Wet-etchable resist underlayer film-forming composition containing a heterocyclic compound having a dicyanostyryl group

Abstract

This invention provides a resist underlayer film that exhibits good resistance to resist solvents and resist developers as alkaline aqueous solutions, while showing removability only to wet etching solutions and preferably solubility. A composition for forming a resist underlayer film comprises: a solvent; and a reaction product of a heterocyclic compound having a dicyanostyrene group, such as a cyclic compound containing an amide group, or, for example, an active proton compound and a heterocyclic compound precursor having an epoxy group.

Description

Technical Field

[0001] The present invention relates to a composition for forming a photoresist underlayer, a photoresist underlayer obtained from the composition for forming a photoresist underlayer, a method for manufacturing a patterned substrate using the composition for forming a photoresist underlayer, a method for manufacturing a semiconductor device, and a heterocyclic compound having a dicyanostyrene group and a method for manufacturing the same. Background Technology

[0002] In semiconductor manufacturing, photolithography is a well-known process that forms a photoresist pattern of desired shape by placing a photoresist underlayer between a substrate and a photoresist film formed thereon. After the photoresist pattern is formed, the photoresist underlayer is removed, and the substrate is processed; this process primarily uses dry etching. Furthermore, dry etching is also used in the process of removing unwanted photoresist patterns and the photoresist underlayer after substrate processing. However, for the purpose of simplifying the process and reducing damage to the processed substrate, wet etching using chemical solutions is sometimes used.

[0003] Patent Document 1 discloses a modified ARC composition, which consists of...

[0004] a. A product of the reaction of a pre-selected phenol- or carboxylic acid-functional dye with a poly(epoxide) resin having an epoxy functionality of greater than 2.0 and less than 10; the product having photo-absorption properties that are effective for ARC coating of the substrate.

[0005] b. Alkylated amino plastic crosslinking agents derived from melamine, urea, benzoguanamine, or glycourea;

[0006] c. a protic acid curing catalyst; and d. a solvent system containing low or medium boiling alcohols; wherein the alcohols comprise at least twenty (20) wt% of the total solvent content and the molar ratio of the alcohols is at least 4 to 1 (4:1) relative to each amount of hydroxymethyl units of the amino plastic;

[0007] It is composed of, and e. has ether or ester bonds derived from poly(epoxide) molecules;

[0008] The improved ARC eliminates the mixing of resist / ARC components through the thermosetting action of ARCs, providing improved optical density under target exposure and ARC layer thickness, and eliminating the need for high molecular weight thermoplastic ARC adhesives with high solubility.

[0009] However, no poly(epoxide) resins with an epoxy functionality of 10 or more have been disclosed, nor have any epoxy compounds containing heterocyclic compounds been disclosed.

[0010] Existing technical documents

[0011] Patent documents

[0012] Patent Document 1: Japanese Patent Publication No. 11-511194 Summary of the Invention

[0013] The problem that the invention aims to solve

[0014] When a photoresist is coated onto a photoresist underlayer and exposed and developed using radiation (e.g., ArF excimer laser, KrF excimer laser, i-ray), the photoresist underlayer must possess good resistance to photoresist solvents, preventing peeling or damage due to the solvent, in order to obtain the desired photoresist pattern. Furthermore, it must also possess good resistance to photoresist developer solutions (alkaline solutions) primarily used in the photoresist development process, preventing peeling or damage. Further, to obtain the desired photoresist pattern, the photoresist underlayer must possess anti-reflective properties, suppressing reflections from the substrate to the radiation used in the photolithography process and suppressing the deterioration of the photoresist pattern caused by standing waves. Furthermore, when the photoresist underlayer is removed by dry etching, a high etch rate (high etching rate) photoresist underlayer must be used to remove it quickly without damaging the substrate. In particular, when the resist underlayer is removed by wet etching with a chemical solution, the resist underlayer is required to have sufficient solubility in the wet etching solution so that it can be easily removed from the substrate.

[0015] On the other hand, organic solvents are used in wet etching solutions for removing the resist and the underlying resist film to minimize damage to the processed substrate. Furthermore, alkaline organic solvents are used to improve the removeability of the resist and the underlying resist film. However, the underlying resist film exhibits good resistance primarily to resist solvents that are organic solvents and resist developers that are alkaline aqueous solutions, while its removeability and, preferably its solubility, is limited in the prior art, only to wet etching solutions. The object of the present invention is to solve the above-mentioned problems.

[0016] Methods for solving problems

[0017] The present invention includes the following solutions.

[0018] [1] A composition for forming a resist underlayer film, comprising a heterocyclic compound having a dicyanostyrene group and a solvent.

[0019] [2] In the composition for forming a resist underlayer film according to [1], the heterocyclic compound having a dicyanostyrene group is a cyclic compound containing an amide group.

[0020] [3] The composition for forming a lower layer film of the resist according to [1] or [2] is wherein the heterocyclic compound having a dicyanostyrene group is an active proton compound and a reaction product of a heterocyclic compound precursor having an epoxy group.

[0021] [4] In the composition for forming a resist underlayer film according to [1] or [2], the dicyanostyrene group is represented by the following formula (1).

[0022]

[0023] (In formula (1), X represents alkyl, hydroxyl, alkoxy, alkoxycarbonyl, halogen atom, cyano or nitro, R represents hydrogen atom, alkyl or aryl, n represents an integer from 0 to 4, and * represents the bonding part of the heterocyclic compound).

[0024] [5] According to the composition for forming a resist underlayer film as described in [1], the heterocyclic compound having a dicyanostyrene group is represented by the following formula (2).

[0025]

[0026] (In equation (2),

[0027] Q represents a group from which m terminal atoms have been removed from a heterocyclic compound.

[0028] m is an integer from 1 to 4.

[0029] Each of the m A atoms is independently a directly bonded or alkylene group having 1 to 10 carbon atoms. The alkylene group may be branched and may be substituted. The alkylene group may contain ether bonds, thioether bonds, or ester bonds.

[0030] Each of the m B's independently represents a direct bond, an ether bond, a thioether bond, or an ester bond.

[0031] Each of the m R1 to R3 atoms independently represents a hydrogen atom, a methyl group, or an ethyl group.

[0032] Each of the m L's is independently represented by the following equation (3),

[0033]

[0034] (In formula (3), Y represents an ether bond, a thioether bond, or an ester bond,

[0035] R represents a hydrogen atom, an alkyl group, or an aryl group.

[0036] n represents an integer from 0 to 4.

[0037] Each of the n X's independently represents an alkyl, hydroxyl, alkoxy, alkoxycarbonyl, halogen, cyano, or nitro group.

[0038] [6] The composition for forming a resist underlayer film according to any one of [1] to [4], wherein the heterocyclic ring is triazine trione.

[0039] [7] In the composition for forming a lower layer of resist film according to [5], Q in the above formula (2) is triazine trione.

[0040] [8] In the composition for forming a resist underlayer film according to [4] or [5], R in the above formula (1) and / or formula (3) is a hydrogen atom.

[0041] [9] In the composition for forming a resist underlayer film according to [5], Y in the above formula (3) represents an ether bond or an ester bond.

[0042]

[10] In the composition for forming a resist underlayer film according to [5], A in the above formula (2) represents direct bonding.

[0043]

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

[10] further comprises a crosslinking agent and / or a crosslinking catalyst.

[0044]

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

[11] is used on a substrate containing copper on its surface.

[0045]

[13] A resist underlayer film, characterized in that it is obtained by removing solvent from a coating film formed by the resist underlayer film forming composition as described in any one of [1] to

[12] .

[0046]

[14] The resist underlayer film according to

[13] is formed on a substrate containing copper on its surface.

[0047]

[15] A method for manufacturing a substrate with patterned surface includes the following steps: coating a resist underlayer film forming composition as described in any one of [1] to

[12] onto a substrate with copper surface and baking it to form a resist underlayer film; coating a resist onto the resist underlayer film and baking it to form a resist film; exposing a semiconductor substrate covered with the resist underlayer film and the resist; developing the exposed resist film and performing patterning.

[0048]

[16] A method for manufacturing a semiconductor device, characterized in that it comprises the following steps:

[0049] A process of forming a resist underlayer film formed by any one of the resist underlayer film forming compositions described in [1] to

[12] on a substrate containing copper on its surface;

[0050] The process of forming a resist film on the aforementioned lower resist film;

[0051] The process of irradiating a resist film with light or electron beams and then developing it to form a resist pattern, followed by the process of removing the underlying resist film exposed between the resist patterns;

[0052] A copper plating process is performed between the aforementioned resist patterns, preferably between resist patterns after the underlayer of the resist film has been removed; and

[0053] The process of removing the resist pattern and the underlying resist film.

