Resist underlayer film forming composition

Abstract

To provide a new resist underlayer film-forming composition capable of giving a hydrophobic underlayer film having high adhesiveness to an upper layer film and hardly peeled off, having good coatability and exhibiting sufficient resistance even to a chemical liquid.SOLUTION: A resist underlayer film-forming composition comprising a polymer comprising structural unit formula (2): (Ar3 represents an aromatic compound having 6 to 60 carbon atoms which may contain a nitrogen atom, R8 is selected from the group consisting of an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an alkynyl group having 2 to 10 carbon atoms, an aryl group having 6 to 40 carbon atoms, and a combination thereof, R6 is selected from the group consisting of a hydrogen atom, a trifluoromethyl group, an aryl group having 6 to 40 carbon atoms, and a heterocyclic group, R7 is selected from the group consisting of a hydrogen atom, a trifluoromethyl group, an aryl group having 6 to 40 carbon atoms, and a heterocyclic group, n3 is 1 or more, and n4 is 0 or 1. ) SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a resist underlayer forming composition, a resist underlayer film which is a fired product of a coated film made from the composition, and a method for manufacturing a semiconductor device using the composition. [Background technology]

[0002] In recent years, there has been a demand for resist underlayer film forming compositions used in lithography processes for semiconductor device manufacturing that do not undergo intermixing with the upper layer, yield excellent resist patterns, and form lithography resist underlayer films with lower dry etching rates compared to the upper layer (hard mask: coated or deposited film) and semiconductor substrate. To address this, the use of polymers having repeating units containing benzene rings or naphthalene rings has been proposed (Patent Document 1). [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] WO 2013 / 047516 A1 [Overview of the project] [Problems that the invention aims to solve]

[0004] However, conventional resist underlayer film forming compositions still fall short of the requirements for a high pure water contact angle, high adhesion to the upper layer film, a hydrophobic underlayer film that is resistant to peeling, and good coatability. Furthermore, in semiconductor manufacturing processes, chemical treatments are sometimes performed, and consequently, the resist underlayer film may also need to exhibit sufficient resistance to the chemicals used in these treatments. [Means for solving the problem]

[0005] This invention solves the above problems. In other words, this invention encompasses the following: [1] A solvent, and the following formula (1), and / or the following formula (2):

Chemical Formula

[10] A step of forming a resist underlayer on a semiconductor substrate using a resist underlayer forming composition described in any one of [1] to [8], A step of forming a resist film on the formed resist underlayer film, A process of forming a resist pattern by irradiating the formed resist film with light or an electron beam and developing it. A step of etching and patterning the resist underlayer film through the formed resist pattern, and Process of processing a semiconductor substrate via a patterned resist underlayer film. A method for manufacturing a semiconductor device containing [a specific component].

[11] A step of forming a resist underlayer on a semiconductor substrate using a resist underlayer forming composition described in any one of [1] to [8], A step of forming a hard mask on the formed resist underlayer film, A step of forming a resist film on the formed hard mask, A process of forming a resist pattern by irradiating the formed resist film with light or an electron beam and developing it. A process of etching a hard mask through the formed resist pattern, A step of etching the resist underlayer film through the etched hard mask, and hard mask removal process A method for manufacturing a semiconductor device containing [a specific component].

[12] Furthermore, A process of forming a vapor-deposited film (spacer) on the underlying film from which the hard mask has been removed. The process of processing the formed vapor-deposited film (spacer) by etching, A step of removing the underlying film, Process of processing semiconductor substrates using spacers A method for manufacturing a semiconductor device as described in

[11] , including the method described in

[11] .

[13] A method for manufacturing a semiconductor device according to any one of the items

[10] to

[12] , wherein the semiconductor substrate is a stepped substrate. [Effects of the Invention]

[0006] The present invention provides a novel resist underlayer forming composition that meets the requirements of exhibiting a high pure water contact angle, high adhesion to the upper layer film, a hydrophobic underlayer film that is difficult to peel off, and good coatability, and also exhibits other good properties such as sufficient resistance to chemicals used in resist underlayer films. [Modes for carrying out the invention]

[0007] <Resist Underlayer Film Forming Composition> The resist underlayer film forming composition according to the present invention comprises a solvent and the following formula (1) and / or the following formula (2): [ka] (In the formula, Ar 1 , and Ar 2 Each represents either a benzene ring or a naphthalene ring, and Ar 1 , and Ar 2 They may be connected via single bonds, Ar 3 This represents an aromatic compound with 6 to 60 carbon atoms that may contain a nitrogen atom. R 1 , and R 2 These are Ar 1 , and Ar 2 A group that substitutes a hydrogen atom on the ring, selected from the group consisting of halogen groups, nitro groups, amino groups, cyano groups, alkyl groups having 1 to 10 carbon atoms, alkenyl groups having 2 to 10 carbon atoms, alkynyl groups having 2 to 10 carbon atoms, aryl groups having 6 to 40 carbon atoms, and combinations thereof, wherein the alkyl group, alkenyl group, alkenyl group and aryl group may contain ether bonds, ketone bonds or ester bonds. R 3 , and R 8 The group is selected from the group consisting of alkyl groups having 1 to 10 carbon atoms, alkenyl groups having 2 to 10 carbon atoms, alkynyl groups having 2 to 10 carbon atoms, aryl groups having 6 to 40 carbon atoms, and combinations thereof, and the alkyl group, alkenyl group, alkynyl group, and aryl group may contain ether bonds, ketone bonds, or ester bonds. R 4 , and R 6The group is selected from the group consisting of a hydrogen atom, a trifluoromethyl group, an aryl group having 6 to 40 carbon atoms, and a heterocyclic group, and the aryl group and the heterocyclic group may be substituted with a halogen group, a nitro group, an amino group, a cyano group, a trifluoromethyl group, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an alkynyl group having 2 to 10 carbon atoms, or an aryl group having 6 to 40 carbon atoms, and the alkyl group, the alkenyl group, the alkynyl group, and the aryl group may contain an ether bond, a ketone bond, or an ester bond. R 5 , and R 7 The group is selected from the group consisting of a hydrogen atom, a trifluoromethyl group, an aryl group having 6 to 40 carbon atoms, and a heterocyclic group, and the aryl group and the heterocyclic group may be substituted with a halogen group, a nitro group, an amino group, a cyano group, a trifluoromethyl group, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an alkynyl group having 2 to 10 carbon atoms, or an aryl group having 6 to 40 carbon atoms, and the alkyl group, the alkenyl group, the alkynyl group, and the aryl group may contain an ether bond, a ketone bond, or an ester bond. And R 4 and R 5 and R 6 and R 7 These may form a ring together with the carbon atoms to which they are bonded. n1 and n2 are integers from 0 to 3, n3 is 1 or greater, Ar 3 An integer less than or equal to the number of substituents that can be substituted, n4 is either 0 or 1, but when n4 is 0, R 8 is Ar 3 It bonds with the nitrogen atoms contained in it. It includes a unit structure (A) represented by .

[0008] <Polymers containing unit structures (A) represented by formula (1) and / or formula (2)> Ar 1 , and Ar2 These represent either a benzene ring or a naphthalene ring, respectively. Ar 1 and Ar 2 These elements may be bonded via single bonds, for example, to form a carbazole skeleton. Ar 1 , and Ar 2 It is preferable that both are benzene rings.

[0009] Ar 3 This represents aromatic compounds with 6 to 60 carbon atoms that may contain a nitrogen atom. Specific examples include benzene, styrene, toluene, xylene, mesitylene, cumene, indene, naphthalene, biphenyl, azulene, anthracene, phenanthrene, naphthacene, triphenylene, pyrene, chrysene, fluorene, 9,9-diphenylfluorene, 9,9-dinaphthylfluorene, indole, phenylindole, purine, quinoline, isoquinoline, quinuclidine, acridine, phenazine, carbazole, and others.

[0010] R 1 , and R 2 These are Ar 1 , and Ar 2 The group is a group that substitutes a hydrogen atom on the ring, and is selected from the group consisting of halogen groups, nitro groups, amino groups, cyano groups, alkyl groups having 1 to 10 carbon atoms, alkenyl groups having 2 to 10 carbon atoms, alkynyl groups having 2 to 10 carbon atoms, aryl groups having 6 to 40 carbon atoms, and combinations thereof, and the alkyl group, alkenyl group, alkynyl group, and aryl group may contain ether bonds, ketone bonds, or ester bonds.

[0011] Also, R 3 , and R 8The alkyl group is selected from the group consisting of alkyl groups having 1 to 10 carbon atoms, alkenyl groups having 2 to 10 carbon atoms, alkynyl groups having 2 to 10 carbon atoms, aryl groups having 6 to 40 carbon atoms, and combinations thereof. The alkyl group, alkenyl group, alkynyl group, and aryl group may contain ether bonds, ketone bonds, or ester bonds, and the aryl group may be substituted with an alkyl group having 1 to 10 carbon atoms substituted with a hydroxyl group (i.e., the aryl group may have a hydroxyalkyl group having 1 to 10 carbon atoms as a substituent). When the aryl group is substituted with an alkyl group substituted with a hydroxyl group, the hydroxyl group is preferably substituted at the benzyl position, and the aryl group also includes those in which aromatic rings are linked by a methine group substituted with a hydroxyl group (i.e., -Ar-C(OH)X 1 X 2 Ar is an aryl group, X 1 and X 2 is a hydrogen atom or any organic group, preferably X 1 , X 2 (Either one is an aromatic group).

