Polymer manufacturing method

Abstract

The present invention provides a method for producing a polymer for a resist underlayer film-forming composition, which allows easy control of the molecular weight and enables conversion of a substituent group within the molecule to be carried out simultaneously with the polymerization reaction. SOLUTION: A method for producing a polymer (X) comprising a plurality of identical or different structural units each having a methoxymethyl group and a ROCH2- group other than a methoxymethyl group (R is a monovalent organic group, a hydrogen atom, or a mixture thereof), and a linking group linking the plurality of structural units, comprising: (A) a step of dissolving a compound (L) having a methoxymethyl group and optionally having a phenolic hydroxyl group and a compound (N) having a functional group that will become a linking group in a compound (M) that reacts with the methoxymethyl group to give a ROCH2- group (where R is a monovalent organic group, a hydrogen atom, or a mixture thereof) other than a methoxymethyl group, to obtain a mixture; and (B) adding an acid catalyst to the mixture to carry out a polymerization reaction; A method comprising:

Description

[Technical Field]

[0001] The present invention relates to a method for producing a polymer, and more particularly to a method for producing a polymer for a resist underlayer film-forming composition. [Background technology]

[0002] In the manufacture of semiconductor devices, microfabrication is performed using a lithography process. In this lithography process, when a resist layer on a substrate is exposed to an ultraviolet laser such as a KrF excimer laser or an ArF excimer laser, a known problem occurs in that the resist pattern does not have the desired shape due to the effects of standing waves generated by the ultraviolet laser's reflection on the substrate surface. To solve this problem, a resist underlayer film (anti-reflective film) is provided between the substrate and the resist layer.

[0003] Compositions for forming such resist underlayer films are required to have good coating properties for uneven substrates where the resist pattern formed on the substrate to be processed has differences in height or density, and to have the ability to minimize film thickness differences after filling and form flat films. Furthermore, with the trend toward finer resist patterns, polymers contained in resist underlayer film-forming compositions are required to have lower molecular weights (approximately 5,000).

[0004] As such a resist underlayer film-forming composition, for example, Patent Document 1 discloses a composition containing a compound represented by the following formula (1):

[0005] [ka]

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

[0007] [Patent Document 1] WO2014 / 171326A1 Summary of the Invention [Problem to be solved by the invention]

[0008] It is desirable that the polymer contained in the resist underlayer film-forming composition be able to appropriately convert functional groups such as alkoxyl groups within the molecule to achieve the required properties. However, when converting the polymer described in Patent Document 1, it is necessary to first synthesize a polymer represented by formula (1) and then convert its substituents and functional groups. However, there is a problem in that the reaction rate of the polymer is fast in the synthesis of the polymer represented by formula (1), making it difficult to obtain a polymer with the desired molecular weight. Generally, the molecular weight of a polymer significantly affects the physical properties of the resulting product, so controlling the molecular weight, i.e., controlling the reaction rate in a polymerization reaction, is a common challenge in polymer production. Furthermore, it is clear that it would be extremely beneficial industrially if conversion of substituents and functional groups within a molecule and polymerization reactions could be carried out simultaneously and easily. [Means for solving the problem]

