Resist underlayer film forming composition

Abstract

Provided is a novel composition for forming a resist underlayer film. This composition for forming a resist underlayer film contains: a polymer (X) which includes structural units the same as or different from each other and having a hydroxymethyl group and a ROCH2- group (R being a monovalent organic group, or a mixture of these), and a linking group linking the aforementioned structural units; and a solvent.

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 thin the resist layer as required by the miniaturization of resist patterns, a lithography process is known in which at least two resist underlayer films are formed and these resist underlayer films are used as mask materials. Examples of materials 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 the 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 initiative] [Problems that the invention aims to solve]

[0008] However, conventional resist underlayer film forming compositions still had shortcomings in meeting requirements such as reducing the amount of sublimation that contaminates the equipment, improving etching resistance in substrate processing, and especially increasing hardness. [Means for solving the problem]

[0009] This invention solves the above problems. In other words, this invention encompasses the following: [1] A resist underlayer film forming composition comprising a polymer (X) having a plurality of identical or different structural units having a hydroxymethyl group and a ROCH2- group (where R is a monovalent organic group or a mixture thereof), and a linking group that links the plurality of structural units, and a solvent. Preferably, R is a monovalent organic group, and if there are multiple R groups within a single structural unit, they may be the same or different. [2] R may be substituted with a phenyl group, a naphthyl group or an anthracenyl group, and may be interrupted by an oxygen atom or a carbonyl group, a saturated or unsaturated linear or branched C2-C chain 20 Aliphatic hydrocarbon group, C3-C 20 A resist underlayer film forming composition according to [1], comprising an alicyclic hydrocarbon group, a hydrogen atom, or a mixture thereof. Preferably, R is A saturated or unsaturated linear or branched C2-C chain may be substituted with a phenyl group, naphthyl group or anthracenyl group, and may be interrupted by an oxygen atom or a carbonyl group. 20 Aliphatic hydrocarbon group, or Saturated or unsaturated, possibly branched C3-C 20 Alicyclic hydrocarbon group If multiple such elements exist within a single structural unit, they may be identical or different. [3] The resist underlayer forming composition according to [1] or [2], wherein the linking group comprises an alkylene group or an ether group. [4] A resist underlayer forming composition according to any one of [1] to [3], wherein the structural unit comprises an aromatic ring, heterocycle, or fused ring which may have a phenolic hydroxyl group and which may have a substituted or unsubstituted amino group. [5] A resist underlayer forming composition according to any one of [1] to [4], further comprising a polymer (X) and a crosslinkable film material (Y). [6] A resist underlayer film forming composition according to any one of [1] to [5], further comprising a crosslinking agent. [7] A resist underlayer forming composition according to any one of [1] to [6], further comprising an acid and / or an acid generator. [8] A resist underlayer film forming composition according to any one of [1] to [7], further comprising a surfactant. [9] The resist underlayer film forming composition according to any one of [1] to [8], wherein the solvent comprises a solvent having a boiling point of 160°C or higher. A resist underlayer film, which is a fired product of a coating film composed of the composition according to any one of [1] to [9] in

[10] .

[11] A step of forming a resist underlayer film on a semiconductor substrate using the composition according to any one of [1] to [9] in [1]; A step of forming a resist film on the formed resist underlayer film; A step of forming a resist pattern by irradiating and developing the formed resist film with light or an electron beam; A step of etching and patterning the resist underlayer film through the formed resist pattern, and A step of processing the semiconductor substrate through the patterned resist underlayer film A method for manufacturing a semiconductor device including the above steps.

[12] A step of forming a resist underlayer film on a semiconductor substrate using the composition according to any one of [1] to [9] in [1]; 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 step of forming a resist pattern by irradiating and developing the formed resist film with light or an electron beam; 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 the patterned hard mask, and A step of processing the semiconductor substrate through the patterned resist underlayer film A method for manufacturing a semiconductor device including the above steps.

Advantages of the Invention

[0010] According to the present invention, a novel resist underlayer film forming composition is provided that meets the requirements of reducing the amount of sublimates that contaminate the device, etching resistance in substrate processing, particularly increased hardness, and retains other good characteristics.

Embodiments for Carrying Out the Invention

[0011] The resist underlayer film forming composition according to the present invention comprises a polymer (X) containing a plurality of identical or different structural units having a hydroxymethyl group and a ROCH2- group (where R is a monovalent organic group or a mixture thereof), and a linking group that connects the plurality of structural units, and a solvent.

[0012] [Polymer (X)] The polymer (X) comprises a plurality of identical or different structural units having a hydroxymethyl group and a ROCH2- group (where R is a monovalent organic group or a mixture thereof), and a linking group that connects the plurality of structural units.

[0013] The monovalent organic group R may preferably be substituted with a phenyl group, a naphthyl group, or an anthracenyl group, and may be interrupted by an oxygen atom or a carbonyl group, forming a saturated or unsaturated linear or branched C2-C chain. 20 Aliphatic hydrocarbon group, C3-C 20 This refers to alicyclic hydrocarbon groups, or mixtures thereof. "Mixture" means that the multiple ROCH2- groups present within a single structural unit may be different, and that the ROCH2- groups in each of two or more structural units may be different.

[0014] 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.

[0015] 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.

[0016] 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.

[0017] The saturated aliphatic hydrocarbon group, unsaturated aliphatic hydrocarbon group, and cyclic alkyl group may be interrupted once or twice or more by an oxygen atom and / or a carbonyl group. Particularly preferably, R is a -CH(CH3)CH2OCH3 group.

[0018] Polymer (X) can be synthesized by polymerizing a compound having a hydroxymethyl group and possibly a phenolic hydroxyl group, a compound that reacts with the hydroxymethyl group to give a ROCH2- group (R is a monovalent organic group or a mixture thereof), and optionally a compound containing a functional group that acts as a linking group (e.g., aldehyde, ketone, ROCH2-Ar-CH2OR (R is a monovalent organic group, a hydrogen atom, or a mixture thereof)) in the presence of an acid catalyst (e.g., a sulfonic acid compound).

[0019] Examples of compounds having a hydroxymethyl group and possibly a phenolic hydroxyl group that can be used in the synthesis of polymer (X) include the compounds exemplified as crosslinking agents described later, but the compounds shown below can be preferably used. [ka]

[0020] Among the examples mentioned above, the compounds shown below can be used more preferably. [ka]

[0021] As a compound that reacts with a hydroxymethyl group used in the synthesis of polymer (X) to give a ROCH2- group (where R is a monovalent organic group or a mixture thereof), an organic compound having a non-phenolic hydroxyl group in the molecule is preferred. Even if the molecule does not have a non-phenolic hydroxyl group, it may be an organic compound having a functional group that can be chemically converted into a non-phenolic hydroxyl group, such as an alkoxy group (-OR), an aldehyde group (-CHO), a carboxyl group (-COOH), an ester group (-COOR), or a ketone group (-COR). There may be one non-phenolic hydroxyl group, or a functional group that can be chemically converted into a non-phenolic hydroxyl group, in the molecule, or two or more. The organic compound can be an aliphatic hydrocarbon (preferably with 10 or fewer carbon atoms), an alicyclic hydrocarbon (preferably with 20 or fewer carbon atoms), or an aromatic hydrocarbon (for example, having at least one hydroxyl group in which the α-carbon is aliphatic). Examples include propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, aliphatic alcohols (e.g., n-butanol), compounds represented by Ar-CH2OH (where Ar is, for example, benzene, naphthalene, anthracene, pyrene, fluorene, or m-terphenyl), aldehydes, ketones, methylol compounds, and the like.

[0022] Examples of organic compounds having an aldehyde group include aliphatic aldehydes such as formaldehyde, paraformaldehyde, butyraldehyde, and crotonaldehyde, and aromatic aldehydes such as furfural, pyridinecarboxaldehyde, benzaldehyde, naphthylaldehyde, anthrylaldehyde, phenanthrylaldehyde, salicylaldehyde, phenylacetaldehyde, biphenylaldehyde, 3-phenylpropionaldehyde, tolylaldehyde, (N,N-dimethylamino)benzaldehyde, acetoxybenzaldehyde, 1-pyrenecarboxaldehyde, and anisaldehyde.

