Method for producing novolac compounds

Abstract

To provide method for producing a novolac compound, which can be produced by a reaction of raw materials in an organic solvent without making the aqueous solution of it, the method involving no toxicity and having excellent reactivity, which can yield a desired reaction product in the presence of both an acid and a base.SOLUTION: A method for producing a novolac compound includes reacting a C6 to 60 aromatic compound with an aldehyde equivalent having a hemiacetal structure represented by formula (1) in the presence of an acid or a base.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a method for producing a novolak compound contained in a resist underlayer film forming composition.

Background Art

[0002] In a lithography process for manufacturing a semiconductor device, prior to forming a photoresist film, a technique of forming a resist pattern having a desired shape by providing a resist underlayer film is known. Patent Document 1 below discloses that a resist underlayer film material containing a novolak compound obtained by condensing a dialdehyde or its acetal equivalent and a benzene derivative can form a useful resist underlayer film (Japanese Patent Application Laid-Open No. 2012-118300). It is also known that a novolak compound obtained by reacting an aromatic compound having a carbazole skeleton and glyoxal can form a resist underlayer film with good coating properties, a small film thickness difference after embedding, and flatness (Japanese Patent Application No. 2020-211449).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the production of novolak compounds using glyoxal, since glyoxal itself is unstable and can only be used in an aqueous solution, and glyoxal is toxic, a method for producing an alternative novolak compound is required.

Means for Solving the Problems

[0005] As a result of diligent research by the inventors, we have discovered a new method for producing a novolac compound without using glyoxal, and have completed the present invention. In other words, the present invention encompasses the following: A first embodiment of the present invention relates to a method for producing novolac compounds obtained by reacting an aromatic compound having 6 to 60 carbon atoms with an aldehyde equivalent having a hemiacetal structure represented by formula (1) in the presence of an acid or a base; [ka] (In formula (1), R1 and R2 each independently represent an alkyl group having 1 to 5 carbon atoms, and R1 and R2 may be linked by a single bond.) A second embodiment of the present invention relates to a method for producing a novolac compound according to claim 1, wherein R1 and R2 in formula (1) are linked by a single bond; A third embodiment of the present invention relates to a method for producing a novolac compound according to the first or second embodiment, wherein the aldehyde equivalent is a compound having the structure represented by formula (2); [ka] A fourth embodiment of the present invention relates to a method for producing a novolac compound according to any one of the first to third embodiments, wherein the aromatic compound having 6 to 60 carbon atoms is a compound having a structure represented by formula (3). [ka] (In formula (3), X represents a single bond, an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an amino group which may be substituted with an alkynyl group having 2 to 10 carbon atoms, or a methylene group which may be substituted with an alkyl group having 1 to 5 carbon atoms; Ar1 ​​and Ar2 each independently represent a benzene ring or naphthalene ring which may be substituted with R3 and R4, respectively; and R3 and R4 each represent a hydrogen atom, a halogen group, a nitro group, an amino group, a hydroxyl group, or an alkyl group having 1 to 20 carbon atoms. The group may be a kyl group, an alkenyl group having 2 to 10 carbon atoms, an alkynyl group having 2 to 10 carbon atoms, an aryl group having 6 to 40 carbon atoms, or a combination thereof, which may include an ether bond, a ketone bond, or an ester bond. n1 and n2 are integers from 1 to 3 when Ar1 and Ar2 are benzene rings, and integers from 1 to 5 when Ar1 and Ar2 are naphthalene rings. Ar1 and Ar2 may be bonded via a single bond, an oxygen atom, or a methylene group. [Effects of the Invention]

[0006] Conventional synthesis of novolac compounds requires the use of glyoxal, which must be in an aqueous solution. However, this invention allows the raw materials themselves to be reacted in an organic solvent, enabling the synthesis of low molecular weight novolac compounds through a simple synthesis process. Furthermore, since glyoxal is not used, it is non-toxic. Furthermore, because the aldehyde equivalent having a hemiacetal structure exhibits excellent reactivity, the present invention allows for obtaining the desired reactant with both acids and bases. [Modes for carrying out the invention]

[0007] The present invention relates to a method for producing novolac compounds obtained by reacting an aromatic compound having 6 to 60 carbon atoms with an aldehyde equivalent having a hemiacetal structure represented by formula (1) in the presence of an acid or a base.