[0012] Examples of halogen groups include fluorine, chlorine, bromine, and iodine.

[0013] Examples of alkyl groups having 1 to 10 carbon atoms include methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, s-butyl group, t-butyl group, n-pentyl group, 1-methyl-n-butyl group, 2-methyl-n-butyl group, 3-methyl-n-butyl group, 1,1-dimethyl-n-propyl group, 1,2-dimethyl-n-propyl group, 2,2-dimethyl-n-propyl group, 1-ethyl-n-propyl group, n-hexyl group, 1-methyl-n-pentyl group, 2-methyl-n-pentyl group, and 3-methyl Examples include -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, and 1-ethyl-2-methyl-n-propyl group.

[0014] Furthermore, cyclic alkyl groups may also be used, for example, cyclopropyl group, cyclobutyl group, 1-methyl-cyclopropyl group, 2-methyl-cyclopropyl group, cyclopentyl group, 1-methyl-cyclobutyl group, 2-methyl-cyclobutyl group, 3-methyl-cyclobutyl group, 1,2-dimethyl-cyclopropyl group, 2,3-dimethyl-cyclopropyl group, 1-ethyl-cyclopropyl group, 2-ethyl-cyclopropyl group, cyclohexyl group, 1-methyl-cyclopentyl group, 2-methyl-cyclopentyl group, 3-methyl-cyclopentyl group, 1-ethyl-cyclobutyl group, 2-ethyl-cyclobutyl group, 3-ethyl-cyclobutyl group, 1,2-dimethyl-cyclobutyl group, 1,3-dimethyl-cyclobutyl group Examples include ethyl-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, 2,2,3-trimethyl-cyclopropyl group, 1-ethyl-2-methyl-cyclopropyl group, 2-ethyl-1-methyl-cyclopropyl group, 2-ethyl-2-methyl-cyclopropyl group, and 2-ethyl-3-methyl-cyclopropyl group.

[0015] Examples of alkenyl groups having 2 to 10 carbon atoms include ethenyl group, 1-propenyl group, 2-propenyl group, 1-methyl-1-ethenyl group, 1-butenyl group, 2-butenyl group, 3-butenyl group, 2-methyl-1-propenyl group, 2-methyl-2-propenyl group, 1-ethylethenyl group, 1-methyl-1-propenyl group, 1-methyl-2-propenyl group, 1-pentenyl group, 2-pentenyl group, 3-pentenyl group, 4-pentenyl group, 1-n-propylethenyl group, 1-methyl-1-butenyl group, 1-methyl-2-butenyl group, and 1-methyl-3-butenyl group. Tenyl group, 2-ethyl-2-propenyl group, 2-methyl-1-butenyl group, 2-methyl-2-butenyl group, 2-methyl-3-butenyl group, 3-methyl-1-butenyl group, 3-methyl-2-butenyl group, 3-methyl-3-butenyl group, 1,1-dimethyl-2-propenyl group, 1-i-propylethenyl group, 1,2-dimethyl-1-propenyl group, 1,2-dimethyl-2-propenyl group, 1-cyclopentenyl group, 2-cyclopentenyl group, 3-cyclopentenyl group, 1-hexenyl group, 2-hexenyl group, 3-hexenyl group, 4-hexenyl group, 5-hexenyl group Xenyl group, 1-methyl-1-pentenyl group, 1-methyl-2-pentenyl group, 1-methyl-3-pentenyl group, 1-methyl-4-pentenyl group, 1-n-butylethenyl group, 2-methyl-1-pentenyl group, 2-methyl-2-pentenyl group, 2-methyl-3-pentenyl group, 2-methyl-4-pentenyl group, 2-n-propyl-2-propenyl group, 3-methyl-1-pentenyl group, 3-methyl-2-pentenyl group, 3-methyl-3-pentenyl group, 3-methyl-4-pentenyl group, 3-ethyl-3-butenyl group, 4-methyl-1-pentenyl group, 4-methyl-2-pentenyl group, 4-methyl-3-pentenyl group, 4-methyl-4-pentenyl group, 1,1-dimethyl-2-butenyl group, 1,1-dimethyl-3-butenyl group, 1,2-dimethyl-1-butenyl group, 1,2-dimethyl-2-butenyl group, 1,2-dimethyl-3-butenyl group, 1-methyl-2-ethyl-2-propenyl group, 1-s-butylethenyl group, 1,3-dimethyl-1-butenyl group, 1,3-dimethyl-2-butenyl group, 1,3-dimethyl-3-butenyl group, 1-i-butylethenyl group, 2,2-dimethyl-3-butenyl group, 2,3-dimethyl-1-butenyl group, 2,3-dimethyl-2-butenyl group, 2,3-dimethyl-3-butenyl group, 2-i-propyl-2-propenyl group, 3,3-dimethyl-1-butenyl group, 1-ethyl-1-butenyl group, 1-ethyl-2-butenyl group, 1-ethyl-3-butenyl group, 1-n-propyl-1-propenyl group, 1-n-propyl-2-propenyl group, 2-ethyl-1-butenyl group, 2-ethyl-2-butenyl group, 2-ethyl-3-butenyl group, 1,1,2-trimethyl-2-propenyl group, 1-t-butylethenyl group, 1-methyl-1-ethyl-2-propenyl group, 1-ethyl-2-methyl-1-propenyl group, 1-ethyl-2-methyl-2-propenyl group, 1-i-propyl-1-propenyl Examples include penyl group, 1-i-propyl-2-propenyl group, 1-methyl-2-cyclopentenyl group, 1-methyl-3-cyclopentenyl group, 2-methyl-1-cyclopentenyl group, 2-methyl-2-cyclopentenyl group, 2-methyl-3-cyclopentenyl group, 2-methyl-4-cyclopentenyl group, 2-methyl-5-cyclopentenyl group, 2-methylene-cyclopentyl group, 3-methyl-1-cyclopentenyl group, 3-methyl-2-cyclopentenyl group, 3-methyl-3-cyclopentenyl group, 3-methyl-4-cyclopentenyl group, 3-methyl-5-cyclopentenyl group, 3-methylene-cyclopentyl group, 1-cyclohexenyl group, 2-cyclohexenyl group, and 3-cyclohexenyl group.

[0016] Examples of alkynyl groups having 2 to 10 carbon atoms include the ethynyl group, 1-propynyl group, and 2-propynyl group.

[0017] Examples of aryl groups having 6 to 40 carbon atoms include phenyl, benzyl, naphthyl, anthracenyl, phenantrenyl, naphthacenyl, triphenylenyl, pyrenyl, and chrysenyl groups.

[0018] The alkyl group, alkenyl group, alkynyl group, and aryl group described above may include an ether bond (-O-), a ketone bond (-CO-), or an ester bond (-COO-, -OCO-).

[0019] R 4 , and R 6 The group is selected from the group consisting of a hydrogen atom, a trifluoromethyl group, an aryl group having 6 to 40 carbon atoms, and a heterocyclic group, and the aryl group and the heterocyclic group may be substituted with a halogen group, a nitro group, an amino group, a cyano group, a trifluoromethyl group, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an alkynyl group having 2 to 10 carbon atoms, or an aryl group having 6 to 40 carbon atoms, and the alkyl group, the alkenyl group, the alkynyl group, and the aryl group may contain an ether bond, a ketone bond, or an ester bond.

[0020] Also, R 5 , and R 7 The group is selected from the group consisting of a hydrogen atom, a trifluoromethyl group, an aryl group having 6 to 40 carbon atoms, and a heterocyclic group, and the aryl group and the heterocyclic group may be substituted with a halogen group, a nitro group, an amino group, a cyano group, a trifluoromethyl group, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an alkynyl group having 2 to 10 carbon atoms, or an aryl group having 6 to 40 carbon atoms, and the alkyl group, the alkenyl group, the alkynyl group, and the aryl group may contain an ether bond, a ketone bond, or an ester bond.

[0021] Heterocyclic groups are substituents derived from heterocyclic compounds, specifically including thiophene, furan, pyridine, pyrimidine, pyrazine, pyrrole, oxazole, thiazole, imidazole, quinoline, carbazole, quinazoline, purine, indidine, benzothiophene, benzofuran, indole, acridine, isoindole, benzimidazole, isoquinoline, quinoxaline, sinnoline, pteridine, chromene (benzopyran), isochromene (benzopyran), xanthene, Examples of groups include thiazole groups, pyrazole groups, imidazoline groups, and azine groups, but among these, thiophene groups, furan groups, pyridine groups, pyrimidine groups, pyrazine groups, pyrrole groups, oxazole groups, thiazole groups, imidazole groups, quinoline groups, carbazole groups, quinazoline groups, purine groups, indidine groups, benzothiophene groups, benzofuran groups, indole groups, and acridine groups are preferred, with the most preferred being thiophene groups, furan groups, pyridine groups, pyrimidine groups, pyrrole groups, oxazole groups, thiazole groups, imidazole groups, and carbazole groups.

[0022] Examples of alkoxy groups having 1 to 10 carbon atoms include groups in which an etheric oxygen atom (-O-) is bonded to the terminal carbon atom of the alkyl group having 1 to 10 carbon atoms. Examples of such alkoxy groups include methoxy group, ethoxy group, n-propoxy group, i-propoxy group, cyclopropoxy group, n-butoxy group, i-butoxy group, s-butoxy group, t-butoxy group, cyclobutoxy group, 1-methyl-cyclopropoxy group, 2-methyl-cyclopropoxy 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, Examples include 1,2-dimethyl-n-propoxy group, 2,2-dimethyl-n-propoxy group, 1-ethyl-n-propoxy group, 1,1-diethyl-n-propoxy group, cyclopentoxy group, 1-methyl-cyclobutoxy group, 2-methyl-cyclobutoxy group, 3-methyl-cyclobutoxy group, 1,2-dimethyl-cyclopropoxy group, 2,3-dimethyl-cyclopropoxy group, 1-ethyl-cyclopropoxy group, and 2-ethyl-cyclopropoxy group.

