Composition for resist underlayer film formation

Abstract

A new resist underlayer film forming composition which meets the requirements of a hydrophobic underlayer film which exhibits a high pure water contact angle, high adhesion to the overlayer film, is not easily peeled, and has good coatability, and which also exhibits other good properties such as sufficient resistance to the chemicals used for the resist underlayer film is provided. A resist underlayer film forming composition comprising: a solvent; and a polymer comprising a unit structure (A) represented by the following formula (1), and / or the following formula (2). (In the formula, Ar 1 and Ar 2 each represent a benzene ring, or a naphthalene ring, Ar 3 represents an aromatic compound having 6 to 60 carbon atoms which can contain a nitrogen atom, R 1 , and R 2 each are a group which substitutes a hydrogen atom on the ring of Ar 1 , and Ar 2 , R 3 , and R 8 are selected from 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 combinations thereof, R 4 , and R 6 are selected from a hydrogen atom, a trifluoromethyl group, an aryl group having 6 to 40 carbon atoms, and a heterocyclic group, R 5 , and R 7 are selected from a hydrogen atom, a trifluoromethyl group, an aryl group having 6 to 40 carbon atoms, and a heterocyclic group, n1 and n2 each are an integer of 0 to 3, n3 is an integer of 1 or more, and is an integer of the number of substituents or less which can substitute Ar 3 , n4 is 0 or 1, and when n4 is 0, R 8 is bonded to the nitrogen atom included in Ar 3 .)

Description

Technical Field

[0001] The present invention relates to a composition for forming a photoresist underlayer film, a photoresist underlayer film as a sintered product of a coating film formed 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 photoresist underlayer film formation compositions used in photolithography processes for semiconductor device manufacturing that can form a photoresist underlayer film that does not mix with the upper layer, obtains excellent photoresist patterns, and has a low dry etching rate compared to the upper layer (hard mask: coated film or vapor-deposited film) and semiconductor substrate. The use of polymers containing repeating units including benzene rings or naphthalene rings has been proposed (Patent Document 1).

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: WO 2013 / 047516 A1 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] However, conventional compositions for forming the underlayer of resist still have unsatisfactory aspects regarding the requirements for obtaining a hydrophobic underlayer that exhibits a high pure water contact angle, strong adhesion to the upper layer, is not easily peeled off, and has good coatability. Furthermore, in semiconductor manufacturing processes, chemical treatment is sometimes performed, but this sometimes necessitates sufficient resistance to the chemical solution also used in the underlayer of the resist.

[0008] Methods for solving problems

[0009] The present invention solves the above-mentioned problems. Specifically, the present invention includes the following solutions.

[0010] [1] A composition for forming a resist underlayer film, comprising: a solvent; and a polymer comprising a unit structure (A) as shown in formula (1) and / or formula (2).

[0011]

[0012] (where Ar) 1 And Ar 2 Each represents a benzene ring or a naphthalene ring, Ar 1 and Ar 2 They can be bonded together via a single bond.

[0013] Ar 3 This refers to aromatic compounds that can contain 6 to 60 carbon atoms and may include nitrogen atoms.

[0014] R 1 and R 2 Each to replace Ar 1 And Ar 2 The group consisting of hydrogen atoms on the ring is selected from halogen, nitro, amino, cyano, alkyl with 1 to 10 carbon atoms, alkenyl with 2 to 10 carbon atoms, alkynyl with 2 to 10 carbon atoms, aryl with 6 to 40 carbon atoms, and combinations thereof, and the alkyl, alkenyl, alkenyl and aryl groups may contain ether bonds, ketone bonds or ester bonds.

[0015] R 3 and R 8 The alkyl group is selected from 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. Furthermore, 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 by an alkyl group having 1 to 10 carbon atoms that has been substituted with a hydroxyl group.

[0016] R 4 and R 6 The group is selected from hydrogen atom, trifluoromethyl, aryl and heterocyclic groups having 6 to 40 carbon atoms, and the aryl and heterocyclic groups can be substituted with halogen, nitro, amino, cyano, trifluoromethyl, alkyl having 1 to 10 carbon atoms, alkoxy having 1 to 10 carbon atoms, alkenyl having 2 to 10 carbon atoms, alkynyl having 2 to 10 carbon atoms, or aryl having 6 to 40 carbon atoms, and the alkyl, alkenyl, alkynyl and aryl groups can contain ether bonds, ketone bonds or ester bonds.

[0017] R 5 and R 7 The group is selected from hydrogen atom, trifluoromethyl, aryl and heterocyclic groups having 6 to 40 carbon atoms, and the aryl and heterocyclic groups can be substituted with halogen, nitro, amino, cyano, trifluoromethyl, alkyl having 1 to 10 carbon atoms, alkoxy having 1 to 10 carbon atoms, alkenyl having 2 to 10 carbon atoms, alkynyl having 2 to 10 carbon atoms, or aryl having 6 to 40 carbon atoms, and the alkyl, alkenyl, alkynyl and aryl groups can contain ether bonds, ketone bonds or ester bonds.

[0018] Furthermore R 4 With R 5 and R 6 With R 7 They can form rings together with the carbon atoms they are bonded to.

[0019] n1 and n2 are each integers between 0 and 3.

[0020] n3 is 1 or higher, and is capable of being in Ar 3The substitution base number is an integer less than or equal to n4, where n4 is 0 or 1. When n4 is 0, R 8 with Ar 3 The nitrogen atoms contained are bonded together.

[0021] [2] According to the composition for forming a resist underlayer film as described in [1], in the above formula (1) Ar 1 And Ar 2 It is a benzene ring.

[0022] [3] According to the composition for forming a resist underlayer film as described in [1], in the above formula (2) Ar 3 It can be a substituted benzene ring, naphthalene ring, or phenylindole ring.

[0023] [4] The composition for forming a resist underlayer film according to any one of [1] to [3], in formula (1) or formula (2) above,

[0024] R 4 and R 6 It is an aryl group with 6 to 40 carbon atoms.

[0025] R 5 and R 7 It is a hydrogen atom.

[0026] [5] The composition for forming a resist underlayer film according to any one of [1] to [4], in formula (1) or formula (2) above,

[0027] R 4 and R 6 It is an aromatic hydrocarbon group with 6 to 16 carbon atoms.

[0028] [6] The composition for forming a resist underlayer film according to any one of [1] to [5] further comprises a crosslinking agent.

[0029] [7] The composition for forming a resist underlayer film according to any one of [1] to [6] further comprises an acid and / or an acid-generating agent.

[0030] [8] In the composition for forming a resist underlayer film according to [1], the boiling point of the solvent is 160°C or higher.

[0031] [9] A resist underlayer film, which is a sintered product of a coating film formed by any one of the resist underlayer film forming compositions described in any one of [1] to [8].

[0032]

[10] A method for manufacturing a semiconductor device, comprising the following steps:

[0033] A process of forming a photoresist underlayer film by using the photoresist underlayer film forming composition described in any one of [1] to [8] on a semiconductor substrate;

[0034] The process of forming a resist film on the formed resist underlayer film;

[0035] The process of irradiating the formed resist film with light or electron beams and developing it to form a resist pattern;

[0036] The process of etching the underlying resist film through the formed resist pattern to perform patterning; and

[0037] The process of processing a semiconductor substrate through a patterned resist underlayer.

[0038]

[11] A method for manufacturing a semiconductor device, comprising the following steps:

[0039] A process of forming a photoresist underlayer film by using the photoresist underlayer film forming composition described in any one of [1] to [8] on a semiconductor substrate;

[0040] The process of forming a hard mask on the formed resist underlayer film;

[0041] The process of forming a resist film on the hard mask;

[0042] The process of irradiating the formed resist film with light or electron beams and developing it to form a resist pattern;

[0043] The process of etching a hard mask through the formed resist pattern;

[0044] The process of etching the underlying resist film through an etched hard mask; and

[0045] The process of removing the hard mask.

[0046]

[12] The method for manufacturing a semiconductor device according to

[11] further comprises the following steps:

[0047] The process of forming a vapor-deposited film (spacer) on the lower film after the hard mask has been removed;

[0048] The process of etching the formed vapor-deposited film (spacer);

[0049] The process of removing the lower film; and

[0050] The process of processing a semiconductor substrate using spacers.