[0054]

[17] According to the manufacturing method described in

[16] , at least one step of removing the resist underlayer film is performed by wet treatment.

[0055]

[18] The compounds shown in formula (4) below.

[0056]

[0057] (In formula (4), A1 to A3 are each independently a directly bonded or substituted alkylene groups with 1 to 6 carbon atoms.)

[0058] B1 through B3 each independently represent direct bonding, ether bonding, thioether bonding, or ester bonding.

[0059] R4~R 12 Each can independently represent a hydrogen atom, a methyl group, or an ethyl group.

[0060] Z1 to Z3 are represented by equation (5).

[0061]

[0062] (In equation (5),

[0063] Each of the n X's independently represents an alkyl, hydroxyl, alkoxy, alkoxycarbonyl, halogen, cyano, or nitro group.

[0064] Y represents an ether bond, a thioether bond, or an ester bond.

[0065] R represents a hydrogen atom, an alkyl group, or an aryl group.

[0066] n represents an integer from 0 to 4.

[0067]

[19] A method for manufacturing a heterocyclic compound having a dicyanostyrene group, comprising the steps of reacting a heterocyclic compound precursor having an epoxy group with a proton compound having a dicyanostyrene group.

[0068]

[20] A method for manufacturing a heterocyclic compound having a dicyanostyrene group, comprising the steps of: reacting a heterocyclic compound precursor having an epoxy group with an active proton compound having a carbonyl group to obtain an intermediate; and cyanotyping the intermediate.

[0069] The effects of the invention

[0070] According to the present invention, a resist underlayer film can be provided that exhibits good resistance to resist solvents that are organic solvents and resist developers that are alkaline aqueous solutions, while exhibiting removability only to wet etching solutions and preferably solubility. Detailed Implementation

[0071] [Composition for forming the lower layer film of the resist]

[0072] The composition for forming a resist underlayer film according to the present invention comprises a heterocyclic compound having a dicyanostyrene group and a solvent.

[0073] [Heterocyclic compounds containing dicyanostyrene groups]

[0074] In this invention, dicyanostyrene group refers to the group represented by the following formula.

[0075]

[0076] (In the formula, X represents alkyl, hydroxyl, alkoxy, alkoxycarbonyl, halogen atom, cyano or nitro, R represents hydrogen atom, alkyl or aryl, n represents an integer from 0 to 4, and * represents the bonding part with the heterocyclic compound.)

[0077] In this invention, the term "heterocyclic compound" refers to substances included in the term "heterocyclic compound" as commonly used in organic chemistry, without particular limitation. Examples include, for instance, furan, thiophene, pyrrole, imidazole, pyran, pyridine, pyrimidine, pyrazine, pyrrolidine, piperidine, piperazine, morpholine, quinine ring, indole, purine, quinoline, isoquinoline, chromene, thiathrone, phenothiazine, and phenanthrene. azine, Ton, acridine, phenazine, carbazole, hydantoin, triazine, cyanuric acid, etc.

[0078] Heterocyclic compounds having a dicyanostyrene group are preferably cyclic compounds containing an amide group. Furthermore, heterocyclic compounds having a dicyanostyrene group are preferably reaction products of a heterocyclic compound precursor having an epoxy group and an active proton compound having a dicyanostyrene group, or reaction products obtained by cyanohydrating a heterocyclic compound precursor having an epoxy group and an active proton compound having a carbonyl group as a reaction intermediate.

[0079] The term "active proton compound" as used in this invention refers to substances included in the term "active proton compound" as commonly used in organic chemistry, without any particular limitation.

[0080] Examples of the aforementioned active proton compounds include compounds having hydroxyl groups, compounds having carboxyl groups, compounds having thiol groups, compounds having amino groups, and compounds having imide groups, but compounds having hydroxyl or carboxyl groups are preferred.

[0081] Examples of carbonyl groups in the above-mentioned active proton compounds containing carbonyl groups include formyl (aldehyde) and ketone groups, but formyl groups are preferred.

[0082] The preferred dicyanostyrene group is represented by the following formula (1-1).

[0083]

[0084] (In formula (1-1), R1 to R3 represent hydrogen atoms, methyl or ethyl groups,

[0085] X represents alkyl, hydroxy, alkoxy, alkoxycarbonyl, cyano, or nitro.

[0086] Y represents an ether bond, a thioether bond, or an ester bond.

[0087] R represents a hydrogen atom, an alkyl group, or an aryl group.

[0088] n represents an integer from 0 to 4, and ** represents the bonding portion of the heterocyclic compound precursor.

[0089] The preferred heterocycle is a triazine trione. In the preferred formula (1-1), R is a hydrogen atom. In the preferred formula (1-1), Y is represented by an ether bond or an ester bond.

[0090] Heterocyclic compounds having a dicyanostyrene group are preferably represented by the following formula (2).

[0091]

[0092] In equation (2),

[0093] Q represents a group from which m terminal atoms have been removed from a heterocyclic compound.

[0094] m is an integer from 1 to 4.

[0095] Each of the m A atoms is independently a directly bonded or alkylene group having 1 to 10 carbon atoms. The alkylene group may be branched and may be substituted. The alkylene group may contain ether bonds, thioether bonds, or ester bonds.

[0096] Each of the m B's independently represents a direct bond, an ether bond, a thioether bond, or an ester bond.

[0097] Each of the m R1 to R3 atoms independently represents a hydrogen atom, a methyl group, or an ethyl group.

[0098] Each of the m L's is independently represented by the following equation (3),

[0099]

[0100] (In formula (3), Y represents an ether bond, a thioether bond, or an ester bond,

[0101] R represents a hydrogen atom, an alkyl group, or an aryl group.

[0102] n represents an integer from 0 to 4.

[0103] Each of the n X's independently represents an alkyl, hydroxyl, alkoxy, alkoxycarbonyl, halogen, cyano, or nitro group.

[0104] In preferred formula (3), Q is triazine trione. In preferred formula (3), R is a hydrogen atom. In preferred formula (3), Y is represented by an ether bond or an ester bond.

[0105] Heterocyclic compounds having a dicyanostyrene group are preferably represented by the following formula (4).

[0106]

[0107] (In equation (4), A4~A 12 Each is independently a directly bonded or substituted alkylene group having 1 to 6 carbon atoms.

[0108] B1 through B3 each independently represent direct bonding, ether bonding, thioether bonding, or ester bonding.

[0109] R1 through R9 each independently represent a hydrogen atom, a methyl group, or an ethyl group.

[0110] X1 to X3 are represented by equation (5).

[0111]

[0112] (In equation (5),

[0113] Each of the n X's independently represents an alkyl, hydroxyl, alkoxy, alkoxycarbonyl, halogen, cyano, or nitro group.

[0114] Y represents an ether bond, a thioether bond, or an ester bond.

[0115] R represents a hydrogen atom, an alkyl group, or an aryl group.

[0116] n represents an integer from 0 to 4.

[0117] Examples of the aforementioned alkyl groups include straight-chain or branched alkyl groups that may or may not have substituents, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl, n-hexyl, isohexyl, n-heptyl, n-octyl, cyclohexyl, 2-ethylhexyl, n-nonyl, isononyl, p-tert-butylcyclohexyl, n-decyl, n-dodecylnonyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecanyl, octadecyl, nonadecanyl, and eicosyl. Preferably, the alkyl group has 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, even more preferably 1 to 8 carbon atoms, and most preferably 1 to 4 carbon atoms.

[0118] Examples of alkoxy groups include those in which an oxygen atom is bonded to an alkyl group. Examples include methoxy, ethoxy, propoxy, and butoxy groups.

[0119] Examples of alkoxycarbonyl groups include those in which an oxygen atom and a carbonyl group are bonded to the aforementioned alkyl group. Examples include methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, and butoxycarbonyl.

[0120] Examples of alkylene groups include divalent groups from which hydrogen atoms have been further removed. Examples include methylene, ethylene, 1,3-propylene, and 1,2-propylene.

[0121] Examples of the aforementioned arylene groups include phenylene, o-methylphenylene, m-methylphenylene, p-methylphenylene, α-naphthylene, β-naphthylene, o-biphenylene, m-biphenylene, p-biphenylene, 1-anthraylene, 2-anthraylene, 9-anthraylene, 1-phenanthylene, 2-phenanthylene, 3-phenanthylene, 4-phenanthylene, and 9-phenanthylene. Preferably, the arylene group has 6 to 14 carbon atoms, and more preferably, it has 6 to 10 carbon atoms.