[0008] [Aldehyde equivalents having a hemiacetal structure] The aldehyde equivalent having a hemiacetal structure is the compound represented by formula (1). [Chemistry] In formula (1), R1 and R2 each independently represent an alkyl group having 1 to 5 carbon atoms, and R1 and R2 may be linked via a single bond.

[0009] Examples of the alkyl group having 1 to 5 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, and the like. Among these, it is preferable that R1 and R2 are methyl groups, and a compound having a cyclic structure in which R1 and R2 are bonded by a single bond as represented by formula (2) is preferable. [Chemistry]

[0010] [Aromatic compound (A) having 6 to 60 carbon atoms] The aromatic compound (A) having 6 to 60 carbon atoms is (a) It may be a monocyclic compound such as benzene or phenol, (b) It may be a condensed ring compound such as naphthalene, anthracene, pyrene, hydroxynaphthalene, naphthol, 9,10-anthraquinone, indenofluorenedione, (c) It may be a heterocyclic compound such as furan, thiophene, pyridine, carbazole, phenothiazine, phenoxazine, indolocarbazole, (d) It may be a compound in which the aromatic rings of (a) to (c) are bonded by a single bond, such as biphenyl, phenylindole, 9,9-bis(4-hydroxyphenyl)fluorene, α,α,α’,α’-tetrakis(4-hydroxyphenyl)-p-xylene, 9,9-fluorenylidene-bisnaphthol, (e) Such as phenylnaphthylamine, -(CH2) nCompounds in which the aromatic rings of (a) to (d) are linked via a spacer exemplified by -(n = 1 to 20), -CH=CH-, -C≡C-, -N=N-, -NH-, -NR-, -NHCO-, -NRCO-, -S-, -COO-, -OCO-, -O-, -CO-, -Ph-, -Ph-Ph-, -Ph-O-Ph- (Ph = C6H4), and -CH=N- may also be used. Here, the substituent R may be exemplified by an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, and an alkynyl group having 2 to 10 carbon atoms, which will be described later.

[0011] In addition to the aromatic compounds exemplified above, pyrimidine, pyrazine, pyrrole, oxazole, thiazole, imidazole, quinoline, fluorene, quinazoline, purine, indolizine, benzothiophene, benzofuran, indole, acridine, etc. may also be mentioned.

[0012] The hydrogen atoms of the aromatic compound (A) having 6 to 60 carbon atoms may be substituted with an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an alkynyl group having 2 to 10 carbon atoms, a hydroxy group, a formyl group, an ether group, or an alkoxy group.

[0013] Examples of the alkyl group having 1 to 20 carbon atoms include linear or branched alkyl groups which may or may not have a substituent, 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 still more preferably an alkyl group having 1 to 4 carbon atoms.

[0014] Examples of alkenyl groups having 2 to 10 carbon atoms, and alkynyl groups having 2 to 10 carbon atoms, include linear or branched alkenyl groups and alkynyl groups that may or may not have substituents, such as vinyl groups, ethynyl groups, 2-propenyl groups, 2-propynyl groups, 2-butenyl groups, 2-butynyl groups, 3-butenyl groups, and 3-butynyl groups.

[0015] Furthermore, the above aromatic compounds may be linked via single bonds or spacers. An example of a spacer is -(CH2) n Examples of substituents R include -(n=1~20), -CH=CH-, -C≡C-, -N=N-, -NH-, -NR-, -NHCO-, -NRCO-, -S-, -COO-, -OCO-, -O-, -CO-, -Ph-, -Ph-Ph-, -Ph-O-Ph-(Ph=C6H4), and one or more combinations of two or more of the following: Two or more of these spacers may be linked together. Examples of substituents R include the alkyl groups with 1 to 20 carbon atoms mentioned above.