[0009] The present invention is intended to solve the above problems. That is, the present invention includes the following. [1] A method for producing a polymer (X) in which a plurality of identical or different structural units each having a methoxymethyl group and a ROCH2- group other than a methoxymethyl group (R is a monovalent organic group, a hydrogen atom, or a mixture thereof) are linked together, comprising the steps of: (A) a step of dissolving a compound (L) having a methoxymethyl group and optionally having a phenolic hydroxyl group in a compound (M) that reacts with the methoxymethyl group to give a ROCH2- group (where R is a monovalent organic group, a hydrogen atom, or a mixture thereof) other than a methoxymethyl group, to obtain a mixture; and (B) adding an acid catalyst to the mixture to carry out a polymerization reaction; A method comprising: [2] Polymer (X) is a polymer comprising a plurality of identical or different structural units each having a methoxymethyl group and a ROCH2- group other than a methoxymethyl group (R is a monovalent organic group, a hydrogen atom, or a mixture thereof), and a linking group connecting the plurality of structural units; Step (A) is a step of dissolving a compound (L) having a methoxymethyl group and optionally having a phenolic hydroxyl group and a compound (N) having a functional group that will serve as a linking group in a compound (M) that reacts with the methoxymethyl group to give a ROCH- group (R is a monovalent organic group, a hydrogen atom, or a mixture thereof) other than a methoxymethyl group, to obtain a mixture; [1] The method described in [1]. [3] The method according to [2], wherein the linking group comprises an alkylene group, an ether group, or a carbonyl group. [4] (C) The method according to any one of [1] to [3], further comprising a step of terminating the polymerization reaction under the condition that the weight-average molecular weight of a sample taken from the mixture during the polymerization reaction in step (B) exceeds 1,000. [5] R is a saturated or unsaturated, linear or branched C2-C alkyl group optionally substituted with a phenyl group, a naphthyl group, or an anthracenyl group, optionally interrupted by an oxygen atom or a carbonyl group. 20 Aliphatic hydrocarbon groups, C3-C 20 The method according to any one of [1] to [4], wherein the alkyl group is an alicyclic hydrocarbon group, an aromatic hydrocarbon group, a hydrogen atom, or a mixture thereof. [6] The method according to any one of [1] to [5], wherein the compound (M) is a glycol ether solvent and / or an alcohol solvent. [7] The method according to [6], wherein the compound (M) is a linear alkyl alcohol having 4 to 10 carbon atoms. [8] The compound (M) ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol mono-n-butyl ether, ethylene glycol mono-iso-butyl ether, ethylene glycol mono-tert-butyl ether, ethylene glycol phenyl ether, propylene glycol monomethyl ether, 3-methoxy-3-methyl-1-butanol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-butyl ether, diethylene glycol mono-iso-butyl ether, dipropylene glycol monomethyl ether, triethylene glycol mono-n-butyl ether, and Tetraethylene glycol mono-n-butyl ether The method according to [6], wherein the glycol ether solvent is at least one selected from the group consisting of: [9] The method according to any one of [1] to [8], wherein the structural unit of the polymer (X) contains an aromatic ring, a heterocyclic ring, or a fused ring, which may have a phenolic hydroxyl group and which may have a substituted or unsubstituted amino group.

[10] The method according to any one of [1] to [9], wherein dioxane is not used. [Effects of the Invention]

[0010] According to the present invention, there is provided a method for producing a polymer for a resist underlayer film-forming composition, which allows easy control of the molecular weight and enables conversion of the substituents within the molecule to be carried out simultaneously with the polymerization reaction. DETAILED DESCRIPTION OF THE INVENTION

[0011] The present invention provides a step (A) of dissolving a compound (L) having a methoxymethyl group and optionally having a phenolic hydroxyl group in a compound (M) that reacts with the methoxymethyl group to give a ROCH2- group (where R is a monovalent organic group, a hydrogen atom, or a mixture thereof) other than a methoxymethyl group, to obtain a mixture; Step (B) of adding an acid catalyst to the mixture to carry out a polymerization reaction; and optionally, a step (C) of terminating the polymerization reaction on the condition that the weight average molecular weight of a sample taken from the mixture during the polymerization reaction in the step (B) exceeds a given value; The present invention relates to a method for producing a polymer (X) in which a plurality of identical or different structural units each having a methoxymethyl group and a ROCH2- group other than a methoxymethyl group (R is a monovalent organic group, a hydrogen atom, or a mixture thereof) are linked together, the method comprising the steps of:

[0012] [Process (A)] Step (A) is a step of dissolving a compound (L) having a methoxymethyl group and optionally having a phenolic hydroxyl group in a compound (M) that reacts with the methoxymethyl group to give a ROCH2- group (R is a monovalent organic group, a hydrogen atom, or a mixture thereof) other than a methoxymethyl group, to obtain a mixture.

[0013] Examples of the compound (L) having a methoxymethyl group and optionally having a phenolic hydroxyl group include 3,3',5,5'-tetramethoxymethyl-4,4'-dihydroxybiphenyl and 3,3',5,5'-tetramethoxymethyl-bisphenol A. The compound (L) is not limited to one type of compound, and two or more types of compounds may be used in combination.

[0014] As the compound (M) that reacts with a methoxymethyl group to give a ROCH2- group (where R is a monovalent organic group, a hydrogen atom, or a mixture thereof) other than a methoxymethyl group, an organic compound having a non-phenolic hydroxyl group in the molecule is preferred. Even if the compound does not have a non-phenolic hydroxyl group in the molecule, it may have a functional group that can be chemically converted to 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). The non-phenolic hydroxyl group or the functional group that can be chemically converted to a non-phenolic hydroxyl group may be one or two or more in the molecule.

