Resist underlayer film forming composition having a benzylidencyanoacetic acid group

Abstract

Provided is a resist underlayer film which, while exhibiting excellent resistance to a resist developer which is a resist solvent or an alkaline aqueous solution, exhibits removability, and preferably solubility, only in wet etching chemicals. This resist underlayer film-forming composition contains: (A) a compound having a partial structure represented by formula (1) (In the formula, R1 and R2 each denote a hydrogen atom, an alkyl group having 1-10 carbon atoms or an aryl group having 6-40 carbon atoms, X denotes an alkyl group having 1-10 carbon atoms, a hydroxyl group, an alkoxy group having 1-10 carbon atoms, an alkoxycarbonyl group having 1-10 carbon atoms, a halogen atom, a cyano group, a nitro group or a combination of these, Y denotes a direct bond, an ether bond, a thioether bond or an ester bond, n is an integer between 0 and 4, and ＊ denotes a site of bonding to a residue of compound (A)); and a solvent.

Description

[Technical Field]

[0001] The present invention relates to a resist underlayer forming composition, a resist underlayer obtained from the resist underlayer forming composition, a method for manufacturing a patterned substrate and a semiconductor device using the resist underlayer forming composition, and a compound having a benzylidencyanoacetic acid ester group, and a method for producing the same. [Background technology]

[0002] In semiconductor manufacturing, the lithography process, which involves creating a resist underlayer film between a substrate and a resist film formed on it to form a resist pattern of a desired shape, is widely known. After forming the resist pattern, the resist underlayer film is removed and the substrate is processed, with dry etching being the primary method used for this process. Furthermore, dry etching is also used in the process of removing unwanted resist patterns and the underlying resist underlayer film after substrate processing, but wet etching using chemical solutions may be used to simplify the process and reduce damage to the processed substrate.

[0003] Patent Document 1 discloses an anti-reflective coating composition having improved spin bowl compatibility. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2004-533637 [Overview of the project] [Problems that the invention aims to solve]

[0005] To obtain a desired resist pattern by coating a resist onto a resist underlayer and exposing and developing it using radiation (e.g., ArF excimer laser light, KrF excimer laser light, i-line), the resist underlayer requires good resistance to resist solvents to prevent peeling or damage. Furthermore, it also requires good resistance to resist developers (alkaline aqueous solutions) mainly used in the resist development process to prevent peeling or damage. In addition, to obtain the desired resist pattern, the resist underlayer requires anti-reflective properties to suppress reflection from the substrate and prevent deterioration of the resist pattern due to standing waves from the radiation used in the lithography process. Moreover, when removing the resist underlayer by dry etching, a resist underlayer with a fast etching rate (high etching rate) is required so that it can be quickly removed by dry etching without damaging the substrate. In particular, when removing the resist underlayer by wet etching with chemicals, the resist underlayer must exhibit sufficient solubility in the wet etching chemicals and be easily removed from the substrate.

[0006] On the other hand, organic solvents are used as wet etching solutions for removing resist and the resist underlayer film in order to reduce damage to the processed substrate. Furthermore, basic organic solvents are used to improve the removeability of the resist and the resist underlayer film. However, conventional techniques have had limitations in that the resist underlayer film exhibits good resistance to resist solvents, which are mainly organic solvents, and resist developers, which are alkaline aqueous solutions, while exhibiting removeability, preferably solubility, only to wet etching solutions. The object of the present invention is to solve the above problems. [Means for solving the problem]

[0007] This invention encompasses the following:

[0008] [1] Formula (1): [ka] (In the formula, R1 and R2 represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an aryl group having 6 to 40 carbon atoms, respectively; X represents an alkyl group having 1 to 10 carbon atoms, a hydroxyl group, an alkoxy group having 1 to 10 carbon atoms, an alkoxycarbonyl group having 1 to 10 carbon atoms, a halogen atom, a cyano group, or a nitro group, or a combination thereof; Y represents a direct bond, an ether bond, a thioether bond, or an ester bond; n represents an integer from 0 to 4; and * indicates the bond site with compound (A) residue.) A resist underlayer film forming composition comprising a compound (A) containing a substructure represented by [formula] and a solvent.

[0009] [2] The aforementioned compound (A) is given by formula (2): [ka] (In the formula, A 1 The resist underlayer forming composition described in [1], where is an m-valent organic group, where m is an integer from 1 to 10, R1 and R2 each represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an aryl group having 6 to 40 carbon atoms, X represents an alkyl group having 1 to 10 carbon atoms, a hydroxyl group, an alkoxy group having 1 to 10 carbon atoms, an alkoxycarbonyl group having 1 to 10 carbon atoms, a halogen atom, a cyano group, or a nitro group, or a combination thereof, Y represents a direct bond, an ether bond, a thioether bond, or an ester bond, and n is an integer from 0 to 4.

[0010] [3] A 1 The resist underlayer forming composition according to [2], comprising a heterocycle.

[0011] [4] The resist underlayer forming composition according to [3], wherein the heterocycle is a triazinetrione.

[0012] [5] The aforementioned compound (A) A compound (a) having m epoxy groups, and The following formula (b): [Chemical formula] (In the formula, R2 represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an aryl group having 6 to 40 carbon atoms, X represents an alkyl group having 1 to 10 carbon atoms, a hydroxy group, an alkoxy group having 1 to 10 carbon atoms, an alkoxycarbonyl group having 1 to 10 carbon atoms, a halogen atom, a cyano group, a nitro group, or a combination thereof, and n represents an integer of 0 to 4.) A compound (b) represented by, and The following formula (c): [Chemical formula] (In the formula, R1 represents a hydrogen atom or an optionally substituted alkyl group having 1 to 10 carbon atoms.) A resist underlayer film forming composition according to any one of [2] to [4], which is a reaction product with a compound (c) represented by.

[0013] [6] The resist underlayer film forming composition according to any one of [1] to [5], further comprising at least one selected from the group consisting of a crosslinking agent, an acid, and an acid generator.

[0014] [7] The resist underlayer film forming composition according to any one of [1] to [6], for application on a substrate containing copper on its surface.

[0015] [8] A resist underlayer film, characterized by being obtained by removing a solvent from a coating film composed of the resist underlayer film forming composition according to any one of [1] to [7].

[0016] [9] A resist underlayer film composed of the resist underlayer film forming composition according to any one of [1] to [7], which is dried or concentrated.

[0017]

[10] A resist underlayer film according to [8] or [9], formed on a substrate containing copper on its surface.

[0018]

[11] A substrate having a copper seed layer and a resist underlayer film according to [8] or [9] formed on the copper seed layer on its surface.

[0019]

[12] A step of forming a resist underlayer film by applying a resist underlayer film forming composition described in any one of items [1] to [7] onto a substrate containing copper on its surface and baking it, A step of forming a resist film by coating the resist on the resist underlayer film and baking it. A step of exposing the resist underlayer film and the semiconductor substrate coated with the resist, and The process of developing and patterning the resist film after exposure. A method for manufacturing patterned substrates, including [the specified method].