[0016] The aromatic compound (A) described above is preferably structured as shown in formula (3) below. [ka] In formula (3), X represents a single bond, an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an amino group which may be substituted with an alkynyl group having 2 to 10 carbon atoms, or a methylene group which may be substituted with an alkyl group having 1 to 5 carbon atoms. Examples of alkyl groups having 1 to 5 carbon atoms include methyl, ethyl, propyl, butyl, and pentyl groups. Examples of amino groups substituted with alkyl groups having 1 to 5 carbon atoms include methylamino, ethylamino, propylamino, butylamino, and pentylamino groups, and examples of methylene groups which may be substituted with alkyl groups having 1 to 5 carbon atoms include dimethylmethylene.

[0017] Ar1 and Ar2 each independently represent a benzene ring or naphthalene ring which may be substituted with R3 and R4, respectively, and Ar1 and Ar2 may be bonded via a single bond, an oxygen atom, or a methylene group.

[0018] R3 and R4 may each contain a hydrogen atom, a halogen group, a nitro group, an amino group, a hydroxyl group, a C1 to C20 alkyl group, a C2 to C10 alkenyl group, a C2 to C10 alkynyl group, a C6 to C40 aryl group, or an ether bond, a ketone bond, or an ester bond. n1 and n2 are integers from 1 to 3 when Ar1 and Ar2 are benzene rings, and integers from 1 to 5 when Ar1 and Ar2 are naphthalene rings. Examples of alkyl groups having 1 to 20 carbon atoms, alkenyl groups having 2 to 10 carbon atoms, and alkynyl groups having 2 to 10 carbon atoms can be found in the examples mentioned above.

[0019] Examples of aryl groups having 6 to 40 carbon atoms include phenyl group, o-methylphenyl group, m-methylphenyl group, p-methylphenyl group, o-chlorophenyl group, m-chlorophenyl group, p-chlorophenyl group, o-fluorophenyl group, p-fluorophenyl group, o-methoxyphenyl group, p-methoxyphenyl group, p-nitrophenyl group, p-cyanophenyl group, α-naphthyl group, β-naphthyl group, o-biphenylyl group, m-biphenylyl group, p-biphenylyl group, 1-anthryl group, 2-anthryl group, 9-anthryl group, 1-phenanthryl group, 2-phenanthryl group, 3-phenanthryl group, 4-phenanthryl group, pyrene group, and 9-phenanthryl group.

[0020] In the compound represented by formula (3), Ar1 and Ar2 are preferably benzene rings or naphthalene rings, and X is preferably a single bond, -NMe-, -NEt-, -NH-, -N(CCH)-, or -C(CH3)(CH3)-. The following are specific examples of compounds represented by formula (3). [ka]

[0021] [solvent] The solvent is not particularly limited as long as it dissolves the aromatic compound and the hemiacetal compound without inhibiting the reaction, but for example, glycol ether solvents can be used. Glycol ether solvents are organic compounds that have both an ether group and a hydroxyl group in one molecule. Specifically, for example, 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, die The solvent is at least one glycol ether solvent selected from the group consisting of ethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-butyl ether, diethylene glycol mono-iso-butyl ether, diethylene glycol diethyl ether, dipropylene glycol monomethyl ether, triethylene glycol mono-n-butyl ether, and tetraethylene glycol mono-n-butyl ether. More preferably, it is diethylene glycol diethyl ether.

[0022] [Acid catalysts and base catalysts] As for acid catalysts, there are no particular limitations as long as they are catalysts that promote the reaction between aromatic compounds and hemiacetal compounds, but examples include trifluoroacetic acid, nitric acid, hydrochloric acid, sulfuric acid, methanesulfonic acid, p-toluenesulfonic acid, phosphoric acid, trifluoromethanesulfonic acid, and 1,1,1-trifluoro-N-((trifluoromethyl)sulfonyl)methanesulfonamide. Examples of base catalysts include sodium hydroxide, potassium hydroxide, and diazabicycloundecene (DBU). [Examples]