[0023] R 4 and R 5 and R 6 and R 7 These may form a ring (for example, a fluorene ring) together with the carbon atoms to which they are bonded.

[0024] n1 and n2 are each integers from 0 to 3, preferably integers from 0 to 2, more preferably integers from 0 to 1, and most preferably 0.

[0025] n3 is 1 or more, preferably 2 or more, and Ar 3 An integer less than or equal to the number of substituents that can be substituted, preferably an integer of 6 or less, more preferably an integer of 4 or less, and most preferably an integer of 2 or less.

[0026] Some preferred compounds represented by formula (1) or formula (2) are as follows: ·Ar 1 , and Ar 2A compound represented by the above formula (1), wherein is a benzene ring. ·Ar 3 A compound represented by the above formula (2), wherein Ar is an optionally substituted benzene ring, naphthalene ring, diphenylfluorene ring, or phenylindole ring. ·R 4 , and R 6 is an aryl group having 6 to 40 carbon atoms, R 5 , and R 7 is a hydrogen atom, which is a compound represented by the above formula (1) or the above formula (2). ·R 4 , and R 6 is an aromatic hydrocarbon group having 6 to 16 carbon atoms, which is a compound represented by the above formula (1) or the above formula (2).

[0027] <Solvent> As the solvent for the resist underlayer film forming composition according to the present invention, any solvent that can dissolve the compound represented by the above formula (1) or the above formula (2) can be used without particular limitation. 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 generally used in lithography processes in combination in consideration of the coating performance of the composition.

[0028] Examples of such solvents include 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 acetate, ethyl hydroxyethyl acetate, methyl 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, and 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, 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.

[0029] Additionally, the following compounds described in WO2018 / 131562A1 can also be used. [ka] (R in equation (i)) 1 , R 2 and R 3 Each of these represents a hydrogen atom, an oxygen atom, a sulfur atom, or an alkyl group having 1 to 20 carbon atoms, which may be interrupted by an amide bond. These groups may be identical or different, and may be bonded to each other to form a ring structure.

[0030] Examples of alkyl groups having 1 to 20 carbon atoms include linear or branched alkyl groups that may or may not have substituents, such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, isopentyl group, neopentyl group, n-hexyl group, isohexyl group, n-heptyl group, n-octyl group, cyclohexyl group, 2-ethylhexyl group, n-nonyl group, isononyl group, p-tert-butylcyclohexyl group, n-decyl group, n-dodecylnonyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, and eicosyl group. Preferably, it is an alkyl group having 1 to 12 carbon atoms, more preferably an alkyl group having 1 to 8 carbon atoms, and even more preferably an alkyl group having 1 to 4 carbon atoms.

[0031] Examples of alkyl groups having 1 to 20 carbon atoms interrupted by an oxygen atom, a sulfur atom, or an amide bond include those containing the structural units -CH2-O-, -CH2-S-, -CH2-NHCO-, or -CH2-CONH-. -O-, -S-, -NHCO-, or -CONH- may be present in one or more units within the alkyl group. Specific examples of alkyl groups having 1 to 20 carbon atoms interrupted by -O-, -S-, -NHCO-, or -CONH- units include methoxy, ethoxy, propoxy, butoxy, methylthio, ethylthio, propylthio, butylthio, methylcarbonylamino, ethylcarbonylamino, propylcarbonylamino, butylcarbonylamino, methylaminocarbonyl, ethylaminocarbonyl, propylaminocarbonyl, and butylaminocarbonyl groups. The group is a methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, dodecyl group, or octadecyl group, each of which is substituted with a methoxy group, ethoxy group, propoxy group, butoxy group, methylthio group, ethylthio group, propylthio group, butylthio group, methylcarbonylamino group, ethylcarbonylamino group, methylaminocarbonyl group, ethylaminocarbonyl group, etc. Preferably, it is a methoxy group, ethoxy group, methylthio group, or ethylthio group, and more preferably, it is a methoxy group or ethoxy group.

[0032] Because these solvents have relatively high boiling points, they are also effective in imparting high embedding and high planarity properties to resist underlayer film-forming compositions.

[0033] The following are specific examples of preferred compounds represented by formula (i). [ka]

[0034] Among the above, 3-methoxy-N,N-dimethylpropionamide, N,N-dimethylisobutylamide, and The following formula: [ka] Compounds represented by formula (i) are preferred, and particularly preferred compounds represented by formula (i) are 3-methoxy-N,N-dimethylpropionamide and N,N-dimethylisobutylamide.

[0035] These solvents can be used individually or in combination of two or more. Among these solvents, those with a boiling point of 160°C or higher are preferred, and propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, ethyl lactate, butyl lactate, cyclohexanone, 3-methoxy-N,N-dimethylpropionamide, N,N-dimethylisobutylamide, 2,5-dimethylhexane-1,6-diyldiacetate (DAH; cas, 89182-68-3), and 1,6-diacetoxyhexane (cas, 6222-17-9) are preferred. Propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, and N,N-dimethylisobutylamide are particularly preferred.

[0036] These solvents can be used individually or in combination of two or more. The proportion of solids remaining in the composition after removing the organic solvent is, for example, 0.5% to 30% by mass, preferably 0.8% to 15% by mass.

[0037] <Optional ingredients> The resist underlayer film forming composition of the present invention may further contain at least one of the following as optional components: a crosslinking agent, an acid and / or an acid generator, a thermal acid generator, and a surfactant.

[0038] (Crosslinking agent) The resist underlayer film forming composition of the present invention may further contain a crosslinking agent. Preferably, the crosslinking agent is a crosslinkable compound having at least two crosslinking substituents. Examples include melamine compounds, substituted urea compounds, and phenolic compounds or polymers thereof, which have crosslinking substituents such as methylol groups and methoxymethyl groups. Specifically, these are compounds such as methoxymethylated glycoluryl, butoxymethylated glycoluryl, methoxymethylated melamine, butoxymethylated melamine, methoxymethylated benzoguanamine, and butoxymethylated benzoguanamine. Examples include tetramethoxymethyl glycoluryl (e.g., PL-LI (tetrakis(methoxymethyl) glycoluryl manufactured by Midori Chemical Co., Ltd.)), tetrabutoxymethyl glycoluryl, and hexamethoxymethylmelamine. Furthermore, as substituted urea compounds, these include compounds such as methoxymethylated urea, butoxymethylated urea, or methoxymethylated thiourea. Examples include tetramethoxymethylurea and tetrabutoxymethylurea. Condensed forms of these compounds can also be used. Examples of phenolic compounds include tetrahydroxymethylbiphenol, tetramethoxymethylbiphenol, tetrahydroxymethylbisphenol, tetramethoxymethylbisphenol, and compounds represented by the following formula. [ka] [ka]

[0039] As the crosslinking agent, a compound having at least two epoxy groups can also be used. Examples of such compounds include tris(2,3-epoxypropyl) isocyanurate, 1,4-butanediol diglycidyl ether, 1,2-epoxy-4-(epoxyethyl)cyclohexane, glycerol triglycidyl ether, diethylene glycol diglycidyl ether, 2,6-diglycidylphenyl glycidyl ether, 1,1,3-tris[p-(2,3-epoxypropoxy)phenyl]propane, 1,2-cyclohexanedicarboxylic acid diglycidyl ester, 4,4'-methylenebis(N,N-diglycidylaniline), 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, trimethylolethane triglycidyl ether, bisphenol-A-diglycidyl ether, and Daicel Corporation's Epolleed® GT-401, GT-403, GT-301, and GT-30 2. Celoxide® 2021, 3000, 1001, 1002, 1003, 1004, 1007, 1009, 1010, 828, 807, 152, 154, 180S75, 871, 872 manufactured by Mitsubishi Chemical Corporation, EPPN201, EPPN202, EPPN102, EPPN103S, EPPN104S, EPPN1020, EPPN1025, EPPN1027 manufactured by Nippon Kayaku Co., Ltd., and Denacol® EX-25 manufactured by Nagase ChemteX Corporation. 2. Examples include EX-611, EX-612, EX-614, EX-622, EX-411, EX-512, EX-522, EX-421, EX-313, EX-314, EX-321, CY175, CY177, CY179, CY182, CY184, CY192 from BASF Japan Ltd., and Epiclon 200, 400, 7015, 835LV, and 850CRP from DIC Corporation. As the compound having at least two epoxy groups, an epoxy resin having an amino group can also be used. Examples of such epoxy resins include YH-434 and YH-434L (manufactured by Shin-Nippon Chemical Epoxy Manufacturing Co., Ltd.).

[0040] The crosslinking agent may also be a compound having at least two blocked isocyanate groups. Examples of such compounds include Takenate® B-830 and B-870N manufactured by Mitsui Chemicals, Inc., and Vestanat® B1358 / 100 manufactured by Evonik Degussa.