[0020]

[13] A step of forming a resist underlayer film on a substrate containing copper on its surface, comprising a resist underlayer film forming composition according to any one of items [1] to [7], A step of forming a resist film on the resist underlayer film, A process comprising: forming a resist pattern by irradiating a resist film with light or an electron beam and then developing it; and then removing the resist underlayer film exposed between the resist patterns. A step of performing copper plating between the formed resist patterns, A step of removing the resist pattern and the underlying resist layer film therebenea, A method for manufacturing a semiconductor device, characterized by including the following:

[0021]

[14] The manufacturing method according to

[13] , wherein at least one of the steps for removing the resist underlayer film is performed by wet treatment.

[0022]

[15] The following equation (2): [ka] (In the formula, A 1 Compound (A) represented by ) where m represents an m-valent organic group, where m is an integer from 1 to 10, R1 and R2 represent a hydrogen atom, an alkyl group with 1 to 10 carbon atoms, or an aryl group with 6 to 40 carbon atoms, respectively, X represents an alkyl group with 1 to 10 carbon atoms, a hydroxyl group, an alkoxy group with 1 to 10 carbon atoms, an alkoxycarbonyl group with 1 to 10 carbon atoms, a halogen atom, a cyano group, or a nitro group, or a combination thereof, Y represents a direct bond, an ether bond, a thioether bond, or an ester bond, and n is an integer from 0 to 4. [Effects of the Invention]

[0023] According to the present invention, it is possible to provide a resist underlayer film that exhibits good resistance to resist solvents, which are mainly organic solvents, and resist developers, which are alkaline aqueous solutions, while exhibiting removeability, preferably solubility, only to wet etching solutions. [Modes for carrying out the invention]

[0024] <Resist Underlayer Film Forming Composition> The resist underlayer film forming composition of the present invention Formula (1): [ka] The compound (A) and a solvent include a substructure represented by the formula (wherein R1 and R2 represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an aryl group having 6 to 40 carbon atoms, X represents an alkyl group having 1 to 10 carbon atoms, a hydroxyl group, an alkoxy group having 1 to 10 carbon atoms, an alkoxycarbonyl group having 1 to 10 carbon atoms, a halogen atom, a cyano group, or a nitro group, or a combination thereof, Y represents a direct bond, an ether bond, a thioether bond, or an ester bond, n represents an integer from 0 to 4, and * indicates a bond with a residue of compound (A).

[0025] The alkyl groups having 1 to 10 carbon atoms include methyl group, ethyl group, n-propyl group, i-propyl group, cyclopropyl group, n-butyl group, i-butyl group, s-butyl group, t-butyl group, cyclobutyl group, 1-methyl-cyclopropyl group, 2-methyl-cyclopropyl 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, and 1-ethyl-n-propyl group. 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, n-hexyl group, 1-methyl-n-pentyl group, 2-methyl-n-pentyl group, 3-methyl-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, 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, 1,2-dimethyl-cyclobutyl group, 1,3-dimethyl-cyclobutyl group, 2,2-dimethyl-cyclobutyl group, 2,3-dimethyl-cyclobutyl group, 2,4-dimethyl-cyclobutyl group, 3,3-dimethyl-cyclobutyl group, 1-n-propyl-cyclopropyl group, 2-n-propyl-cyclopropyl group, 1-i-propyl-cyclopropyl group, 2-i-propyl-cyclopropyl group, 1,2,2-trimethyl-cyclopropyl group, 1,2,3-trimethyl-cyclopropyl group, 2,2,Examples include 3-trimethylcyclopropyl group, 1-ethyl-2-methylcyclopropyl group, 2-ethyl-1-methylcyclopropyl group, 2-ethyl-2-methylcyclopropyl group, 2-ethyl-3-methylcyclopropyl group, and decyl group.

[0026] Examples of the aryl group 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, and 9-phenanthryl group.

[0027] Examples of the alkoxy groups having 1 to 10 carbon atoms include groups in which an oxygen atom is bonded to the alkyl group. For example, methoxy group, ethoxy group, n-propoxy group, i-propoxy group, n-butoxy group, i-butoxy group, s-butoxy group, t-butoxy group, n-pentoxy group, 1-methyl-n-butoxy group, 2-methyl-n-butoxy group, 3-methyl-n-butoxy group, 1,1-dimethyl-n-propoxy group, 1,2-dimethyl-n-propoxy group, 2,2-dimethyl-n-propoxy group, 1-ethyl-n-propoxy group, n-hexyloxy group, 1-methyl-n-pentyloxy group, 2-methyl-n-pentyloxy group, 3-methyl-n-pentyloxy group, 4-methyl-n-pentyloxy group, Examples include 1,1-dimethyl-n-butoxy group, 1,2-dimethyl-n-butoxy group, 1,3-dimethyl-n-butoxy group, 2,2-dimethyl-n-butoxy group, 2,3-dimethyl-n-butoxy group, 3,3-dimethyl-n-butoxy group, 1-ethyl-n-butoxy group, 2-ethyl-n-butoxy group, 1,1,2-trimethyl-n-propoxy group, 1,2,2-trimethyl-n-propoxy group, 1-ethyl-1-methyl-n-propoxy group, 1-ethyl-2-methyl-n-propoxy group, n-heptyloxy group, n-octyloxy group, n-nonyloxy group, and n-decanyloxy group.

[0028] Examples of the alkoxycarbonyl group having 1 to 10 carbon atoms include groups in which an oxygen atom and a carbonyl group are bonded to the alkyl group. Examples include methoxycarbonyl group, ethoxycarbonyl group, propoxycarbonyl group, and butoxycarbonyl group.

[0029] Examples of the halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms.

[0030] The aforementioned compound (A) is given by formula (2): [ka] (In the formula, A 1) may be expressed as follows: represents an m-valent organic group, where m is an integer from 1 to 10; R1 and R2 represent a hydrogen atom, an alkyl group with 1 to 10 carbon atoms, or an aryl group with 6 to 40 carbon atoms, respectively; X represents an alkyl group with 1 to 10 carbon atoms, a hydroxyl group, an alkoxy group with 1 to 10 carbon atoms, an alkoxycarbonyl group with 1 to 10 carbon atoms, a halogen atom, a cyano group, or a nitro group, or a combination thereof; Y represents a direct bond, an ether bond, a thioether bond, or an ester bond; and n represents an integer from 0 to 4.

[0031] A 1 The organic group is not limited to any m-valent organic group that produces the effects of the present invention, but may include a heterocyclic, aromatic, or hydrocarbon group that may be interrupted by an oxygen atom.

[0032] A 1 However, it may include complex algebras.