[0023] Examples of organic compounds having the aforementioned ketone group include diaryl ketones such as diphenyl ketone, phenyl naphthyl ketone, dinaphthyl ketone, phenyl tolyl ketone, ditolyl ketone, 9-fluorenone, anthraquinone, and acenaphthaquinone, and spiroketones such as 11H-benzo[b]fluoren-11-one, 9H-tribenzo[a,f,l]triindene-9,14,15-trione, and indeno[1,2-b]fluoren-6,12-dione.

[0024] The structural units of the polymer (X) obtained in this manner preferably include aromatic rings, heterocycles, or fused rings, which may have phenolic hydroxyl groups and may have substituted or unsubstituted amino groups. A benzene ring is preferred as the aromatic ring. Furthermore, the linking groups that connect the multiple structural units preferably include alkylene groups or ether groups.

[0025] The compounds used in the synthesis of polymer (X) are not limited to one compound, but may be two or more compounds used in combination. Therefore, the multiple structural units having a hydroxymethyl group and a ROCH2- group (where R is a monovalent organic group, or a mixture thereof) may be identical or different.

[0026] 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. It can be, for example, 1,000 or more, 2,000 or more, 500,000 or less, or 100,000 or less, on a standard polystyrene basis.

[0027] [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.

[0028] 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.

[0029] 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, dibutyl adipate, etc.

[0030] These solvents can be used alone or in combinations of two or more. The proportion of the solid content excluding the organic solvent from the composition is, for example, 0.5% to 30% by mass, preferably 0.8% to 15% by mass.

[0031] Also, the following compounds described in WO2018 / 131562A1 can be used. [Chemical formula] (In formula (i), R 1 , R 2 and R 3 each represent 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, may be the same or different from each other, and may be bonded to each other to form a ring structure.)

[0032] 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.

[0033] 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.

[0034] 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.

[0035] The following are specific examples of preferred compounds represented by formula (i). [ka]

[0036] 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.

[0037] 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.

[0038] [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.

[0039] (Crosslinking agent) The resist underlayer film forming composition of the present invention may further contain a crosslinking agent (provided the crosslinking agent is not the same as polymer X). 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 a methylol group and a methoxymethyl group. Specifically, examples include compounds such as methoxymethylated glycoluryl, butoxymethylated glycoluryl, methoxymethylated melamine, butoxymethylated melamine, methoxymethylated benzoguanamine, and butoxymethylated benzoguanamine, for example, tetramethoxymethylglycoluryl, tetrabutoxymethylglycoluryl, and hexamethoxymethylmelamine. Furthermore, as substituted urea compounds, examples include compounds such as methoxymethylated urea, butoxymethylated urea, or methoxymethylated thiourea, for example, tetramethoxymethylurea and tetrabutoxymethylurea. Condensed products 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]

[0040] 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.).

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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 n is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and the alkyl groups described above can be used. n1 is an integer from 1 to 4, n2 is an integer from 1 to (5-n1), and (n1+n2) is an integer from 2 to 5. n3 is an integer from 1 to 4, n4 is from 0 to (4-n3), and (n3+n4) is an integer from 1 to 4. The oligomers and polymers can be used with a number of repeating unit structures ranging from 2 to 100, or from 2 to 50.

[0045] Examples of compounds, polymers, and oligomers of formulas (4) and (5) are given below. [ka] [ka] [ka]

[0046] 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, compound (4-24) can be obtained from Asahi Organic Chemicals Co., Ltd. under the trade name TM-BIP-A, and compound (4-28) can be obtained from Finechem Co., Ltd. under the trade name PGME-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.

[0047] You may add one of these crosslinking agents, or you may add two or more in combination.

[0048] (Acids and / or acid generators) The resist underlayer film forming composition according to the present invention may contain an acid and / or an acid generator.

[0049] Examples of acids include carboxylic acid compounds such as p-toluenesulfonic acid, trifluoromethanesulfonic acid, pyridinium p-toluenesulfonic acid, pyridinium phenolsulfonic acid, salicylic acid, 5-sulfosalicylic acid, 4-phenolsulfonic acid, camphorsulfonic acid, 4-chlorobenzenesulfonic acid, benzenedisulfonic acid, 1-naphthalenesulfonic acid, citric acid, benzoic acid, hydroxybenzoic acid, and naphthalenecarboxylic acid, as well as inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, and phosphoric acid. Only one type of acid 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 solid content.

[0050] 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.

[0051] 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.

[0052] Examples of sulfonimide compounds include N-(trifluoromethanesulfonyloxy)succinimide, N-(nonafluoron-butanesulfonyloxy)succinimide, N-(camphorsulfonyloxy)succinimide, and N-(trifluoromethanesulfonyloxy)naphthalimide.

[0053] 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.

[0054] 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 the solid content of the resist underlayer film forming composition.

[0055] (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.

[0056] [Membrane material (Y)] The polymer (X) according to the present invention can also be used as a crosslinking agent for the film material (Y). That is, the resist underlayer film-forming composition according to the present invention further comprises a film material (Y) that can crosslink with the polymer (X). The film material (Y) can be said to be a film material that can crosslink with the polymer (X).

[0057] The membrane material (Y) 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.

[0058] More specifically, examples include the film materials (a) through (z) disclosed in the section [Film Material (Y)] of Japanese Patent Application No. 2020-033333 (WO2021 / 172295A1).

[0059] The above crosslinkable film material (Y) 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.

[0060] When the resist underlayer film-forming composition according to the present invention contains a crosslinkable film material (Y) (film material or polymer), the content of the crosslinkable film material (Y) 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.

[0061] 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.

[0062] (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.

[0063] (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.

[0064] (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.

[0065] 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 proportion of all components in the resist underlayer film forming composition excluding the solvent. The proportion of the polymer in the solid content is preferably in the order of 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.

[0066] 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.

[0067] 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.

[0068] [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 (e.g., silicon wafer substrates, silicon / silicon dioxide coated substrates, silicon nitride 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 firing may be carried out in two stages, with the temperature and firing time being changed in each stage. 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.

[0069] 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.

[0070] Furthermore, by applying the resist underlayer 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, a resist underlayer can be formed in which the step difference between the stepped portion and the non-stepped portion is in the range of 3 to 70 nm.

[0071] [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.

[0072] 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.

[0073] The process of forming a resist underlayer film using the resist underlayer film forming composition according to the present invention is as described above.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] [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.

[0078] In the release process of optical nanoimprint technology, adhesion between the resist composition and the substrate is crucial. If the adhesion between the resist composition and the substrate is poor, when the mold is pulled apart during the release process, some of the photocured product obtained by curing the resist composition may peel off while remaining attached to the mold, resulting in pattern peeling defects. As a technique to improve the adhesion between the resist composition and the substrate, a technique has been proposed to form an adhesion layer between the resist composition and the substrate, which is a layer that adheres the resist composition and the substrate together.

[0079] Furthermore, highly etching-resistant layers are sometimes used for pattern formation in nanoimprinting. Organic materials and silicone materials are commonly used as materials for highly etching-resistant layers. In addition, adhesion layers and silicon-containing silicone layers can be formed on the nanoimprint resist underlayer film by coating or vapor deposition. If these adhesion layers and silicon-containing silicone layers are hydrophobic and exhibit a high pure water contact angle, it is expected that the adhesion between the films will be improved and peeling will be less likely if the underlayer film is also hydrophobic and exhibits a high pure water contact angle. Conversely, if the adhesion layers and silicone layers are hydrophilic and exhibit a low pure water contact angle, it is expected that the adhesion between the films will be improved and peeling will be less likely if the underlayer film is also hydrophilic and exhibits a low pure water contact angle.

[0080] Furthermore, depending on the properties of the adhesion film, silicone layer, and underlying film, elements such as He, H2, N2, and air can be used.

[0081] The polymer (X) according to the present invention exhibits a desired pure water contact angle not only during low-temperature firing but also during high-temperature firing, and maintains the desired pure water contact angle even when mixed with a crosslinking agent, acid catalyst, and surfactant as a material. This makes it possible to improve adhesion to the upper film and is expected to exhibit good permeability to gases such as He, H2, N2, and air. Furthermore, the polymer (X) according to the present invention exhibits good planarization properties, and by changing the molecular framework, the optical constants and etching rate can be adjusted to suit the process.