[0041] The crosslinking agent may also be a compound having at least two vinyl ether groups. Examples of such compounds include bis(4-(vinyloxymethyl)cyclohexylmethyl)glutarate, tri(ethylene glycol) divinyl ether, divinyl adipate ester, diethylene glycol divinyl ether, 1,2,4-tris(4-vinyloxybutyl) trimellitate, 1,3,5-tris(4-vinyloxybutyl) trimellitate, bis(4-(vinyloxy)butyl) terephthalate, bis(4-(vinyloxy)butyl) isophthalate, ethylene glycol divinyl ether, 1,4-butanediol divinyl ether, tetramethylene glycol divinyl ether, tetraethylene glycol divinyl ether, neopentyl glycol divinyl ether, trimethylolpropane trivinyl ether, trimethylolethane trivinyl ether, hexanediol divinyl ether, 1,4-cyclohexanediol divinyl ether, tetraethylene glycol divinyl ether, pentaerythritol divinyl ether, pentaerythritol trivinyl ether, and cyclohexanedimethanol divinyl ether.

[0042] Furthermore, a crosslinking agent with high heat resistance can be used as the crosslinking agent. Preferably, a crosslinking agent with high heat resistance is a compound containing a crosslinking substituent having an aromatic ring (e.g., a benzene ring, a naphthalene ring) in its molecule.

[0043] Examples of this compound include compounds having the substructure of formula (4) below, or polymers or oligomers having the repeating unit of formula (5) below. [ka] In the above, R 11 , R 12 , R 13 and R 14 each represent a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and the above-mentioned examples can be applied to these alkyl groups. n1 is an integer of 1 to 4, n2 is an integer of 1 to (5-n1), and (n1+n2) represents an integer of 2 to 5. n3 is an integer of 1 to 4, n4 is an integer of 0 to (4-n3), and (n3+n4) represents an integer of 1 to 4. Oligomers and polymers can be used with the number of repeating unit structures in the range of 2 to 100, or 2 to 50.

[0044] Compounds, polymers and oligomers of formula (4) and formula (5) are exemplified below.

Chemical Formula

Chemical Formula

Chemical Formula

[0045] The above compounds are commercially available from Asahi Organic Chemicals Industry Co., Ltd. and Honshu Chemical Industry Co., Ltd. For example, among the above crosslinking agents, the compound of formula (4-23) is available from Honshu Chemical Industry Co., Ltd. under the trade name TMOM-BP, and the compound of formula (4-24) is available from Asahi Organic Chemicals Industry Co., Ltd. under the trade name TM-BIP-A. The amount of crosslinking agent added varies depending on the coating solvent used, the substrate used, the required solution viscosity, the required film shape, etc., but is 0.001% by mass or more, 0.01% by mass or more, 0.05% by mass or more, 0.5% by mass or more, or 1.0% by mass or more relative to the total solids, and is 80% by mass or less, 50% by mass or less, 40% by mass or less, 20% by mass or less, or 10% by mass or less. These crosslinking agents may undergo crosslinking reactions by self-condensation, but if crosslinkable substituents are present in the polymer of the present invention, they can undergo crosslinking reactions with those crosslinkable substituents.

[0046] You may add one of these crosslinking agents, or you may add two or more in combination.

[0047] (Acids and / or their salts and / or acid generators) The resist underlayer forming composition according to the present invention may contain an acid and / or a salt thereof and / or an acid generator.

[0048] Examples of acids include carboxylic acid compounds such as p-toluenesulfonic acid, trifluoromethanesulfonic acid, salicylic acid, 5-sulfosalicylic acid, 4-phenolsulfonic acid, camphorsulfonic acid, 4-chlorobenzenesulfonic acid, benzenedisulfonic acid, 1-naphthalenesulfonic acid, citric acid, benzoic acid, hydroxybenzoic acid, and naphthalenecarboxylic acid, as well as inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, and phosphoric acid. As the salt, the aforementioned acid salts can also be used. While the salt is not limited, ammonia derivative salts such as trimethylamine salt and triethylamine salt, pyridine derivative salts, morpholine derivative salts, etc., can be suitably used. Only one type of acid and / or its salt may be used, or two or more types may be used in combination. The amount added is usually 0.0001 to 20% by mass, preferably 0.0005 to 10% by mass, and more preferably 0.01 to 5% by mass, relative to the total solids.

[0049] Examples of acid generators include thermal acid generators and photoacid generators. Examples of thermal acid generators include 2,4,4,6-tetrabromocyclohexadienone, benzoin tosylate, 2-nitrobenzyl tosylate, K-PURE® CXC-1612, CXC-1614, TAG-2172, TAG-2179, TAG-2678, TAG-2689, TAG-2700 (manufactured by King Industries), and SI-45, SI-60, SI-80, SI-100, SI-110, SI-150 (manufactured by Sanshin Chemical Industry Co., Ltd.), as well as quaternary ammonium salts of trifluoroacetic acid, alkyl organic sulfonates, and the like.

[0050] 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.

[0051] Examples of iodonium salt compounds include iodonium salt compounds such as diphenyliodonium hexafluorophosphonate, diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoron-butanesulfonate, diphenyliodonium perfluoron-octanesulfonate, diphenyliodonium camphorsulfonate, bis(4-tert-butylphenyl)iodonium camphorsulfonate and bis(4-tert-butylphenyl)iodonium trifluoromethanesulfonate, as well as sulfonium salt compounds such as triphenylsulfonium hexafluoroantimonate, triphenylsulfonium nonafluoron-butanesulfonate, triphenylsulfonium camphorsulfonate and triphenylsulfonium trifluoromethanesulfonate.

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

[0053] Examples of disulfonyl diazomethane compounds include bis(trifluoromethylsulfonyl)diazomethane, bis(cyclohexylsulfonyl)diazomethane, bis(phenylsulfonyl)diazomethane, bis(p-toluenesulfonyl)diazomethane, bis(2,4-dimethylbenzenesulfonyl)diazomethane, and methylsulfonyl-p-toluenesulfonyldiazomethane.

[0054] Only one type of acid generator may be used, or two or more types may be used in combination. When an acid generator is used, the ratio is 0.01 to 10 parts by mass, or 0.1 to 8 parts by mass, or 0.5 to 5 parts by mass, per 100 parts by mass of solid content of the resist underlayer film forming composition.

[0055] (Surfactants) 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 alkylaryl ethers such as polyoxyethylene octylphenyl ether and polyoxyethylene nonylphenyl ether; polyoxyethylene-polyoxypropylene block copolymers; sorbitan fatty acid esters such as sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, sorbitan trioleate, and sorbitan tristearate; polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, and polyoxyethylene sorbitan monostearate. Nonionic surfactants such as polyoxyethylene sorbitan fatty acid esters including areates, polyoxyethylene sorbitan trioleate, and polyoxyethylene sorbitan tristearate; F-Top® EF301, EF303, EF352 (manufactured by Mitsubishi Materials Electronic Chemicals Co., Ltd.); Megafac® F171, F173, R-30, R-30-N, R-40, R-40 Examples of fluorine-based surfactants include LM (manufactured by DIC Corporation), Florard FC430, FC431 (manufactured by Sumitomo 3M Co., Ltd.), Asahi Guard® AG710, Surflon® S-382, SC101, SC102, SC103, SC104, SC105, SC106 (manufactured by Asahi Glass Co., Ltd.), and organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.). One of these surfactants may be added, or two or more may be added in combination. The content ratio of the surfactant is, for example, 0.01% to 5% by mass relative to the solid content of the resist underlayer film forming composition of the present invention excluding the solvent described later.

[0056] The resist underlayer film forming composition of the present invention may further contain absorbents, rheology modifiers, adhesion aids, and the like. Rheology modifiers are effective in improving the fluidity of the underlayer film forming composition. Adhesion aids are effective in improving the adhesion between the semiconductor substrate or resist and the underlayer film.

[0057] (Photo-absorbing agent) Examples of light absorbers include commercially available light absorbers listed in "Technology and Market of Industrial Dyes" (CMC Publishing) and "Dye Handbook" (edited by the Society of Synthetic Organic Chemistry), such as CIDisperse Yellow 1,3,4,5,7,8,13,23,31,49,50,51,54,60,64,66,68,79,82,88,90,93,102,114 and 124; CIDisperse Orange 1,5,13,25,29,30,31,44,57,72 and 73; CIDisperse Red 1,5,7,13,17,19,43,50,54,58,65,72,73,88,117,137,143,199 and 210; CIDisperse Violet 43; CIDisperse Blue 96; and CIFluorescent Brightening Agent. 112, 135 and 163; CISolvent Orange 2 and 45; CISolvent Red 1, 3, 8, 23, 24, 25, 27 and 49; CIPigment Green 10; CIPigment Brown 2, etc., can be suitably used. The above light absorbers are usually blended in a proportion of 10% by mass or less, preferably 5% by mass or less, relative to the total solid content of the resist underlayer film forming composition.

[0058] (Rheological modifier) Rheology modifiers are primarily added to improve the fluidity of the resist underlayer film-forming composition, particularly in the baking process, to improve the uniformity of the resist underlayer film thickness and enhance the filling of holes by the resist underlayer film-forming composition. Specific examples include phthalate derivatives such as dimethyl phthalate, diethyl phthalate, diisobutyl phthalate, dihexyl phthalate, and butyl isodecyl phthalate; adipic acid derivatives such as din-normal butyl adipate, diisobutyl adipate, diisooctyl adipate, and octyldecyl adipate; maleic acid derivatives such as din-normal butyl malate, diethyl malate, and dinonyl malate; oleic acid derivatives such as methyl oleate, butyl oleate, and tetrahydrofurfuryl oleate; or stearic acid derivatives such as n-butyl stearate and glyceryl stearate. These rheology modifiers are typically blended in a proportion of less than 30% by mass relative to the total solid content of the resist underlayer film-forming composition.