[0015] The compound (M) is not limited to one type of compound, and two or more types of compounds may be used in combination. Therefore, the structural units having a methoxymethyl group and a ROCH2- group other than a methoxymethyl group (R is a monovalent organic group, a hydrogen atom, or a mixture thereof) may be the same or different.

[0016] The monovalent organic group R is preferably a saturated or unsaturated, linear or branched C-C alkyl group which may be substituted with a phenyl group, a naphthyl group, or an anthracenyl group and which may be interrupted by an oxygen atom or a carbonyl group. 20 (Preferably C2-C 10 ) Aliphatic hydrocarbon group, C3-C 20 The ROCH2- groups may be alicyclic hydrocarbon groups, aromatic hydrocarbon groups (preferably aromatic hydrocarbon groups having at least one hydroxyl group whose α-carbon is aliphatic), or mixtures thereof. The term "mixed" means that the ROCH2- groups present in a single structural unit may be different, and also means that the ROCH2- groups in two or more structural units may be different.

[0017] Typical saturated aliphatic hydrocarbon groups are straight-chain or branched alkyl groups having 2 to 20 carbon atoms, such as ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, t-butyl, n-pentyl, 1-methyl-n-butyl, 2-methyl-n-butyl, 3-methyl-n-butyl, 1,1-dimethyl-n-propyl, 1,2-dimethyl-n-propyl, 2,2-dimethyl-n-propyl, 1-ethyl-n-propyl, n-hexyl, 1-methyl-n-pentyl, 2-methyl-n-pentyl ... Examples of alkyl groups include 1-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.

[0018] Cyclic alkyl groups can also be used. Examples of cyclic alkyl groups having 3 to 20 carbon atoms include cyclopropyl, cyclobutyl, 1-methylcyclopropyl, 2-methylcyclopropyl, cyclopentyl, 1-methylcyclobutyl, 2-methylcyclobutyl, 3-methylcyclobutyl, 1,2-dimethylcyclopropyl, 2,3-dimethylcyclopropyl, 1-ethylcyclopropyl, 2-ethylcyclopropyl, cyclohexyl, 1-methylcyclopentyl, 2-methylcyclopentyl, 3-methylcyclopentyl, 1-ethylcyclobutyl, 2-ethylcyclobutyl, 3-ethylcyclobutyl, 1,2-dimethylcyclobutyl Examples of such cyclopropyl groups include methyl, 1,3-dimethyl-cyclobutyl, 2,2-dimethyl-cyclobutyl, 2,3-dimethyl-cyclobutyl, 2,4-dimethyl-cyclobutyl, 3,3-dimethyl-cyclobutyl, 1-n-propyl-cyclopropyl, 2-n-propyl-cyclopropyl, 1-i-propyl-cyclopropyl, 2-i-propyl-cyclopropyl, 1,2,2-trimethyl-cyclopropyl, 1,2,3-trimethyl-cyclopropyl, 2,2,3-trimethyl-cyclopropyl, 1-ethyl-2-methyl-cyclopropyl, 2-ethyl-1-methyl-cyclopropyl, 2-ethyl-2-methyl-cyclopropyl, and 2-ethyl-3-methyl-cyclopropyl groups.

[0019] Typical unsaturated aliphatic hydrocarbon groups are alkenyl groups having 2 to 20 carbon atoms, such as ethenyl, 1-propenyl, 2-propenyl, 1-methyl-1-ethenyl, 1-butenyl, 2-butenyl, 3-butenyl, 2-methyl-1-propenyl, 2-methyl-2-propenyl, 1-ethylethenyl, 1-methyl-1-propenyl, 1-methyl-2-propenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl, 1-n-propylethenyl, 1-methyl-1-butenyl, 1-methyl-2-prop ... -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-hexenyl group phenyl, 4-hexenyl, 5-hexenyl, 1-methyl-1-pentenyl, 1-methyl-2-pentenyl, 1-methyl-3-pentenyl, 1-methyl-4-pentenyl, 1-n-butylethenyl, 2-methyl-1-pentenyl, 2-methyl-2-pentenyl, 2-methyl-3-pentenyl, 2-methyl-4-pentenyl, 2-n-propyl-2-propenyl, 3-methyl-1-pentenyl, 3-methyl-2-pentenyl, 3-methyl-3-pentenyl, 3-methyl-4-pentenyl, 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 of the alkyl group 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.