[0033] The heterocyclic compounds referred to in this invention mean those included in the term heterocyclic compounds commonly used in organic chemistry, and are not particularly limited. Examples include furan, thiophene, pyrrole, imidazole, pyran, pyridine, pyrimidine, pyrazine, pyrrolidine, piperidine, piperazine, morpholine, quinuclidine, indole, purine, quinoline, isoquinoline, chromene, thiantrene, phenothiazine, phenoxazine, xanthene, acridine, phenazine, carbazole, hydantoin, triazine, cyanuric acid, etc. The heterocyclic compound may be a triazinetrione.

[0034] Examples of epoxy group-containing compounds for producing compound (A) of the present invention, that is, compounds (a) having m epoxy groups (the definition of m is as described above), include the following group of compounds, which include compounds represented by the following formulas (B-1) to (B-18).

[0035] [ka] [ka] The epoxy group-containing compounds mentioned above may include aromatic ring structures with 6 to 40 carbon atoms. Specific examples include aromatic ring structures derived from benzene, naphthalene, anthracene, acenaphthene, fluorene, triphenylene, phenalene, phenanthrene, indene, indane, indacene, pyrene, chrysene, perylene, naphthacene, pentacene, coronene, heptacene, benzo[a]anthracene, dibenzophenanthrene, and dibenzo[a,j]anthracene.

[0036] The aforementioned compound (A) A compound (a) having m epoxy groups, The following formula (b): [ka] (In the formula, R2 represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an aryl group having 6 to 40 carbon atoms; X represents an alkyl group having 1 to 10 carbon atoms, a hydroxyl group, an alkoxy group having 1 to 10 carbon atoms, an alkoxycarbonyl group having 1 to 10 carbon atoms, a halogen atom, a cyano group, or a nitro group, or a combination thereof; and n represents an integer from 0 to 4.) Compound (b) represented by, The following formula (c): [ka] The reaction product may be a compound (c) represented by (wherein R1 represents a hydrogen atom or an optionally substituted alkyl group having 1 to 10 carbon atoms).

[0037] Specific examples of compounds (a) having m epoxy groups include the above group of compounds, which includes the compounds represented by formulas (B-1) to (B-18) described above.

[0038] Specific examples of compounds represented by formula (b) include the compounds represented by the following formula.

[0039] [ka] Specific examples of compounds represented by formula (c) include the compounds represented by the following formula.

[0040] [ka] The above reaction product can be produced by known methods, for example, by the method described in the examples.

[0041] The weight-average molecular weight of compound (A) is, for example, in the range of 300 to 3,000.

[0042] Furthermore, the resist underlayer film forming composition of the present invention is defined by the following formula (1): [ka] (In the formula, R1 and R2 represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an aryl group having 6 to 40 carbon atoms, respectively; X represents an alkyl group having 1 to 10 carbon atoms, a hydroxyl group, an alkoxy group having 1 to 10 carbon atoms, an alkoxycarbonyl group having 1 to 10 carbon atoms, a halogen atom, a cyano group, or a nitro group, or a combination thereof; Y represents a direct bond, an ether bond, a thioether bond, or an ester bond; n represents an integer from 0 to 4; and * indicates a bond with a bisphenol-type novolac resin.) It may be a bisphenol-type novolac resin having a substructure represented by .

[0043] In this case, the resist underlayer film forming composition of the present invention is a composition for forming a resist underlayer film that can be removed by a chemical solution used to wet etch a copper substrate or the like, as described later. For this purpose, the resist underlayer film forming composition of the present invention can also be a composition for application on a substrate containing copper on its surface.

[0044] <Solvent> The solvent used in the resist underlayer film forming composition according to the present invention is not particularly limited, as long as it is a solvent capable of dissolving the above-mentioned compounds and other components. In particular, since the resist underlayer film forming composition according to the present invention is used in a uniform solution state, it is recommended to use a solvent commonly used in lithography processes in combination, considering its coating performance.

[0045] Such solvents include, for example, methyl cellosolve acetate, ethyl cellosolve acetate, propylene glycol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, methyl isobutyl carbinol, propylene glycol monobutyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether acetate, toluene, xylene, methyl ethyl ketone, cyclopentanone, cyclohexanone, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxyethyl ethyl hydroxyethyl ethyl 2-hydroxy-3-methylbutanoate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl 3-ethoxypropionate, methyl pyruvate, ethyl pyruvate, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol Diethylene glycol monobutyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether, diethylene glycol dibutyl ether, propylene glycol monomethyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether, propylene glycol dipropyl ether, propylene glycol dibutyl ether, ethyl lactate, propyl lactate, isopropyl lactate, butyl lactate, isobutyl lactate, methyl formate, ethyl formate, propyl formate, isopropyl formate, butyl formate, isobutyl formate, amyl formate, isoamyl formate, methyl acetate, ethyl acetate, amyl acetate, isoamyl acetate, hexyl acetate, methyl propionate, ethyl propionate, propyl propionate, isopropyl propionate, butyl propionate, isobutyl propionate, methyl butyrate, ethyl butyrate, propyl butyrate, isopropyl butyrate,Butyl butyrate, isobutyl butyrate, ethyl hydroxyethyl, ethyl 2-hydroxy-2-methylpropionate, methyl 3-methoxy-2-methylpropionate, methyl 2-hydroxy-3-methylbutyrate, ethyl methoxyethyl, ethyl ethoxyethyl, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-methoxybutyl acetate, 3-methoxypropyl acetate, 3-methyl-3-methoxybutyl acetate, 3-methyl Examples of solvents include 3-3-methoxybutylpropionate, 3-methyl-3-methoxybutyl butyrate, methyl acetoacetate, toluene, xylene, methyl ethyl ketone, methyl propyl ketone, methyl butyl ketone, 2-heptanone, 3-heptanone, 4-heptanone, cyclohexanone, N,N-dimethylformamide, N-methylacetamide, N,N-dimethylacetamide, N-methylpyrrolidone, 4-methyl-2-pentanol, and γ-butyrolactone. These solvents can be used individually or in combination of two or more.

[0046] Propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, ethyl lactate, butyl lactate, cyclohexanone, etc. are preferred. Propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate are particularly preferred.

[0047] [Crosslinking agent] The resist underlayer film forming composition of the present invention may contain a crosslinking agent component. Examples of such crosslinking agents include melamine-based, substituted urea-based, or polymer-based versions thereof. Preferably, the crosslinking agent has at least two crosslinking substituents and is a compound such as methoxymethylated glycoluryl (e.g., tetramethoxymethyl glycoluryl), butoxymethylated glycoluryl, methoxymethylated melamine, butoxymethylated melamine, methoxymethylated benzoguanamine, butoxymethylated benzoguanamine, methoxymethylated urea, butoxymethylated urea, or methoxymethylated thiourea. Condensed forms of these compounds can also be used.

[0048] In addition, as the crosslinking agent, a compound containing a crosslink-forming substituent having an aromatic ring (for example, benzene ring, naphthalene ring) in the molecule can be used.