[0059] (Adhesion aid) Adhesion aids are added primarily to improve the adhesion between the substrate or resist and the resist underlayer film-forming composition, and especially to prevent the resist from peeling off during development. Specific examples include chlorosilanes such as trimethylchlorosilane, dimethylmethylolchlorosilane, methyldiphenylchlorosilane, and chloromethyldimethylchlorosilane; alkoxysilanes such as trimethylmethoxysilane, dimethyldiethoxysilane, methyldimethoxysilane, dimethylmethylolethoxysilane, diphenyldimethoxysilane, and phenyltriethoxysilane; silazanes such as hexamethyldisilazane, N,N'-bis(trimethylsilyl)urea, dimethyltrimethylsilylamine, and trimethylsilylimidazole; and methyloltric Examples of adhesive aids include silanes such as lorosilane, γ-chloropropyltrimethoxysilane, γ-aminopropyltriethoxysilane, and γ-glycidoxypropyltrimethoxysilane; heterocyclic compounds such as benzotriazole, benzimidazole, indazole, imidazole, 2-mercaptobenzimidazole, 2-mercaptobenzothiazole, 2-mercaptobenzoxazole, urazole, thiouracil, mercaptoimidazole, and mercaptopyrimidine; and ureas such as 1,1-dimethylurea and 1,3-dimethylurea, or thiourea compounds. These adhesive aids are usually blended in a proportion of less than 5% by mass, preferably less than 2% by mass, relative to the total solid content of the resist underlayer film forming composition.

[0060] The solid content of the resist underlayer film forming composition according to the present invention is usually 0.1 to 70% by mass, preferably 0.1 to 60% by mass. The solid content is the proportion of all components in the resist underlayer film forming composition excluding the solvent. The proportion of the polymer in the solid content is preferably in the order of 1 to 100% by mass, 1 to 99.9% by mass, 50 to 99.9% by mass, 50 to 95% by mass, and 50 to 90% by mass.

[0061] 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.

[0062] 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.

[0063] <Underlying resist film> The resist underlayer can be formed using the resist underlayer forming composition according to the present invention as follows. The resist underlayer forming composition of the present invention is applied to a substrate used in the manufacture of semiconductor devices (for example, silicon wafer substrates, silicon dioxide substrates (SiO2 substrates), silicon nitride substrates (SiN substrates), silicon oxide nitride substrates (SiON substrates), titanium nitride substrates (TiN substrates), tungsten substrates (W substrates), glass substrates, ITO substrates, polyimide substrates, and low-k material coated substrates, etc.) using an appropriate coating method such as a spinner or coater, and then fired using a heating means such as a hot plate to form a resist underlayer. The firing conditions are appropriately selected from a firing temperature of 80°C to 600°C and a firing time of 0.3 to 60 minutes. Preferably, the firing temperature is 150°C to 350°C and the firing time is 0.5 to 2 minutes. Air may be used as the atmospheric gas during firing, or an inert gas such as nitrogen or argon may be used. The thickness of the underlying film formed here can be, for example, 10 to 1000 nm, 20 to 500 nm, 30 to 400 nm, or 50 to 300 nm. Furthermore, if a quartz substrate is used as the substrate, a replica (mold replica) of the quartz imprint mold can be fabricated.

[0064] Furthermore, an inorganic resist underlayer (hard mask) can also 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. Note that the hard mask in this invention encompasses both silicon hard masks and CVD films.

[0065] Furthermore, an adhesion layer and / or a silicone layer containing 99% by mass or less, or 50% by mass or less, of Si can be formed on the resist underlayer film according to the present invention by coating or vapor deposition. For example, in addition to the method of forming the adhesion layer described in Japanese Patent Application Publication No. 2013-202982 and Japanese Patent No. 5827180, and the silicon-containing resist underlayer film (inorganic resist underlayer film) forming composition described in WO2009 / 104552A1 by spin coating, a Si-based inorganic material film can be formed by CVD or the like.

[0066] Furthermore, by applying the resist underlayer film forming composition according to the present invention onto a semiconductor substrate having a stepped portion and a non-stepped portion (a so-called stepped substrate) and firing it, a resist underlayer film with a reduced step difference between the stepped portion and the non-stepped portion can be formed.

[0067] <Manufacturing method for semiconductor devices> The method for manufacturing a semiconductor device according to the present invention is: A step of forming a resist underlayer film on a semiconductor substrate using the resist underlayer film forming composition according to the present invention, A step of forming a resist film on the formed resist underlayer film, A process of forming a resist pattern by irradiating the formed resist film with light or an electron beam and developing it. A step of etching and patterning the resist underlayer film through the formed resist pattern, and Process of processing a semiconductor substrate via a patterned resist underlayer film. Includes.

[0068] The method for manufacturing a semiconductor device according to the present invention is: A step of forming a resist underlayer film on a semiconductor substrate using the resist underlayer film forming composition according to the present invention, A step of forming a hard mask on the formed resist underlayer film, A step of forming a resist film on the formed hard mask, A process of forming a resist pattern by irradiating the formed resist film with light or an electron beam and developing it. A process of etching a hard mask through the formed resist pattern, A step of etching the resist underlayer film through the etched hard mask, and hard mask removal process Includes.

[0069] Preferably, further, A process of forming a vapor-deposited film (spacer) on the underlying film from which the hard mask has been removed. The process of processing the formed vapor-deposited film (spacer) by etching, A step of removing the underlying film, Process of processing semiconductor substrates using spacers Includes.

[0070] The above semiconductor substrate may also be a stepped substrate.

[0071] The process of forming a resist underlayer film using the resist underlayer film forming composition according to the present invention is as described above.

[0072] Next, a resist film, such as a photoresist layer, is formed on the resist underlayer. The photoresist layer can be formed by a well-known method, namely, by coating the photoresist composition solution onto the underlayer and firing. The thickness of the photoresist is, for example, 50 to 10,000 nm, or 100 to 2,000 nm, or 200 to 1,000 nm.

[0073] 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).

[0074] 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, KrF excimer lasers (wavelength 248 nm), ArF excimer lasers (wavelength 193 nm), and F2 excimer lasers (wavelength 157 nm) can be used. Among these, ArF excimer lasers (wavelength 193 nm) and EUV (wavelength 13.5 nm) are 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.

[0075] 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.

[0076] Alternatively, to maintain and improve high resolution and depth of field, a method can be employed in which a substrate on which a resist film is formed is immersed in a liquid medium for exposure. In this case, the resist underlayer film is required to have resistance to the liquid medium used, and it is possible to form a resist underlayer film that meets such requirements using the resist underlayer film forming composition according to the present invention.

[0077] 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 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. The development conditions are appropriately selected from a temperature of 5 to 50°C and a time of 10 to 600 seconds.

[0078] Then, the inorganic underlayer (intermediate layer) is removed using the patterned photoresist (upper layer) as a protective film. Next, the organic underlayer (lower layer) is removed using the film consisting of the patterned photoresist and inorganic underlayer (intermediate layer) as a protective film. Finally, the semiconductor substrate is processed using the patterned inorganic underlayer (intermediate layer) and organic underlayer (lower layer) as protective films.

[0079] First, the inorganic underlayer (intermediate layer) in the area 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. It is preferable to use halogen-based gases for dry etching of the inorganic underlayer, and more preferably fluorine-based gases. Examples of fluorine-based gases include tetrafluoromethane (CF4), perfluorocyclobutane (C4F8), perfluoropropane (C3F8), trifluoromethane, and difluoromethane (CH2F2).

[0080] Subsequently, the organic underlayer film is removed using a protective film consisting of a patterned photoresist and an inorganic underlayer film. The organic underlayer film (underlayer) is preferably removed by dry etching with an oxygen-based gas. This is because the inorganic underlayer film, which contains many silicon atoms, is difficult to remove by dry etching with an oxygen-based gas.

[0081] In addition, wet etching is sometimes performed to simplify the process steps and reduce damage to the processed substrate, but with the resist underlayer film forming composition according to the present invention, it is also possible to form a resist underlayer film that exhibits sufficient resistance to the chemicals used.

[0082] 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).

[0083] 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.

[0084] In this invention, an organic underlayer film can be formed on a substrate, followed by an inorganic underlayer film, and then a photoresist can be coated on top of that. This narrows the pattern width of the photoresist, and even when the photoresist is coated thinly to prevent pattern collapse, the substrate can be processed 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.

[0085] 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.

[0086] 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. [Examples]

[0087] The present invention will be described in more detail below with reference to examples, but the present invention is not limited in any way by the following examples. The equipment used to measure the weight-average molecular weight of the compounds obtained in the following synthesis examples is shown. Equipment: HLC-8320GPC manufactured by Tosoh Corporation GPC column: TSKgel Super-MultiporeHZ-N (2 tubes) Column temperature: 40℃ Flow rate: 0.35mL / min Eluent:THF Standard sample: Polystyrene

[0088] <Synthesis Example 1> 35.00 g of diphenylamine (manufactured by Tokyo Chemical Industry Co., Ltd.), 21.97 g of benzaldehyde (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.60 g of methanesulfonic acid (manufactured by Tokyo Chemical Industry Co., Ltd., hereafter referred to as MSA), and 230.25 g of propylene glycol monomethyl ether acetate (hereafter referred to as PGMEA) were placed in a flask. The mixture was then heated to 115°C under nitrogen and reacted for approximately 7 hours. After stopping the reaction, the mixture was precipitated with methanol and dried to obtain resin (1-1). The weight-average molecular weight Mw, measured in polystyrene equivalent by GPC, was approximately 5,100.