[0020] Preferably, R is a saturated or unsaturated, linear or branched C-C alkyl group optionally substituted with a phenyl group, a naphthyl group or an anthracenyl group and optionally interrupted by an oxygen atom or a carbonyl group. 20 Aliphatic hydrocarbon groups, C3-C 20 It is an alicyclic hydrocarbon group, a hydrogen atom, or a mixture thereof.

[0021] The saturated aliphatic hydrocarbon group, unsaturated aliphatic hydrocarbon group, and cyclic alkyl group may be interrupted once or twice or more times by an oxygen atom and / or a carbonyl group. Particularly preferred are —CH2CH2CH2CH3 and —CH(CH3)CH2OCH3 groups.

[0022] Preferably, compound (M) is a glycol ether solvent, which is an organic compound having both an ether group and a hydroxyl group in one molecule.

[0023] More preferably, compound (M) is at least one glycol ether solvent selected from the group consisting of ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol mono-n-butyl ether, ethylene glycol mono-iso-butyl ether, ethylene glycol mono-tert-butyl ether, ethylene glycol phenyl ether, propylene glycol monomethyl ether, 3-methoxy-3methyl-1-butanol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-butyl ether, diethylene glycol mono-iso-butyl ether, dipropylene glycol monomethyl ether, triethylene glycol mono-n-butyl ether, and tetraethylene glycol mono-n-butyl ether. More preferably, the compound (M) is propylene glycol monomethyl ether or propylene glycol monomethyl ether acetate.

[0024] Preferably, compound (M) is an alcoholic solvent. More preferably, the compound (M) is a linear alkyl alcohol having 4 to 10 carbon atoms. More preferably, compound (M) is an aliphatic alcohol (for example, 1-butanol) or a compound represented by Ar-CH2OH (Ar is, for example, benzene, naphthalene, anthracene, pyrene, fluorene, or m-terphenyl). Even more preferably, compound (M) is 1-butanol.

[0025] Examples of the organic compound 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.

[0026] Examples of the organic compound having a 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 spiro ketones such as 11H-benzo[b]fluoren-11-one, 9H-tribenzo[a,f,l]triindene-9,14,15-trione, and indeno[1,2-b]fluorene-6,12-dione.

[0027] Examples of the organic compound having a carboxyl group include aromatic carboxylic acids such as trimesic acid.

[0028] The ratio of compound (M) to compound (L) is not particularly limited as long as compound (L) can be uniformly dissolved in compound (M), but is usually in the range of 1:1 to 30:1, preferably 2:1 to 20:1, and more preferably 3:1 to 10:1 by mass.

[0029] Optionally, a compound (N) containing a functional group that serves as a linking group may be added. The linking group preferably contains an alkylene group, an ether group, or a carbonyl group. Examples of the compound (N) include aldehydes, ketones, ROCH-Ar-CHOR (where R is a monovalent organic group, a hydrogen atom, or a mixture thereof), and the like.

[0030] It is preferable not to use dioxane, since it is not a compound that gives a ROCH2- group (where R is a monovalent organic group, a hydrogen atom, or a mixture thereof) other than a methoxymethyl group, and it is also a substance that is harmful to the human body.

[0031] The method and apparatus for dissolving compound (L) in compound (M) are not particularly limited, and known methods are sufficient. Heating at a temperature below the boiling point of compound (M) promotes dissolution. This step is preferably carried out in an inert atmosphere, such as a nitrogen atmosphere, to prevent inhibition of the polymerization reaction by moisture in the air.

[0032] [Process (B)] Step (B) is a step in which an acid catalyst is added to the mixture from step (A) to carry out a polymerization reaction.

[0033] The acid catalyst is not particularly limited as long as it is a catalyst that promotes the reaction between the methoxymethyl group of compound (L) and compound (M), and examples thereof include trifluoroacetic acid, nitric acid, hydrochloric acid, sulfuric acid, methanesulfonic acid, para-toluenesulfonic acid, phosphoric acid, trifluoromethanesulfonic acid, and 1,1,1-trifluoro-N-((trifluoromethyl)sulfonyl)methanesulfonamide.