[0082] (Curable composition) The photoresist formed on the resist underlayer film is not particularly limited as long as it is sensitive to the light used for exposure. Both negative and positive photoresists can be used. Examples include positive photoresists consisting of novolac resin and 1,2-naphthoquinone diazide sulfonic acid ester, chemically amplified photoresists consisting of a binder having a group that decomposes with acid to increase the alkali dissolution rate and a photoacid generator, chemically amplified photoresists consisting of a low molecular weight compound that decomposes with acid to increase the alkali dissolution rate of the photoresist, an alkali-soluble binder and a photoacid generator, and chemically amplified photoresists consisting of a binder having a group that decomposes with acid to increase the alkali dissolution rate, a low molecular weight compound that decomposes with acid to increase the alkali dissolution rate of the photoresist and a photoacid generator. Examples include APEX-E (Chypre Corporation), PAR710 (Sumitomo Chemical Co., Ltd.), and SEPR430 (Shin-Etsu Chemical Co., Ltd.). Furthermore, examples include fluorine-containing polymer-based photoresists, such as those described in Proc.SPIE, Vol.3999, 330-334 (2000), Proc.SPIE, Vol.3999, 357-364 (2000), and Proc.SPIE, Vol.3999, 365-374 (2000).

[0083] (Step of applying the curable composition) This step involves applying a curable composition onto a resist underlayer film formed by the resist underlayer film manufacturing method according to the present invention. Methods for applying the curable composition include, for example, inkjet coating, dip coating, air knife coating, curtain coating, wire bar coating, gravure coating, extrusion coating, spin coating, and slit scanning. Inkjet coating is suitable for applying the curable composition as droplets, while spin coating is suitable for coating the curable composition. In this step, an adhesion layer and / or a silicone layer containing 99% by mass or less, or 50% by mass or less, of Si can also be formed on the resist underlayer film by coating or vapor deposition, and the curable composition can be applied thereon.

[0084] (Step of bringing the curable composition into contact with the mold) In this process, the curable composition is brought into contact with the mold. For example, by bringing a liquid curable composition into contact with a mold having a prototype pattern for transferring the pattern shape, a liquid film is formed in which the curable composition fills the depressions of the fine pattern on the surface of the mold.

[0085] Considering the process of irradiating with light or electron beams, which will be described later, it is recommended to use a mold made of a light-transmitting material as the base material. Specifically, the mold base material is preferably a light-transmitting resin such as glass, quartz, PMMA, or polycarbonate resin, a transparent metal vapor-deposited film, a flexible film such as polydimethylsiloxane, a photocurable film, or a metal film. Quartz is more preferably used as the mold base material because it has a small coefficient of thermal expansion and low pattern distortion.

[0086] The fine patterns on the surface of the mold preferably have a pattern height of 4 nm or more and 200 nm or less. A certain pattern height is necessary to improve the processing accuracy of the substrate, but a lower pattern height results in less force being used to separate the mold from the cured film in the process of separating the cured film and the mold described later, and also reduces the number of defects remaining on the mask side due to the resist pattern being torn off. Considering these factors, it is recommended to select and adopt a pattern height with an appropriate balance. Furthermore, the elastic deformation of the resist pattern due to the impact when peeling off the mold may cause adjacent resist patterns to come into contact, resulting in adhesion or damage to the resist patterns. This can sometimes be avoided by keeping the pattern height approximately twice the pattern width (aspect ratio of 2 or less).

[0087] To improve the release properties between the curable composition and the mold surface, the mold may be pre-treated. One method of surface treatment is to apply a release agent to the mold surface to form a release agent layer. Examples of release agents include silicone-based release agents, fluorine-based release agents, hydrocarbon-based release agents, polyethylene-based release agents, polypropylene-based release agents, paraffin-based release agents, montan-based release agents, and carnauba-based release agents. Preferably, fluorine-based and hydrocarbon-based release agents are used. A commercially available product is, for example, Optool® DSX manufactured by Daikin Industries, Ltd. One type of release agent may be used alone, or two or more types may be used in combination.

[0088] In this process, the pressure applied to the curable composition when bringing the mold into contact with the curable composition is not particularly limited. A pressure of 0 MPa or higher and 100 MPa or lower is recommended. Preferably, the pressure is 0 MPa or higher and 50 MPa or lower, 30 MPa or lower, or 20 MPa or lower.

[0089] If the press-spreading of droplets of the curable composition is progressing in the preceding step (the step of applying the curable composition), the spreading of the curable composition in this step will be completed quickly. As a result, the time during which the mold and the curable composition are in contact can be shortened. The contact time is not particularly limited, but is preferably 0.1 seconds or more, 600 seconds or less, 3 seconds or less, or 1 second or less. If the contact time is too short, the spreading and filling will be insufficient, and defects called unfilled defects may occur.

[0090] This process can be carried out under any of the following conditions: under an atmospheric atmosphere, under a reduced pressure atmosphere, or under an inert gas atmosphere. Preferably, it is carried out under a pressure of 0.0001 atmospheres or more and 10 atmospheres or less. To prevent the influence of oxygen and moisture on the curing reaction, it is recommended to carry out the process under a reduced pressure atmosphere or an inert gas atmosphere. Specific examples of inert gases that can be used to create an inert gas atmosphere include nitrogen, carbon dioxide, helium, argon, CFCs, HCFCs, HFCs, or mixtures thereof.

[0091] This process may be carried out in an atmosphere containing a condensable gas (hereinafter referred to as a "condensable gas atmosphere"). In this specification, a condensable gas is a gas that, when filled together with the curable composition into the recesses of the fine pattern formed on the mold and into the gaps between the mold and the substrate, condenses and liquefies due to the capillary pressure generated during filling. The condensable gas exists as a gas in the atmosphere before the curable composition and the mold come into contact in this process. When this process is carried out in a condensable gas atmosphere, the gas filling the recesses of the fine pattern liquefies due to the capillary pressure generated by the curable composition, eliminating bubbles and resulting in superior filling performance. The condensable gas may be dissolved in the curable composition.

[0092] The boiling point of the condensable gas is not limited as long as it is below the ambient temperature of this process, but is preferably -10°C or higher, or +10°C or higher and +23°C or lower.

[0093] The vapor pressure of the condensable gas at the ambient temperature of this process is not particularly limited as long as it is below the mold pressure. Preferably, it is in the range of 0.1 MPa to 0.4 MPa.

[0094] Examples of condensable gases include chlorofluorocarbons (CFCs) such as trichlorofluoromethane, fluorocarbons (FCs), hydrochlorofluorocarbons (HCFCs), hydrofluorocarbons (HFCs) such as 1,1,1,3,3-pentafluoropropane (CHF2CH2CF3, HFC-245fa, PFP), and hydrofluoroethers (HFEs) such as pentafluoroethyl methyl ether (CF3CF2OCH3, HFE-245mc).

[0095] Condensible gases may be used individually or in mixtures of two or more. These condensable gases may also be mixed with non-condensable gases such as air, nitrogen, carbon dioxide, helium, and argon. Air and helium are preferred non-condensable gases to be mixed with condensable gases.

[0096] (A process of curing a curable composition by irradiating it with light or an electron beam to form a cured film.) In this process, the curable composition is irradiated with light or an electron beam to form a cured film. Specifically, the curable composition filled in the fine pattern of the mold is irradiated with light or an electron beam through the mold, and the curable composition filled in the fine pattern of the mold is cured in that state, thereby forming a cured film with a patterned shape.

[0097] The light or electron beam is selected according to the sensitivity wavelength of the curable composition. Specifically, ultraviolet light, X-rays, electron beams, etc. with wavelengths of 150 nm to 400 nm can be appropriately selected and used. Examples of light or electron beam light sources include high-pressure mercury lamps, ultra-high-pressure mercury lamps, low-pressure mercury lamps, deep-UV lamps, carbon arc lamps, chemical lamps, metal halide lamps, xenon lamps, KrF excimer lasers, ArF excimer lasers, F2 excimer lasers, etc. There may be one or more light sources. Irradiation may be performed on the entire curable composition filled in the fine pattern of the mold, or on only a part of it. Light irradiation may be performed intermittently multiple times over the entire area of ​​the substrate, or it may be performed continuously over the entire area. It is also possible to perform the first irradiation on a part of the substrate and the second irradiation on a different area.

[0098] The cured film obtained in this manner preferably has a pattern with a size of 1 nm or more, or 10 nm or more, 10 mm or less, or 100 μm or less.