[0122] The term "halogen atom" usually refers to the atoms of fluorine, chlorine, bromine, and iodine.

[0123] The ester bond referred to in this invention includes -COO- and -OCO-.

[0124] [Modulation of heterocyclic compounds with dicyanostyrene groups]

[0125] The above-mentioned heterocyclic compounds having a dicyanostyrene group can be obtained by the following two methods.

[0126] (Synthetic method 1 for heterocyclic compounds with dicyanostyrene group)

[0127] It can be obtained by reacting an active proton compound having a dicyanostyrene group with a heterocyclic compound precursor having an epoxy group by any known method.

[0128] Reactive proton compounds having a dicyanostyrene group are obtained by cyanohydrinizing a reactive proton compound having a carbonyl group. If an illustrative synthetic scheme is given, it is described below.

[0129] Synthesis of protonated compounds with dicyanostyrene groups

[0130]

[0131] If we illustrate a synthetic scheme for reacting an active proton compound having a dicyanostyrene group with a heterocyclic compound precursor having an epoxy group, it is as follows.

[0132] Synthesis of heterocyclic compounds with dicyanostyrene groups 1

[0133]

[0134] (Synthesis of heterocyclic compounds with dicyanostyrene group 2)

[0135] The process includes the following steps: reacting a heterocyclic compound precursor having an epoxy group with a reactive proton compound having a carbonyl group to obtain an intermediate compound; and cyaniding (dicyanation) the intermediate compound by, for example, the method described above. If an illustrative synthetic scheme is given, it is as follows.

[0136] Synthesis of heterocyclic compounds with dicyanostyrene group 2

[0137]

[0138] As precursors of heterocyclic compounds having epoxy groups in this application, examples can be made of the following formulas (B-1) to (B-17), but are not limited to them.

[0139]

[0140] As the so-called active proton compound with a carbonyl group in this application, examples can be made of the following formulas (C-1) to (C-40), but are not limited to them.

[0141]

[0142]

[0143] Examples of catalysts that can activate epoxy groups and can be used in the above reactions include, for example, ethyltriphenyl bromide. Tetrabutyl bromide That kind of season Salts, such as quaternary ammonium salts like benzyltriethylammonium chloride. The amount used is typically 0.001 to 1 equivalent relative to the epoxy group.

[0144] The above reactions can proceed even without a solvent, but they are usually carried out using a solvent. Any solvent that does not hinder the reaction can be used. Examples include 1,2-dimethoxyethane, diethylene glycol dimethyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, tetrahydrofuran, and dimethyl ether. Alkane and other ethers.

[0145] The reaction temperature is typically between 40℃ and 200℃. The reaction time varies depending on the reaction temperature, but is usually between 30 minutes and 50 hours.

[0146] The weight-average molecular weight (Mw) of compounds obtained by operating as described above is typically 200–3,000 or 500–2,000.

[0147] [solvent]

[0148] As a solvent for the resist underlayer film forming composition of the present invention, any solvent capable of dissolving the aforementioned heterocyclic compound containing dicyanostyrene and other components may be used without particular limitation. In particular, since the resist underlayer film forming composition of the present invention is used in a uniform solution state, it is recommended to use it in solvents commonly used in photolithography processes, taking into account its coating performance.

[0149] Examples of such solvents include, for instance, methyl cellosolve acetate, ethyl cellosolve acetate, propylene glycol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, methyl isobutyl methanol, 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 ethoxylate, ethyl hydroxyacetate, methyl 2-hydroxy-3-methylbutyrate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate Ester, ethyl 3-ethoxypropionate, methyl 3-ethoxypropionate, methyl pyruvate, ethyl pyruvate, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene 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, isopropyl lactate Butyl acetate, 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 acetate, ethyl 2-hydroxy-2-methylpropionate, methyl 3-methoxy-2-methylpropionate, methyl 2-hydroxy-3-methylbutyrate, ethyl methoxyethyl acetate, ethyl ethoxyethyl acetate, 3-methyl Methyl oxypropionate, ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-methoxybutylacetate, 3-methoxypropylacetate, 3-methyl-3-methoxybutylacetate, 3-methyl-3-methoxybutylpropionate, 3-methyl-3-methoxybutylbutyrate, 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, etc. These solvents can be used alone or in combination of two or more.

[0150] Preferred ingredients include propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, ethyl lactate, butyl lactate, and cyclohexanone. Propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate are particularly preferred.

[0151] [Cross-linking agent component]

[0152] The resist underlayer film forming composition of the present invention may include a crosslinking agent component. Examples of such crosslinking agents include melamine-based, substituted urea-based, or polymeric forms thereof. Preferably, the crosslinking agent has at least two crosslinking-forming substituents, such as methoxymethylated glycourea (e.g., tetramethoxymethylated glycourea), butoxymethylated glycourea, methoxymethylated melamine, butoxymethylated melamine, methoxymethylated benzoguanamine, butoxymethylated benzoguanamine, methoxymethylated urea, butoxymethylated urea, or methoxymethylated thiourea. Condensates of these compounds may also be used.

[0153] Furthermore, as the aforementioned crosslinking agent, compounds containing crosslinking substituents with aromatic rings (e.g., benzene rings, naphthalene rings) can be used.

[0154] Examples of such compounds include compounds having a partial structure of formula (6), polymers or oligomers having repeating units of formula (7).

[0155]

[0156] The above R a R b R c and R d Alkyl groups having 1 to 10 hydrogen or carbon atoms, where na, nb, nc, and nd each represent an integer from 0 to 3. The above examples can be used for the alkyl groups.

[0157] Examples of compounds, polymers, and oligomers of formulas (6) and (7) are shown below.

[0158]

[0159] The above-mentioned compounds can be obtained as products of Asahi Organic Materials Co., Ltd. and Honshu Chemical Industry Co., Ltd. For example, the compound of formula (D-24) in the above-mentioned crosslinking agent can be obtained by Asahi Organic Materials Co., Ltd. under the trade name TM-BIP-A.

[0160] The amount of crosslinking agent added varies depending on the coating solvent used, the substrate used, the required solution viscosity, the required film shape, etc., but is 0.001 to 80% by mass relative to the total solid content, preferably 0.01 to 50% by mass, and more preferably 0.05 to 40% by mass. These crosslinking agents may sometimes undergo crosslinking reactions caused by self-condensation, but when crosslinking substituents are present in the reaction products of the present invention, crosslinking reactions can occur with these crosslinking substituents.

[0161] [Acids and / or acid-producing agents]

[0162] The composition for forming the resist underlayer film of the present invention may contain acid and / or acid-generating agent.

[0163] Examples of acids include p-toluenesulfonic acid, trifluoromethanesulfonic acid, and pyridine. Trifluoromethanesulfonic acid, pyridine p-Toluenesulfonic acid, pyridine Phenolic sulfonic acid, salicylic acid, 5-sulfosalicylic acid, 4-phenol sulfonic acid, camphor sulfonic acid, 4-chlorobenzene sulfonic acid, benzene disulfonic acid, 1-naphthalene sulfonic acid, citric acid, benzoic acid, hydroxybenzoic acid, naphthoic acid, etc.

[0164] Acids may be used alone, or in combination of two or more. The mixing amount relative to the total solid content is typically 0.0001 to 20% by mass, preferably 0.0005 to 10% by mass, and more preferably 0.01 to 3% by mass.

[0165] Examples of acid-producing agents include thermal acid-producing agents and photo-producing acid-producing agents.

[0166] Pyridine is an example of a heat-generating acid agent. Trifluoromethanesulfonic acid, pyridine p-Toluenesulfonic acid, pyridine Phenol sulfonic acid, 2,4,4,6-tetrabromocyclohexadienone, benzoin toluene sulfonate, 2-nitrobenzyl toluene sulfonate, and other organic alkyl sulfonates, etc.

[0167] Photoacid-generating agents produce acid during the exposure of the photoresist. Therefore, the acidity of the lower film can be adjusted. This is a method to match the acidity of the lower film with that of the upper photoresist. Furthermore, by adjusting the acidity of the lower film, the pattern shape of the photoresist formed on the upper layer can be adjusted.

[0168] Examples of photoacid-generating agents included in the resist lower layer film forming composition of the present invention include: Salt compounds, sulfonylimide compounds, and disulfonyldiazomethane compounds, etc.