[0049] Examples of this compound include a compound having a partial structure of the following formula (6), a polymer or oligomer having a repeating unit of the following formula (7).

Chemical formula

[0050] The compounds, polymers, and oligomers of formula (6) and formula (7) are exemplified below.

Chemical formula

Chemical formula

[0051] The above compounds can be obtained as products of Asahi Organic Materials Industry Co., Ltd. and Honshu Chemical Industry Co., Ltd. For example, among the above crosslinking agents, the compound of formula (D-24) can be obtained from Asahi Organic Materials Industry Co., Ltd. under the trade name TM-BIP-A. The addition amount of the crosslinking agent varies depending on the coating solvent used, the base substrate used, the required solution viscosity, the required film shape, etc., but is 0.001 to 80% by mass, preferably 0.01 to 50% by mass, more preferably 0.05 to 40% by mass based on the total solid content. Although these crosslinking agents may cause a crosslinking reaction by self-condensation, when a crosslinkable substituent is present in the above reaction product of the present invention, they can cause a crosslinking reaction with those crosslinkable substituents.

[0052] [Acids and / or acid generators] The resist underlayer film forming composition of the present invention may contain an acid and / or an acid generator. Examples of acids include p-toluenesulfonic acid, trifluoromethanesulfonic acid, pyridinium 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. 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 3% by mass, relative to the total solid content.

[0053] Examples of acid generators include thermal acid generators and photoacid generators. Examples of thermal acid generators include pyridinium trifluoromethanesulfonic acid, pyridinium p-toluenesulfonic acid, pyridinium phenolsulfonic acid, 2,4,4,6-tetrabromocyclohexadienone, benzoin tosylate, 2-nitrobenzyl tosylate, and other alkyl organic sulfonates.

[0054] The photoacid generator produces acid when the resist is exposed to light. Therefore, the acidity of the underlying film can be adjusted. This is one method for matching the acidity of the underlying film to that of the upper resist. Furthermore, adjusting the acidity of the underlying film allows for adjustment of the pattern shape of the resist formed on the upper layer. Examples of photoacid generators included in the resist underlayer film forming composition of the present invention include onium salt compounds, sulfonimide compounds, and disulfonyl diazomethane compounds.

[0055] 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.

[0056] Examples of sulfonimide compounds include N-(trifluoromethanesulfonyloxy)succinimide, N-(nonafluoron-butanesulfonyloxy)succinimide, N-(camphorsulfonyloxy)succinimide, and N-(trifluoromethanesulfonyloxy)naphthalimide.

[0057] 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.

[0058] 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, its proportion is typically 0.0001 to 20% by mass, preferably 0.0005 to 10% by mass, and more preferably 0.01 to 3% by mass, based on 100 parts by mass of the solid content of the resist underlayer film forming composition.

[0059] [Other ingredients] The resist underlayer film forming composition of the present invention does not produce pinholes or striations, and surfactants can be added to further improve the coatability against surface unevenness. Examples of surfactants include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, and polyoxyethylene oleyl ether; polyoxyethylene alkyl allyl ethers such as polyoxyethylene octylphenol ether and polyoxyethylene nonylphenol 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 Examples include nonionic surfactants such as polyoxyethylene sorbitan fatty acid esters like ethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, and polyoxyethylene sorbitan tristearate; fluorine-based surfactants such as F-Top EF301, EF303, EF352 (manufactured by Tochem Products Co., Ltd., product name), Megafac F171, F173, R-40, R-40N, R-40LM (manufactured by DIC Corporation, product name), Florard FC430, FC431 (manufactured by Sumitomo 3M Limited, product name), Asahi Guard AG710, Surflon S-382, SC101, SC102, SC103, SC104, SC105, SC106 (manufactured by Asahi Glass Co., Ltd., product name); and organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.). The amount of these surfactants blended is usually 2.0% by mass or less, preferably 1.0% by mass or less, relative to the total solid content of the resist underlayer film material. These surfactants may be used individually or in combination of two or more. When surfactants are used, the ratio is 0.0001 to 5 parts by mass, or 0.001 to 1 part by mass, or 0.01 to 0.5 parts by mass, per 100 parts by mass of solid content of the resist underlayer film forming composition.

[0060] The resist underlayer film forming composition of the present invention may 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] The solid content of the resist underlayer film forming composition according to the present invention is typically 0.1-70% by mass, 0.1-60% by mass, 0.1-50% by mass, 0.1-40% by mass, 0.1-30% by mass, 0.1-20% by mass, 0.1-10% by mass, 0.1-5% by mass, 0.1-3% by mass, and 0.1-2% by mass. The solid content is the percentage of all components in the resist underlayer film forming composition excluding the solvent. The percentage of the above reaction products in the solid content is preferably in the order of 1-100% by mass, 1-99.9% by mass, 50-99.9% by mass, 50-95% by mass, and 50-90% by mass.

[0065] 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.

[0066] 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.

[0067] [substrate] In the present invention, substrates used in the manufacture of semiconductor devices include, for example, silicon wafer substrates, silicon / silicon dioxide coated substrates, silicon nitride substrates, glass substrates, ITO substrates, polyimide substrates, and low-dielectric material (low-k material) coated substrates. Recently, in the field of three-dimensional packaging in semiconductor manufacturing processes, the FOWLP process has begun to be applied with the aim of achieving high-speed response and power saving by shortening the wiring length between semiconductor chips. In the RDL (redistribution) process that creates wiring between semiconductor chips, copper (Cu) is used as the wiring material, and as copper wiring becomes finer, it becomes necessary to apply an anti-reflective film (resist underlayer film forming composition). The resist underlayer film forming composition according to the present invention can be suitably applied to substrates that contain copper on the surface.

[0068] [Method for manufacturing resist underlayer films and semiconductor devices] The following describes how to manufacture a resist underlayer film and a semiconductor device using the resist underlayer film forming composition according to the present invention.

[0069] The resist underlayer film forming composition of the present invention is applied to a substrate used in the manufacture of the above-mentioned semiconductor device (for example, a substrate containing copper on its surface) by a suitable coating method such as a spinner or coater, and then fired to form a resist underlayer film. The firing conditions are appropriately selected from a firing temperature of 80°C to 400°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. The thickness of the underlying film formed is, for example, 10 to 1000 nm, or 20 to 500 nm, or 30 to 400 nm, or 50 to 300 nm.

[0070] Furthermore, an inorganic resist underlayer (hard mask) can be formed on the organic resist underlayer according to the present invention. For example, in addition to the method of forming the silicon-containing resist underlayer (inorganic resist underlayer) formation composition described in WO2009 / 104552A1 by spin coating, a Si-based inorganic material film can be formed by CVD or the like.

[0071] Next, a resist film, such as a photoresist layer, is formed on the resist underlayer film. The photoresist layer can be formed by a well-known method of removing the solvent from the coating film made of the resist underlayer film forming composition, that is, by coating the photoresist composition solution onto the underlayer film and firing it. The thickness of the photoresist is, for example, 50 to 10,000 nm or 100 to 2,000 nm.