[0089] [ka]

[0090] <Synthesis Example 2> 35.00 g of carbazole (manufactured by Tokyo Chemical Industry Co., Ltd.), 32.72 g of 1-naphthaldehyde (manufactured by Tokyo Chemical Industry Co., Ltd.), 2.01 g of MSA, and 162.71 g of PGMEA were placed in a flask. The mixture was then heated to 120°C under nitrogen and reacted for approximately 7 hours. After stopping the reaction, the mixture was precipitated with methanol and dried to obtain resin (1-2). The weight-average molecular weight Mw, measured in polystyrene equivalent by GPC, was approximately 2,600.

[0091] [ka]

[0092] <Synthesis Example 3> 50.00 g of 2-phenylindole (manufactured by Tokyo Chemical Industry Co., Ltd.), 40.41 g of 1-naphthaldehyde (manufactured by Tokyo Chemical Industry Co., Ltd.), 4.97 g of MSA, and 143.07 g of PGMEA were placed in a flask. The mixture was then heated to 120°C under nitrogen and reacted for approximately 7 hours. After stopping the reaction, the mixture was precipitated with methanol and dried to obtain resin (1-3). The weight-average molecular weight Mw, measured in polystyrene equivalent by GPC, was approximately 1,700.

[0093] [ka]

[0094] <Synthesis Example 4> 45.00 g of 1,5-dihydroxynaphthalene (manufactured by Tokyo Chemical Industry Co., Ltd.), 29.79 g of benzaldehyde (manufactured by Tokyo Chemical Industry Co., Ltd.), 5.40 g of MSA, and 187.11 g of PGMEA were placed in a flask. The mixture was then heated under nitrogen until reflux was achieved and the reaction was allowed to proceed for approximately 1.5 hours. After the reaction was stopped, the mixture was diluted with propylene glycol monomethyl ether (hereinafter referred to as PGME), precipitated with water / methanol, and dried to obtain resin (1-4). The weight-average molecular weight Mw, measured in polystyrene equivalent by GPC, was approximately 4,600.

[0095] [ka]

[0096] <Synthesis Example 5> 60.00 g of 9,9-bis(4-hydroxyphenyl)fluorene (manufactured by Tokyo Chemical Industry Co., Ltd.), 18.17 g of benzaldehyde (manufactured by Tokyo Chemical Industry Co., Ltd.), 3.29 g of MSA, and 99.56 g of PGMEA were placed in a flask. The mixture was then heated under nitrogen until reflux was achieved and the reaction was allowed to proceed for approximately 4 hours. After the reaction was stopped, the mixture was diluted with PGMEA, precipitated with water / methanol, and dried to obtain resin (1-5). The weight-average molecular weight Mw, measured in polystyrene equivalent by GPC, was approximately 4,100.

[0097] [ka]

[0098] <Synthesis Example 6> 70.00 g of 2,2-biphenol (manufactured by Tokyo Chemical Industry Co., Ltd.), 29.36 g of 1-naphthaldehyde (manufactured by Tokyo Chemical Industry Co., Ltd.), 43.28 g of 1-pyrenecarboxylaldehyde (manufactured by Aldrich), 10.83 g of MSA, and 54.81 g of PGME were placed in a flask. The mixture was then heated to 120°C under nitrogen and reacted for 24 hours. After stopping the reaction, the mixture was precipitated with methanol and dried to obtain resin (1-6). The weight-average molecular weight Mw, measured in polystyrene equivalent by GPC, was approximately 5,000.

[0099] [ka]

[0100] <Synthesis Example 7> 10.00 g of the resin obtained in Synthesis Example 1, 6.97 g of propargyl bromide (manufactured by Tokyo Chemical Industry Co., Ltd., hereafter referred to as PBr), 2.17 g of tetrabutylammonium iodide (hereafter referred to as TBAI), 21.53 g of tetrahydrofuran (hereafter referred to as THF), and 7.18 g of 25% sodium hydroxide aqueous solution were placed in a flask. The mixture was then heated to 55°C under nitrogen and reacted for approximately 15 hours. After stopping the reaction, the organic layer was repeatedly separated with methyl isobutyl ketone (hereafter referred to as MIBK) and water to concentrate the organic layer, redissolved in PGMEA, reprecipitated with methanol, and dried to obtain resin (1-7). The weight-average molecular weight Mw, measured in polystyrene equivalent by GPC, was approximately 6,100.

[0101] [ka]

[0102] <Synthesis Example 8> 10.00 g of the resin obtained in Synthesis Example 2, 6.89 g of PBr, 3.21 g of TBAI, 22.61 g of THF, and 7.54 g of 25% sodium hydroxide aqueous solution were placed in a flask. The mixture was then heated to 55°C under nitrogen and reacted for approximately 18 hours. After stopping the reaction, the organic layer was concentrated by repeated liquid-liquid extraction with MIBK and water, redissolved in PGMEA, reprecipitated with methanol, and dried to obtain resin (1-8). The weight-average molecular weight Mw, measured in polystyrene equivalent by GPC, was approximately 3,000.

[0103] [ka]

[0104] <Synthesis Example 9> 15.00 g of the resin obtained in Synthesis Example 3, 10.52 g of PBr, 4.90 g of TBAI, 34.21 g of THF, and 11.40 g of 25% sodium hydroxide aqueous solution were placed in a flask. The mixture was then heated to 55°C under nitrogen and reacted for approximately 15 hours. After stopping the reaction, the organic layer was concentrated by repeated liquid-liquid extraction with MIBK and water, redissolved in PGMEA, reprecipitation with methanol, and dried to obtain resin (1-9). The weight-average molecular weight Mw, measured in polystyrene equivalent by GPC, was approximately 1,900.

[0105] [ka]

[0106] <Synthesis Example 10> 15.00 g of the resin obtained in Synthesis Example 4, 12.57 g of PBr, 5.85 g of tetrabutylammonium bromide (hereafter referred to as TBAB), 37.60 g of THF, and 12.53 g of 25% sodium hydroxide aqueous solution were placed in a flask. The mixture was then heated to 55°C under nitrogen and reacted for approximately 16 hours. After stopping the reaction, the organic layer was concentrated by repeated liquid-liquid extraction with MIBK and water, redissolved in PGMEA, reprecipitated with water / methanol, and dried to obtain resin (1-10). The weight-average molecular weight Mw, measured in polystyrene equivalent by GPC, was approximately 6,900.

[0107] [ka]

[0108] <Synthesis Example 11> 15.00 g of the resin obtained in Synthesis Example 5, 13.57 g of PBr, 6.32 g of TBAB, 39.25 g of THF, and 13.08 g of 25% sodium hydroxide aqueous solution were placed in a flask. The mixture was then heated to 55°C under nitrogen and reacted for approximately 16 hours. After stopping the reaction, the organic layer was concentrated by repeated liquid-liquid extraction with MIBK and water, redissolved in PGMEA, reprecipitated with water / methanol, and dried to obtain resin (1-11). The weight-average molecular weight Mw, measured in polystyrene equivalent by GPC, was approximately 4,600.

[0109] [ka]

[0110] <Synthesis Example 12> 10.00 g of the resin obtained in Synthesis Example 6, 12.78 g of PBr, 5.86 g of TBAB, 21.48 g of THF, and 7.16 g of 25% sodium hydroxide aqueous solution were placed in a flask. The mixture was then heated to 55°C under nitrogen and reacted for approximately 15 hours. After stopping the reaction, the organic layer was concentrated by repeated liquid-liquid extraction with MIBK and water, redissolved in PGMEA, reprecipitated with water / methanol, and dried to obtain resin (1-12). The weight-average molecular weight Mw, measured in polystyrene equivalent by GPC, was approximately 6,300.

[0111] [ka]

[0112] <Synthesis Example 13> 10.00 g of the resin obtained in Synthesis Example 1, 10.99 g of α-chloro-p-xylene (manufactured by Tokyo Chemical Industry Co., Ltd., hereafter referred to as CMX), 5.77 g of TBAI, 16.06 g of THF, and 10.71 g of 25% sodium hydroxide aqueous solution were placed in a flask. The mixture was then heated to 55°C under nitrogen and reacted for approximately 15 hours. After stopping the reaction, the organic layer was repeatedly separated using a mixed solvent of MIBK and cyclohexanone (hereafter referred to as CYH) and water to concentrate the organic layer, redissolve it in CYH, reprecipitate with methanol, and dry to obtain resin (1-13). The weight-average molecular weight Mw, measured in polystyrene equivalent by GPC, was approximately 5,500.

[0113] [ka]

[0114] <Synthesis Example 14> 10.00 g of the resin obtained in Synthesis Example 2, 9.91 g of benzyl bromide (manufactured by Tokyo Chemical Industry Co., Ltd., hereafter referred to as BBr), 3.21 g of TBAI, 26.01 g of THF, and 8.67 g of 25% sodium hydroxide aqueous solution were placed in a flask. The mixture was then heated to 55°C under nitrogen and reacted for approximately 18 hours. After stopping the reaction, the organic layer was repeatedly separated using a mixed solvent of MIBK and CYH and water to concentrate the layer, redissolve it in CYH, reprecipitate with methanol, and dried to obtain resin (1-14). The weight-average molecular weight Mw, measured in polystyrene equivalent by GPC, was approximately 2,800.