[0169] As Salt compounds, such as diphenyliodine, can be cited as an example. Hexafluorophosphate, diphenyliodine Trifluoromethanesulfonate, diphenyliodine Nonafluoro-n-butane sulfonate, diphenyl iodide Perfluorooctane sulfonate, diphenyl iodide Camphor sulfonate, bis(4-tert-butylphenyl)iodine Camphor sulfonate and bis(4-tert-butylphenyl)iodine Iodine, such as trifluoromethanesulfonate Sulfonate compounds, and sulfonate compounds such as triphenylsulfonium hexafluoroantimonate, triphenylsulfonium nonafluoro n-butane sulfonate, triphenylsulfonium camphor sulfonate, and triphenylsulfonium trifluoromethane sulfonate.

[0170] Examples of sulfonylimide compounds include N-(trifluoromethanesulfonyloxy)succinimide, N-(nonafluoron-butanesulfonyloxy)succinimide, N-(camphorsulfonyloxy)succinimide, and N-(trifluoromethanesulfonyloxy)naphthalenediformimide.

[0171] Examples of disulfonyldiazomethane compounds include, for example, bis(trifluoromethylsulfonyl)diazomethane, bis(cyclohexylsulfonyl)diazomethane, bis(phenylsulfonyl)diazomethane, bis(p-toluenesulfonyl)diazomethane, bis(2,4-dimethylbenzenesulfonyl)diazomethane, and methylsulfonyl-p-toluenesulfonyldiazomethane.

[0172] Acid-producing agents can be used alone, or two or more can be used in combination.

[0173] When using an acid-generating agent, its proportion, relative to 100 parts by weight of the solid component of the composition for forming the lower layer of the resist film, is typically 0.0001 to 20% by weight, preferably 0.0005 to 10% by weight, and more preferably 0.01 to 3% by weight.

[0174] [Other ingredients]

[0175] In order to prevent pinholes, streaks, etc., and to further improve the coating properties against surface unevenness, a surfactant may be mixed into the resist lower film forming composition of the present invention. Examples of surfactants include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, and polyoxyethylene oil-based ether; polyoxyethylene alkyl allyl ethers such as polyoxyethylene octylphenol ether and polyoxyethylene nonylphenol ether; polyoxyethylene / polyoxypropylene block copolymers; sorbitol monolaurate, sorbitol monopalmitate, sorbitol monostearate, sorbitol monooleate, sorbitol monooleate, sorbitol trioleate, and sorbitol tristearate; and polyoxyethylene sorbitol monolaurate, polyoxyethylene sorbitol monopalmitate, polyoxyethylene sorbitol monostearate, polyoxyethylene sorbitol trioleate, and polyoxyethylene sorbitol tristearate. Polyoxyethylene sorbitan fatty acid esters and other non-ionic surfactants, such as acid esters, Etotron EF301, EF303, EF352 (manufactured by Toto Co., Ltd. , trade name), メガファック F171, F173, R-40, R-40N, R-40LM (made by DIC Co., Ltd., trade name), フロラード FC430, F Fluoropolymer surfactants such as C431 (manufactured by Sumitomo Silem Co., Ltd., trade name), Asahigard AG710, Servolon S-382, SC101, SC102, SC103, SC104, SC105, and SC106 (manufactured by Asahi Glass Co., Ltd., trade name), and organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.) are used. The amount of these surfactants mixed is typically 2.0% by mass or less, preferably 1.0% by mass or less, relative to the total solid content of the photoresist underlayer film material. These surfactants can be used alone or in combination of two or more. When using surfactants, the proportion is 0.0001 to 5 parts by mass, 0.001 to 1 part by mass, or 0.01 to 0.5 parts by mass relative to 100 parts by mass of the solid content of the photoresist underlayer film forming composition.

[0176] In the resist underlayer film forming composition of the present invention, light absorbers, rheology modifiers, adhesive additives, etc., may be added. Rheology modifiers are effective in improving the flowability of the underlayer film forming composition. Adhesive additives are effective in improving the adhesion between the semiconductor substrate or resist and the underlayer film.

[0177] As light absorbers, commercially available light absorbers listed in publications such as "Technology and Market of Industrial Pigments" (CMC Publishing) and "Dye Handbook" (Organic Synthetic Chemistry Society) are suitable, including CI Disperse 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; and CI Disperse Orange 1, 5, and 13. 25, 29, 30, 31, 44, 57, 72 and 73; CI Disperse Red 1, 5, 7, 13, 17, 19, 43, 50, 54, 58, 65, 72, 73, 88, 117, 137, 143, 199 and 210; CI Disperse Violet 43; CI Disperse Blue 96; CI Fluorescent Whitening Agent 112, 135 and 163; CI Solvent Orange 2 and 45; CI Solvent Red 1, 3, 8, 23, 24, 25, 27 and 49; CI Pigment Green 10; CI Pigment Brown 2, etc. The above-mentioned light absorbers are generally mixed in a proportion of 10% by mass or less, preferably 5% by mass or less, relative to the total solid components of the composition for forming the resist underlayer film.

[0178] Rheology modifiers are mainly added to improve the flowability of the composition for forming the lower resist film, especially during the baking process, to improve the uniformity of the film thickness of the lower resist film and to improve the filling ability of the composition for forming the lower resist film into the pores. Specific examples include phthalic acid derivatives such as dimethyl phthalate, diethyl phthalate, diisobutyl phthalate, dihexyl phthalate, and butyl isodecyl phthalate; adipic acid derivatives such as di-n-butyl adipate, diisobutyl adipate, diisooctyl adipate, and octyl decyl adipate; maleic acid derivatives such as di-n-butyl maleate, diethyl maleate, and dinonyl maleate; 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 proportions of less than 30% by mass relative to the total solid components of the composition for forming the resist underlayer film.

[0179] Adhesive aids are mainly added to improve the adhesion between the substrate or photoresist and the composition used to form the underlying film of the photoresist, especially to prevent the photoresist from peeling off during development. Specific examples include chlorosilanes such as trimethylchlorosilane, dimethylhydroxymethylchlorosilane, methyldiphenylchlorosilane, and chloromethyldimethylchlorosilane; alkoxysilanes such as trimethylmethoxysilane, dimethyldiethoxysilane, methyldimethoxysilane, dimethylhydroxymethylethoxysilane, diphenyldimethoxysilane, and phenyltriethoxysilane; silazanes such as hexamethyldisilazane, N,N'-bis(trimethylsilyl)urea, dimethyltrimethylsilylamine, and trimethylsilylimidazolium; silanes such as hydroxymethyltrichlorosilane, γ-chloropropyltrimethoxysilane, γ-aminopropyltriethoxysilane, and γ-epoxypropoxypropyltrimethoxysilane; and benzotriazole, benzimidazole, indazole, imidazole, 2-mercaptobenzimidazole, 2-mercaptobenzothiazole, and 2-mercaptobenzo[]. Heterocyclic compounds such as azoles, urazoles, thiouracil, mercaptoimidazoles, and mercaptopyrimidines, ureas such as 1,1-dimethylurea and 1,3-dimethylurea, or thiourea compounds. These adhesive aids are typically formulated in proportions of less than 5% by mass, preferably less than 2% by mass, relative to the total solids content of the composition for forming the resist underlayer.

[0180] The solid content of the resist underlayer film forming composition of the present invention is typically 0.1 to 70% by mass, preferably 0.1 to 60% by mass. The solid content refers to the percentage of all components remaining after removing the solvent from the resist underlayer film forming composition. The proportion of the above-mentioned reaction products in the solid content is preferably in the following order: 1 to 100% by mass, 1 to 99.9% by mass, 50 to 99.9% by mass, 50 to 95% by mass, and 50 to 90% by mass.

[0181] One criterion for evaluating whether a resist underlayer film forming composition is a homogeneous solution is to observe the permeability of a specific microfilter. The resist underlayer film forming composition of the present invention exhibits a homogeneous solution state when passing through a microfilter with a pore size of 0.1 μm.

[0182] Examples of materials for the aforementioned microfilters include fluorinated resins 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.

[0183] [Substrate]

[0184] In this invention, the 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-k material coated substrates.

[0185] It should be noted that recently, in the field of three-dimensional mounting in semiconductor manufacturing processes, the FOWLP process has begun to be applied for the purpose of improving high-speed response and power saving by shortening the wiring length between semiconductor chips. In the RDL (rewiring) process for fabricating wiring between semiconductor chips, copper (Cu) is used as the wiring component. With the miniaturization of copper wiring, an anti-reflective film (a composition for forming a resist underlayer) is required. The resist underlayer composition involved in this invention can also be suitable for application to substrates with copper surfaces.

[0186] [Resist underlayer film and semiconductor device manufacturing method]

[0187] The following describes a method for manufacturing a photoresist underlayer film and a semiconductor device using the photoresist underlayer film formation composition of the present invention.