[0072] 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).

[0073] Next, a resist pattern is formed by irradiation with light or an electron beam and development. First, exposure is performed through a predetermined mask. Near-ultraviolet, far-ultraviolet, or extreme ultraviolet (e.g., EUV (wavelength 13.5 nm)) is used for exposure. Specifically, i-line (wavelength 365 nm), KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), and F2 excimer laser (wavelength 157 nm) can be used. Among these, i-line (wavelength 365 nm) is preferred. After exposure, post-exposure baking can be performed as needed. Post-exposure baking is performed under conditions appropriately selected from a heating temperature of 70°C to 150°C and a heating time of 0.3 to 10 minutes.

[0074] Furthermore, in this invention, electron beam lithography resists can be used instead of photoresists as the resist. Both negative and positive electron beam resists can be used. Examples include chemically amplified resists consisting of an acid generator and a binder having a group that decomposes with acid to change the alkali dissolution rate, chemically amplified resists consisting of an alkali-soluble binder, an acid generator, and a low-molecular-weight compound that decomposes with acid to change the alkali dissolution rate of the resist, chemically amplified resists consisting of an acid generator, a binder having a group that decomposes with acid to change the alkali dissolution rate, and a low-molecular-weight compound that decomposes with acid to change the alkali dissolution rate of the resist, non-chemically amplified resists consisting of a binder having a group that decomposes with electron beams to change the alkali dissolution rate, and non-chemically amplified resists consisting of a binder having a portion that is cut by an electron beam to change the alkali dissolution rate. When using these electron beam resists, a resist pattern can be formed in the same way as when using photoresists, with an electron beam as the irradiation source.

[0075] Next, development is performed using a developing solution. This removes the photoresist from the exposed areas, for example, if a positive-type photoresist is used, and forms a photoresist pattern. Examples of developers include aqueous solutions of alkali metal hydroxides such as potassium hydroxide and sodium hydroxide, aqueous solutions of quaternary ammonium hydroxides such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, and choline, and alkaline aqueous solutions of amines such as ethanolamine, propylamine, and ethylenediamine. Furthermore, surfactants can be added to these developers. Development conditions are appropriately selected from a temperature of 5 to 50°C and a time of 10 to 600 seconds.

[0076] In this invention, an organic underlayer film (lower layer) can be formed on a substrate, followed by an inorganic underlayer film (intermediate layer), and then a photoresist (upper layer) can be coated on top of that. This narrows the pattern width of the photoresist, and even when the photoresist is thinly coated to prevent pattern collapse, substrate processing becomes possible by selecting an appropriate etching gas. For example, a fluorine-based gas that provides a sufficiently fast etching rate for the photoresist can be used as the etching gas to process the underlayer film of the resist, and a fluorine-based gas that provides a sufficiently fast etching rate for the inorganic underlayer can be used as the etching gas to process the substrate, and an oxygen-based gas that provides a sufficiently fast etching rate for the organic underlayer can be used as the etching gas to process the substrate.

[0077] Then, the inorganic underlayer is removed using the photoresist pattern formed in this way as a protective film, and subsequently, the organic underlayer is removed using the film consisting of the patterned photoresist and inorganic underlayer as a protective film. Finally, the semiconductor substrate is processed using the patterned inorganic and organic underlayers as protective films.

[0078] First, the inorganic underlayer film in the areas where the photoresist has been removed is removed by dry etching to expose the semiconductor substrate. Gases such as tetrafluoromethane (CF4), perfluorocyclobutane (C4F8), perfluoropropane (C3F8), trifluoromethane, carbon monoxide, argon, oxygen, nitrogen, sulfur hexafluoride, difluoromethane, nitrogen trifluoride and chlorine trifluoride, chlorine, trichloroborane and dichloroborane can be used for dry etching of the inorganic underlayer film. It is preferable to use halogen-based gases for dry etching of the inorganic underlayer film, and more preferably fluorine-based gases. Examples of fluorine-based gases include tetrafluoromethane (CF4), perfluorocyclobutane (C4F8), perfluoropropane (C3F8), trifluoromethane, and difluoromethane (CH2F2).

[0079] Subsequently, the organic underlayer is removed using a protective film consisting of a patterned photoresist and an inorganic underlayer. Since inorganic underlayers containing many silicon atoms are difficult to remove by dry etching with oxygen-based gases, organic underlayers are often removed by dry etching with oxygen-based gases.

[0080] Finally, the semiconductor substrate is processed. Preferably, the semiconductor substrate is processed by dry etching using a fluorine-based gas. Examples of fluorinated gases include tetrafluoromethane (CF4), perfluorocyclobutane (C4F8), perfluoropropane (C3F8), trifluoromethane, and difluoromethane (CH2F2).

[0081] Furthermore, an organic anti-reflective coating can be formed on top of the resist underlayer before the photoresist is formed. There are no particular restrictions on the anti-reflective coating composition used; any composition that has been conventionally used in lithography processes can be arbitrarily selected and used, and the anti-reflective coating can be formed by conventional methods, such as coating with a spinner or coater and firing.

[0082] The resist underlayer formed from the resist underlayer forming composition may also have absorption properties for certain wavelengths of light used in the lithography process. In such cases, it can function as an anti-reflective film that prevents reflected light from the substrate. Furthermore, the underlayer formed with the resist underlayer forming composition of the present invention can also function as a hard mask. The underlayer of the present invention can also be used as a layer to prevent interaction between the substrate and the photoresist, a layer that prevents adverse effects on the substrate from materials used in the photoresist or substances generated during exposure to the photoresist, a layer that prevents the diffusion of substances generated from the substrate to the upper photoresist during heating and firing, and a barrier layer to reduce the poisoning effect of the photoresist layer by the semiconductor substrate dielectric layer.

[0083] Furthermore, the underlayer film formed from the resist underlayer film forming composition can be applied to a substrate with via holes formed in a dual damascene process and used as a filler material that can completely fill the holes. It can also be used as a planarizing material to flatten the surface of an uneven semiconductor substrate.

[0084] On the other hand, in order to simplify the process, reduce substrate damage, and lower costs, methods using wet etching with chemicals are being considered as an alternative to dry etching removal. However, conventional resist underlayer formation compositions require a cured film with solvent resistance in order to suppress mixing with the resist during resist coating. Furthermore, a developer is required to resolve the resist during resist patterning, and resistance to this developer is also essential. Therefore, it has been difficult with conventional technology to make the cured film insoluble in resist solvents and developers, but soluble only in wet etching solutions. However, the resist underlayer formation composition according to the present invention makes it possible to provide a resist underlayer that can be etched (removed) with such a wet etching solution.