[0023] The weight-average molecular weights shown in the following examples in this specification were obtained by gel permeation chromatography (hereinafter abbreviated as GPC in this specification). A GPC instrument manufactured by Tosoh Corporation (HLC-8320GPC) was used for the measurement, and the measurement conditions were as follows. <Measurement conditions for Examples 1 to 4> GPC columns: TSKgelSuperH-RC, TSKgelSuperMultipore HZ-N, TSKgelSuperMultipore HZ-N (manufactured by Tosoh Corporation) Column temperature: 40℃ Solvent: Tetrahydrofuran (Kanto Chemical, for high-performance liquid chromatography) Standard sample: Polystyrene (Shodex) <Measurement conditions for Example 5 and Comparative Example 1> GPC columns: TSKgel Guard Columns PWXL, TSKgel G6000PW, TSKgel G4000PW (manufactured by Tosoh Corporation) Column temperature: 40℃ Solvent: Ultrapure water Standard sample: Standard polyethyleneoxide (manufactured by Tosoh Corporation)

[0024] Furthermore, the abbreviations listed in the following examples represent the following meanings. ECz: Ethylcarbazole Cz: Carbazole B0464: 4,4'-Dihydroxybiphenyl B0494: 2,2-Bis(4-hydroxyphenyl)propane DEGDE: Diethylene glycol diethyl ether THF: Tetrahydrofuran PTS·H2O: p-toluenesulfonic acid monohydrate

[0025] (Example 1) 6.00 g of ECz (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.42 g of Cz (manufactured by Tokyo Chemical Industry Co., Ltd.), 2.64 g of 1,4-dioxane-2,3-diol (manufactured by Tokyo Chemical Industry Co., Ltd.), and 15.00 g of diethylene glycol diethyl ether (manufactured by Tokyo Chemical Industry Co., Ltd., hereafter referred to as DEGDE) were placed in a flask. The mixture was heated to approximately 150°C under nitrogen, and 3.00 g of DEGDE was added. 0.82g of dissolved PTS·H2O (manufactured by Tokyo Chemical Industry Co., Ltd.) was added dropwise. While stirring at approximately 150°C, 0.1g of the reaction solution was sampled, and a 3g dilution was prepared using THF. GPC was measured to confirm the Mw.

[0026] (Example 2) 6.00 g of 2,2'-dihydroxybiphenyl (manufactured by Tokyo Chemical Industry Co., Ltd.), 2.64 g of 1,4-dioxan-2,3-diol (manufactured by Tokyo Chemical Industry Co., Ltd.), and 27.00 g of DEGDE (manufactured by Tokyo Chemical Industry Co., Ltd.) were placed in a flask. The flask was heated to approximately 150°C under nitrogen, and 0.61 g of PTS·H2O (manufactured by Tokyo Chemical Industry Co., Ltd.), dissolved in 3.00 g of DEGDE, was added dropwise. While stirring at approximately 150°C, a 0.1 g sample of the reaction solution was taken, and a 3 g dilution was prepared with THF. The GPC was measured to confirm the Mw.

[0027] (Example 3) 6.00g of B0464 (manufactured by Tokyo Chemical Industry Co., Ltd.), 2.64g of 1,4-dioxane-2,3-diol (manufactured by Tokyo Chemical Industry Co., Ltd.), and 39.00g of DEGDE (manufactured by Tokyo Chemical Industry Co., Ltd.) were placed in a flask. The flask was heated to approximately 150°C under nitrogen, and 0.61g of PTS·H2O (manufactured by Tokyo Chemical Industry Co., Ltd.), dissolved in 3.00g of DEGDE, was added dropwise. While stirring at approximately 150°C, a 0.1g sample of the reaction solution was taken, and a 3g dilution was prepared using THF. The GPC was measured to confirm the Mw.