[0188] The resist underlayer film of the present invention is formed by coating the substrate (e.g., a substrate with copper on its surface) used in the manufacture of the aforementioned semiconductor device with the resist underlayer film composition of the present invention by a suitable coating method such as a spin coater or a coating machine, and then firing it.

[0189] 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. Here, the thickness of the formed lower layer film is, for example, 10 to 1000 nm, 20 to 500 nm, 30 to 400 nm, or 50 to 300 nm.

[0190] In addition, an inorganic photoresist underlayer film (hard mask) can also be formed on the organic photoresist underlayer film of the present invention. For example, in addition to the method described in WO2009 / 104552A1 for forming a silicon-containing photoresist underlayer film (inorganic photoresist underlayer film) by spin coating, a Si-based inorganic material film can also be formed by CVD or the like.

[0191] Next, a photoresist film, such as a photoresist layer, is formed on the photoresist underlayer film. The formation of the photoresist layer can be performed by a known method of removing solvent from a coating film formed from the composition for forming the photoresist underlayer film, i.e., coating and firing a photoresist composition solution onto the underlayer film. The film thickness as the photoresist is, for example, 50–10000 nm, or 100–2000 nm.

[0192] As a photoresist formed on the underlying resist film, there are no particular limitations on the light exposure used. Both negative and positive photoresists can be used. Examples include: positive photoresists composed of phenolic varnish resin and 1,2-naphthoquinone diazonyl sulfonate; chemically amplified photoresists composed of a binder having groups that increase the rate of alkali dissolution through acid decomposition and a photoacid generator; chemically amplified photoresists composed of low-molecular-weight compounds that increase the rate of alkali dissolution through acid decomposition, alkali-soluble binders, and photoacid generators; and chemically amplified photoresists composed of a binder having groups that increase the rate of alkali dissolution through acid decomposition, low-molecular-weight compounds that increase the rate of alkali dissolution through acid decomposition, and photoacid generators, etc. Examples include APEX-E manufactured by Sprint, PAR710 manufactured by Sumitomo Chemical Industries, Ltd., and SEPR430 manufactured by Shin-Etsu Chemical Industries, Ltd. Furthermore, examples include fluorinated polymer photoresists as described in Proc. SPIE, Vol. 3999, 330-334 (2000), Proc. SPIE, Vol. 3999, 357-364 (2000), and Proc. SPIE, Vol. 3999, 365-374 (2000).

[0193] Next, a resist pattern is formed by irradiation and development with light or electron beams. First, exposure is performed through a prescribed mask. Near-ultraviolet, far-ultraviolet, or ultraviolet light (e.g., EUV (wavelength 13.5 nm)) is used for exposure. Specifically, i-rays (wavelength 365 nm), KrF excimer lasers (wavelength 248 nm), ArF excimer lasers (wavelength 193 nm), and F2 excimer lasers (wavelength 157 nm) can be used. Among these, i-rays (wavelength 365 nm) are preferred. After exposure, post-exposure baking may 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.

[0194] Furthermore, in this invention, an electron beam lithography resist can be used instead of a photoresist. Both negative and positive electron beam resists can be used. Examples include: chemically amplified resists composed of an acid-generating agent and a binder having groups that change the rate of alkali dissolution through acid decomposition; chemically amplified resists composed of an alkali-soluble binder, an acid-generating agent, and a low-molecular-weight compound that changes the rate of alkali dissolution through acid decomposition; chemically amplified resists composed of an acid-generating agent, a binder having groups that change the rate of alkali dissolution through acid decomposition, and a low-molecular-weight compound that changes the rate of alkali dissolution through acid decomposition; non-chemically amplified resists composed of a binder having groups that change the rate of alkali dissolution through electron beam decomposition; and non-chemically amplified resists composed of a binder having a portion where the rate of alkali dissolution changes when electron beams are cut off. When using these electron beam resists, the irradiation source can be electron beams, and resist patterns can be formed in the same way as when using photoresist.

[0195] Next, development is performed using a developer. Thus, for example, when a positive photoresist is used, the exposed portion of the photoresist is removed, forming a photoresist pattern.

[0196] Examples of developing solutions 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 may be added to these developing solutions. Developing conditions are appropriately selected from a temperature range of 5–50°C and a development time range of 10–600 seconds.

[0197] In this invention, an organic lower layer film (lower layer) can be formed on a substrate, followed by an inorganic lower layer film (intermediate layer), and then a photoresist (upper layer) can be coated on top of that. This narrows the pattern width of the photoresist, allowing for substrate processing even when the photoresist is thinly coated to prevent pattern collapse, by selecting an appropriate etching gas. For example, a fluorine-based gas with a sufficiently fast etching rate relative to the photoresist can be used as the etching gas to process the lower layer film; a fluorine-based gas with a sufficiently fast etching rate relative to the inorganic lower layer film can also be used; and an oxygen-based gas with a sufficiently fast etching rate relative to the organic lower layer film can be used.

[0198] Then, using the patterned photoresist formed in this process as a protective film, the inorganic underlayer film is removed. Next, using a film composed of the patterned photoresist and the inorganic underlayer film as a protective film, the organic underlayer film is removed. Finally, using the patterned inorganic and organic underlayer films as protective films, the semiconductor substrate is processed.

[0199] First, the inorganic underlayer film, to which the photoresist has been removed, is removed by dry etching, exposing the semiconductor substrate. Gases that can be used in the dry etching of the inorganic underlayer film include tetrafluoromethane (CF4), perfluorocyclobutane (C4F8), perfluoropropane (C3F8), trifluoromethane, carbon monoxide, argon, oxygen, nitrogen, sulfur hexafluoride, difluoromethane, nitrogen trifluoride and chlorine trifluoride, chlorine, trichloroborane, and dichloroborane. Halogen-based gases are preferred for the dry etching of the inorganic underlayer film, and fluorine-based gases are more preferred. Examples of fluorine-based gases include tetrafluoromethane (CF4), perfluorocyclobutane (C4F8), perfluoropropane (C3F8), trifluoromethane, and difluoromethane (CH2F2).

[0200] Then, the organic underlying film is removed using a film consisting of patterned photoresist and an inorganic underlying film as a protective film.

[0201] Because inorganic underlayers containing large amounts of silicon atoms are not easily removed by dry etching using oxygen-based gases, organic underlayers are often removed by dry etching using oxygen-based gases.

[0202] Finally, the semiconductor substrate is processed. The semiconductor substrate is preferably processed by dry etching using fluorine-based gases.

[0203] Examples of fluorine-based gases include tetrafluoromethane (CF4), perfluorocyclobutane (C4F8), perfluoropropane (C3F8), trifluoromethane, and difluoromethane (CH2F2).

[0204] Furthermore, an organic antireflective film can be formed on top of the photoresist underlayer before the formation of the photoresist. There are no particular limitations on the antireflective film composition used herein; any antireflective film composition conventionally used in photolithography processes can be selected. Moreover, the antireflective film can be formed using conventional methods, such as coating and firing with a spin coater or coater.

[0205] The photoresist underlayer film formed by the composition for forming the photoresist underlayer film sometimes absorbs light according to the wavelength of the light used in the photolithography process. Therefore, in such cases, it can function as an anti-reflective film that prevents reflected light from the substrate. Furthermore, the underlayer film formed by the composition for forming the photoresist underlayer film of the present invention can also function as a hard mask. The underlayer film of the present invention can also be used as a layer to prevent interaction between the substrate and the photoresist, a layer that prevents the adverse effects of the material used in the photoresist or substances generated during exposure to the photoresist on the substrate, a layer that prevents the diffusion of substances generated from the substrate during heating and firing onto the upper photoresist layer, and a barrier layer that reduces the poisoning effect of the photoresist layer caused by the dielectric layer of the semiconductor substrate.

[0206] Furthermore, the lower layer film formed from the resist lower layer film forming composition can be applied to substrates with through-holes used in dual damascene processes as an embedded material that can fill the cavities without gaps. Additionally, it can also be used as a planarizing material for planarizing the surface of semiconductor substrates with uneven surfaces.

[0207] On the other hand, wet etching removal methods using chemical solutions have also been studied to simplify the process, reduce substrate damage, and reduce costs, replacing dry etching. However, the resist underlayer film formed by conventional resist underlayer film forming compositions originally required a solvent-resistant cured film to prevent mixing with the resist during resist coating. Furthermore, during resist patterning, a developer is required for resist imaging, making resistance to that developer essential. Therefore, it is difficult in the prior art for the cured film to be insoluble in resist solvents and developers, but soluble only in wet etching solutions. However, the resist underlayer film forming composition according to the present invention provides a resist underlayer film that can be etched (removed) with a wet etching solution.