[0085] The wet etching solution preferably contains an organic solvent, and may also contain an acidic compound or a basic compound. Examples of organic solvents include dimethyl sulfoxide, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, N-ethylpyrrolidone, ethylene glycol, propylene glycol, and diethylene glycol dimethyl ether. Examples of acidic compounds include inorganic acids or organic acids. Examples of inorganic acids include hydrochloric acid, sulfuric acid, nitric acid, and phosphoric acid. Examples of organic acids include p-toluenesulfonic acid, trifluoromethanesulfonic acid, salicylic acid, 5-sulfosalicylic acid, 4-phenolsulfonic acid, camphorsulfonic acid, 4-chlorobenzenesulfonic acid, benzenedisulfonic acid, 1-naphthalenesulfonic acid, acetic acid, propionic acid, trifluoroacetic acid, citric acid, benzoic acid, hydroxybenzoic acid, and naphthalenecarboxylic acid. Furthermore, basic compounds include inorganic bases or organic bases. Examples of inorganic bases include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, quaternary ammonium hydroxides such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, and choline, and amines such as ethanolamine, propylamine, diethylaminoethanol, and ethylenediamine. In addition, the wet etching solution may use only one organic solvent or a combination of two or more. Furthermore, the acidic compound or basic compound may be used only one or a combination of two or more. The amount of the acidic compound or basic compound added to the wet etching solution is 0.01 to 20% by weight, preferably 0.1 to 5% by weight, and particularly preferably 0.2 to 1% by weight. Preferably, the wet etching solution is an organic solvent containing a basic compound, and particularly preferably a mixture containing dimethyl sulfoxide and tetramethylammonium hydroxide.

[0086] Recently, the FOWLP (Fan-Out Wafer Level Package) process has begun to be applied in the field of three-dimensional packaging in semiconductor manufacturing processes, and a resist underlayer can be applied in the RDL (redistribution) process that forms copper wiring.

[0087] In a typical RDL process, the following is described, but this is not limited to this. First, a photosensitive insulating film is deposited on the semiconductor chip, and then the semiconductor chip electrode area is opened by patterning through light irradiation (exposure) and development. Next, a copper seed layer is deposited by sputtering for the formation of copper wiring, which will be the wiring material, through a plating process. Furthermore, a resist underlayer and a photoresist layer are deposited in sequence, and then the resist is patterned by light irradiation and development. Unnecessary resist underlayers are removed by dry etching, and electrolytic copper plating is performed on the copper seed layer between the exposed resist patterns to form the copper wiring that will become the first wiring layer. Furthermore, unnecessary resist, resist underlayers, and copper seed layers are removed by dry etching, wet etching, or both. Furthermore, the formed copper wiring layer is covered again with an insulating film, and then the copper seed layer, resist underlayer, and resist are deposited in that order, and the second copper wiring layer is formed by resist patterning, resist underlayer removal, and copper plating. This process is repeated to form the desired copper wiring, and then bumps for electrode extraction are formed.

[0088] The resist underlayer forming composition according to the present invention allows the resist underlayer to be removed by wet etching, and therefore can be particularly suitably used as a resist underlayer in such RDL processes from the viewpoint of simplifying the process and reducing damage to the processed substrate. [Examples]

[0089] The present invention will now be specifically described with reference to examples, but the present invention is not limited to these examples.

[0090] The equipment used to measure the weight-average molecular weight of the polymers obtained in the synthesis examples below is shown.

[0091] Equipment: Tosoh Corporation HLC-8320GPC GPC Columns: Shodex[Registered Trademark] Asahipak[Registered Trademark] (Showa Denko Corporation) Column temperature: 40℃ Flow rate: 0.35mL / min Eluent: Tetrahydrofuran (THF) Standard sample: Polystyrene (Tosoh Corporation)

[0092] <Synthesis Example 1> 5.00 g of triazinetrione type epoxy compound (product name: TEPIC, manufactured by Nissan Chemical Corporation, epoxy functional value: 10.03 eq. / kg), 6.12 g of 4-hydroxybenzaldehyde, 0.43 g of tetrabutylphosphonium bromide, and 46.17 g of propylene glycol monomethyl ether were added to a reaction flask and heated and stirred under a nitrogen atmosphere at an internal temperature of 105°C for 24 hours. Subsequently, after the reaction solution was cooled to room temperature, a solution of 5.01 g of methyl cyanoacetate dissolved in 20.06 g of propylene glycol monomethyl ether was added to the system and heated and stirred under a nitrogen atmosphere at an internal temperature of 105°C for 4 hours. The resulting reaction product corresponds to formula (1-1), and the weight-average molecular weight Mw, measured in polystyrene equivalent by GPC, was 970. [ka]

[0093] <Synthesis Example 2> 5.00 g of triazinetrione type epoxy compound (product name: TEPIC, manufactured by Nissan Chemical Corporation, epoxy functional value: 10.03 eq. / kg), 6.12 g of 4-hydroxybenzaldehyde, 0.43 g of tetrabutylphosphonium bromide, and 46.17 g of propylene glycol monomethyl ether were added to a reaction flask and heated and stirred under a nitrogen atmosphere at an internal temperature of 105°C for 24 hours. Subsequently, after the reaction solution was cooled to room temperature, a solution of 4.35 g of cyanoacetic acid dissolved in 17.39 g of propylene glycol monomethyl ether was added to the system, and the mixture was further heated and stirred under a nitrogen atmosphere at an internal temperature of 105°C for 4 hours. The resulting reaction product corresponds to formula (1-2), and the weight-average molecular weight Mw, measured in polystyrene equivalent by GPC, was 800. [ka]

[0094] <Synthesis Example 3> 15.00 g of phenol novolac type epoxy resin (product name: DEN, manufactured by Dow Chemical, epoxy functional value: 5.55 eq. / kg), 10.17 g of 4-hydroxybenzaldehyde, 1.41 g of tetrabutylphosphonium bromide, and 39.87 g of propylene glycol monomethyl ether were added to a reaction flask and heated under reflux under a nitrogen atmosphere for 24 hours. Subsequently, a solution of 5.50 g of malononitrile dissolved in 34.99 g of propylene glycol monomethyl ether was added to the system and heated under reflux for a further 4 hours. The resulting reaction product corresponds to formula (1-3), and the weight-average molecular weight Mw, measured in polystyrene equivalent by GPC, was 2,100. [ka]

[0095] <Synthesis Example 4> Under a nitrogen atmosphere, 20 g of glycidyl methacrylate was reacted with 0.25 g of azobisisobutyronitrile in 81 g of propylene glycol monomethyl ether acetate (hereinafter abbreviated as PGMEA) at 75°C for 24 hours to synthesize a polyglycidyl methacrylate polymer. Next, 26.30 g of α-cyano-4-hydroxycinnamic acid was graft polymerized with the epoxy groups of the polyglycidyl methacrylate polymer (20% solid content in PGMEA) in the presence of 0.20 g of benzyltriethylammonium chloride. The graft polymerization reaction was carried out by dissolving each component in a mixed solvent consisting of 464.34 g of ethyl lactate and 154.45 g of PGMEA, with a mass ratio of 75:25 (ethyl lactate:PGMEA). α-cyano-4-hydroxycinnamic acid was dissolved in the solution at approximately 90°C. The reaction was carried out at 120°C for 4-5 hours under a nitrogen atmosphere. [ka]