[0051]

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

[10] to

[12] , the semiconductor substrate is a high-low difference substrate.

[0052] The effects of the invention

[0053] According to the present invention, a new composition for forming a resist underlayer film is provided, which addresses the requirements of obtaining a hydrophobic underlayer film that exhibits a high pure water contact angle, high adhesion to the upper film, is not easily peeled off, and has good coatability, and also exhibits other good properties such as sufficient resistance to the solution also used in the resist underlayer film. Detailed Implementation

[0054] <Composition for forming a lower layer film of resist>

[0055] The composition for forming a resist underlayer film according to the present invention comprises a solvent and a unit structure (A) shown in the following formula (1) and / or the following formula (2).

[0056]

[0057] (where Ar) 1 And Ar 2 Each represents a benzene ring or a naphthalene ring, Ar 1 And Ar 2 They can be bonded together via a single bond.

[0058] Ar 3 This refers to aromatic compounds that can contain 6 to 60 carbon atoms and may include nitrogen atoms.

[0059] R 1 and R 2 Each to replace Ar 1 And Ar 2 The group consisting of hydrogen atoms on the ring is selected from halogen, nitro, amino, cyano, alkyl with 1 to 10 carbon atoms, alkenyl with 2 to 10 carbon atoms, alkynyl with 2 to 10 carbon atoms, aryl with 6 to 40 carbon atoms, and combinations thereof, and the alkyl, alkenyl, alkenyl and aryl groups may contain ether bonds, ketone bonds or ester bonds.

[0060] R 3 and R 8 The group is selected from 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, alkenyl, alkynyl, and aryl groups may contain ether bonds, ketone bonds, or ester bonds.

[0061] R 4 and R 6The group is selected from hydrogen atom, trifluoromethyl, aryl and heterocyclic groups having 6 to 40 carbon atoms, and the aryl and heterocyclic groups can be substituted with halogen, nitro, amino, cyano, trifluoromethyl, alkyl having 1 to 10 carbon atoms, alkoxy having 1 to 10 carbon atoms, alkenyl having 2 to 10 carbon atoms, alkynyl having 2 to 10 carbon atoms, or aryl having 6 to 40 carbon atoms, and the alkyl, alkenyl, alkynyl and aryl groups can contain ether bonds, ketone bonds or ester bonds.

[0062] R 5 and R 7 The group is selected from hydrogen atom, trifluoromethyl, aryl and heterocyclic groups having 6 to 40 carbon atoms, and the aryl and heterocyclic groups can be substituted with halogen, nitro, amino, cyano, trifluoromethyl, alkyl having 1 to 10 carbon atoms, alkoxy having 1 to 10 carbon atoms, alkenyl having 2 to 10 carbon atoms, alkynyl having 2 to 10 carbon atoms, or aryl having 6 to 40 carbon atoms, and the alkyl, alkenyl, alkynyl and aryl groups can contain ether bonds, ketone bonds or ester bonds.

[0063] Furthermore R 4 With R 5 and R 6 With R 7 They can form rings together with the carbon atoms they are bonded to.

[0064] n1 and n2 are each integers between 0 and 3.

[0065] n3 is 1 or higher, and is capable of being in Ar 3 The substitution base number is an integer less than or equal to n4, where n4 is 0 or 1. When n4 is 0, R 8 with Ar 3 The nitrogen atoms contained are bonded together.

[0066] <Polymers containing unit structures (A) shown in formula (1) and / or formula (2)>

[0067] Ar 1 And Ar 2 Each represents either a benzene ring or a naphthalene ring.

[0068] Ar 1 and Ar 2 They can be linked via single bonds to form, for example, a carbazole skeleton.

[0069] Preferred Ar 1 And Ar 2 Both are benzene rings.

[0070] Ar 3This refers to aromatic compounds with 6 to 60 carbon atoms that may contain nitrogen atoms. Specific examples include benzene, styrene, toluene, xylene, mesitylene, isopropylbenzene, indene, naphthalene, biphenyl, azulene, anthracene, phenanthrene, tetraphenylene, benzo[9,10]phenanthrene, pyrene, etc. Fluorene, 9,9-diphenylfluorene, 9,9-dinaphthylfluorene, indole, phenylindole, purine, quinoline, isoquinoline, quinine ring, acridine, phenazine, carbazole, etc.

[0071] R 1 and R 2 Each to replace Ar 1 And Ar 2 The group consisting of hydrogen atoms on the ring is selected from halogen, nitro, amino, cyano, alkyl with 1 to 10 carbon atoms, alkenyl with 2 to 10 carbon atoms, alkynyl with 2 to 10 carbon atoms, aryl with 6 to 40 carbon atoms, and combinations thereof, and the alkyl, alkenyl, alkynyl, and aryl group may contain ether bonds, ketone bonds, or ester bonds.

[0072] In addition, R 3 and R 8 The aryl group is selected from 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, alkenyl, alkynyl, and aryl groups may contain ether bonds, ketone bonds, or ester bonds. The aryl group may be substituted with a hydroxyl-substituted alkyl group having 1 to 10 carbon atoms (i.e., the aryl group may have a hydroxyl-substituted alkyl group having 1 to 10 carbon atoms as a substituent). When the hydroxyl-substituted alkyl group is substituted on the aryl group, the hydroxyl group is preferably substituted at the benzyl position. Furthermore, the aryl group also contains a group in which aromatic rings are linked to each other by hydroxyl-substituted methine groups (i.e., -Ar-C(OH)X). 1 X 2 Ar is aryl, X 1 and X 2 It can be a hydrogen atom or any organic group, preferably X. 1 X 2 (Any one of which is an aromatic group).

[0073] Examples of halogen groups include fluorine, chlorine, bromine, and iodine.

[0074] Examples of alkyl groups having 1 to 10 carbon atoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, 1-methyl-n-butyl, 2-methyl-n-butyl, 3-methyl-n-butyl, 1,1-dimethyl-n-propyl, 1,2-dimethyl-n-propyl, 2,2-dimethyl-n-propyl, 1-ethyl-n-propyl, n-hexyl, 1-methyl-n-pentyl, 2-methyl-n-pentyl, and 3-methyl-n-pentyl. 4-Methyl-n-pentyl, 1,1-dimethyl-n-butyl, 1,2-dimethyl-n-butyl, 1,3-dimethyl-n-butyl, 2,2-dimethyl-n-butyl, 2,3-dimethyl-n-butyl, 3,3-dimethyl-n-butyl, 1-ethyl-n-butyl, 2-ethyl-n-butyl, 1,1,2-trimethyl-n-propyl, 1,2,2-trimethyl-n-propyl, 1-ethyl-1-methyl-n-propyl, 1-ethyl-2-methyl-n-propyl, etc.

[0075] In addition, it can be a cyclic alkyl group, such as cyclopropyl, cyclobutyl, 1-methyl-cyclopropyl, 2-methyl-cyclopropyl, cyclopentyl, 1-methyl-cyclobutyl, 2-methyl-cyclobutyl, 3-methyl-cyclobutyl, 1,2-dimethyl-cyclopropyl, 2,3-dimethyl-cyclopropyl, 1-ethyl-cyclopropyl, 2-ethyl-cyclopropyl, cyclohexyl, 1-methyl-cyclopentyl, 2-methyl-cyclopentyl, 3-methyl-cyclopentyl, 1-ethyl-cyclobutyl, 2-ethyl-cyclobutyl, 3-ethyl-cyclobutyl, 1,2-dimethyl-cyclobutyl, 1,3-dimethyl-cyclobutyl 2,2-Dimethyl-cyclobutyl, 2,3-Dimethyl-cyclobutyl, 2,4-Dimethyl-cyclobutyl, 3,3-Dimethyl-cyclobutyl, 1-n-propyl-cyclopropyl, 2-n-propyl-cyclopropyl, 1-isopropyl-cyclopropyl, 2-isopropyl-cyclopropyl, 1,2,2-trimethyl-cyclopropyl, 1,2,3-trimethyl-cyclopropyl, 2,2,3-trimethyl-cyclopropyl, 1-ethyl-2-methyl-cyclopropyl, 2-ethyl-1-methyl-cyclopropyl, 2-ethyl-2-methyl-cyclopropyl, and 2-ethyl-3-methyl-cyclopropyl, etc.