[0208] As a wet etching solution, it is preferable to include an organic solvent, which may contain acidic or basic compounds. 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 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 naphthoic acid. Furthermore, as alkaline compounds, inorganic or organic bases can be cited. Examples of inorganic bases include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, tetramethylammonium hydroxide, tetraethylammonium hydroxide, quaternary ammonium hydroxides such as choline, ethanolamine, propylamine, diethylaminoethanol, and ethylenediamine. Further, the aforementioned wet etching solution may use only one organic solvent, or may use a combination of two or more. Additionally, only one acidic or alkaline compound may be used, or may use a combination of two or more. The mixing amount of the acidic or alkaline compound relative 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. Furthermore, as the wet etching solution, an organic solvent containing an alkaline compound is preferred, and a mixture containing dimethyl sulfoxide and tetramethylammonium hydroxide is particularly preferred.

[0209] It should be noted that recently, in the field of 3D mounting in semiconductor manufacturing processes, the FOWLP (Fan-Out Wafer Level Package) process has begun to be applied. In the RDL (Rewiring) process that forms copper wiring, a photoresist underlayer film can be applied.

[0210] In a representative RDL process, the following description is provided, but is not limited to this. First, after a photosensitive insulating film is formed on a semiconductor chip, patterning is performed by light irradiation (exposure) and development, thereby opening the electrode portion of the semiconductor chip. Next, a copper seed layer for forming copper wiring components that will be formed by plating is formed by sputtering. Further, after a resist underlayer and a photoresist layer are formed sequentially, light irradiation and development are performed to pattern the resist. The unwanted resist underlayer is 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 forms the first wiring layer. Further, the unwanted resist, resist underlayer, and copper seed layer are removed by dry etching, wet etching, or both. Furthermore, after the formed copper wiring layer is coated again with an insulating film, a film is formed in the order of copper seed layer, resist underlayer, and resist. The resist pattern is formed, the resist underlayer is removed, and copper is plated to form the second copper wiring layer. This process is repeated until the target copper wiring is formed, and then bumps for electrode removal are formed.

[0211] The composition for forming the resist underlayer of the present invention is particularly suitable as a resist underlayer in such RDL processes because it can remove the resist underlayer by wet etching, from the viewpoint of simplifying the process and reducing damage to the processed substrate.

[0212] Example

[0213] The following examples illustrate the content of the present invention in detail, but the present invention is not limited thereto.

[0214] The apparatus used to determine the weight-average molecular weight of the polymers obtained in the following synthesis examples is shown.

[0215] Device: HLC-8320GPC manufactured by Higashikata Co., Ltd.

[0216] GPC pillars: Shodex (registered trademark) · Asahipak (registered trademark) (Showa Denko Co., Ltd.)

[0217] Column temperature: 40℃

[0218] Flow rate: 0.35 mL / min

[0219] Eluent: Tetrahydrofuran (THF)

[0220] Standard sample: Polystyrene (Tosoo Corporation)

[0221] <Synthesis example 1>

[0222] 10.00 g of triazine-type epoxy compound (product name: TEPIC, manufactured by Nissan Chemical Co., Ltd., epoxy functionality: 10.03 eq. / kg), 12.25 g of 4-hydroxybenzaldehyde, and tetrabutyl bromide were added. 0.85 g of propylene glycol monomethyl ether and 53.90 g of propylene glycol monomethyl ether were added to a reaction flask, and the mixture was heated under reflux for 23 hours under a nitrogen atmosphere. Next, a solution containing 6.63 g of malononitrile dissolved in 15.46 g of propylene glycol monomethyl ether was added to the system, and the mixture was further heated under reflux for 5 hours. The resulting reaction product corresponds to formula (A-1), and its weight-average molecular weight (Mw) as determined by GPC (converted to polystyrene) is 800.

[0223]

[0224] <Synthesis example 2>

[0225] 9.00 g of triazine epoxy compound (product name: TEPIC, manufactured by Nissan Chemical Co., Ltd., epoxy functionality: 10.03 eq. / kg), 5.51 g of 4-hydroxybenzaldehyde, 6.78 g of p-aldehyde benzoic acid, and tetrabutyl bromide were prepared. 1.53 g of propylene glycol monomethyl ether and 34.23 g of propylene glycol monomethyl ether were added to a reaction flask, and the mixture was heated under reflux for 23 hours under a nitrogen atmosphere. Next, a solution of 5.96 g of malononitrile dissolved in 32.93 g of propylene glycol monomethyl ether was added to the system, and the mixture was further heated under reflux for 4 hours. The resulting reaction product corresponds to formula (A-2), and its weight-average molecular weight (Mw) as determined by GPC (converted to polystyrene) is 900.

[0226]

[0227] (L1 represents the bonding portion with L2 and L3)

[0228] <Comparative Synthesis Example 1>

[0229] 15.00g of phenolic varnish-type epoxy resin (product name: DEN, manufactured by DOU KEMICAL, epoxy functionality: 5.55 eq. / kg), 10.17g of 4-hydroxybenzaldehyde, and tetrabutyl bromide were added. 1.41 g of propylene glycol monomethyl ether and 39.87 g of propylene glycol monomethyl ether were added to a reaction flask, and the mixture was heated under reflux for 24 hours under a nitrogen atmosphere. Next, a solution containing 5.50 g of malononitrile dissolved in 34.99 g of propylene glycol monomethyl ether was added to the system, and the mixture was further heated under reflux for 4 hours. The resulting reaction product corresponds to formula (A-3), and its weight-average molecular weight (Mw) calculated by GPC based on polystyrene is 2100.

[0230]

[0231] <Comparative Synthesis Example 2>

[0232] 12.00g of phenolic varnish-type epoxy resin (product name: DEN, manufactured by DOU KEMICAL, epoxy functionality: 5.55 eq. / kg), 4.07g of 4-hydroxybenzaldehyde, 5.00g of p-aldehyde benzoic acid, and tetrabutyl bromide were added. 1.13 g of propylene glycol monomethyl ether and 33.30 g of propylene glycol monomethyl ether were added to a reaction flask, and the mixture was heated under reflux for 23 hours under a nitrogen atmosphere. Next, a solution containing 4.40 g of malononitrile dissolved in 28.77 g of propylene glycol monomethyl ether was added to the system, and the mixture was further heated under reflux for 4 hours. The resulting reaction product corresponds to formula (A-4), and its weight-average molecular weight (Mw) as determined by GPC (converted to polystyrene) is 2400.

[0233]

[0234] <Comparative Synthesis Example 3>

[0235] 12.00g of cyclohexane-type epoxy resin (product name: EHPE3150, manufactured by Daicel Co., Ltd., epoxy functionality: 5.99 eq. / kg), 4.39g of 4-hydroxybenzaldehyde, 5.40g of p-aldehyde benzoic acid, and tetrabutyl bromide were added. 1.22 g of propylene glycol monomethyl ether and 34.50 g of propylene glycol monomethyl ether were added to a reaction flask, and the mixture was heated under reflux for 23 hours under a nitrogen atmosphere. Further, a solution containing 4.75 g of malononitrile dissolved in 30.25 g of propylene glycol monomethyl ether was added to the system, followed by heating under reflux for 4 hours. The resulting reaction product corresponds to formula (A-5), and the weight-average molecular weight (Mw) obtained by GPC, converted to polystyrene, is 5400.

[0236]

[0237] <Example 1>

[0238] To 6.72 g of a solution (solid content 25.8 wt%) equivalent to the reaction product of formula (A-1) above, 0.35 g of tetramethoxymethylglyurone as a crosslinking agent and pyridine as a crosslinking catalyst were added. A solution of a composition for forming a photoresist underlayer was prepared by mixing 0.02 g of p-toluenesulfonate, 14.54 g of propylene glycol monomethyl ether, and 8.37 g of propylene glycol monomethyl ether acetate.

[0239] <Example 2>

[0240] To 7.56 g of a solution (solid content 23.9 wt%) equivalent to the reaction product of formula (A-2) above, 0.27 g of tetramethoxymethylglyoxal as a crosslinking agent and pyridine as a crosslinking catalyst were added. A solution of a composition for forming a photoresist underlayer was prepared by mixing 0.02 g of p-toluenesulfonate, 13.78 g of propylene glycol monomethyl ether, and 8.37 g of propylene glycol monomethyl ether acetate.