[0034] The amount of the acid catalyst used is not particularly limited, but is usually about 1 to 30 parts by mass, preferably 2 to 20 parts by mass, and more preferably about 3 to 10 parts by mass, per 100 parts by mass of compound (L).

[0035] The method and apparatus for carrying out the polymerization reaction are not particularly limited, and known methods are sufficient. Heating at a temperature below the boiling point of compound (M) promotes the polymerization reaction. It is preferable to carry out this step in an inert atmosphere, for example, a nitrogen atmosphere, to prevent inhibition of the polymerization reaction by moisture in the air.

[0036] [Process (C)] The optional step (C) is a step of terminating the polymerization reaction on the condition that the weight average molecular weight of a sample taken from the mixture during the polymerization reaction in step (B) exceeds a given value.

[0037] The method for collecting samples from the mixture during the polymerization reaction is not particularly limited, and can be carried out by known means.

[0038] The method for determining the weight-average molecular weight of a sample is not particularly limited, and can be performed by a known method, for example, a method and apparatus using GPC.

[0039] The given value is a value established to determine the time at which the polymerization reaction must be stopped in order to achieve the target weight average molecular weight of the final product of polymer (X), and this value may vary depending on the target weight average molecular weight of the final product of polymer (X), but may be, for example, 1,000, 2,000, or 3,000.

[0040] The means for terminating the polymerization reaction is not particularly limited and can be carried out by known means, such as adding a polymerization inhibitor, heating or cooling treatment, removing raw materials or solvents, or stopping the supply thereof.

[0041] In the method according to the present invention, it is preferable not to use dioxane throughout the entire process.

[0042] Polymer The polymer (X) thus obtained is a polymer in which a plurality of identical or different structural units each having a methoxymethyl group and a ROCH2- group other than a methoxymethyl group (R is a monovalent organic group, a hydrogen atom, or a mixture thereof) are linked together. The polymer (X) may optionally have a linking group linking the plurality of structural units.

[0043] Preferably, the structural unit of the polymer (X) contains an aromatic ring, a heterocyclic ring, or a fused ring, which may have a phenolic hydroxyl group and a substituted or unsubstituted amino group, and the linking group connecting the structural units preferably contains an alkylene group, an ether group, or a carbonyl group.

[0044] The weight average molecular weight of the polymer (X) according to the present invention is not particularly limited and is, in terms of standard polystyrene, for example, 1,000 or more, for example, 2,000 or more, and for example, 500,000 or less, for example, 100,000 or less.

[0045] [Resist underlayer film-forming composition] A resist underlayer film-forming composition can be prepared by dissolving the polymer (X) according to the present invention in an appropriate solvent, and can be used in the form of a homogeneous solution. Furthermore, the resist underlayer film-forming composition containing the polymer (X) according to the present invention may further contain at least one of a crosslinking agent, an acid and / or an acid generator, a thermal acid generator, and a surfactant as an optional component. Furthermore, a light absorber, a rheology control agent, an adhesive aid, etc. may be added to the resist underlayer film forming composition containing the polymer (X) according to the present invention. Suitable solvents, crosslinkers, acids and / or acid generators, thermal acid generators, surfactants, light absorbers, rheology modifiers, and adhesive aids are as described in Japanese Patent Application No. 2020-33333.

[0046] [Membrane material (Y)] The polymer (X) according to the present invention can also be used as a crosslinking agent for the membrane material (Y). The membrane material (Y) is as described in Japanese Patent Application No. 2020-33333.

[0047] [Resist Underlayer Film] A resist underlayer film can be formed using the resist underlayer film-forming composition according to the present invention. Details are as described in Japanese Patent Application No. 2020-33333.

[0048] [Method of manufacturing a semiconductor device] A semiconductor device can be manufactured using the resist underlayer film-forming composition according to the present invention. Details are as described in Japanese Patent Application No. 2020-33333.

[0049] [Formation of resist underlayer film by nanoimprint method] The step of forming the resist underlayer film can also be performed by a nanoimprint method, as described in Japanese Patent Application No. 2020-33333. [Example]

[0050] Specific examples of the composition according to the present invention will be described below using the following examples, but the present invention is not limited thereto.