[0076] Examples of alkenyl groups having 2 to 10 carbon atoms include vinyl, 1-propenyl, 2-propenyl, 1-methyl-1-vinyl, 1-butenyl, 2-butenyl, 3-butenyl, 2-methyl-1-propenyl, 2-methyl-2-propenyl, 1-ethylvinyl, 1-methyl-1-propenyl, 1-methyl-2-propenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl, 1-n-propylvinyl, 1-methyl-1-butenyl, 1-methyl-2-butenyl, 1-methyl-3-butenyl, 2-ethyl-2-propenyl, 2-methyl-1-butenyl, 2-methyl-2-butenyl, 2-methyl-3- Butenyl, 3-methyl-1-butenyl, 3-methyl-2-butenyl, 3-methyl-3-butenyl, 1,1-dimethyl-2-propenyl, 1-isopropylvinyl, 1,2-dimethyl-1-propenyl, 1,2-dimethyl-2-propenyl, 1-cyclopentenyl, 2-cyclopentenyl, 3-cyclopentenyl, 1-hexenyl, 2-hexenyl, 3-hexenyl, 4-hexenyl, 5-hexenyl, 1-methyl-1-pentenyl, 1-methyl-2-pentenyl, 1-methyl-3-pentenyl, 1-methyl-4-pentenyl, 1-n-butylvinyl, 2-methyl-1-pentenyl, 2-methyl-2-pentenyl, 2-methyl-3-pentenyl 2-Methyl-4-pentenyl, 2-n-propyl-2-propenyl, 3-methyl-1-pentenyl, 3-methyl-2-pentenyl, 3-methyl-3-pentenyl, 3-methyl-4-pentenyl, 3-ethyl-3-butenyl, 4-methyl-1-pentenyl, 4-methyl-2-pentenyl, 4-methyl-3-pentenyl, 4-methyl-4-pentenyl, 1,1-dimethyl-2-butenyl, 1,1-dimethyl-3-butenyl, 1,2-dimethyl-1-butenyl, 1,2-dimethyl-2-butenyl, 1,2-dimethyl-3-butenyl, 1-methyl-2-ethyl-2-propenyl, 1-sec-butylvinyl, 1,3- Dimethyl-1-butenyl, 1,3-dimethyl-2-butenyl, 1,3-dimethyl-3-butenyl, 1-isobutylvinyl, 2,2-dimethyl-3-butenyl, 2,3-dimethyl-1-butenyl, 2,3-dimethyl-2-butenyl, 2,3-dimethyl-3-butenyl, 2-isopropyl-2-propenyl, 3,3-dimethyl-1-butenyl, 1-ethyl-1-butenyl, 1-ethyl-2-butenyl, 1-ethyl-3-butenyl, 1-n-propyl-1-propenyl, 1-n-propyl-2-propenyl, 2-ethyl-1-butenyl, 2-ethyl-2-butenyl, 2-ethyl-3-butenyl, 1,1,2-Trimethyl-2-propenyl, 1-tert-butylvinyl, 1-Methyl-1-ethyl-2-propenyl, 1-Ethyl-2-methyl-1-propenyl, 1-Ethyl-2-methyl-2-propenyl, 1-Isopropyl-1-propenyl, 1-Isopropyl-2-propenyl, 1-Methyl-2-cyclopentenyl, 1-Methyl-3-cyclopentenyl, 2-Methyl-1-cyclopentenyl, 2-Methyl-2-cyclopentene The list includes 2-methyl-3-cyclopentenyl, 2-methyl-4-cyclopentenyl, 2-methyl-5-cyclopentenyl, 2-methylene-cyclopentenyl, 3-methyl-1-cyclopentenyl, 3-methyl-2-cyclopentenyl, 3-methyl-3-cyclopentenyl, 3-methyl-4-cyclopentenyl, 3-methyl-5-cyclopentenyl, 3-methylene-cyclopentenyl, 1-cyclohexenyl, 2-cyclohexenyl, and 3-cyclohexenyl, among others.

[0077] Examples of alkynyl groups with 2 to 10 carbon atoms include ethynyl, 1-propynyl, and 2-propynyl.

[0078] Examples of aryl groups with 6 to 40 carbon atoms include phenyl, benzyl, naphthyl, anthraceneyl, phenanthryl, tetraphenyl, benzo[9,10]phenanthryl, pyrene, etc. Base, etc.

[0079] The aforementioned alkyl, alkenyl, alkynyl, and aryl groups may contain ether bonds (-O-), ketone bonds (-CO-), or ester bonds (-COO-, -OCO-).

[0080] R 4 and R 6 The group is selected from hydrogen atom, trifluoromethyl, aryl and heterocyclic groups having 6 to 40 carbon atoms, and the aryl and heterocyclic groups can be substituted by halogen, nitro, amino, cyano, trifluoromethyl, alkyl having 1 to 10 carbon atoms, alkoxy having 1 to 10 carbon atoms, alkenyl having 2 to 10 carbon atoms, alkynyl having 2 to 10 carbon atoms, or aryl having 6 to 40 carbon atoms, and the alkyl, alkenyl, alkynyl and aryl groups can contain ether bonds, ketone bonds or ester bonds.

[0081] In addition, R 5 and R 7 The group is selected from hydrogen atom, trifluoromethyl, aryl group with 6 to 40 carbon atoms, and heterocyclic group, and the aryl group and the heterocyclic group can be substituted by halogen, nitro, amino, cyano, trifluoromethyl, alkyl group with 1 to 10 carbon atoms, alkoxy group with 1 to 10 carbon atoms, alkenyl group with 2 to 10 carbon atoms, alkynyl group with 2 to 10 carbon atoms, and aryl group with 6 to 40 carbon atoms, and the alkyl group, alkenyl group, alkynyl group and the aryl group can contain ether bond, ketone bond or ester bond.

[0082] A heterocyclic group is a substituent derived from a heterocyclic compound. Examples include thiophene, furanyl, pyridyl, pyrimidinyl, pyrazinyl, and pyrroleyl groups. Azolyl, thiazolyl, imidazolyl, quinolinyl, carbazole, quinazolinyl, purine, indole, benzothiophene, benzofuranyl, indole, acridine, isoindolyl, benzimidazolyl, isoquinolinyl, quinoxalinyl, cinnamyl, pteridine, chromenyl (benzopyranyl), isochrynyl (benzopyranyl) The compounds are tonyl, thiazolyl, pyrazolyl, imidazolinyl, and azazinyl, but thienyl, furanyl, pyridyl, pyrimidinyl, pyrazinyl, and pyrroleyl are preferred among them. Azolyl, thiazolyl, imidazolyl, quinolinyl, carbazole, quinazolinyl, purine, indole, benzothiophene, benzofuranyl, indole, and acridineyl, with thiophene, furanyl, pyridinyl, pyrimidinyl, and pyrroleyl being the most preferred. Azolyl, thiazolyl, imidazole, and carbazole.

[0083] Examples of alkoxy groups with 1 to 10 carbon atoms include groups formed by combining an etheric oxygen atom (-O-) with the terminal carbon atom of an alkyl group with 1 to 10 carbon atoms. Examples of such alkoxy groups include methoxy, ethoxy, n-propoxy, isopropoxy, cyclopropoxy, n-butoxy, isobutoxy, sec-butoxy, tert-butoxy, cyclobutoxy, 1-methyl-cyclopropoxy, 2-methyl-cyclopropoxy, n-pentoxy, 1-methyl-n-butoxy, 2-methyl-n-butoxy, 3-methyl-n-butoxy, 1,1-dimethyl-n-propoxy, 1,2-dimethyl-n-propoxy, 2,2-dimethyl-n-propoxy, 1-ethyl-n-propoxy, 1,1-diethyl-n-propoxy, cyclopentoxy, 1-methyl-cyclobutoxy, 2-methyl-cyclobutoxy, 3-methyl-cyclobutoxy, 1,2-dimethyl-cyclopropoxy, 2,3-dimethyl-cyclopropoxy, 1-ethyl-cyclopropoxy, 2-ethyl-cyclopropoxy, etc.