[0241] <Example 3>

[0242] To 6.96 g of a solution (solid content 23.9 wt%) equivalent to the reaction product of formula (A-2) above, 0.42 g of 3,3',5,5'-tetratetra(methoxymethyl)-4,4'-dihydroxybiphenyl (product name: TMOM-BP, manufactured by Honshu Chemical Industry Co., Ltd.) as a crosslinking agent and pyridine as a crosslinking catalyst were added. A solution of a composition for forming a photoresist underlayer was prepared by mixing 0.02 g of p-toluenesulfonate, 14.23 g of propylene glycol monomethyl ether, and 8.37 g of propylene glycol monomethyl ether acetate.

[0243] <Example 4>

[0244] Pyridine was added as a crosslinking catalyst to 8.20 g of a solution (solid content 23.9 wt%) equivalent to the reaction product of the above formula (A-2). A solution of a composition for forming a photoresist underlayer was prepared by mixing 0.14 g of trifluoromethane sulfonate, 13.29 g of propylene glycol monomethyl ether, and 8.37 g of propylene glycol monomethyl ether acetate.

[0245] <Comparative Example 1>

[0246] To 7.58 g of a solution (solid content 22.9 wt%) equivalent to the reaction product of formula (A-3) above, 0.35 g of tetramethoxymethylglyurone as a crosslinking agent and pyridine as a crosslinking catalyst were added. A solution of a composition for forming a photoresist underlayer was prepared by mixing 0.02 g of p-toluenesulfonate, 13.69 g of propylene glycol monomethyl ether, and 8.37 g of propylene glycol monomethyl ether acetate.

[0247] <Comparative Example 2>

[0248] To 7.98 g of a solution (solid content 22.7 wt%) equivalent to the reaction product of formula (A-4) above, 0.27 g of tetramethoxymethylglyoxal as a crosslinking agent and pyridine as a crosslinking catalyst were added. A solution of a composition for forming a photoresist underlayer was prepared by mixing 0.02 g of p-toluenesulfonate, 13.36 g of propylene glycol monomethyl ether, and 8.37 g of propylene glycol monomethyl ether acetate.

[0249] <Comparative Example 3>

[0250] To 7.35 g of a solution (solid content 22.7 wt%) equivalent to the reaction product of formula (A-4) above, 0.42 g of 3,3',5,5'-tetratetra(methoxymethyl)-4,4'-dihydroxybiphenyl (product name: TMOM-BP, manufactured by Honshu Chemical Industry Co., Ltd.) as a crosslinking agent and pyridine as a crosslinking catalyst were added. A solution of a composition for forming a photoresist underlayer was prepared by mixing 0.02 g of p-toluenesulfonate, 13.85 g of propylene glycol monomethyl ether, and 8.37 g of propylene glycol monomethyl ether acetate.

[0251] <Comparative Example 4>

[0252] Pyridine was added as a crosslinking catalyst to 8.81 g of a solution (solid content 22.7 wt%) equivalent to the reaction product of formula (A-4) above. A solution of a composition for forming a photoresist underlayer was prepared by mixing 0.10 g of trifluoromethane sulfonate, 12.72 g of propylene glycol monomethyl ether, and 8.37 g of propylene glycol monomethyl ether acetate.

[0253] <Comparative Example 5>

[0254] To 8.12 g of a solution (solid content 22.3 wt%) equivalent to the reaction product of formula (A-5) above, 0.27 g of tetramethoxymethylglyoxal as a crosslinking agent and pyridine as a crosslinking catalyst were added. A solution of a composition for forming a photoresist underlayer was prepared by mixing 0.02 g of p-toluenesulfonate, 13.22 g of propylene glycol monomethyl ether, and 8.37 g of propylene glycol monomethyl ether acetate.

[0255] [Evaluation of optical constants]

[0256] As an evaluation of optical constants, the photoresist underlayer film formation compositions modulated in Examples 1 to 4 were coated onto a silicon wafer using a spin coater to achieve a film thickness of approximately 50 nm, and then baked (fired) at 200°C for 90 seconds on a hot plate. The resulting photoresist underlayer film was then measured using a VUV-VASE spectrometer (JAWoolam) at wavelengths of 193 nm (ArF excimer laser wavelength), 248 nm (KrF excimer laser wavelength), and 365 nm (i-ray wavelength). The results are shown in Table 1.

[0257] [Table 1]

[0258] Table 1

[0259]

[0260] In Examples 1 to 4, suitable n and k values ​​were observed at 193 nm, 248 nm, and 365 nm. Based on the above results, the coating film obtained from the resist underlayer film formation composition obtained in Examples 1 to 4 exhibits an anti-reflection function in photolithography processes using radiation such as ArF excimer lasers, KrF excimer lasers, and i-rays, which can suppress reflections (standing waves) from the substrate, the main cause of undesirable resist patterns. Therefore, it is useful as a resist underlayer film.

[0261] [Evaluation of Etching Selectivity]

[0262] As an evaluation of the etch selectivity, the photoresist underlayer film forming compositions prepared in Examples 1-4 and Comparative Examples 1-5 were coated onto a silicon wafer using a spin coater to achieve a film thickness of approximately 170 nm, and then baked (fired) at 200°C for 90 seconds on a hot plate. The resulting coated film was then subjected to dry etching using a dry etching apparatus (product name: RIE-10NR, manufactured by Samko Co., Ltd.) with CF4 gas, and the ratio of the dry etching rate of the photoresist underlayer film (dry etching rate selectivity) was measured. The results of the etch selectivity measurement are shown in Table 2. It should be noted that a higher etch selectivity indicates a faster dry etching rate.

[0263] [Table 2]

[0264] Table 2

[0265]

[0266] Based on the above results, the resist underlayer compositions of Examples 1 to 4 exhibit a higher etch selectivity compared to the resist underlayer compositions of Comparative Examples 1 and 5, thus demonstrating a faster dry etching speed. In other words, the etching time during dry etching of the resist underlayer can be shortened, and undesirable reduction in resist film thickness can be suppressed when the resist underlayer is removed by dry etching. Furthermore, since shortening the dry etching time reduces undesirable etch damage to the substrate caused by the resist underlayer, it is particularly useful as a resist underlayer.

[0267] [Removal Test of Corrosion Solvent]

[0268] As an evaluation of the removability of the resist solvent (organic solvent), the resist underlayer film forming compositions prepared in Examples 1 to 4 were coated onto a copper substrate with a film thickness of 100 nm, and heated at 200°C for 90 seconds to form a resist underlayer film with a film thickness of 170 nm. Next, the copper substrate coated with the above-mentioned resist underlayer film composition was immersed in propylene glycol monomethyl ether (PGME) or propylene glycol monomethyl ether acetate (PGMEA), which are common resist solvents, at room temperature for 1 minute, and the removability of the coated film after immersion was visually observed. The results are shown in Table 3. It should be noted that if the coated film was removed, it was determined that it did not have resistance to the resist solvent (organic solvent), and if it was not removed, it was determined that it had resistance.

[0269] [Table 3]

[0270] Table 3

[0271]

[0272] Based on the above results, for the resist underlayer film compositions of Examples 1 to 4, the coating film on the copper substrate was not removed (stripped) relative to PGME and PGMEA, therefore it can be said that it has good resistance to these organic solvents (resist solvents). That is, the coating film obtained from the resist underlayer film compositions of Examples 1 to 4 is useful as a resist underlayer film because it can suppress undesirable peeling caused by resist solvents.

[0273] [Removability test against photoresist and developer]

[0274] As an evaluation of the removability of the resist developer (alkaline aqueous solution), the resist underlayer film forming compositions prepared in Examples 1 to 6 were coated onto a copper substrate with a film thickness of 100 nm, and heated at 200°C for 90 seconds to form a resist underlayer film with a film thickness of 170 nm. Next, the copper substrate coated with the above-mentioned resist underlayer film composition was immersed in a 2.38 wt% tetramethylammonium hydroxide (tetramethylammonium hydroxide: TMAH) aqueous solution (product name: NMD-3, manufactured by Tokyo Ohka Kogyo Co., Ltd.) as an alkaline aqueous solution for 1 minute at room temperature, and the removability of the coated film after immersion was visually observed. The results are shown in Table 4. It should be noted that if the coated film was removed, it was determined that it did not have resistance to the resist developer (alkaline aqueous solution), and if it was not removed, it was determined that it had resistance.

[0275] [Table 4]

[0276] Table 4

[0277]

[0278] Based on the above results, for the resist underlayer film compositions of Examples 1 to 4, the coating film on the copper substrate was not removed (peeled) relative to the TMAH aqueous solution, therefore it can be said that it has good resistance to the resist developer (alkaline aqueous solution). That is, the coating film obtained from the resist underlayer film compositions of Examples 1 to 6 is useful as a resist underlayer film for development processes that require alkaline aqueous solutions because it does not experience undesirable peeling due to the resist developer.