[0099] (The process of separating the hardened film from the mold) In this step, the cured film and the mold are separated. By separating the cured film having a pattern shape from the mold, a cured film having a pattern shape that is an inverse pattern of the fine pattern formed on the mold is obtained in a self-supporting state.

[0100] The method for separating the patterned cured film from the mold is not particularly limited, as long as it involves moving the cured film and the mold in a direction that moves them apart relative to each other, and there are no particular limitations on the physical damage to any part of the patterned cured film, nor are there any particular limitations on the various conditions. For example, the substrate may be fixed and the mold may be moved away from the substrate to separate them, or the mold may be fixed and the substrate may be moved away from the mold to separate them. Alternatively, the substrate and the mold may be pulled and moved in opposite directions to separate them.

[0101] Furthermore, if the process of bringing the curable composition into contact with the mold is carried out under a condensable gas atmosphere, the condensable gas vaporizes as the pressure at the interface where the cured film and the mold come into contact decreases when the cured film and the mold are separated in this process. This reduces the release force required to separate the cured film and the mold.

[0102] Through the above process, a cured film can be prepared that has a desired uneven pattern shape derived from the uneven shape of the mold, at a desired position. [Examples]

[0103] The HPLC purity shown in the synthesis examples below in this specification is the result of measurement by high-performance liquid chromatography (hereinafter abbreviated as HPLC in this specification). A Shimadzu HPLC instrument (LC-2010A HT) was used for the measurement, and the measurement conditions were as follows. HPLC column: Inertsil ODS-3 (5μm, 4.6×250mm, GL Sciences Co., Ltd.) Column temperature: 40℃ Flow rate: 1.0mL / min. Solvent: Acetonitrile / 0.2% phosphoric acid aqueous solution = 70 / 30 (0-5 min.) → 70 / 30 (10-15 min.)

[0104] The weight-average molecular weights shown in the synthesis examples below in this specification are the results of measurements performed by gel permeation chromatography (hereinafter abbreviated as GPC in this specification). A GPC instrument manufactured by Tosoh Corporation (HLC-8320GPC) was used for the measurements, and the measurement conditions were as follows. GPC columns: TSKgelSuperH-RC, TSKgelSuperMultipore HZ-N, TSKgelSuperMultipore HZ-N (manufactured by Tosoh Corporation) Column temperature: 40℃ Solvent: Tetrahydrofuran (Kanto Chemical Co., Ltd., for high-performance liquid chromatography) Standard sample: Polystyrene (Shodex)

[0105] <Synthesis Example 1> Synthesis of monomer (A) (TM-BP) In a four-necked flask equipped with a stirring bar and condenser, 100.00 g (0.54 mmol) of 4,4′-biphenol (Tokyo Chemical Industries, Ltd.) and 260.00 g of 17% sodium hydroxide aqueous solution (Kanto Chemical Co., Ltd.) were added and the mixture was heated to 40°C while stirring. At 40°C, 170.00 g (2.09 mmol) of 37% formaldehyde aqueous solution (Kanto Chemical Co., Ltd.) was added dropwise, and the mixture was stirred at the same temperature for 17.5 hours. After the reaction mixture was cooled to below 10°C, 237.00 g of 17% hydrochloric acid was added dropwise. The resulting precipitate was filtered off, and the filtrate was washed twice sequentially with 200 g of pure water. The obtained crystals were placed in 200 g of tetrahydrofuran (Kanto Chemical Co., Ltd., special grade), stirred for 1 hour, then the crystals were filtered off, and the filtrate was washed twice with 50 g of tetrahydrofuran. The obtained crystals were dried under reduced pressure at 40°C to obtain monomer (A) in yield of 27.8%. The purity measured by HPLC was 99.1%. [ka]

[0106] <Synthesis Example 2> Synthesis of monomer (B) (HM-THPE) In a four-necked flask equipped with a stirring bar and condenser, 30.00 g (98 mmol) of 1,1,1-tris(4-hydroxyphenyl)ethane (Tokyo Chemical Industries, Ltd.) and 115.20 g of 17% sodium hydroxide aqueous solution (Kanto Chemical Co., Ltd.) were added and the mixture was heated to 40°C while stirring. At 40°C, 48.08 g (592 mmol) of 37% formaldehyde aqueous solution (Kanto Chemical Co., Ltd.) was added dropwise, and the mixture was stirred at the same temperature for 20 hours. 450 g of ethyl acetate (Kanto Chemical Co., Ltd.) was added to the reaction mixture and cooled to below 10°C, after which 105.01 g of 17% hydrochloric acid was added dropwise. After separating the organic layer, it was washed twice with 120 g of pure water, once with 120 g of saturated sodium bicarbonate, and twice with 120 g of pure water. The resulting organic layer was then concentrated under reduced pressure at 40°C to obtain monomer (B) in 72.9% yield. The purity measured by GPC was 75.8%. [ka]

[0107] <Synthesis Example 3> Synthesis of monomer (C) (HM-THPEI) In a four-necked flask equipped with a stirring bar and condenser, 10.00 g (23.6 mmol) of α,α,α'-tris(4-hydroxyphenyl)-1-ethyl-4-isopropylbenzene (Tokyo Chemical Industries, Ltd.), 4.74 g of sodium hydroxide aqueous solution (Kanto Chemical Co., Ltd.), and 40.00 g of pure water were added and the mixture was heated to 40°C while stirring. At 40°C, 11.57 g (143 mmol) of 37% formaldehyde aqueous solution (Kanto Chemical Co., Ltd.) was added dropwise, and the mixture was stirred at the same temperature for 27 hours. 160 g of 4-methyl-2-pentanone (Kanto Chemical Co., Ltd.) was added to the reaction mixture and cooled to below 10°C, after which 25.00 g of 6N hydrochloric acid (Kanto Chemical Co., Ltd.) was added dropwise. After separating the organic layer, it was washed twice with 40g of pure water, once with 40g of saturated sodium bicarbonate, and twice with 40g of pure water. The resulting organic layer was then concentrated under reduced pressure at 40°C to obtain monomer (C) in 95.5% yield. The purity, as measured by GPC, was 70.7%. [ka]

[0108] <Synthesis Example 4> Synthesis of monomer (D) (HM-THPM) In a four-necked flask equipped with a stirring bar and condenser, 10.00 g (34.2 mmol) of tris(4-hydroxyphenyl)methane (Tokyo Chemical Industries, Ltd.), 6.88 g (171 mmol) of sodium hydroxide (Kanto Chemical Co., Ltd.), and 40.00 g of pure water were added and heated to 40°C while stirring. At 40°C, 16.8 g (207 mmol) of 37% formaldehyde aqueous solution (Kanto Chemical Co., Ltd.) was added dropwise, and the mixture was stirred at the same temperature for 16 hours. 160 g of 4-methyl-2-pentanone (Kanto Chemical Co., Ltd.) was added to the reaction mixture and cooled to below 10°C, after which 25 g of 20% hydrochloric acid was added dropwise. After separating the organic layer, it was washed twice with 40 g of pure water, once with 40 g of saturated sodium bicarbonate, and twice with 40 g of pure water in sequence. The resulting organic layer was then concentrated under reduced pressure at 40°C to obtain monomer (D) in 77.3% yield. The purity measured by GPC was 90.6%. [ka]

[0109] <Synthesis Example 5> Synthesis of monomer (E) (TM-DHPPE) In a four-necked flask equipped with a stirring bar and condenser, 10.00 g (34.4 mmol) of 1,1-bis(4-hydroxyphenyl)-1-phenylethane (Tokyo Chemical Industries, Ltd.), 4.15 g (103 mmol) of sodium hydroxide (Kanto Chemical Co., Ltd.), and 40.00 g of pure water were added and heated to 40°C while stirring. At 40°C, 11.32 g (140 mmol) of 37% formaldehyde aqueous solution (Kanto Chemical Co., Ltd.) was added dropwise, and the mixture was stirred at the same temperature for 20 hours. 160 g of 4-methyl-2-pentanone (Kanto Chemical Co., Ltd.) was added to the reaction mixture and cooled to below 10°C, after which 25 g of 20% hydrochloric acid was added dropwise. After separating the organic layer, it was washed twice with 40 g of pure water, once with 40 g of saturated sodium bicarbonate, and twice with 40 g of pure water in sequence. The resulting organic layer was then concentrated under reduced pressure at 40°C to obtain monomer (E) in 73.8% yield. The purity measured by GPC was 91.9%. [ka]