[0084] R 4 With R 5 and R 6 With R 7 They can combine with carbon atoms to form rings (e.g., fluorene rings).

[0085] 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.

[0086] n3 is 1 or more, preferably 2 or more, and is capable of being in Ar 3 The substitution base number is an integer less than or equal to 6, more preferably an integer less than or equal to 4, and most preferably an integer less than or equal to 2.

[0087] Among the compounds shown in formula (1) or formula (2) above, several preferred substances are described below.

[0088] ·Ar 1 And Ar 2 The compound is a benzene ring as shown in formula (1) above.

[0089] ·Ar 3 The compound represented by formula (2) above is a benzene ring, naphthalene ring, diphenylfluorene ring, or phenylindole ring that can be substituted.

[0090] ·R 4 and R 6 It is an aryl group with 6 to 40 carbon atoms, R 5 and R 7 Compounds represented by formula (1) or formula (2) above, which are hydrogen atoms.

[0091] ·R 4 and R 6 Compounds of the above formula (1) or formula (2) having an aromatic hydrocarbon group having 6 to 16 carbon atoms.

[0092] <Solvent>

[0093] As a solvent for the resist underlayer film forming composition of the present invention, any solvent capable of dissolving the compound shown in formula (1) or formula (2) above can 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 generally used in photolithography processes, taking into account its coating performance.

[0094] 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, and ethyl 3-methoxypropionate. Ethyl 3-ethoxypropionate, methyl 3-ethoxypropionate, methyl pyruvate, ethyl pyruvate, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol 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.

[0095] Alternatively, the following compounds described in WO2018 / 131562A1 may also be used.

[0096]

[0097] (R in equation (i)) 1 R 2and R 3 Each alkyl group represents a hydrogen atom or an alkyl group with 1 to 20 carbon atoms, which can be interrupted by an oxygen atom, a sulfur atom, or an amide bond. These groups can be the same or different and can combine to form a ring structure.

[0098] Examples of alkyl groups having 1 to 20 carbon atoms include straight-chain or branched alkyl groups, which may or may not have substituents. Examples include 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. Alkyl groups having 1 to 12 carbon atoms are preferred, alkyl groups having 1 to 8 carbon atoms are more preferred, and alkyl groups having 1 to 4 carbon atoms are even more preferred.

[0099] Examples of alkyl groups containing 1 to 20 carbon atoms whose carbon atoms are interrupted by oxygen, sulfur, or amide bonds include, for example, groups containing the structural units -CH2-O-, -CH2-S-, -CH2-NHCO-, or -CH2-CONH-. -O-, -S-, -NHCO-, or -CONH- may have one or more units in the aforementioned alkyl groups. Specific examples of alkyl groups with 1 to 20 carbon atoms whose carbon atom number is interrupted by -O-, -S-, -NHCO-, or -CONH- units include methoxy, ethoxy, propoxy, butoxy, methylthio, ethylthio, propylthio, butylthio, methylcarbonylamino, ethylcarbonylamino, propylcarbonylamino, butylcarbonylamino, methylaminocarbonyl, ethylaminocarbonyl, propylaminocarbonyl, butylaminocarbonyl, etc., and more preferably methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl, or octadecyl groups, and each of which is obtained by substitution with methoxy, ethoxy, propoxy, butoxy, methylthio, ethylthio, propylthio, butylthio, methylcarbonylamino, ethylcarbonylamino, methylaminocarbonyl, ethylaminocarbonyl, etc. Preferably methoxy, ethoxy, methylthio, or ethylthio, more preferably methoxy or ethoxy.

[0100] These solvents, due to their high boiling points, are also effective in imparting high embedding and high planarization properties to compositions used for forming resist underlayer films.

[0101] The following shows specific examples of preferred compounds represented by formula (i).

[0102]

[0103] Of the above, 3-methoxy-N,N-dimethylpropionamide, N,N-dimethylisobutylamide, and compounds represented by the following formulas are preferred.

[0104]

[0105] 3-Methoxy-N,N-dimethylpropionamide and N,N-dimethylisobutylamide are particularly preferred as compounds represented by formula (i).

[0106] These solvents can be used alone or in combination of two or more. Preferably, these solvents are substances with a boiling point of 160°C or higher, including 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-dimethyldiacetate (DAH; CAS, 89182-68-3), and 1,6-diacetoxyhexane (CAS, 6222-17-9). Particularly preferred are propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, and N,N-dimethylisobutylamide.

[0107] These solvents can be used alone or in combination of two or more. The proportion of solids after removing the organic solvent from the above composition is, for example, 0.5% to 30% by mass, preferably 0.8% to 15% by mass.

[0108] <Optional Ingredients>

[0109] The resist underlayer film forming composition of the present invention may further contain at least one of a crosslinking agent, an acid and / or an acid-generating agent, a thermal acid-generating agent, and a surfactant as optional components.

[0110] (Cross-linking agent)

[0111] The resist underlayer film forming composition of the present invention may further contain a crosslinking agent. As the aforementioned crosslinking agent, a crosslinking compound having at least two crosslinking-forming substituents is preferably used. Examples include melamine-based compounds, substituted urea-based compounds, and phenolic compounds or polymers thereof having crosslinking-forming substituents such as hydroxymethyl and methoxymethyl. Specifically, compounds such as methoxymethylated glycourea, butoxymethylated glycourea, methoxymethylated melamine, butoxymethylated melamine, methoxymethylated benzoguanidine, and butoxymethylated benzoguanidine can be cited as examples, such as tetramethoxymethylglycourea (e.g., PL-LI (Midori Chemical Co., Ltd. produced tetra(methoxymethyl)glycourea), tetrabutoxymethylglycourea, and hexamethoxymethylmelamine). Furthermore, as substituted urea compounds, compounds such as methoxymethylated urea, butoxymethylated urea, or methoxymethylated thiourea can be cited as examples, such as tetramethoxymethylurea and tetrabutoxymethylurea. Condensates of these compounds can also be used. As phenolic compounds, examples include tetrahydroxymethylbiphenol, tetramethoxymethylbiphenol, tetrahydroxymethylbisphenol, tetramethoxymethylbisphenol, and compounds shown in the following formulas.

[0112]

[0113] As a crosslinking agent as described above, compounds having at least two epoxy groups can also be used. Examples of such compounds include, for instance, 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), and 3,4-epoxycyclohexylmethyl-3 4-Epoxycyclohexane carboxylate, trimethylolethane triglycidyl ether, bisphenol A-diglycidyl ether, Ecolide (registered trademark) GT-401, Ecolide GT-403, Ecolide GT-301, Ecolide GT-302, Celokise (registered trademark) 2021, Celokise 3000, 1001, 1002, 1003, 1004, 1007, 1009, 1010, 828, 807, 152, 1 (Mitsubishi Chemical Co., Ltd.) 54. 180S75, 871, 872, EPPN201, EPPN202, EOCN-102, EOCN-103S, EOCN-104S, EOCN-1020, EOCN-1025, E manufactured by Nippon Kayaku Co., Ltd. OCN-1027, デナコール〔Registered Trademark] EX-252, デナコールE manufactured by Nakotsu Co., Ltd. X-611、Dynamic EX-612、Dynamic EX-614、Dynamic EX-622、Dynamic EX-622 EX-411、デナコールEX-512、デナコールEX-522、デナコールEX-421、デナコールEX-313, デナコールEX-314, デナコールEX-321, C made by BASF Japan Co., Ltd. Y175, CY177, CY179, CY182, CY184, CY192, DIC Co., Ltd. madeン200, エピクロン400, エピクロン7015, エピクロン835LV, エピクロン850CRP. In addition to the above-mentioned compounds having at least two epoxy groups, epoxy resins having amino groups can also be used. Examples of such epoxy resins include YH-434 and YH-434L (manufactured by Shin-Nippon Chemical Epokish Co., Ltd.).

[0114] Alternatively, compounds having at least two blocked isocyanate groups can also be used as the aforementioned crosslinking agent. Examples of such compounds include, for instance, Taknet (registered trademark) B-830 and Taknet B-870N manufactured by Mitsui Chemicals Co., Ltd., and VESTANAT (registered trademark) B1358 / 100 manufactured by Ebony Deca Co., Ltd.