[0028] (Example 4) 6.00g of B0494 (manufactured by Tokyo Chemical Industry Co., Ltd.), 2.64g of 1,4-dioxane-2,3-diol (manufactured by Tokyo Chemical Industry Co., Ltd.), and 15.00g of DEGDE (manufactured by Tokyo Chemical Industry Co., Ltd.) were placed in a flask. The flask was heated to approximately 150°C under nitrogen, and 0.61g of PTS·H2O (manufactured by Tokyo Chemical Industry Co., Ltd.), dissolved in 3.00g of DEGDE, was added dropwise. While stirring at approximately 150°C, a 0.1g sample of the reaction solution was taken, and a 3g dilution was prepared using THF. The GPC was measured to confirm the Mw.

[0029] (Example 5) 5.00 g of 2,2'-dihydroxybiphenyl (manufactured by Tokyo Chemical Industry Co., Ltd.), 2.42 g of 1,4-dioxane-2,3-diol (manufactured by Tokyo Chemical Industry Co., Ltd.), and 30.00 g of DEGDE (manufactured by Tokyo Chemical Industry Co., Ltd.) were placed in a flask. The mixture was heated to approximately 100°C under nitrogen, and 12.89 g of 25% sodium hydroxide aqueous solution (manufactured by Kanto Chemical Co., Ltd.) was added dropwise. While stirring at approximately 100°C, a 0.1 g sample of the reaction solution was taken, and a 3 g dilution was prepared using THF. The GPC was measured to confirm the Mw.

[0030] (Comparative Example 1) 5.00 g of 2,2'-dihydroxybiphenyl (manufactured by Tokyo Chemical Industry Co., Ltd.), 5.69 g of terephthalaldehyde bis-diethyl acetal (manufactured by Tokyo Chemical Industry Co., Ltd.), and 30.00 g of DEGDE (manufactured by Tokyo Chemical Industry Co., Ltd.) were placed in a flask. The mixture was heated to approximately 100°C under nitrogen, and 12.89 g of 25% sodium hydroxide aqueous solution (manufactured by Kanto Chemical Co., Ltd.) was added dropwise. While stirring at approximately 100°C, 0.1 g of the reaction solution was sampled after the start of the reaction and again 24 hours later, and a 3 g dilution was prepared using THF. When GPC was measured, there was no change in the GPC waveform between the start of the reaction and 24 hours later, and polymer formation could not be confirmed.

[0031] (Comparative Example 2) 5.00 g of 2,2'-dihydroxybiphenyl (manufactured by Tokyo Chemical Industry Co., Ltd.), 5.69 g of terephthalaldehyde bis-diethyl acetal (manufactured by Tokyo Chemical Industry Co., Ltd.), and 30.00 g of DEGDE (manufactured by Tokyo Chemical Industry Co., Ltd.) were placed in a flask. The mixture was heated to approximately 100°C under nitrogen, and 0.39 g of methanesulfonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) was added dropwise. The mixture was stirred at approximately 100°C. Then, a 0.1g sample of the reaction solution was taken, and a 3g dilution was prepared using THF. The GPC was measured to confirm the Mw.

[0032] In Examples 1 to 5 and Comparative Examples 1 and 2, Mw was tracked by sampling during the reaction and summarized in Table 1. In all cases, polymer formation was confirmed. Furthermore, while the acetal-based methods in Comparative Examples 1 and 2 only yielded novolac compounds under acidic conditions, as can be seen from Examples 1 to 5, the method of the present invention allows for the acquisition of novolac compounds under both acidic and basic conditions.

[0033] [Table 1]

Claims

1. A method for producing a novolac compound obtained by reacting an aromatic compound having 6 to 60 carbon atoms with an aldehyde equivalent having a hemiacetal structure represented by formula (1) in the presence of an acid or a base, 【Chemistry 1】 (In formula (1), R １ , R ２ Each of these independently represents an alkyl group having 1 to 5 carbon atoms, R １ and R ２ They may also be connected via a single bond. The aforementioned aromatic compounds having 6 to 60 carbon atoms are 【Chemistry 2】 A method for producing novolac compounds.

2. In formula (1) above, R １ and R ２ A method for producing a novolac compound according to claim 1, wherein the compounds are linked via a single bond.

3. A method for producing a novolac compound according to claim 1 or claim 2, wherein the aldehyde equivalent is a compound having the structure represented by formula (2). 【Transformation 3】

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