[0110] <Synthesis Example 6> Synthesis of polymer (01) (poly-TM-BP) In a four-necked flask equipped with a stirring bar and a condenser, a solution was prepared by dissolving 8.00 g (26.12 mmol) of monomer (A) obtained in Synthesis Example 1, 40.79 g of propylene glycol monomethyl ether, and 0.013 g (0.13 mmol) of methanesulfonic acid (Tokyo Chemical Industries, Ltd.) in 4.53 g of propylene glycol monomethyl ether. The mixture was heated to 85°C under nitrogen and stirred at 85°C for 64 hours. After cooling to below 30°C, the resulting reaction mixture was added dropwise to 450 mL of methanol (Kanto Chemical Co., Ltd., special grade) / water (6 / 4) mixed solvent to precipitate the polymer. The precipitate was filtered off, and the filtrate was washed in three parts with 110 mL of methanol / water (6 / 4), and the polymer was vacuum dried to obtain the polymer. The weight-average molecular weight (Mw) measured on a standard polystyrene basis by GPC was 2,267, and the yield was 69.8%. This polymer has a repeating unit structure represented by the following formula (01). The obtained polymer was diluted to a solid content concentration of 30% with propylene glycol monomethyl ether acetate, and equal amounts of cation exchange resin and anion exchange resin were added to the solid content, respectively. The mixture was stirred for 4 hours. The ion exchange resin was filtered to obtain polymer (01) solution. [ka]

[0111] <Synthesis Example 7> Synthesis of polymer (02) (poly-HM-THPE) In a four-necked flask equipped with a stirring bar and condenser, 25.00 g (51.39 mmol) of monomer (B) obtained in Synthesis Example 2, 95.00 g of propylene glycol monomethyl ether, and 0.049 g (0.51 mmol) of methanesulfonic acid (Tokyo Chemical Industries, Ltd.) were dissolved in 5.00 g of propylene glycol monomethyl ether to form a solution. The mixture was heated to 85°C under nitrogen and stirred at 85°C for 23 hours. After cooling to below 30°C, 1,100 mL of the resulting reaction mixture was added dropwise to a methanol (Kanto Chemical Co., Ltd., special grade) / water (5 / 5) mixed solvent to precipitate the polymer. The precipitate was filtered off, and the filtrate was washed in three parts with 110 mL of methanol / water (5 / 5), and the polymer was obtained by vacuum drying. The weight-average molecular weight (Mw) measured on a standard polystyrene basis by GPC was 4,590, and the yield was 90.5%. This polymer has a repeating unit structure represented by the following formula (02). The obtained polymer was diluted to a solid content concentration of 30% with propylene glycol monomethyl ether acetate, and the same amount of cation exchange resin and anion exchange resin as the amount of solid content were added, respectively, and the mixture was stirred for 4 hours. The ion exchange resin was filtered to obtain a polymer (02) solution. [ka]

[0112] <Synthesis Example 8> Synthesis of polymer (03) (poly-HM-THPEI) In a four-necked flask equipped with a stirring bar and a condenser, a solution was prepared by dissolving 6.00 g (9.92 mmol) of monomer (C) obtained in Synthesis Example 3, 40.79 g of propylene glycol monomethyl ether, and 0.010 g (0.10 mmol) of methanesulfonic acid (Tokyo Chemical Industries, Ltd.) in 3.4 g of propylene glycol monomethyl ether. This solution was then placed in the flask and heated to 85°C under nitrogen, where it was stirred for 49.5 hours. After cooling to below 30°C, the resulting reaction mixture was added dropwise to 360 mL of methanol (Kanto Chemical Co., Ltd., special grade) / water (5 / 5) mixed solvent to precipitate the polymer. The precipitate was filtered off, and the filtrate was washed in three separate washes with 90 mL of methanol / water (5 / 5), followed by vacuum drying to obtain the polymer. The weight-average molecular weight (Mw), measured on a standard polystyrene basis by GPC, was 4,595, and the yield was 72.3%. This polymer has a repeating unit structure represented by the following formula (03). The obtained polymer was diluted to a solid content concentration of 30% with propylene glycol monomethyl ether acetate, and equal amounts of cation exchange resin and anion exchange resin were added to the solid content, respectively. The mixture was stirred for 4 hours. The ion exchange resin was filtered to obtain polymer (03) solution. [ka]

[0113] <Synthesis Example 9> Synthesis of polymer (04) (poly-HM-THPM) In a four-necked flask equipped with a stirring bar and a condenser, a solution was prepared by dissolving 10.00 g (21.16 mmol) of monomer (D) obtained in Synthesis Example 4, 36.00 g of propylene glycol monomethyl ether, and 0.012 g (0.11 mmol) of methanesulfonic acid (Tokyo Chemical Industries, Ltd.) in 4.00 g of propylene glycol monomethyl ether. The mixture was heated to 85°C under nitrogen and stirred at 85°C for 23 hours. After cooling to below 30°C, the resulting reaction mixture was added dropwise to 450 mL of methanol (Kanto Chemical Co., Ltd., special grade) / water (3 / 7) mixed solvent to precipitate the polymer. The precipitate was filtered off, and the filtrate was washed in three parts with 120 mL of methanol / water (3 / 7), and the polymer was vacuum dried to obtain the polymer. The weight-average molecular weight (Mw) measured on a standard polystyrene basis by GPC was 2,184, and the yield was 64.8%. This polymer has a repeating unit structure represented by the following formula (04). The obtained polymer was diluted to a solid content concentration of 30% with propylene glycol monomethyl ether acetate, and equal amounts of cation exchange resin and anion exchange resin were added to the solid content, respectively. The mixture was stirred for 4 hours. The ion exchange resin was filtered to obtain polymer (04) solution. [ka]

[0114] <Synthesis Example 10> Synthesis of polymer (05) (poly-TM-DHPPE) In a four-necked flask equipped with a stirring bar and a condenser, a solution was prepared by dissolving 9.00 g (21.93 mmol) of monomer (E) obtained in Synthesis Example 5, 32.00 g of propylene glycol monomethyl ether, and 0.011 g (0.11 mmol) of methanesulfonic acid (Tokyo Chemical Industries, Ltd.) in 3.60 g of propylene glycol monomethyl ether. The mixture was heated to 85°C under nitrogen and stirred for 23 hours. After cooling to below 30°C, 90 mL of ethyl acetate (Kanto Chemical Co., Ltd., special grade) and 90 mL of water were added to the resulting reaction mixture and separated. The organic layer was then washed twice with 40 mL of water. The resulting organic layer was concentrated under reduced pressure at 40°C to obtain the polymer. The weight-average molecular weight (Mw), measured on a standard polystyrene basis by GPC, was 789. This polymer has a repeating unit structure represented by the following formula (05). The obtained polymer was diluted to a solid content concentration of 30% with propylene glycol monomethyl ether acetate, and equal amounts of cation exchange resin and anion exchange resin were added to the solid content, respectively. The mixture was stirred for 4 hours. The ion exchange resin was filtered to obtain polymer (05) solution. [ka]

[0115] <Synthesis Example 11> Synthesis of polymer (06) (poly-TM-BIP-A) In a four-necked flask equipped with a stirring bar and condenser, a solution was prepared by dissolving 15.00 g (43.05 mmol) of 2,2-bis(4-hydroxy-3,5-dihydroxymethylphenyl)propane (Asahi Organic Chemicals), 76.48 g of propylene glycol monomethyl ether, and 0.021 g (0.22 mmol) of methanesulfonic acid (Tokyo Chemical Industries, Ltd.) in 8.5 g of propylene glycol monomethyl ether. This solution was then placed in the flask and heated to 85°C under nitrogen, where it was stirred for 16 hours. After cooling to below 30°C, 220 mL of the resulting reaction mixture was separated from ethyl acetate (Kanto Chemical Co., Ltd., special grade) and 100 mL of water. The organic layer was then washed twice with 100 mL of water. The resulting organic layer was concentrated under reduced pressure at 40°C to obtain the polymer. The weight-average molecular weight (Mw), measured on a standard polystyrene basis by GPC, was 1,194. This polymer has a repeating unit structure represented by the following formula (06). The obtained polymer was diluted to a solid content concentration of 30% with propylene glycol monomethyl ether acetate, and equal amounts of cation exchange resin and anion exchange resin were added to the solid content, respectively. The mixture was stirred for 4 hours. The ion exchange resin was filtered to obtain polymer (06) solution. [ka]