[0115] Alternatively, compounds having at least two vinyl ether groups can also be used as crosslinking agents. Examples of such compounds include, for instance, bis(4-(vinyloxymethyl)cyclohexylmethyl)glutarate, tri(ethylene glycol) divinyl ether, divinyl adipate, diethylene glycol divinyl ether, 1,2,4-tris(4-vinyloxybutyl)trimethacrylate, 1,3,5-tris(4-vinyloxybutyl)trimethacrylate, 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 cyclohexanediethanol divinyl ether.

[0116] Furthermore, as the aforementioned crosslinking agent, a crosslinking agent with high heat resistance can be used. Preferably, a compound containing a crosslinking-forming substituent with an aromatic ring (e.g., a benzene ring, naphthalene ring) is used as the crosslinking agent.

[0117] Examples of such compounds include compounds having a partial structure of formula (4), polymers or oligomers having repeating units of formula (5).

[0118]

[0119] The above R 11 R 12 R 13 and R 14 Alkyl groups having 1 to 10 hydrogen or carbon atoms can be used as illustrated above. n1 is an integer from 1 to 4, n2 is an integer from 1 to (5-n1), and (n1+n2) represents an integer from 2 to 5. n3 is an integer from 1 to 4, n4 is from 0 to (4-n3), and (n3+n4) represents an integer from 1 to 4. Oligomers and polymers can be used in the range of 2 to 100 or 2 to 50 repeating unit structures.

[0120] The following examples illustrate compounds, polymers, and oligomers of formulas (4) and (5).

[0121]

[0122]

[0123] The above-mentioned compounds can be obtained as products of Asahi Organic Materials Co., Ltd. and Honshu Chemical Industry Co., Ltd. For example, among the above-mentioned crosslinking agents, the compound of formula (4-23) can be obtained by Honshu Chemical Industry Co., Ltd. under the trade name TMOM-BP, and the compound of formula (4-24) can be obtained by Asahi Organic Materials Co., Ltd. under the trade name TM-BIP-A.

[0124] 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 solid content, 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 sometimes undergo crosslinking reactions caused by self-condensation, but when crosslinking substituents are present in the polymers of the present invention, crosslinking reactions can occur with these crosslinking substituents.

[0125] You can add one of these various crosslinking agents, or you can add two or more in combination.

[0126] (Acid and / or its salts and / or acid-producing agents)

[0127] The composition for forming a resist underlayer film according to the present invention may contain an acid and / or its salt and / or an acid-generating agent.

[0128] Examples of 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, citric acid, benzoic acid, hydroxybenzoic acid, naphthoic acid and other carboxylic acid compounds, as well as inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, and phosphoric acid.

[0129] Salts of the aforementioned acids can also be used as salts. There are no limitations on the salt composition; salts of ammonia derivatives such as trimethylamine and triethylamine, pyridine derivatives, and morpholine derivatives are suitable.

[0130] The acid and / or its salt may be used alone, or two or more may be used in combination. The mixing amount relative to the total solids content is typically 0.0001 to 20% by mass, preferably 0.0005 to 10% by mass, and more preferably 0.01 to 5% by mass.

[0131] Examples of acid-producing agents include thermal acid-producing agents and photo-producing acid-producing agents.

[0132] Examples of heat-generating acid agents include 2,4,4,6-tetrabromocyclohexadienone, benzoin toluene sulfonate, 2-nitrobenzyl toluene sulfonate, K-PURE (registered trademark) CXC-1612, K-PURE CXC-1614, K-PURE TAG-2172, K-PURE TAG-2179, K-PURE TAG-2678, K-PURE TAG2689, K-PURE TAG2700 (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 and alkyl esters of organic sulfonic acids.

[0133] The photoacid generator produces acid during the exposure of the photoresist. Therefore, the acidity of the lower film can be adjusted. This is a method to make the acidity of the lower film match the acidity 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.

[0134] Examples of photoacid-generating agents included in the resist lower layer film forming composition of the present invention include:

[0135] Salt compounds, sulfonylimide compounds, and disulfonyldiazomethane compounds, etc.

[0136] 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 nonafluorobutane sulfonate, triphenylsulfonium camphor sulfonate and triphenylsulfonium trifluoromethane sulfonate.

[0137] Examples of sulfonylimide compounds include N-(trifluoromethanesulfonyloxy)succinimide, N-(nonafluoron-butanesulfonyloxy)succinimide, N-(camphorsulfonyloxy)succinimide, and N-(trifluoromethanesulfonyloxy)naphthalenediformimide.

[0138] 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.

[0139] Acid-producing agents can be used alone, or two or more can be used in combination.

[0140] When using an acid-generating agent, the proportion of the acid-generating agent is 0.01 to 10 parts by weight, or 0.1 to 8 parts by weight, or 0.5 to 5 parts by weight, relative to 100 parts by weight of the solid component of the composition for forming the lower layer of the resist.

[0141] (surfactant)

[0142] In the resist lower film forming composition of the present invention, in order to prevent pinholes, streaks, etc., and to further improve the coating performance on uneven surfaces, a surfactant can be added. Examples of surfactants include, for example, polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, and polyoxyethylene oil-based ether; polyoxyethylene alkyl aryl ethers such as polyoxyethylene octylphenyl ether and polyoxyethylene nonylphenyl ether; polyoxyethylene / polyoxypropylene block copolymers; sorbitol monolaurate, sorbitol monopalmitate, sorbitol monostearate, and sorbitol monooleate. Sorbitol trioleate, sorbitol tristearate, and other sorbitol fatty acid esters; polyoxyethylene sorbitol monolaurate, polyoxyethylene sorbitol monopalmitate, polyoxyethylene sorbitol monostearate, polyoxyethylene sorbitol trioleate, polyoxyethylene sorbitol tristearate, and other polyoxyethylene sorbitol fatty acid esters, as well as nonionic surfactants; EF3 (registered trademark). 01. EFT EF303, EFT EF352 (Mitsubishi Microelectronics Co., Ltd. ), メガファック [registered trademark] F171, メガファック F173, メガファックR-30、メガファックR-30-N、メガファックR-40、メガファックR-4 0-LM (manufactured by DIC Co., Ltd.), Fluoro FC430, Fluoro FC431 (Sumitomo Fluoropolymer surfactants such as Asahi Glass Co., Ltd., Asahi Guard (registered trademark) AG710, Servolon (registered trademark) S-382, Servolon SC101, Servolon SC102, Servolon SC103, Servolon SC104, Servolon SC105, and Servolon SC106 (manufactured by Asahi Glass Co., Ltd.), and organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.) can be added. One surfactant selected from these surfactants may be added, or two or more may be added in combination. The content ratio of the above surfactants relative to the solid content after removing the solvent described later from the resist lower film forming composition of the present invention is, for example, 0.01% to 5% by mass.

[0143] In the resist underlayer film forming composition of the present invention, light absorbers, rheology modifiers, adhesive additives, etc., may be further 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.

[0144] (Light absorber)

[0145] As light absorbers, commercially available light absorbers such as those listed in "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; 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 blended 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.

[0146] (rheology modifier)

[0147] Rheology modifiers are primarily added to improve the flowability of the composition for forming the lower resist film, especially during the baking process, to enhance the uniformity of the lower resist film thickness and improve the filling ability of the composition for forming the lower resist film into cavities. 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 octyldecyl 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 solids of the composition for forming the resist underlayer film.

[0148] (Adhesive additive)

[0149] Adhesive aids are mainly used to improve the adhesion between the substrate or resist and the composition used to form the underlying film of the resist, especially during development, in order to prevent the resist from peeling off. 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.

[0150] 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 aforementioned polymer 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.

[0151] 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 presents a homogeneous solution state when passing through a microfilter with a pore size of 0.1 μm.

[0152] 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.

[0153] <Resist Underlayer>

[0154] The resist underlayer film can be formed using the resist underlayer film forming composition of the present invention, as follows.