[0051] The apparatus used to measure the weight-average molecular weight of the reaction products obtained in the following synthesis examples is shown below. Apparatus: Tosoh Corporation HLC-8320GPC GPC column: TSKgel Super-MultiporeHZ-N (2 columns) Column temperature: 40℃ Flow rate: 0.35ml / min Eluent:THF Standard sample: polystyrene

[0052] The chemical structures (examples) and abbreviations of the main raw materials used are as follows: [ka]

[0053] [ka]

[0054] [ka]

[0055] [Example 1] A flask was charged with 260.00 g of TMOM-BP (Honshu Chemical Co., Ltd.) and 1,430 g of propylene glycol monomethyl ether (hereinafter referred to as PGME). The mixture was then heated to approximately 90°C under nitrogen, and 17.26 g of methanesulfonic acid (Tokyo Chemical Industry Co., Ltd.) dissolved in 130.00 g of PGME was added dropwise. After approximately 45 hours, the mixture was precipitated with methanol and water and dried to obtain polymer (1-I). Note that the actual structural unit is a crosslink formed by bonding any ROCH2- group containing a methoxymethyl group to a hydroxy group, or between ROCH2- groups. However, since the chemical formula would be extremely complicated to represent this state, only the structural unit is shown. The same applies below. The weight-average molecular weight Mw measured by GPC in terms of polystyrene was approximately 4,500. Furthermore, the introduction of PGME was 1 The resulting resin was dissolved in PGMEA and subjected to ion exchange using a cation exchange resin and an anion exchange resin for 4 hours to obtain the target polymer solution.

[0056] [ka]

[0057] (Tracking of reaction over time) In Example 1, methanesulfonic acid dissolved in PGME was added dropwise, and the mixture was stirred at approximately 90°C. 0.1 g of the reaction solution was sampled over time and diluted with THF to prepare 3 g of diluted solution. GPC was measured for each diluted solution to confirm the weight average molecular weight (Mw). The results are shown in Table 1.

[0058] [Table 1]

[0059] [Example 2] 68.99 g of TMOM-BP (manufactured by Honshu Chemical Co., Ltd.) and 379.44 g of PGME were placed in a flask. The mixture was then heated to approximately 90°C under nitrogen, and 4.57 g of methanesulfonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) dissolved in 34.50 g of PGME was added dropwise. After approximately 47.5 hours, the mixture was precipitated with methanol and water and dried to obtain polymer (1-2). The weight-average molecular weight (Mw) measured by GPC in terms of polystyrene was approximately 5,400. The introduction of PGME was 1 The resin was dissolved in PGMEA and subjected to ion exchange using a cation exchange resin and an anion exchange resin for 4 hours to obtain the target polymer solution.

[0060] [ka]

[0061] (Tracking of reaction over time) The change over time in the weight average molecular weight Mw of the polymer (1-2) obtained by the method of Example 2 was monitored in the same manner as in Example 1, and the same results as in Table 1 above were obtained.

[0062] [Example 3] 30.00 g of TMOM-BP (manufactured by Honshu Chemical Industry Co., Ltd.) and 165.07 g of 1-butanol (manufactured by Tokyo Chemical Industry Co., Ltd.) were placed in a flask. The mixture was then heated to approximately 90°C under nitrogen, and 1.99 g of methanesulfonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) dissolved in 15.05 g of 1-butanol was added dropwise. After approximately 81.5 hours, the mixture was precipitated with methanol and water and dried to obtain polymer (1-3). The weight-average molecular weight (Mw) measured by GPC in terms of polystyrene was approximately 3,487. The introduction of 1-butyl groups was also confirmed. 1 The resin was dissolved in PGME and subjected to ion exchange using a cation exchange resin and an anion exchange resin for 4 hours to obtain the target polymer solution.

[0063] [ka]

[0064] (Tracking of reaction over time) The change over time in the weight average molecular weight Mw of the polymer (1-3) obtained by the method of Example 3 was monitored in the same manner as in Example 1. The results are shown in Table 2.

[0065] [Table 2]

[0066] [Example 4] A flask was charged with 34.50 g of TMOM-BP (Honshu Chemical Co., Ltd.), 33.16 g of TM-BIP-A, and 379.44 g of PGME. The mixture was then heated to approximately 90°C under nitrogen, and 2.29 g of methanesulfonic acid (Tokyo Chemical Industry Co., Ltd.) dissolved in 34.50 g of PGME was added dropwise. After approximately 125.5 hours, the mixture was precipitated with methanol and water and dried to obtain polymer (1-4). The weight-average molecular weight (Mw) measured by GPC in terms of polystyrene was approximately 4,296. The introduction of PGME was also 1 The resulting resin was dissolved in PGME and subjected to ion exchange using a cation exchange resin and an anion exchange resin for 4 hours to obtain the target polymer solution.