[0116] <Synthesis Example 12> Synthesis of polymer (07) (poly-TM-BIP-BZ) In a four-necked flask equipped with a stirring bar and condenser, a solution was prepared by dissolving 10.00 g (25.22 mmol) of TM-BIP-BZ (Asahi Organic Chemicals), 36.00 g of propylene glycol monomethyl ether, and 0.024 g (0.25 mmol) of methanesulfonic acid (Tokyo Chemical Industries, Ltd.) in 4.00 g of propylene glycol monomethyl ether. This solution was then placed in the flask and heated to 85°C under nitrogen, where it was stirred for 19 hours. After cooling to below 30°C, the resulting reaction mixture was added dropwise to 450 mL of methanol (Kanto Chemical Co., Ltd., special grade) / water (5 / 5) mixed solvent to precipitate the polymer. The precipitate was filtered off, and the filtrate was washed in three separate washes with 120 mL of methanol / water (5 / 5), followed by vacuum drying to obtain the polymer. The weight-average molecular weight (Mw) measured on a standard polystyrene basis by GPC was 1,432, and the yield was 87.9%. This polymer has a repeating unit structure represented by the following formula (07). The obtained polymer was diluted to a solid content concentration of 30% with propylene glycol monomethyl ether acetate, and the same amount of cation exchange resin and anion exchange resin as the amount of solid content were added, respectively, and the mixture was stirred for 4 hours. The ion exchange resin was filtered to obtain a polymer (07) solution. [ka]

[0117] <Synthesis Example 13> Synthesis of polymer (08) (TM-BP / 4,4'BP) In a four-necked flask equipped with a stirring bar and a condenser, a solution was prepared by dissolving 7.00 g (22.85 mmol) of monomer (A) obtained in Synthesis Example 1, 57.39 g of propylene glycol monomethyl ether, and 0.033 g (0.33 mmol) of methanesulfonic acid (Tokyo Chemical Industries, Ltd.) in 6.38 g of propylene glycol monomethyl ether. The solution was then heated to 85°C under nitrogen and stirred at 85°C for 46 hours. After cooling to below 30°C, the resulting reaction mixture was added dropwise to 680 mL of methanol (Kanto Chemical Co., Ltd., special grade) to precipitate the polymer. The precipitate was filtered off, and the filtrate was washed in three batches with 170 mL of methanol. The polymer was then vacuum dried to obtain the polymer. The weight-average molecular weight (Mw), measured on a standard polystyrene basis by GPC, was 1,143, and the yield was 67.9%. This polymer has a repeating unit structure represented by the following formula (08). The obtained polymer was diluted to a solid content concentration of 30% with propylene glycol monomethyl ether acetate, and equal amounts of cation exchange resin and anion exchange resin were added to the solid content, respectively. The mixture was stirred for 4 hours. The ion exchange resin was filtered to obtain polymer (08) solution. [ka]

[0118] <Synthesis Example 14> Synthesis of Polymer (09) (TM-BP / THPE) In a four-necked flask equipped with a stirring bar and a condenser, a solution was prepared by dissolving 4.99 g (16.32 mmol) of monomer (A) obtained in Synthesis Example 1, 5.00 g (16.32 mmol) of 1,1,1-tris(4-hydroxyphenyl)ethane (Tokyo Chemical Industries, Ltd.), 50.98 g of propylene glycol monomethyl ether, and 0.016 g (0.16 mmol) of methanesulfonic acid (Tokyo Chemical Industries, Ltd.) in 5.67 g of propylene glycol monomethyl ether. The mixture was heated to 85°C under nitrogen and stirred at 85°C for 47 hours. After cooling to below 30°C, the resulting reaction mixture was added dropwise to 590 mL of methanol (Kanto Chemical Co., Ltd., special grade) / water (3 / 7) mixed solvent to precipitate the polymer. The precipitate was filtered off, and the filtrate was washed in three parts with 150 mL of methanol / water (3 / 7), and then vacuum dried to obtain the polymer. The weight-average molecular weight (Mw) measured on a standard polystyrene basis by GPC was 1,381, and the yield was 69.9%. This polymer has a repeating unit structure represented by the following formula (09). The obtained polymer was diluted to a solid content concentration of 30% with propylene glycol monomethyl ether acetate, and equal amounts of cation exchange resin and anion exchange resin were added, respectively, and the mixture was stirred for 4 hours. The ion exchange resin was filtered to obtain a polymer (09) solution. [ka]

[0119] <Synthesis Example 15> Synthesis of Polymer (10) (TM-BP / Cz) In a four-necked flask equipped with a stirring bar and a condenser, a solution was prepared by dissolving 7.00 g (22.85 mmol) of monomer (A) obtained in Synthesis Example 1, 3.82 g (22.85 mmol) of carbazole (Tokyo Chemical Industries, Ltd.), 55.17 g of propylene glycol monomethyl ether, and 0.022 g (0.23 mmol) of methanesulfonic acid (Tokyo Chemical Industries, Ltd.) in 6.13 g of propylene glycol monomethyl ether. The solution was then heated to 85°C under nitrogen and stirred at 85°C for 4 hours. After cooling to below 30°C, the resulting reaction mixture was added dropwise to 630 mL of methanol (Kanto Chemical Co., Ltd., special grade) to precipitate the polymer. The precipitate was filtered off, and the filtrate was washed in three batches with 160 mL of methanol. The polymer was then vacuum dried to obtain the polymer. The weight-average molecular weight (Mw), measured on a standard polystyrene basis by GPC, was 14,916, and the yield was 71.5%. This polymer has a repeating unit structure represented by the following formula (10). The obtained polymer was diluted to a solid content concentration of 30% with propylene glycol monomethyl ether acetate, and the same amount of cation exchange resin and anion exchange resin as the amount of solid content were added, respectively, and the mixture was stirred for 4 hours. The ion exchange resin was filtered to obtain a polymer (10) solution. [ka]

[0120] <Synthesis Example 16> Synthesis of Polymer (11) (TM-BP / Pyrene) In a four-necked flask equipped with a stirring bar and a condenser, a solution was prepared by dissolving 3.00 g (19.79 mmol) of monomer (A) obtained in Synthesis Example 1, 1.99 g (9.79 mmol) of pyrene (Tokyo Chemical Industries, Ltd.), 17.92 g of propylene glycol monomethyl ether, and 0.010 g (0.01 mmol) of methanesulfonic acid (Tokyo Chemical Industries, Ltd.) in 1.99 g of propylene glycol monomethyl ether. This solution was then placed in the flask and heated to 85°C under nitrogen, where it was stirred for 27 hours. After cooling to below 30°C, the resulting reaction mixture was added dropwise to 270 mL of methanol (Kanto Chemical, special grade) to precipitate the polymer. The precipitate was filtered off, and the filtrate was washed in three batches with 70 mL of methanol. The polymer was then vacuum-dried. The weight-average molecular weight (Mw), measured on a standard polystyrene basis by GPC, was 4,134, and the yield was 64.5%. This polymer has a repeating unit structure represented by the following formula (11). The obtained polymer was diluted to a solid content concentration of 30% with propylene glycol monomethyl ether acetate, and the same amount of cation exchange resin and anion exchange resin as the amount of solid content were added, respectively, and the mixture was stirred for 4 hours. The ion exchange resin was filtered to obtain the polymer solution. [ka]

[0121] <Synthesis Example 17> Synthesis of Polymer (12) (TM-BP / 1-Hydroxypyrene) In a four-necked flask equipped with a stirring bar and condenser, 25.00 g (81.62 mmol) of monomer (A) obtained in Synthesis Example 1, 17.81 g (81.62 mmol) of 1-hydroxypyrene (Tokyo Chemical Industries, Ltd.), 171.18 g of propylene glycol monomethyl ether, and 0.0784 g (0.82 mmol) of methanesulfonic acid (Tokyo Chemical Industries, Ltd.) were added. The mixture was heated to 85°C under nitrogen and stirred at 85°C for 21 hours. After cooling to below 30°C, the resulting reaction mixture was added dropwise to 2000 mL of methanol (Kanto Chemical, special grade) to precipitate the polymer. The precipitate was filtered off, and the filtrate was washed in three parts with 5000 mL of methanol. The polymer was then vacuum dried to obtain the polymer. The weight-average molecular weight (Mw) measured on a standard polystyrene basis by GPC was 8,645, and the yield was 55.8%. This polymer has a repeating unit structure represented by the following formula (12). The obtained polymer was diluted to a solid content concentration of 30% with propylene glycol monomethyl ether acetate, and the same amount of cation exchange resin and anion exchange resin as the amount of solid content were added, respectively, and the mixture was stirred for 4 hours. The ion exchange resin was filtered to obtain the polymer solution. [ka]