[0096] <Synthesis Example 5> 10.00 g of triazinetrione-type epoxy compound (product name: TEPIC, manufactured by Nissan Chemical Corporation, epoxy functional value: 10.03 eq. / kg), 12.25 g of 4-hydroxybenzaldehyde, 0.85 g of tetrabutylphosphonium bromide, and 53.90 g of propylene glycol monomethyl ether were added to a reaction flask and heated under reflux under a nitrogen atmosphere for 23 hours. Subsequently, a solution of 6.63 g of malononitrile dissolved in 15.46 g of propylene glycol monomethyl ether was added to the system and heated under reflux for a further 5 hours. The resulting reaction product corresponds to formula (1-5), and the weight-average molecular weight Mw, measured in polystyrene equivalent by GPC, was 800. [ka]

[0097] <Reference synthesis example 1> 3.00 g of bisphenol A type novolac epoxy compound (product name: jER(registered trademark) 157S70, manufactured by Mitsubishi Chemical Corporation, epoxy functional value: 4.78 eq. / kg), 1.75 g of 4-hydroxybenzaldehyde, 0.12 g of tetrabutylphosphonium bromide, and 27.61 g of propylene glycol monomethyl ether were added to a reaction flask and heated and stirred under a nitrogen atmosphere at an internal temperature of 105°C for 24 hours. Subsequently, after the reaction solution was cooled to room temperature, a solution of 1.44 g of methyl cyanoacetate dissolved in 8.13 g of propylene glycol monomethyl ether was added to the system, and the mixture was further heated and stirred under a nitrogen atmosphere at an internal temperature of 105°C for 4 hours. The resulting reaction product corresponds to formula (1-6), and the weight-average molecular weight Mw, measured in polystyrene equivalent by GPC, was 6,600. [ka]

[0098] <Example 1> To 0.544 g of a solution of the reaction product corresponding to formula (1-1) (solid content 17.1% by weight), 0.024 g of tetramethoxymethyl glycoluryl (trade name: POWDER LINK [registered trademark] 1174, manufactured by Japan Scientific Industries, Ltd.) as a crosslinking agent, 0.001 g of pyridinium-p-toluenesulfonate, 0.002 g of Megafac R-30N (manufactured by DIC Corporation, trade name), 7.18 g of propylene glycol monomethyl ether, and 1.98 g of propylene glycol monomethyl ether acetate were added to prepare a solution of the resist underlayer film forming composition.

[0099] <Example 2> To 0.568 g of a solution of the reaction product corresponding to formula (1-2) above (solid content 16.4% by weight), 0.024 g of tetramethoxymethyl glycoluryl (trade name: POWDER LINK [registered trademark] 1174, manufactured by Japan Scientific Industries, Ltd.) as a crosslinking agent, 0.001 g of pyridinium-p-toluenesulfonate, 0.002 g of Megafac R-30N (manufactured by DIC Corporation, trade name), 7.15 g of propylene glycol monomethyl ether, and 1.98 g of propylene glycol monomethyl ether acetate were added to prepare a solution of the resist underlayer film forming composition.

[0100] <Comparative Example 1> To 1.645 g of a solution of the reaction product corresponding to formula (1-3) above (solid content 28.6% by weight), 0.118 g of tetramethoxymethyl glycoluryl (trade name: POWDER LINK [registered trademark] 1174, manufactured by Japan Scientific Industries, Ltd.) as a crosslinking agent, and 0.012 g of pyridinium-p-toluenesulfonate, 7.521 g of propylene glycol monomethyl ether, and 0.708 g of propylene glycol monomethyl ether acetate as crosslinking catalysts were added to prepare a solution of the resist underlayer film forming composition.

[0101] <Comparative Example 2> To 250 g of a solution of the reaction product corresponding to formula (1-4) above, 2.97 g of hexamethoxymethylmelamine ([Trade name] Cymel[Registered Trademark] 303 LF, manufactured by CYTEC) as a crosslinking agent, 0.15 g of p-toluenesulfonic acid monohydrate, 91.37 g of ethyl lactate, and 30.46 g of propylene glycol monomethyl ether acetate as crosslinking catalysts were added to prepare a solution of the resist underlayer film forming composition.

[0102] <Comparative Example 3> To 6.72 g of a solution of the reaction product corresponding to the above formula (1-5) (solid content 25.8% by weight), 0.35 g of tetramethoxymethyl glycoluryl (trade name: POWDER LINK [registered trademark] 1174, manufactured by Japan Scientific Industries, Ltd.) as a crosslinking agent, and 0.02 g of pyridinium-p-toluenesulfonate, 14.54 g of propylene glycol monomethyl ether, and 8.37 g of propylene glycol monomethyl ether acetate as crosslinking catalysts were added to prepare a solution of the resist underlayer film forming composition.

[0103] <Reference example 1> To 0.847 g of a solution of the reaction product corresponding to formula (1-6) above (solid content 11.0% by weight), 0.024 g of tetramethoxymethyl glycoluryl (trade name: POWDER LINK [registered trademark] 1174, manufactured by Japan Scientific Industries, Ltd.) as a crosslinking agent, 0.001 g of pyridinium-p-toluenesulfonate, 0.002 g of Megafac R-30N (manufactured by DIC Corporation, trade name), 6.87 g of propylene glycol monomethyl ether, and 1.98 g of propylene glycol monomethyl ether acetate were added to prepare a solution of the resist underlayer film forming composition.

[0104] <Evaluation of optical constants> To evaluate the optical constants, the lithography resist underlayer compositions prepared in Example 1 and Example 2 were coated onto a silicon wafer using a spin coater to a thickness of approximately 50 nm, and then baked on a hot plate at 200°C for 90 seconds. The n-value (refractive index) and k-value (attenuation coefficient) of the obtained resist underlayer film were measured at wavelengths of 193 nm (ArF excimer laser wavelength), 248 nm (KrF excimer laser wavelength), and 365 nm (i-line wavelength) using a spectroscopic ellipsometer (VUV-VASE, JAWoolam). The results are shown in Table 1. [Table 1] Examples 1 and 2 exhibit appropriate n and k values ​​at 193 nm, 248 nm, and 365 nm. Based on these results, the coating films obtained from the resist underlayer compositions in Examples 1 and 2 possess an anti-reflective function that suppresses reflection (standing waves) from the underlying substrate, which can cause undesirable resist patterns, during lithography processes using radiation such as ArF excimer lasers, KrF excimer lasers, and i-rays. Therefore, they are useful as resist underlayers.