[0155] The resist underlayer film forming composition of the present invention is applied to a substrate used in the manufacture of semiconductor devices (e.g., silicon wafer substrate, silicon dioxide substrate (SiO2 substrate), silicon nitride substrate (SiN substrate), silicon oxide nitride substrate (SiON substrate), titanium nitride substrate (TiN substrate), tungsten substrate (W substrate), glass substrate, ITO substrate, polyimide substrate, and low-k material coated substrate, etc.) using a suitable coating method such as a spin coater or coating machine. Then, the resist underlayer film is formed by firing using a heating means such as a hot plate. 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, or inactive gases such as nitrogen or argon, can be used as the atmosphere gas during firing. Here, the thickness of the underlying film is, for example, 10–1000 nm, 20–500 nm, 30–400 nm, or 50–300 nm. Furthermore, if a quartz substrate is used as the substrate, a replica of the quartz embossed model (model replica) can be fabricated.

[0156] Furthermore, 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 of forming a silicon-containing photoresist underlayer film (inorganic photoresist underlayer film) composition as described in WO2009 / 104552A1 by spin coating, a Si-based inorganic material film can also be formed by CVD or the like. Furthermore, the hard mask in the present invention includes either a silicon hard mask or a CVD film.

[0157] Furthermore, an adhesive layer and / or an organosilicon layer containing 99% by mass or less, or 50% by mass or less, of Si can also be formed on the resist underlayer film of the present invention by coating or vapor deposition. For example, in addition to the method of forming the adhesive layer described in Japanese Patent Application Publication No. 2013-202982, Japanese Patent No. 5827180, and the silicon-containing resist underlayer film (inorganic resist underlayer film) composition described in WO2009 / 104552A1 by spin coating, Si-based inorganic material films can also be formed by CVD or the like.

[0158] Furthermore, by coating the resist underlayer film forming composition of the present invention onto a semiconductor substrate having portions with height differences and portions without height differences (so-called height difference substrate), and then firing it, a resist underlayer film with a small height difference between the portions having the height difference and the portions without the height difference can be formed.

[0159] <Methods for Manufacturing Semiconductor Devices>

[0160] The method for manufacturing a semiconductor device according to the present invention includes the following steps:

[0161] The process of forming a photoresist underlayer film by using the photoresist underlayer film forming composition of the present invention on a semiconductor substrate;

[0162] The process of forming a resist film on the formed resist underlayer film;

[0163] The process of irradiating the formed resist film with light or electron beams and developing it to form a resist pattern;

[0164] The process of etching the underlying resist film through the formed resist pattern to perform patterning; and

[0165] The process of processing a semiconductor substrate through a patterned resist underlayer.

[0166] The method for manufacturing a semiconductor device according to the present invention includes the following steps:

[0167] The process of forming a photoresist underlayer film by using the photoresist underlayer film forming composition of the present invention on a semiconductor substrate;

[0168] The process of forming a hard mask on the formed resist underlayer film;

[0169] The process of forming a resist film on the hard mask;

[0170] The process of irradiating the formed resist film with light or electron beams and developing it to form a resist pattern;

[0171] The process of etching a hard mask through the formed resist pattern;

[0172] The process of etching the underlying resist film through an etched hard mask; and

[0173] The process of removing the hard mask.

[0174] Preferably, it further includes the following steps:

[0175] The process of forming a vapor-deposited film (spacer) on the lower film after the hard mask has been removed;

[0176] The process of etching the formed vapor-deposited film (spacer);

[0177] The process of removing the lower film; and

[0178] The process of processing a semiconductor substrate using spacers.

[0179] The aforementioned semiconductor substrate can be a substrate with a high-low gradient.

[0180] The process of forming a resist underlayer film using the resist underlayer film forming composition of the present invention is as described above.

[0181] Next, a photoresist film, such as a photoresist layer, is formed on the lower photoresist film. The photoresist layer can be formed by a known method, namely, by coating and firing a photoresist composition solution onto the lower photoresist film. The thickness of the photoresist film is, for example, 50–10000 nm, 100–2000 nm, or 200–1000 nm.

[0182] As a photoresist formed on the underlayer of the resist film, there are no particular limitations as long as the light sensitivity used for exposure is considered. 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 and a photoacid-generating agent having groups that increase the rate of alkali dissolution through acid decomposition; chemically amplified photoresists composed of low-molecular-weight compounds that increase the rate of alkali dissolution through acid decomposition, alkali-soluble binders, and photoacid-generating agents; and chemically amplified photoresists composed of a binder with 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-generating agents. 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).

[0183] Next, a resist pattern is formed by irradiation with light or electron beams and development. First, exposure is performed through a prescribed mask. Exposure is performed using near-ultraviolet, far-ultraviolet, or ultraviolet light (e.g., EUV (wavelength 13.5 nm)). 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 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.

[0184] 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. Types 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 portions where the rate of alkali dissolution changes due to electron beam cutting. When using these electron beam resists, the irradiation source can be electron beams, and the resist pattern can be formed in the same way as when using a photoresist.

[0185] Alternatively, to maintain or improve high resolution and depth of focus, the substrate with the resist film formed can be exposed by immersing it in a liquid medium. In this case, resistance to the liquid medium used in the resist underlayer film is also required, but it is possible to form a resist underlayer film that meets such requirements using the resist underlayer film forming composition of the present invention.

[0186] 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.

[0187] 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 can be added to these developing solutions. Developing conditions can be appropriately selected from a temperature of 5–50°C and a time of 10–600 seconds.

[0188] Then, using the pattern of the photoresist (upper layer) formed in this operation as a protective film, the inorganic lower layer (intermediate layer) is removed. Next, using the film composed of the patterned photoresist and the inorganic lower layer (intermediate layer) as a protective film, the organic lower layer (lower layer) is removed. Finally, using the patterned inorganic lower layer (intermediate layer) and organic lower layer (lower layer) as protective films, the semiconductor substrate is processed.

[0189] First, the inorganic lower layer (intermediate layer), to which the photoresist has been removed, is removed by dry etching, exposing the semiconductor substrate. The dry etching of the inorganic lower layer can utilize 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. Halogen-based gases are preferred for the dry etching of the inorganic lower layer, and fluorine-based gases are more preferred. Examples of fluorine-based gases include tetrafluoromethane (CF4), perfluorocyclobutane (C4F8), perfluoropropane (C3F8), trifluoromethane, and difluoromethane (CH2F2).

[0190] Then, the organic underlayer is removed using a film composed of patterned photoresist and an inorganic underlayer as a protective film. The organic underlayer (underlayer) is preferably removed by dry etching with an oxygen-based gas. This is because the inorganic underlayer, which contains a large number of silicon atoms, is not easily removed by dry etching with an oxygen-based gas.

[0191] In addition, wet etching is sometimes performed for the purpose of simplifying the process and reducing damage to the substrate. However, the resist underlayer film forming composition according to the present invention can also form a resist underlayer film that exhibits sufficient resistance to the solvent used.

[0192] Finally, the semiconductor substrate is processed. The semiconductor substrate is preferably processed by dry etching using a fluorine-based gas.

[0193] Examples of fluorine-based gases include tetrafluoromethane (CF4), perfluorocyclobutane (C4F8), perfluoropropane (C3F8), trifluoromethane, and difluoromethane (CH2F2).

[0194] 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 therein; any material 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.

[0195] 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 onto it. This allows for substrate processing even when the photoresist pattern width is narrowed and a thin layer of photoresist is applied 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 to process the underlayer film; a fluorine-based gas with a sufficiently fast etching rate relative to the inorganic underlayer film can also be used; and an oxygen-based gas with a sufficiently fast etching rate relative to the organic underlayer film can be used.

[0196] The photoresist underlayer film formed by the composition for forming the photoresist underlayer film sometimes absorbs light depending on the wavelength of the light used in the photolithography process. Furthermore, 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.

[0197] Furthermore, the underlying film formed from the resist underlying film formation 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 planarization material for planarizing the surface of semiconductor substrates with uneven surfaces.

[0198] Example

[0199] The present invention will be further described in detail below with reference to embodiments and the like, but the present invention is not limited to the following embodiments and the like.

[0200] The apparatus used to determine the weight-average molecular weight of the compounds obtained in the following synthetic examples is shown.

[0201] Device: HLC-8320GPC manufactured by Higashikata Co., Ltd.