[0279] [Removability test of wet etching solution]

[0280] As an evaluation of the removability of the wet etching solution (alkaline organic solvent), the resist underlayer film forming compositions prepared in Examples 1-4 and Comparative Examples 1, 3, and 5 were coated onto a copper substrate with a film thickness of 100 nm and heated at 200°C for 90 seconds to form a resist underlayer film with a film thickness of 170 nm. Next, the copper substrate coated with the above-mentioned resist underlayer film composition was immersed in a 0.5 wt% tetramethylammonium hydroxide (TMAH) dimethyl sulfoxide solution at 50°C for 5 minutes, and the removability of the coated film after immersion was visually observed. The results are shown in Table 5. It should be noted that if the coated film was removed, it was judged to have good removability (peelability) to the alkaline organic solvent; if it was not removed, it was judged to have poor removability (peelability).

[0281] [Table 5]

[0282] Table 5

[0283]

[0284] Based on the above results, the resist underlayer film compositions of Examples 1 to 4, compared with those of Comparative Examples 1, 3, and 5, exhibited sufficient removability from wet etching solutions (alkaline organic solvents) on the copper substrate. In other words, the coating films obtained from the resist underlayer film compositions of Examples 1 to 4 demonstrate good removability (peelability) from wet etching solutions, and are therefore useful in semiconductor manufacturing processes where the resist underlayer film is removed using wet etching solutions.

[0285] [Solubility test of wet etching solution]

[0286] As an evaluation of the solubility of the wet etching solution (alkaline organic solvent), the resist underlayer film formation compositions prepared in Examples 1-4 and Comparative Examples 1-5 were coated onto a silicon wafer substrate and heated at 200°C for 90 seconds to form a resist underlayer film with a thickness of 170 nm. Next, the formed resist underlayer film was peeled off from the substrate, and the resulting coating film was immersed in a 0.5 wt% tetramethylammonium hydroxide (TMAH) dimethyl sulfoxide solution at 50°C for 5 minutes. The solubility of the immersed coating film was visually observed. The results are shown in Table 6. It should be noted that if the coating film dissolved, it was judged to have good solubility in the wet etching solution; if it did not dissolve (insoluble), it was judged to have poor solubility.

[0287] [Table 6]

[0288] Table 6

[0289]

[0290] Based on the above results, the resist underlayer film compositions of Examples 1 to 4, compared with those of Comparative Examples 1 to 5, exhibited sufficient solubility in the wet etching solution (alkaline organic solvent). That is, the coating films obtained from the resist underlayer film compositions of Examples 1 to 4 showed good solubility in the wet etching solution, and are therefore useful in semiconductor manufacturing processes where the resist underlayer film is removed using a wet etching solution. In particular, the coating films obtained from the resist underlayer film compositions of Examples 1 to 4 not only can be removed with the wet etching solution, but also exhibit sufficient solubility, thus preventing undesirable contamination of the etching solution caused by the uneven dispersion of the removed film (stripping film) as foreign matter (defects) in the etching solution, making them even more useful as resist underlayer films.

[0291] Industry availability

[0292] According to the present invention, a resist underlayer film can be provided that exhibits good resistance to resist solvents that are organic solvents and resist developers that are alkaline aqueous solutions, while exhibiting removability only to wet etching solutions and preferably solubility.

Claims

1. A composition for forming a resist underlayer film, comprising a heterocyclic compound having a dicyanostyrene group, and a solvent, The heterocyclic compound having a dicyanostyrene group is a cyclic compound containing an amide group.

2. The composition for forming a lower layer of resist film according to claim 1, wherein the heterocyclic compound having a dicyanostyrene group is a reaction product of an active proton compound and a heterocyclic compound precursor having an epoxy group.

3. The composition for forming a resist underlayer film according to claim 1, wherein the dicyanostyrene group is represented by the following formula (1), In formula (1), X represents alkyl, hydroxyl, alkoxy, alkoxycarbonyl, halogen atom, cyano or nitro, R represents hydrogen atom, alkyl or aryl, n represents an integer from 0 to 4, and * represents the bonding part of the heterocyclic compound.

4. The composition for forming a resist underlayer film according to claim 1, wherein the heterocyclic compound having a dicyanostyrene group is represented by the following formula (2), In equation (2), Q represents a group from which m terminal atoms have been removed from a heterocyclic compound. m is an integer from 1 to 4. Each of the m A atoms is independently a directly bonded or alkylene group having 1 to 10 carbon atoms, wherein the alkylene group may or may not be branched and may or may not be substituted, and may or may not contain ether bonds, thioether bonds, or ester bonds. Each of the m B's independently represents a direct bond, an ether bond, a thioether bond, or an ester bond. Each of the m R1 to R3 atoms independently represents a hydrogen atom, a methyl group, or an ethyl group. Each of the m L's is independently represented by the following equation (3), In formula (3), Y represents an ether bond, a thioether bond, or an ester bond. R represents a hydrogen atom, an alkyl group, or an aryl group. n represents an integer from 0 to 4. Each of the n X's independently represents an alkyl, hydroxyl, alkoxy, alkoxycarbonyl, halogen, cyano, or nitro group.

5. The composition for forming a resist underlayer film according to any one of claims 1 to 4, wherein the heterocyclic ring is a triazine trione.

6. The composition for forming a resist underlayer film according to claim 4, wherein Q in formula (2) is triazine trione.

7. The composition for forming a resist underlayer film according to claim 3 or 4, wherein R in formula (1) and / or formula (3) is a hydrogen atom.

8. The composition for forming a resist underlayer film according to claim 4, wherein Y in formula (3) represents an ether bond or an ester bond.

9. The composition for forming a resist underlayer film according to claim 4, wherein A in formula (2) represents direct bonding.

10. The composition for forming a resist underlayer film according to any one of claims 1 to 4, further comprising a crosslinking agent and / or a crosslinking catalyst.

11. The composition for forming a resist underlayer film according to any one of claims 1 to 4, used on a substrate containing copper on its surface.

12. A resist underlayer film, characterized in that, It is obtained by removing the solvent from a coating film formed by the composition for forming a resist underlayer film according to any one of claims 1 to 11.

13. The resist underlayer film according to claim 12, which is formed on a substrate with a copper-containing surface.

14. A method for manufacturing a patterned substrate, comprising the steps of: coating a resist underlayer film forming composition according to any one of claims 1 to 11 onto a substrate containing copper on its surface and baking it to form a resist underlayer film; coating a resist onto the resist underlayer film and baking it to form a resist film; exposing a semiconductor substrate covered with the resist underlayer film and the resist to the light; and developing the exposed resist film to form a pattern.

15. A method for manufacturing a semiconductor device, characterized in that, Includes the following processes: The process of forming a photoresist underlayer film formed by the composition for forming a photoresist underlayer film according to any one of claims 1 to 11 on a substrate containing copper on its surface; The process of forming a resist film on the lower resist film; The process of irradiating a resist film with light or electron beams and then developing it to form a resist pattern, followed by the process of removing the underlying resist film exposed between the resist patterns; A copper plating process is performed between the formed resist patterns; as well as The process of removing the resist pattern and the underlying resist film.

16. The manufacturing method according to claim 15, wherein at least one step of removing the resist underlayer film is performed using a wet process.

17. The compound represented by the following formula (4), In formula (4), A1 to A3 are each independently a directly bonded, substituted, or unsubstituted alkylene group with 1 to 6 carbon atoms. B1 through B3 each independently represent direct bonding, ether bonding, thioether bonding, or ester bonding. R4~R 12 Each can independently represent a hydrogen atom, a methyl group, or an ethyl group. Z1 to Z3 are represented by equation (5). In equation (5), Each of the n X's independently represents an alkyl, hydroxyl, alkoxy, alkoxycarbonyl, halogen, cyano, or nitro group. R represents a hydrogen atom, an alkyl group, or an aryl group. Y represents an ether bond, a thioether bond, or an ester bond. n represents an integer from 0 to 4.

18. A method for manufacturing a heterocyclic compound having a dicyanostyrene group, comprising the steps of reacting a heterocyclic compound precursor having an epoxy group with a protonated compound having a dicyanostyrene group.

19. A method for manufacturing a heterocyclic compound having a dicyanostyrene group, comprising the steps of: reacting a heterocyclic compound precursor having an epoxy group with an active proton compound having a carbonyl group to obtain an intermediate; and cyanotyping the intermediate.

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