[0067] [ka]

[0068] (Tracking of reaction over time) The change over time in the weight average molecular weight Mw of the polymer (1-4) obtained by the method of Example 4 was monitored in the same manner as in Example 1. The results are shown in Table 3.

[0069] [Table 3]

[0070] [Example 5] A flask was charged with 34.50 g of TMOM-BP (Honshu Chemical Co., Ltd.), 0.31 g of PL-LI (Midori Chemical Co., Ltd.), and 189.73 g of PGME. The mixture was then heated to approximately 90°C under nitrogen, and 2.29 g of methanesulfonic acid (Tokyo Chemical Industry Co., Ltd.) dissolved in 17.25 g of PGME was added dropwise. After approximately 48 hours, the mixture was precipitated with methanol and water and dried to obtain polymer (1-5). The weight-average molecular weight (Mw) measured by GPC in terms of polystyrene was approximately 3,978. The introduction of PGME was also 1 The resulting resin was dissolved in PGME and subjected to ion exchange using a cation exchange resin and an anion exchange resin for 4 hours to obtain the target polymer solution.

[0071] [ka]

[0072] (Tracking of reaction over time) The change over time in the weight average molecular weight Mw of the polymer (1-5) obtained by the method of Example 5 was monitored in the same manner as in Example 1. The results are shown in Table 4.

[0073] [Table 4]

[0074] [Example 6] A flask was charged with 68.99 g of TMOM-BP (manufactured by Honshu Chemical Industry Co., Ltd.), 40.00 g of trimesic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), and 379.42 g of PGME. The mixture was then heated to approximately 90°C under nitrogen, and 4.57 g of methanesulfonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) dissolved in 34.49 g of PGME was added dropwise. After approximately 26.5 hours, the mixture was precipitated with methanol, water, and aqueous ammonia, and dried to obtain polymer (1-11). The weight-average molecular weight (Mw) measured by GPC in terms of polystyrene was approximately 4,200. The introduction of PGME was 1The resulting resin was dissolved in PGME and subjected to ion exchange using a cation exchange resin and an anion exchange resin for 4 hours to obtain the target polymer solution.

[0075] [ka]

[0076] [Comparative Example 1] A flask was charged with 69.00 g of TMOM-BP (Honshu Chemical Co., Ltd.) and 379.50 g of 1,4-dioxane. The mixture was heated to approximately 90°C under nitrogen, and 4.57 g of methanesulfonic acid (Tokyo Chemical Industry Co., Ltd.) dissolved in 34.50 g of PGME was added dropwise. After stirring at approximately 90°C, 0.1 g of the reaction solution was sampled over time, and 3 g of each diluted solution was prepared with THF. GPC was measured for each diluted solution to determine the weight-average molecular weight (Mw). The results are shown in Table 5.

[0077] Comparative Example 2 A flask was charged with 69.00 g of TMOM-BP (Honshu Chemical Co., Ltd.) and 379.50 g of PGMEA. The mixture was heated to approximately 90°C under nitrogen, and 4.57 g of methanesulfonic acid (Tokyo Chemical Industry Co., Ltd.) dissolved in 34.50 g of PGME was added dropwise. While stirring at approximately 90°C, 0.1 g of the reaction solution was sampled over time, and 3 g of each diluted solution was prepared with THF. GPC was measured for each diluted solution to determine the weight-average molecular weight (Mw). The results are shown in Table 5.

[0078] Comparative Example 3 A flask was charged with 69.00 g of TMOM-BP (Honshu Chemical Co., Ltd.) and 379.50 g of PGMEA. The mixture was heated to approximately 75°C under nitrogen, and 4.57 g of methanesulfonic acid (Tokyo Chemical Industry Co., Ltd.) dissolved in 34.50 g of PGME was added dropwise. While stirring at approximately 75°C, 0.1 g of the reaction solution was sampled over time, and 3 g of each diluted solution was prepared with THF. GPC was measured for each diluted solution to determine the weight-average molecular weight (Mw). The results are shown in Table 5.