[0122] <Comparative Synthesis Example 1> Synthesis of Polymer (13) (Cz / BA) In a flask equipped with a stirring bar and condenser, 30.00 g (179.4 mmol) of carbazole (manufactured by Tokyo Chemical Industry Co., Ltd.), 19.04 g (179.42 mmol) of benzaldehyde (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.35 g (3.59 mmol) of methanesulfonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), and 146.77 g of propylene glycol monomethyl ether acetate were added. The mixture was then heated under nitrogen and refluxed, and stirred for 8 hours. After cooling to below 30°C, the resulting reaction mixture was added dropwise to 1800 mL of methanol (Kanto Chemical Co., Ltd., special grade) to precipitate the polymer. The precipitate was filtered, and the filtrate was washed in three batches with 450 mL of methanol. The polymer was then vacuum-dried. The weight-average molecular weight (Mw), measured on a standard polystyrene basis by GPC, was 5,795, and the yield was 50.9%. This polymer has a repeating unit structure represented by the following formula (13). The obtained polymer was diluted to a solid content concentration of 30% with propylene glycol monomethyl ether acetate, and the same amount of cation exchange resin and anion exchange resin as the amount of solid content were added, respectively, and the mixture was stirred for 4 hours. The ion exchange resin was filtered to obtain a polymer (13) solution. [ka]

[0123] <Comparative Synthesis Example 2> (Synthesis of Polymer (14)) (BT-NA-PCA) Under nitrogen, 25.00 g of 2,2'-biphenol (manufactured by Tokyo Chemical Industry Co., Ltd.), 10.5 g of 1-naphthaldehyde (manufactured by Tokyo Chemical Industry Co., Ltd.), 15.5 g of 1-pyrenecarboxaldehyde (manufactured by Aldrich), and 3.87 g of methanesulfonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) were placed in a 100 mL two-necked flask. The mixture was then heated to 120 °C, allowed to cool to room temperature for approximately 24 hours, precipitated with methanol, and the resulting precipitate was dried. The weight-average molecular weight Mw, measured in polystyrene equivalent by GPC, was 2,000. The obtained polymer was diluted to a solid content concentration of 30% with propylene glycol monomethyl ether acetate, and the same amount of cation exchange resin and anion exchange resin as the solid content were added, respectively, and the mixture was stirred for 4 hours. The ion exchange resin was filtered to obtain polymer (14) solution.

[0124] <Example 1> 3.47 g of polymer (01) obtained in Synthesis Example 6 was mixed with 0.09 g of a propylene glycol monomethyl ether acetate solution containing 1% surfactant (DIC Corporation, product name: Megafac [product name] R-40, fluorine-based surfactant), 2.75 g of propylene glycol monomethyl ether, and 3.70 g of propylene glycol monomethyl ether acetate. 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.

[0125] <Example 2> 3.67 g of polymer (02) obtained in Synthesis Example 7 was mixed with 0.09 g of a propylene glycol monomethyl ether acetate solution containing 1% surfactant (DIC Corporation, product name: Megafac [product name] R-40, fluorine-based surfactant), 2.73 g of propylene glycol monomethyl ether, and 3.51 g of propylene glycol monomethyl ether acetate. 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] <Example 3> 3.55 g of polymer (03) obtained in Synthesis Example 8 was mixed with 0.09 g of a propylene glycol monomethyl ether acetate solution containing 1% surfactant (DIC Corporation, product name: Megafac [product name] R-40, fluorine-based surfactant), 2.75 g of propylene glycol monomethyl ether, and 3.62 g of propylene glycol monomethyl ether acetate. 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.

[0127] <Example 4> 3.86 g of polymer (04) obtained in Synthesis Example 9 was mixed with 0.09 g of a propylene glycol monomethyl ether acetate solution containing 1% surfactant (DIC Corporation, product name: Megafac [product name] R-40, fluorine-based surfactant), 2.75 g of propylene glycol monomethyl ether, and 3.31 g of propylene glycol monomethyl ether acetate. 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.

[0128] <Example 5> 4.83 g of polymer (05) obtained in Synthesis Example 10 was mixed with 0.12 g of a propylene glycol monomethyl ether acetate solution containing 1% surfactant (DIC Corporation, product name: Megafac [product name] R-40, fluorine-based surfactant), 0.24 g of a propylene glycol monomethyl ether solution containing 5% pyridinium p-toluenesulfonate, 1.81 g of propylene glycol monomethyl ether, and 1.00 g of propylene glycol monomethyl ether acetate. 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.

[0129] <Example 6> 4.37 g of polymer (06) obtained in Synthesis Example 11 was mixed with 0.15 g of a propylene glycol monomethyl ether acetate solution containing 1% surfactant (DIC Corporation, product name: Megafac [product name] R-40, fluorine-based surfactant), 0.30 g of a propylene glycol monomethyl ether solution containing 5% pyridinium p-toluenesulfonate, 2.27 g of propylene glycol monomethyl ether, and 2.93 g of propylene glycol monomethyl ether acetate. 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.

[0130] <Example 7> 4.28 g of polymer (07) obtained in Synthesis Example 12 was mixed with 0.12 g of a propylene glycol monomethyl ether acetate solution containing 1% surfactant (DIC Corporation, product name: Megafac [product name] R-40, fluorine-based surfactant), 0.24 g of a propylene glycol monomethyl ether solution containing 5% pyridinium p-toluenesulfonate, 2.41 g of propylene glycol monomethyl ether, and 2.97 g of propylene glycol monomethyl ether acetate. 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.

[0131] <Example 8> 4.02 g of polymer (08) obtained in Synthesis Example 13 was mixed with 0.10 g of a propylene glycol monomethyl ether acetate solution containing 1% surfactant (DIC Corporation, product name: Megafac [product name] R-40, fluorine-based surfactant), 2.70 g of propylene glycol monomethyl ether, and 3.18 g of propylene glycol monomethyl ether acetate. 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.

[0132] <Example 9> 4.94 g of polymer (09) obtained in Synthesis Example 14 was mixed with 0.12 g of a propylene glycol monomethyl ether acetate solution containing 1% surfactant (DIC Corporation, product name: Megafac [product name] R-40, fluorine-based surfactant), 2.64 g of propylene glycol monomethyl ether, and 2.30 g of propylene glycol monomethyl ether acetate. 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.

[0133] <Example 10> 4.00 g of polymer (10) obtained in Synthesis Example 15 was mixed with 0.10 g of a propylene glycol monomethyl ether acetate solution containing 1% surfactant (DIC Corporation, product name: Megafac [product name] R-40, fluorine-based surfactant), 2.70 g of propylene glycol monomethyl ether, and 3.20 g of propylene glycol monomethyl ether acetate. 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.

[0134] <Example 11> 4.92 g of polymer (11) obtained in Synthesis Example 16 was mixed with 0.12 g of a propylene glycol monomethyl ether acetate solution containing 1% surfactant (DIC Corporation, product name: Megafac [product name] R-40, fluorine-based surfactant), 0.24 g of a propylene glycol monomethyl ether solution containing 5% pyridinium p-toluenesulfonate, 3.01 g of propylene glycol monomethyl ether, 0.47 g of propylene glycol monomethyl ether acetate, and 3.24 g of cyclohexanone. 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.

[0135] <Example 12> 4.50 g of polymer (12) obtained in Synthesis Example 17 was mixed with 0.13 g of a propylene glycol monomethyl ether acetate solution containing 1% surfactant (DIC Corporation, product name: Megafac [product name] R-40, fluorine-based surfactant), 6.38 g of propylene glycol monomethyl ether, and 3.99 g of propylene glycol monomethyl ether acetate. 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.

