forming a resist pattern by irradiating the formed resist film with light or an electron beam and developing it. A step of etching and patterning the resist underlayer film through the formed resist pattern, and Process of processing a semiconductor substrate via a patterned resist underlayer film. A method for manufacturing a semiconductor device containing [a specific component].

17. A step of forming a resist underlayer film on a semiconductor substrate using the composition described in any one of Claims 1 to 14, A step of forming a hard mask on the formed resist underlayer film, A step of forming a resist film on the formed hard mask, A process of forming a resist pattern by irradiating the formed resist film with light or an electron beam and developing it. A step of etching and patterning the hard mask through the formed resist pattern, and A step of etching and patterning the resist underlayer film through a patterned hard mask, and Process of processing a semiconductor substrate via a patterned resist underlayer film. A method for manufacturing a semiconductor device containing [a specific component].

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

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