[0202] GPC column: TSKgel Super-MultiporeHZ-N (2 columns)

[0203] Column temperature: 40℃

[0204] Flow rate: 0.35 mL / min

[0205] Elution buffer: THF

[0206] Standard sample: polystyrene

[0207] <Synthesis example 1>

[0208] 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., hereinafter referred to as MSA), and 230.25 g of propylene glycol monomethyl ether acetate (hereinafter referred to as PGMEA) were added to a flask. The mixture was then heated under nitrogen to 115°C and reacted for approximately 7 hours. After the reaction was stopped, the resin was precipitated with methanol and dried to obtain resin (1-1). The weight-average molecular weight (Mw) converted to polystyrene by GPC was approximately 5,100.

[0209]

[0210] <Synthesis example 2>

[0211] 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 added to a flask. The mixture was then heated to 120°C under nitrogen and allowed to react for approximately 7 hours. After the reaction was stopped, the resin was precipitated with methanol and dried to obtain resin (1-2). The weight-average molecular weight (Mw) converted to polystyrene by GPC was approximately 2,600.

[0212]

[0213] <Synthesis Example 3>

[0214] 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 added to a flask. The mixture was then heated to 120°C under nitrogen and allowed to react for approximately 7 hours. After the reaction was stopped, the resin was precipitated with methanol and dried to obtain resin (1-3). The weight-average molecular weight (Mw) converted to polystyrene by GPC was approximately 1,700.

[0215]

[0216] <Synthesis Example 4>

[0217] 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 added to a flask. The mixture was then heated under nitrogen until reflux, allowing the reaction 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) converted to polystyrene by GPC was approximately 4,600.

[0218]

[0219] <Synthesis example 5>

[0220] 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 added to a flask. The mixture was then heated under nitrogen until reflux was reached, allowing the reaction 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) converted to polystyrene by GPC was approximately 4,100.

[0221]

[0222] <Synthesis example 6>

[0223] 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-pyrenealdehyde (manufactured by Artritchi Co., Ltd.), 10.83 g of MSA, and 54.81 g of PGME were added to a flask. The mixture was then heated to 120°C under nitrogen and allowed to react for 24 hours. After the reaction was stopped, the resin was precipitated with methanol and dried to obtain resin (1-6). The weight-average molecular weight (Mw) converted to polystyrene by GPC was approximately 5,000.

[0224]

[0225] <Synthesis Example 7>

[0226] In a flask, 10.00 g of the resin obtained in Synthesis Example 1, 6.97 g of propargyl bromide (manufactured by Tokyo Chemical Industry Co., Ltd., hereinafter referred to as PBr), 2.17 g of tetrabutylammonium iodide (hereinafter referred to as TBAI), 21.53 g of tetrahydrofuran (hereinafter referred to as THF), and 7.18 g of 25% sodium hydroxide aqueous solution were added. The mixture was then heated under nitrogen to 55°C and allowed to react for approximately 15 hours. After the reaction was stopped, the organic layer was concentrated by repeated separation operations with methyl isobutyl ketone (hereinafter referred to as MIBK) and water, then dissolved in PGMEA, reprecipitated with methanol, and dried to obtain resin (1-7). The weight-average molecular weight (Mw) determined by GPC to be equivalent to polystyrene was approximately 6,100.

[0227]

[0228] <Synthesis example 8>

[0229] 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 added to a flask. The mixture was then heated under nitrogen to 55°C and allowed to react for approximately 18 hours. After the reaction was stopped, the organic layer was concentrated by repeated separation with MIBK and water, then dissolved in PGMEA, reprecipitated with methanol, and dried to obtain resin (1-8). The weight-average molecular weight (Mw) determined by GPC to be equivalent to polystyrene was approximately 3,000.

[0230]

[0231] <Synthesis Example 9>

[0232] 15.00 g of the resin obtained in Synthesis Example 3, 10.52 g of PBr, 4.90 g of TBAI, 4.21 g of THF, and 11.40 g of 25% sodium hydroxide aqueous solution were added to a flask. The mixture was then heated under nitrogen to 55°C and allowed to react for approximately 15 hours. After the reaction was stopped, the organic layer was concentrated by repeated separation with MIBK and water, then dissolved in PGMEA, reprecipitated with methanol, and dried to obtain resin (1-9). The weight-average molecular weight (Mw) converted to polystyrene by GPC was approximately 1,900.

[0233]

[0234] <Synthesis Example 10>

[0235] 15.00 g of the resin obtained in Synthesis Example 4, 12.57 g of PBr, 5.85 g of tetrabutylammonium bromide (hereinafter referred to as TBAB), 37.60 g of THF, and 12.53 g of 25% sodium hydroxide aqueous solution were added to a flask. The mixture was then heated under nitrogen to 55°C and allowed to react for approximately 16 hours. After the reaction was stopped, the organic layer was concentrated by repeated separation with MIBK and water, then dissolved in PGMEA, and reprecipitated using water / methanol. The precipitate was then dried to obtain resin (1-10). The weight-average molecular weight (Mw) determined by GPC to be equivalent to polystyrene was approximately 6,900.

[0236]

[0237] <Synthesis Example 11>

[0238] 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 added to a flask. The mixture was then heated under nitrogen to 55°C and allowed to react for approximately 16 hours. After the reaction was stopped, the organic layer was concentrated by repeated separation with MIBK and water, then dissolved in PGMEA, and reprecipitated using water / methanol. The precipitate was then dried to obtain the resin (1-11). The weight-average molecular weight (Mw) converted to polystyrene by GPC was approximately 4,600.

[0239]

[0240] <Synthesis Example 12>

[0241] 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 added to a flask. The mixture was then heated under nitrogen to 55°C and allowed to react for approximately 15 hours. After the reaction was stopped, the organic layer was concentrated by repeated separation with MIBK and water, then dissolved in PGMEA, and reprecipitated using water / methanol. The precipitate was then dried to obtain resin (1-12). The weight-average molecular weight (Mw) converted to polystyrene by GPC was approximately 6,300.

[0242]

[0243] <Synthesis Example 13>

[0244] 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., hereinafter 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 added to a flask. The mixture was then heated to 55°C under nitrogen atmosphere and allowed to react for approximately 15 hours. After the reaction was stopped, the organic layer was repeatedly separated using a mixed solvent of MIBK and cyclohexanone (hereinafter referred to as CYH) and water. The organic layer was concentrated, dissolved in CYH, reprecipitated using methanol, and dried to obtain the resin (1-13). The weight-average molecular weight (Mw) determined by GPC to be equivalent to polystyrene was approximately 5,500.

[0245]

[0246] <Synthesis Example 14>

[0247] 10.00 g of the resin obtained in Synthesis Example 2, 9.91 g of benzyl bromide (manufactured by Tokyo Chemical Industry Co., Ltd., hereinafter 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 added to a flask. The mixture was then heated under nitrogen to 55°C and allowed to react for approximately 18 hours. After the reaction was stopped, the organic layer was repeatedly separated using a mixed solvent of MIBK and CYH and water. The organic layer was concentrated, dissolved in CYH, and reprecipitated using methanol. The resin was then dried to obtain resin (1-14). The weight-average molecular weight (Mw) converted to polystyrene by GPC was approximately 2,800.

[0248]

[0249] <Synthesis Example 15>

[0250] 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 added to a flask. The mixture was then heated under nitrogen to 55°C and allowed to react for approximately 15 hours. After the reaction was stopped, the organic layer was repeatedly separated using a mixed solvent of MIBK and CYH and water. The organic layer was concentrated, dissolved in CYH, and reprecipitated using methanol. The mixture was then dried to obtain resin (1-15). The weight-average molecular weight (Mw) determined by GPC to be equivalent to polystyrene was approximately 6,000.

[0251]

[0252] <Example 1>

[0253] The resin obtained in Synthesis Example 7 was dissolved in PGMEA, and ion exchange was performed for 4 hours using both cation exchange and anion exchange resins to obtain a compound solution with a concentration of 19.48%. 0.12 g of PL-LI (manufactured by Midori Chemical Co., Ltd.) containing 2% pyridine by mass was added to 2.43 g of this resin solution. 0.36 g of p-toluenesulfonic acid PGME, 0.05 g of PGMEA containing 1% by mass surfactant (DIC Corporation, Megfack R-40), 8.07 g of PGMEA, and 3.97 g of PGME were dissolved and filtered using a polytetrafluoroethylene microfilter with a pore size of 0.1 μm to prepare a solution of the composition for forming the lower layer film of the resist.