[0105] <Evaluation of etching selectivity> To evaluate the etching selectivity ratio, the lithography resist underlayer film forming compositions prepared in Examples 1 and 2 and Comparative Examples 1 to 3 were coated onto a silicon wafer using a spin coater to a thickness of approximately 100 nm, and then baked on a hot plate at 200°C for 90 seconds. The resulting coated films were then dry-etched using a dry etching apparatus (product name: RIE-10NR, manufactured by Samco Co., Ltd.) with CF4 gas, and the ratio of the dry etching rates of the resist underlayer film (dry etching rate selectivity ratio) was measured. The measurement results of the etching selectivity ratio are shown in Table 2. Note that a higher etching selectivity ratio indicates a faster dry etching rate. [Table 2] From the results above, it can be said that the resist underlayer compositions of Examples 1 and 2 have a higher etching selectivity ratio and therefore a faster dry etching rate compared to the resist underlayer compositions of Comparative Examples 1 to 3. In other words, it is possible to shorten the etching time during dry etching of the resist underlayer, and the reduction in resist thickness can be suppressed when removing the resist underlayer by dry etching. Furthermore, shortening the dry etching time reduces undesirable etching damage to the substrate beneath the resist underlayer, making it particularly useful as a resist underlayer.

[0106] <Resistance test to resist solvents> To evaluate resistance to resist solvents (organic solvents), the resist underlayer compositions prepared in Example 1 and Example 2 were applied to a copper substrate with a thickness of 50 nm, and heated at 200°C for 90 seconds to form a resist underlayer with a thickness of 20 nm. Next, the copper substrate coated with the resist underlayer composition was immersed in propylene glycol monomethyl ether acetate (PGMEA), a common resist solvent, at room temperature for 1 minute, and the resistance of the coated film after immersion was visually observed. The results are shown in Table 3. If the coated film was removed, it was judged that it did not have resistance to resist solvents (organic solvents); if it was not removed, it was judged that it had resistance. [Table 3] From the above results, it can be said that the coated films on the copper substrate in the resist underlayer compositions of Example 1 and Example 2 were not removed (peeled) by PGMEA, indicating good chemical resistance to resist solvents. In other words, the coated films obtained from the resist underlayer compositions of Example 1 and Example 2 are useful as resist underlayers because they can suppress the undesirable peeling phenomenon caused by resist solvents.

[0107] <Solubility test in wet etching solution> To evaluate solubility in wet etching solutions (basic organic solvents), the resist underlayer film-forming compositions prepared in Example 1, Example 2, and Comparative Example 1 were applied to a copper substrate with a thickness of 50 nm, and heated at 200°C for 90 seconds to form a resist underlayer film with a thickness of 20 nm. Next, the copper substrate coated with the resist underlayer film composition was immersed in a dimethyl sulfoxide solution of 0.5 wt% tetramethylammonium hydroxide (TMAH), a basic organic solvent, at 50°C for 5 minutes, and the solubility of the coated film after immersion was visually observed. The results are shown in Table 4. If the coated film was removed, it was judged to have good solubility (peelability) in the basic organic solvent; if it was not removed, it was judged to lack good solubility (peelability). [Table 4] From the above results, the resist underlayer compositions of Example 1 and Example 2 showed sufficient solubility in wet etching solutions (basic organic solvents) on a copper substrate compared to the resist underlayer composition of Comparative Example 1. In other words, the coated films obtained from the resist underlayer compositions of Example 1 and Example 2 exhibit good solubility (extractability) in wet etching solutions, making them useful in semiconductor manufacturing processes where the resist underlayer is removed with a wet etching solution. [Industrial applicability]

[0108] According to the present invention, it is possible to provide a resist underlayer film that exhibits good resistance to resist solvents, which are mainly organic solvents, and resist developers, which are alkaline aqueous solutions, while exhibiting removeability, preferably solubility, only to wet etching solutions.

Claims

1. Formula (2): 【Chemistry 25】 A resist underlayer film forming composition comprising a compound (A) represented by the formula (wherein A1 represents an m-valent organic group containing a triazinetrione, m represents an integer from 1 to 10, R1 and R2 each represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an aryl group having 6 to 40 carbon atoms, X represents an alkyl group having 1 to 10 carbon atoms, a hydroxyl group, an alkoxy group having 1 to 10 carbon atoms, an alkoxycarbonyl group having 1 to 10 carbon atoms, a halogen atom, a cyano group, or a nitro group or a combination thereof, Y represents a direct bond, an ether bond, a thioether bond, or an ester bond, and n represents an integer from 0 to 4), and a solvent.

2. The compound (A) is A compound (a) having m epoxy groups, The following equation (b): 【Chemistry 26】 (In the formula, R² represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an aryl group having 6 to 40 carbon atoms; X represents an alkyl group having 1 to 10 carbon atoms, a hydroxyl group, an alkoxy group having 1 to 10 carbon atoms, an alkoxycarbonyl group having 1 to 10 carbon atoms, a halogen atom, a cyano group, or a nitro group, or a combination thereof; and n represents an integer from 0 to 4.) Compound (b) represented by, Formula (c): 【Chemistry 27】 The resist underlayer film forming composition according to claim 1, which is a reaction product with a compound (c) represented by (wherein R1 represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, which may be substituted).

3. The resist underlayer film forming composition according to claim 1 or 2, further comprising at least one selected from the group consisting of a crosslinking agent, an acid, and an acid generator.

4. A resist underlayer film forming composition according to any one of claims 1 to 3, for application on a substrate containing copper on its surface.

5. A resist underlayer film characterized by being obtained by removing a solvent from a coating film made of the resist underlayer film forming composition according to any one of Claims 1 to 4.

6. A resist underlayer film comprising a resist underlayer film forming composition according to any one of claims 1 to 4, which has been dried or concentrated.

7. A resist underlayer film according to claim 5 or 6, formed on a substrate containing copper on its surface.

8. A substrate having a copper seed layer on its surface and a resist underlayer film according to claim 5 or 6 formed on the copper seed layer.

9. A step of forming a resist underlayer film by applying the resist underlayer film forming composition according to any one of Claims 1 to 4 onto a substrate containing copper on its surface and baking it, A step of forming a resist film by coating the resist on the resist underlayer film and baking it. A step of exposing the resist underlayer film and the semiconductor substrate coated with the resist, and The process of developing and patterning the resist film after exposure. A method for manufacturing patterned substrates, including [the specified method].

10. A step of forming a resist underlayer film on a substrate containing copper on its surface, comprising a resist underlayer film forming composition according to any one of Claims 1 to 4, A step of forming a resist film on the resist underlayer film, A process comprising: forming a resist pattern by irradiating a resist film with light or an electron beam and then developing it; and then removing the resist underlayer film exposed between the resist patterns. A step of performing copper plating between the formed resist patterns, A step of removing the resist pattern and the underlying resist layer film therebenea, A method for manufacturing a semiconductor device, characterized by including the following:

11. The manufacturing method according to claim 10, wherein at least one of the steps for removing the resist underlayer film is performed by wet treatment.

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