[0115] [ka]

[0116] <Synthesis Example 15> 10.00 g of the resin obtained in Synthesis Example 6, 15.55 g of BBr, 4.40 g of TBAB, 22.46 g of THF, and 7.49 g of 25% sodium hydroxide aqueous solution were placed in a flask. The mixture was then heated to 55°C under nitrogen and reacted for approximately 15 hours. After stopping the reaction, the organic layer was repeatedly separated using a mixed solvent of MIBK and CYH and water to concentrate the layer, redissolve it in CYH, reprecipitate with methanol, and dried to obtain resin (1-15). The weight-average molecular weight Mw, measured in polystyrene equivalent by GPC, was approximately 6,000.

[0117] [ka]

[0118] <Example 1> The resin obtained in Synthesis Example 7 was dissolved in PGMEA, and ion exchange was carried out for 4 hours using a cation exchange resin and anion exchange resin to obtain a 19.48% compound solution. To 2.43 g of this resin solution, 0.12 g of PL-LI (manufactured by Midori Chemical Co., Ltd.), 0.36 g of PGME containing 2% by mass pyridinium p-toluenesulfonic acid, 0.05 g of PGMEA containing 1% by mass surfactant (manufactured by DIC Corporation, Megafac R-40), 8.07 g of PGMEA, and 3.97 g of PGME were added and dissolved. The solution was filtered through a polytetrafluoroethylene microfilter with a pore size of 0.1 μm to prepare a solution of the resist underlayer film forming composition.

[0119] <Example 2> The resin obtained in Synthesis Example 8 was dissolved in PGMEA, and ion exchange was carried out for 4 hours using a cation exchange resin and anion exchange resin to obtain an 18.63% compound solution. 2.54 g of this resin solution was mixed with 0.12 g of PL-LI, 0.36 g of PGME containing 2% by mass pyridinium p-toluenesulfonic acid, 0.05 g of PGMEA containing 1% by mass surfactant, 7.96 g of PGMEA, and 3.97 g of PGME, and dissolved. The mixture was then filtered through a polytetrafluoroethylene microfilter with a pore size of 0.1 μm to prepare a solution of the resist underlayer film forming composition.

[0120] <Example 3> The resin obtained in Synthesis Example 9 was dissolved in PGMEA, and ion exchange was carried out for 4 hours using a cation exchange resin and anion exchange resin to obtain a 22.47% compound solution. 2.53 g of this resin solution was mixed with 0.11 g of PL-LI, 0.85 g of PGME containing 2% by mass pyridinium p-toluenesulfonic acid, 0.06 g of PGMEA containing 1% by mass surfactant, 11.49 g of PGMEA, and 4.95 g of PGME, and dissolved. The mixture was then filtered through a polytetrafluoroethylene microfilter with a pore size of 0.1 μm to prepare a solution of the resist underlayer film forming composition.

[0121] <Example 4> The resin obtained in Synthesis Example 10 was dissolved in PGMEA, and ion exchange was carried out for 4 hours using a cation exchange resin and anion exchange resin to obtain a 19.21% compound solution. 3.60 g of this resin solution was mixed with 0.17 g of PL-LI, 0.52 g of PGME containing 2% by mass pyridinium p-toluenesulfonic acid, 0.07 g of PGMEA containing 1% by mass surfactant, 13.91 g of PGMEA, and 6.73 g of PGME, and dissolved. The mixture was then filtered through a polytetrafluoroethylene microfilter with a pore size of 0.1 μm to prepare a solution of the resist underlayer film forming composition.

[0122] <Example 5> The resin obtained in Synthesis Example 11 was dissolved in PGMEA, and ion exchange was carried out for 4 hours using a cation exchange resin and anion exchange resin to obtain a 21.25% compound solution. 3.25 g of this resin solution was mixed with 0.17 g of PL-LI, 0.52 g of PGME containing 2% by mass pyridinium p-toluenesulfonic acid, 0.07 g of PGMEA containing 1% by mass surfactant, 14.26 g of PGMEA, and 6.73 g of PGME, and dissolved. The mixture was then filtered through a polytetrafluoroethylene microfilter with a pore size of 0.1 μm to prepare a solution of the resist underlayer film forming composition.

[0123] <Example 6> The resin obtained in Synthesis Example 12 was dissolved in PGMEA, and ion exchange was carried out for 4 hours using a cation exchange resin and anion exchange resin to obtain a 19.44% compound solution. 2.44 g of this resin solution was mixed with 0.12 g of PL-LI, 0.36 g of PGME containing 2% by mass pyridinium p-toluenesulfonic acid, 0.05 g of PGMEA containing 1% by mass surfactant, 8.07 g of PGMEA, and 3.97 g of PGME, and dissolved. The mixture was then filtered through a polytetrafluoroethylene microfilter with a pore size of 0.1 μm to prepare a solution of the resist underlayer film forming composition.

[0124] <Example 7> The resin obtained in Synthesis Example 13 was dissolved in CYH, and ion exchange was carried out for 4 hours using a cation exchange resin and anion exchange resin to obtain a 19.77% compound solution. 2.40 g of this resin solution was mixed with 0.12 g of PL-LI, 0.36 g of PGME containing 2% by mass of pyridinium p-toluenesulfonic acid, 0.05 g of PGMEA containing 1% by mass of surfactant, 2.83 g of PGMEA, 3.53 g of PGME, and 6.72 g of CYH, and dissolved. The mixture was then filtered through a polytetrafluoroethylene microfilter with a pore size of 0.1 μm to prepare a solution of the resist underlayer film forming composition.

[0125] <Example 8> The resin obtained in Synthesis Example 14 was dissolved in CYH, and ion exchange was carried out for 4 hours using a cation exchange resin and anion exchange resin to obtain a 21.63% compound solution. 2.19 g of this resin solution was mixed with 0.12 g of PL-LI, 0.36 g of PGME containing 2% by mass of pyridinium p-toluenesulfonic acid, 0.05 g of PGMEA containing 1% by mass of surfactant, 2.83 g of PGMEA, 2.53 g of PGME, and 6.92 g of CYH, and dissolved. The mixture was then filtered through a polytetrafluoroethylene microfilter with a pore size of 0.1 μm to prepare a solution of the resist underlayer film forming composition.

[0126] <Example 9> The resin obtained in Synthesis Example 15 was dissolved in CYH, and ion exchange was carried out for 4 hours using a cation exchange resin and anion exchange resin to obtain a 19.56% compound solution. 2.42 g of this resin solution was mixed with 0.12 g of PL-LI, 0.36 g of PGME containing 2% by mass of pyridinium p-toluenesulfonic acid, 0.05 g of PGMEA containing 1% by mass of surfactant, 2.83 g of PGMEA, 2.53 g of PGME, and 6.69 g of CYH, and dissolved. The mixture was filtered through a polytetrafluoroethylene microfilter with a pore size of 0.1 μm to prepare a solution of the resist underlayer film forming composition.

[0127] <Comparative Example 1> The resin obtained in Synthesis Example 1 was dissolved in PGMEA, and ion exchange was carried out for 4 hours using a cation exchange resin and anion exchange resin to obtain an 18.73% compound solution. 2.53 g of this resin solution was mixed with 0.12 g of PL-LI, 0.36 g of PGME containing 2% by mass pyridinium p-toluenesulfonic acid, 0.05 g of PGMEA containing 1% by mass surfactant, 7.98 g of PGMEA, and 3.97 g of PGME, and dissolved. The mixture was then filtered through a polytetrafluoroethylene microfilter with a pore size of 0.1 μm to prepare a solution of the resist underlayer film forming composition.

[0128] <Comparative Example 2> The resin obtained in Synthesis Example 2 was dissolved in PGMEA, and ion exchange was carried out for 4 hours using a cation exchange resin and anion exchange resin to obtain a 17.08% compound solution. 2.77 g of this resin solution was mixed with 0.12 g of PL-LI, 0.36 g of PGME containing 2% by mass pyridinium p-toluenesulfonic acid, 0.05 g of PGMEA containing 1% by mass surfactant, 7.73 g of PGMEA, and 3.97 g of PGME, and dissolved. The mixture was then filtered through a polytetrafluoroethylene microfilter with a pore size of 0.1 μm to prepare a solution of the resist underlayer film forming composition.

[0129] <Comparative Example 3> The resin obtained in Synthesis Example 3 was dissolved in PGMEA, and ion exchange was carried out for 4 hours using a cation exchange resin and anion exchange resin to obtain a 20.20% compound solution. To 2.41 g of this resin solution, 0.10 g of PL-LI, 0.73 g of PGME containing 2% by mass pyridinium p-toluenesulfonic acid, 0.05 g of PGMEA containing 1% by mass surfactant, 0.91 g of PGMEA, 2.16 g of PGME, and 8.64 g of CYH were added and dissolved. The solution was filtered through a polytetrafluoroethylene microfilter with a pore size of 0.1 μm to prepare a solution of the resist underlayer film forming composition.

[0130] <Comparative Example 4> The resin obtained in Synthesis Example 4 was dissolved in PGME, and ion exchange was carried out for 4 hours using a cation exchange resin and an anion exchange resin to obtain an 18.06% compound solution. 3.83 g of this resin solution was mixed with 0.17 g of PL-LI, 0.52 g of PGME containing 2% by mass pyridinium p-toluenesulfonic acid, 0.07 g of PGMEA containing 1% by mass surfactant, 7.17 g of PGMEA, and 13.24 g of PGME, and dissolved. The mixture was then filtered through a polytetrafluoroethylene microfilter with a pore size of 0.1 μm to prepare a solution of the resist underlayer film forming composition.