[0079] Comparative Example 4 A flask was charged with 69.00 g of TMOM-BP (Honshu Chemical Co., Ltd.) and 379.50 g of PGMEA. The mixture was heated to approximately 65°C under nitrogen, and 4.57 g of methanesulfonic acid (Tokyo Chemical Industry Co., Ltd.) dissolved in 34.50 g of PGME was added dropwise. While stirring at approximately 65°C, 0.1 g of the reaction solution was sampled over time, and 3 g of each diluted solution was prepared with THF. GPC was measured for each diluted solution to determine the weight-average molecular weight (Mw). The results are shown in Table 5.

[0080] [Table 5]

[0081] In Comparative Example 1, the polymerization reaction proceeded so rapidly that it was difficult to control the molecular weight of the polymer. Furthermore, the use of harmful dioxane created an unfavorable working environment. In Comparative Example 2, the polymerization reaction proceeded even more rapidly, making it impossible to control the molecular weight of the polymer. Conversely, in Comparative Examples 3 and 4, the polymerization reaction barely proceeded, making them unsuitable for practical use. In contrast, in the Examples, the progress of the polymerization reaction was appropriately controlled, and as a result, the molecular weight of the polymer could be easily controlled. Also, in the Examples, conversion of the substituents in the molecule could be carried out simultaneously with the polymerization reaction. [Industrial Applicability]

[0082] According to the present invention, there is provided a method for producing a polymer for a resist underlayer film-forming composition, which allows easy control of the molecular weight and enables conversion of the substituents within the molecule to be carried out simultaneously with the polymerization reaction.

Claims

1. Methoxymethyl group and ROCH other than methoxymethyl group ２ 1. A method for producing a polymer (X) comprising a plurality of identical or different structural units each having a - group (R is a monovalent organic group, a hydrogen atom, or a mixture thereof), and a linking group connecting the plurality of structural units, the method comprising the steps of: (A) A compound (L) having a methoxymethyl group and optionally having a phenolic hydroxyl group and a compound (N) having a functional group that will become a linking group are reacted with the methoxymethyl group to form a ROCH group other than a methoxymethyl group. ２ -group (R is a monovalent organic group, a hydrogen atom, or a mixture thereof) to obtain a mixture; (B) A step of adding an acid catalyst to the mixture to carry out a polymerization reaction. A method comprising:

2. The method of claim 1 , wherein the linking group comprises an alkylene group, an ether group, or a carbonyl group.

3. The method according to claim 1 or 2, wherein the compound (L) has at least one phenolic hydroxyl group.

4. The method according to any one of claims 1 to 3, further comprising the step (C) of terminating the polymerization reaction under the condition that the weight average molecular weight of a sample taken from the mixture during the polymerization reaction in step (B) exceeds 1,000.

5. R is a saturated or unsaturated, linear or branched C alkyl group which may be substituted with a phenyl group, a naphthyl group or an anthracenyl group and which may be interrupted by an oxygen atom or a carbonyl group. ２ -C ２０ Aliphatic hydrocarbon group, C ３ -C ２０ The method according to any one of claims 1 to 4, wherein the alkyl group is an alicyclic hydrocarbon group, an aromatic hydrocarbon group, a hydrogen atom, or a mixture thereof.

6. The method according to any one of claims 1 to 5, wherein the compound (M) is a glycol ether solvent and / or an alcohol solvent.

7. The method according to claim 6, wherein the compound (M) is a linear alkyl alcohol having 4 to 10 carbon atoms.

8. The compound (M) ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol mono-n-butyl ether, ethylene glycol mono-iso-butyl ether, ethylene glycol mono-tert-butyl ether, ethylene glycol phenyl ether, propylene glycol monomethyl ether, 3-methoxy-3-methyl-1-butanol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-butyl ether, diethylene glycol mono-iso-butyl ether, dipropylene glycol monomethyl ether, triethylene glycol mono-n-butyl ether, and Tetraethylene glycol mono-n-butyl ether 6. The method of claim 5, wherein the at least one glycol ether solvent is selected from the group consisting of:

9. The method according to any one of claims 1 to 8, wherein the structural unit of the polymer (X) comprises an aromatic ring, a heterocyclic ring, or a fused ring, each of which may have a substituted or unsubstituted amino group.

10. 10. The method of claim 1, wherein no dioxane is used.

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