[0136] <Comparative Example 1> 43.91 g of polymer (13) obtained in Comparative Synthesis Example 1 was mixed with 1.23 g of a propylene glycol monomethyl ether acetate solution containing 1% surfactant (DIC Corporation, product name: Megafac [product name] R-40, fluorine-based surfactant), 1.23 g of TMOM-BP (Honshu Chemical Industry Co., Ltd., crosslinking agent), 12.25 g of a propylene glycol monomethyl ether solution containing 1% pyridinium p-toluenesulfonate, 28.82 g of propylene glycol monomethyl ether, and 62.68 g of propylene glycol monomethyl ether acetate. 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.

[0137] <Comparative Example 2> To 3.02 g of the polymer (14) solution obtained in Comparative Synthesis Example 2 (solid content 29.9% by mass), 0.10 g of propylene glycol monomethyl ether acetate containing 1% by mass surfactant (DIC Corporation, Megafac R-40), 3.68 g of propylene glycol monomethyl ether acetate, and 2.68 g of propylene glycol monomethyl ether 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.

[0138] <Film formation test in air>

[0139] (Elution test into photoresist solvent) The resist underlayer-forming compositions prepared in Examples 1 through 12 and Comparative Example 1 were each coated onto a silicon wafer using a spin coater. A resist underlayer (thickness 60 nm) was formed by baking at 300°C for 90 seconds on a hot plate. These resist underlayers were immersed in a PGME / PGMEA mixed solvent (mass mixing ratio 70 / 30), which is used as a solvent for photoresist solutions. If the film was insoluble in this solvent, it was marked with "○", and the results are shown in Table 1.

[0140] [Table 1]

[0141] (Optical constant measurement) The solutions of the resist underlayer film-forming compositions prepared in Examples 1 through 12 and Comparative Example 1 were each coated onto a silicon wafer using a spin coater. 400 The resist underlayer film (thickness 50 nm) was formed by firing at 90°C for 90 seconds. The refractive index (n value) and optical absorption coefficient (k value, also called the attenuation coefficient) of these resist underlayer films were measured at a wavelength of 193 nm using a spectroscopic ellipsometer. The results are shown in Table 2.

[0142] [Table 2]

[0143] Using the resist underlayer-forming compositions prepared in Examples 1 through 12 and Comparative Example 1, resist underlayer films were formed on silicon wafers in the same manner as described above. The dry etching rates of these resist underlayer films were measured using RIE-10NR (manufactured by Samco Co., Ltd.) under conditions where O2 / N2 was used as the etching gas. The dry etching rates of each resist underlayer film were calculated with the dry etching rate of Comparative Example 1 set to 1.00. The results are shown in Table 3 as "relative dry etching rates".

[0144] [Table 3]

[0145] As described above, the etching resistance of the resist underlayer film can be freely controlled by changing the type of polymer.

[0146] (Measurement of sublimation volume of the resist underlayer) 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 Examples 1 to 12 and Comparative Example 2 were each applied to a silicon wafer, and the amount of sublimation was measured when the film thickness reached 50 nm after firing at 400°C for 90 seconds. The results are shown in Table 4. The values ​​listed in the table are (amount of sublimation in Examples 1 to 12) / (amount of sublimation in Comparative Example 2).

[0147] [Table 4]

[0148] (Hardness test) The resist underlayer-forming compositions prepared in Examples 1 through 12 and Comparative Example 1 were applied to silicon wafers and then baked at 400°C for 90 seconds to form a 200 nm resist underlayer film. The elastic modulus and hardness of this cured resist film were evaluated using a Bruker TI-980 triboidentor. The results are shown in Table 5.

[0149] [Table 5]

[0150] As described above, by using a material with a cross-linked structure in the polymer, the hardness of the resist underlayer can be significantly increased.

[0151] <Film deposition test under a nitrogen atmosphere> (Measurement of membrane contraction rate) The resist underlayer film-forming compositions prepared in Example 4, Comparative Example 1, and Comparative Example 2 were each coated onto a silicon wafer using a spinner. Then, they were baked on a hot plate in air at 350°C for 1 minute to form a resist underlayer film (film thickness approximately 0.25 μm), and the film thickness A was measured. This substrate was further baked in a nitrogen atmosphere at 450°C for 90 seconds or at 600°C for 5 minutes, and the film thickness B was measured. The film shrinkage rate was defined as the value obtained by (film thickness B / film thickness A) × 100.

[0152] When comparing films fired under the same firing conditions, the film shrinkage rate of the underlayer film obtained from the resist underlayer film-forming composition prepared in Example 4 was lower than that of the underlayer film obtained from the resist underlayer film-forming composition prepared in Comparative Example 1 or Comparative Example 2. This has the advantage of less sublimation and less equipment contamination, and a lower shrinkage rate is also advantageous in terms of in-plane uniformity of the film.

[0153] [Table 6]

[0154] (Hardness test) Using the resist underlayer-forming compositions prepared in Example 4, Comparative Example 1, and Comparative Example 2, a resist underlayer film was formed on a silicon wafer by the same method as described above. A nanoindentation test was performed using a nanoindenter manufactured by Toyo Technica Co., Ltd., and the hardness of the resist underlayer film was measured. When comparing films fired under the same firing conditions, Example 4 showed higher hardness than Comparative Examples 1 and 2, even when fired under a nitrogen atmosphere, indicating its advantage for processing by etching.

[0155] [Table 7]

[0156] (Measurement of dry etching rate) The resist underlayer-forming compositions prepared in Example 4, Comparative Example 1, and Comparative Example 2 were each coated onto silicon wafers using a spinner. Subsequently, they were baked on a hot plate at 350°C for 1 minute, followed by baking under a nitrogen atmosphere at 450°C for 90 seconds or 600°C for 5 minutes to form a resist underlayer (thickness 0.2 μm). The dry etching rates of these resist underlayers were then measured using a Samco RIE system under conditions where CF4 was used as the dry etching gas.

[0157] The dry etching rate (ER) of the film obtained by baking Comparative Example 2 at 400°C for 90 seconds was set to 1.00, and the dry etching rate was calculated. The results are shown in Table 8 below as "relative dry etching rate". The resist underlayer film formed in Example 4 by baking at 600°C for 5 minutes exhibits characteristics such as low film shrinkage rate and high hardness, while also showing a low ER, indicating high etching resistance and being advantageous for processing by etching.

[0158] [Table 8] [Industrial applicability]

[0159] The present invention provides a novel resist underlayer forming composition that meets the requirements for reducing the amount of sublimation contaminating the equipment, improving etching resistance in substrate processing, increasing the bending resistance of the resulting resist underlayer film, particularly increasing its hardness, while maintaining other desirable properties.

Claims

1. Hydroxymethyl group and ROCH ２ A resist underlayer film forming composition comprising a polymer (X) containing a group (where R is a monovalent organic group or a mixture thereof) and a plurality of identical or different structural units including an aromatic ring, heterocycle, or fused ring having at least one phenolic hydroxyl group or a substituted or unsubstituted amino group, and a linking group connecting the plurality of structural units, and a solvent.

2. R may be substituted with a phenyl group, a naphthyl group, or anthracenyl group, and may be interrupted by an oxygen atom or a carbonyl group, a saturated or unsaturated linear or branched C ２ -C ２０ Aliphatic hydrocarbon group, C ３ -C ２０ The resist underlayer film forming composition according to claim 1, comprising an alicyclic hydrocarbon group, a hydrogen atom, or a mixture thereof.

3. The resist underlayer film forming composition according to claim 1, wherein the linking group comprises an alkylene group or an ether group.

4. The resist underlayer film forming composition according to any one of claims 1 to 3, further comprising a polymer (X) and a film material (Y) capable of crosslinking.

5. The resist underlayer film forming composition according to any one of claims 1 to 3, further comprising a crosslinking agent.

6. The resist underlayer film forming composition according to any one of claims 1 to 3, further comprising an acid and / or an acid generator.

7. The resist underlayer film forming composition according to any one of claims 1 to 3, further comprising a surfactant.

8. The resist underlayer film forming composition according to any one of claims 1 to 3, wherein the solvent comprises a solvent having a boiling point of 160°C or higher.

9. 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 3.

10. A step of forming a resist underlayer film on a semiconductor substrate using the composition described in any one of Claims 1 to 3, 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].

11. A step of forming a resist underlayer film on a semiconductor substrate using the composition described in any one of Claims 1 to 3, 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].

Images