[0131] <Comparative Example 5> The resin obtained in Synthesis Example 5 was dissolved in PGMEA, and ion exchange was carried out for 4 hours using a cation exchange resin and anion exchange resin to obtain a 19.44% compound solution. 3.56 g of this resin solution was mixed with 0.17 g of PL-LI, 0.52 g of PGME containing 2% by mass pyridinium p-toluenesulfonic acid, 0.07 g of PGMEA containing 1% by mass surfactant, 13.95 g of PGMEA, and 6.73 g of PGME, and dissolved. The mixture was then filtered through a polytetrafluoroethylene microfilter with a pore size of 0.1 μm to prepare a solution of the resist underlayer film forming composition.

[0132] <Comparative Example 6> The resin obtained in Synthesis Example 6 was dissolved in PGMEA, and ion exchange was carried out for 4 hours using a cation exchange resin and anion exchange resin to obtain a 29.80% compound solution. 2.78 g of this resin solution was mixed with 0.21 g of PL-LI, 0.62 g of PGME containing 2% by mass pyridinium p-toluenesulfonic acid, 0.08 g of PGMEA containing 1% by mass surfactant, 7.73 g of PGMEA, and 3.58 g of PGME, and dissolved. The mixture was then filtered through a polytetrafluoroethylene microfilter with a pore size of 0.1 μm to prepare a solution of the resist underlayer film forming composition.

[0133] (Contact angle measurement) The polymer solutions used in Comparative Examples 1-6 and Examples 1-9 were coated onto silicon wafers using a spin coater and baked on a hot plate at 160°C for 60 seconds to form a polymer film. The contact angle of the polymer with respect to pure water was then measured using a contact angle meter manufactured by Kyowa Interface Science Co., Ltd. The contact angles of the polymers used in the examples corresponding to those used in the comparative examples were compared, and a higher contact angle for the polymer used in the example was judged as "○".

[0134] [Table 1]

[0135] Comparing Comparative Example 1-Example 1 and Example 7, Comparative Example 2-Example 2 and Example 8, Comparative Example 3-Example 3, Comparative Example 4-Example 4, Comparative Example 5-Example 5, Comparative Example 6-Example 6 and Example 9, the polymers used in the examples showed a higher contact angle than the polymers used in the comparative examples.

[0136] (Leaching test into resist solvent) The resist underlayer-forming compositions prepared in Comparative Examples 1-6 and Examples 1-9 were applied to silicon wafers using a spin coater, and then baked on a hot plate at 240°C for 60 seconds or 350°C for 60 seconds to form a resist underlayer (thickness 65 nm). These resist underlayers were immersed in a general-purpose thinner, PGME / PGMEA = 7 / 3. The resist underlayers were insoluble, confirming sufficient curability.

[0137] [Table 2]

[0138] (Applicability test) The resist underlayer film-forming compositions prepared in Comparative Examples 1-6 and Examples 1-9 were coated onto silicon wafers using a spin coater, and then baked on a hot plate at 240°C for 60 seconds or 350°C for 60 seconds to form a resist underlayer film. A coating-type silicon solution was then applied to the upper layer and baked at 215°C for 60 seconds to form a silicon film. The film thickness was then measured and the value was calculated according to the formula: "Film thickness variation (maximum film thickness - minimum film thickness) / average film thickness × 100". A low value indicates good coating performance. If the coating performance was good compared to the example corresponding to the comparative example, it was judged as "○".

[0139] [Table 3]

[0140] Comparing Comparative Examples 1-1 and 7, Comparative Examples 2-2 and 8, Comparative Examples 3-3, Comparative Examples 4-4, Comparative Examples 5-5, and Comparative Examples 6-6 and 9, the examples have better coating properties than the comparative examples. This is because the polymer is hydrophobic, which improves coating properties.

[0141] (Drug resistance test) Solutions of the resist underlayer-forming compositions prepared in Comparative Examples 1-6 and Examples 1-9 were applied onto SiON using a spin coater. A resist underlayer (thickness 65 nm) was formed by firing on a hot plate at 240°C for 60 seconds or 350°C for 60 seconds. A silicon hard mask layer (thickness 20 nm) and a resist layer (AR2772JN-14, manufactured by JSR Corporation, thickness 120 nm) were formed on top of this, and a resist pattern was obtained by exposure and development at a wavelength of 193 nm using a mask. Subsequently, dry etching was performed using a Lam Research Corporation etching apparatus with fluorine-based gas and oxygen-based gas to transfer the resist pattern to the resist underlayer. The pattern shape was confirmed using a Hitachi Technologies CG-4100, and it was confirmed that a 50 nm line pattern had been obtained.

[0142] The pattern wafers obtained here were cut and immersed in SARC-410 (manufactured by Integris Japan Co., Ltd.) heated to 30°C. After immersion, the wafers were removed, rinsed with water, and dried. These were then observed with a scanning electron microscope (Regulus8240) to check whether the pattern shape formed by the resist underlayer film had deteriorated or whether the pattern had collapsed. If the pattern shape did not deteriorate and no pattern collapse occurred, the wafer had high chemical resistance. A "○" was given if the pattern shape did not deteriorate or the pattern did not collapse even after immersion in the chemical solution for a longer period than a comparative example with a similar structure.

[0143] [Table 4]

[0144] As can be seen from Comparative Example 1-Example 1, Comparative Example 2-Example 2, Comparative Example 3-Example 3, Comparative Example 4-Example 4, Comparative Example 5-Example 5, and Comparative Example 6-Example 6, when fired at 240°C, chemical resistance to alkaline solutions can be improved by modifying with amino groups or hydroxyl groups. Similarly, chemical resistance is also improved when fired at a high temperature of 350°C. Therefore, this material can be applied to processes that use chemical solutions. [Industrial applicability]

[0145] The present invention provides a novel resist underlayer forming composition that meets the requirements of exhibiting a high pure water contact angle, high adhesion to the upper layer film, a hydrophobic underlayer film that is difficult to peel off, and good coatability, and also exhibits other good properties such as sufficient resistance to chemicals used in resist underlayer films.

Claims

1. Solvent, and the following formula (2): 【Chemistry 27】 (In the formula, Ar ３ R represents an aromatic group with 6 to 60 carbon atoms that contains an indole ring. ８ The group is selected from the group consisting of alkyl groups having 1 to 10 carbon atoms, alkenyl groups having 2 to 10 carbon atoms, alkynyl groups having 2 to 10 carbon atoms, aryl groups having 6 to 40 carbon atoms, and combinations thereof, and the alkyl group, alkenyl group, alkynyl group, and aryl group may contain ether bonds, ketone bonds, or ester bonds, and the aryl group may be substituted with alkyl groups having 1 to 10 carbon atoms that are substituted with hydroxyl groups. R ６ The group is selected from the group consisting of a hydrogen atom, a trifluoromethyl group, an aryl group having 6 to 40 carbon atoms, and a heterocyclic group, and the aryl group and the heterocyclic group may be substituted with a halogen group, a nitro group, an amino group, a cyano group, a trifluoromethyl group, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an alkynyl group having 2 to 10 carbon atoms, or an aryl group having 6 to 40 carbon atoms, and the alkyl group, the alkenyl group, the alkynyl group, and the aryl group may contain an ether bond, a ketone bond, or an ester bond. R ７ The group is selected from the group consisting of a hydrogen atom, a trifluoromethyl group, an aryl group having 6 to 40 carbon atoms, and a heterocyclic group, and the aryl group and the heterocyclic group may be substituted with a halogen group, a nitro group, an amino group, a cyano group, a trifluoromethyl group, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an alkynyl group having 2 to 10 carbon atoms, or an aryl group having 6 to 40 carbon atoms, and the alkyl group, the alkenyl group, the alkynyl group, and the aryl group may contain an ether bond, a ketone bond, or an ester bond. And R ６ and R ７ These may form a ring together with the carbon atoms to which they are bonded. n3 is 1 or greater, and Ar ３ An integer less than or equal to the number of substituents that can be substituted, n4 is 0, and R ８ is Ar ３ bonds to the nitrogen atom contained in .) A resist underlayer film forming composition comprising a polymer containing a unit structure (A) represented by , wherein the polymer is such that when only the polymer is dissolved in a solvent, coated onto a silicon wafer, and fired at 160°C to form a film, the contact angle with pure water is improved compared to a film formed by dissolving only a polymer that does not contain the polymer and whose nitrogen atom on Ar3 of formula (2) is not substituted in the solvent, coating it onto a silicon wafer, and firing at 160°C.

2. In the above formula (2), R6 is an aryl group having 6 to 40 carbon atoms. R7 is a hydrogen atom. The resist underlayer film forming composition according to claim 1.

3. In the above formula (2), R6 is an aromatic hydrocarbon group having 6 to 16 carbon atoms. The resist underlayer film forming composition according to claim 1 or 2.

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

5. The resist underlayer film forming composition according to any one of claims 1 to 4, further comprising an acid and / or an acid generator.

6. The resist underlayer film forming composition according to claim 1, wherein the boiling point of the solvent is 160°C or higher.

7. A resist underlayer film which is a fired product of a coated film made from the resist underlayer film forming composition according to any one of claims 1 to 6.

Images