[0254] <Example 2>

[0255] The resin obtained in Synthesis Example 8 was dissolved in PGMEA, and ion exchange was performed for 4 hours using both cation and anion exchange resins to obtain a compound solution with a concentration of 18.63%. 0.12 g of PL-LI containing 2% pyridine was added to 2.54 g of this resin solution. Dissolve 0.36 g of p-toluenesulfonic acid PGME, 0.05 g of PGMEA containing 1% by mass of surfactant, 7.96 g of PGMEA, and 3.97 g of PGME in the solution, and filter the solution using a microfilter made of polytetrafluoroethylene with a pore size of 0.1 μm to prepare a solution of the composition for forming the lower layer film of the resist.

[0256] <Example 3>

[0257] The resin obtained in Synthesis Example 9 was dissolved in PGMEA, and ion exchange was performed for 4 hours using both cation and anion exchange resins to obtain a 22.47% compound solution. 0.11 g of PL-LI containing 2% pyridine was added to 2.53 g of this resin solution. Dissolve 0.85 g of p-toluenesulfonic acid PGME, 0.06 g of PGMEA containing 1% by mass of surfactant, 11.49 g of PGMEA, and 4.95 g of PGME in the solution, and filter the solution using a micro-filter made of polytetrafluoroethylene with a pore size of 0.1 μm to prepare a solution of the composition for forming the lower layer film of the resist.

[0258] <Example 4>

[0259] The resin obtained in Synthesis Example 10 was dissolved in PGMEA, and ion exchange was performed for 4 hours using both cation and anion exchange resins to obtain a 19.21% compound solution. 0.17 g of PL-LI and a compound containing 2% by mass pyridine were added to 3.60 g of this resin solution. Dissolve 0.52 g of p-toluenesulfonic acid PGME, 0.07 g of PGMEA containing 1% by mass of surfactant, 13.91 g of PGMEA, and 6.73 g of PGME in the solution, and filter the solution using a micro-filter made of polytetrafluoroethylene with a pore size of 0.1 μm to prepare a composition for forming the lower layer film of the resist.

[0260] <Example 5>

[0261] The resin obtained in Synthesis Example 11 was dissolved in PGMEA, and ion exchange was performed for 4 hours using both cation and anion exchange resins to obtain a 21.25% compound solution. 0.17 g of PL-LI and a compound containing 2% by mass pyridine were added to 3.25 g of this resin solution. Dissolve 0.52 g of p-toluenesulfonic acid PGME, 0.07 g of PGMEA containing 1% by mass of surfactant, 14.26 g of PGMEA, and 6.73 g of PGME in the solution, and filter the solution using a microfilter made of polytetrafluoroethylene with a pore size of 0.1 μm to prepare a composition for forming the lower layer film of the resist.

[0262] <Example 6>

[0263] The resin obtained in Synthesis Example 12 was dissolved in PGMEA, and ion exchange was performed for 4 hours using both cation and anion exchange resins to obtain a 19.44% compound solution. 0.12 g of PL-LI and a compound containing 2% pyridine by mass were then added to 2.44 g of this resin solution. Dissolve 0.36 g of p-toluenesulfonic acid PGME, 0.05 g of PGMEA containing 1% by mass of surfactant, 8.07 g of PGMEA, and 3.97 g of PGME in the solution, and filter the solution using a micro-filter made of polytetrafluoroethylene with a pore size of 0.1 μm to prepare a composition for forming the lower layer film of the resist.

[0264] <Example 7>

[0265] The resin obtained in Synthesis Example 13 was dissolved in CYH, and ion exchange was performed for 4 hours using both cation and anion exchange resins to obtain a 19.77% compound solution. 0.12 g of PL-LI containing 2% pyridine was added to 2.40 g of this resin solution. Dissolve 0.36 g of p-toluenesulfonic acid PGME, 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 filter the solution using a microfilter made of polytetrafluoroethylene with a pore size of 0.1 μm to prepare a composition for forming the lower layer film of the resist.

[0266] <Example 8>

[0267] The resin obtained in Synthesis Example 14 was dissolved in CYH, and ion exchange was performed for 4 hours using both cation and anion exchange resins to obtain a 21.63% compound solution. 0.12 g of PL-LI containing 2% pyridine was added to 2.19 g of this resin solution. Dissolve 0.36 g of p-toluenesulfonic acid PGME, 0.05 g of PGMEA containing 1% by mass surfactant, 2.83 g of PGMEA, 2.53 g of PGME, and 6.92 g of CYH, and filter the solution using a microfilter made of polytetrafluoroethylene with a pore size of 0.1 μm to prepare a composition for forming the lower layer film of the resist.

[0268] <Example 9>

[0269] The resin obtained in Synthesis Example 15 was dissolved in CYH, and ion exchange was performed for 4 hours using cation exchange resin and anion exchange resin to obtain a 19.56% compound solution. 0.12 g of PL-LI containing 2% pyridine was added to 2.42 g of this resin solution. Dissolve 0.36 g of p-toluenesulfonic acid PGME, 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 filter the solution using a microfilter made of polytetrafluoroethylene with a pore size of 0.1 μm to prepare a composition for forming the lower layer film of the resist.

[0270] <Comparative Example 1>

[0271] The resin obtained in Synthesis Example 1 was dissolved in PGMEA, and ion exchange was performed for 4 hours using both cation and anion exchange resins to obtain a compound solution with a concentration of 18.73%. 0.12 g of PL-LI containing 2% pyridine was added to 2.53 g of this resin solution. Dissolve 0.36 g of p-toluenesulfonic acid PGME, 0.05 g of PGMEA containing 1% by mass of surfactant, 7.98 g of PGMEA, and 3.97 g of PGME in the solution, and filter the solution using a micro-filter made of polytetrafluoroethylene with a pore size of 0.1 μm to prepare a solution of the composition for forming the lower layer film of the resist.

[0272] <Comparative Example 2>

[0273] The resin obtained in Synthesis Example 2 was dissolved in PGMEA, and ion exchange was performed for 4 hours using both cation and anion exchange resins to obtain a 17.08% compound solution. 0.12 g of PL-LI containing 2% pyridine was added to 2.77 g of this resin solution. Dissolve 0.36 g of p-toluenesulfonic acid PGME, 0.05 g of PGMEA containing 1% by mass of surfactant, 7.73 g of PGMEA, and 3.97 g of PGME in the solution, and filter the solution using a micro-filter made of polytetrafluoroethylene with a pore size of 0.1 μm to prepare a solution of the composition for forming the lower layer film of the resist.

[0274] <Comparative Example 3>

[0275] The resin obtained in Synthesis Example 3 was dissolved in PGMEA, and ion exchange was performed for 4 hours using both cation and anion exchange resins to obtain a 20.20% compound solution. 0.10 g of PL-LI containing 2% pyridine by mass was added to 2.41 g of this resin solution. Dissolve 0.73 g of p-toluenesulfonic acid PGME, 0.05 g of PGMEA containing 1% by mass of surfactant, 0.91 g of PGMEA, 2.16 g of PGME, and 8.64 g of CYH, and filter the solution using a microfilter made of polytetrafluoroethylene with a pore size of 0.1 μm to prepare a composition for forming the lower layer film of the resist.

[0276] <Comparative Example 4>

[0277] The resin obtained in Synthesis Example 4 was dissolved in PGME, and ion exchange was performed for 4 hours using both cation and anion exchange resins to obtain a compound solution with a concentration of 18.06%. 0.17 g of PL-LI containing 2% pyridine was added to 3.83 g of this resin solution. Dissolve 0.52 g of p-toluenesulfonic acid PGME, 0.07 g of PGMEA containing 1% by mass surfactant, 7.17 g of PGMEA, and 13.24 g of PGME in the solution, and filter the solution using a microfilter made of polytetrafluoroethylene with a pore size of 0.1 μm to prepare a composition for forming the lower layer film of the resist.

[0278] <Comparative Example 5>

[0279] The resin obtained in Synthesis Example 5 was dissolved in PGMEA, and ion exchange was performed for 4 hours using both cation and anion exchange resins to obtain a 19.44% compound solution. 0.17 g of PL-LI containing 2% pyridine was added to 3.56 g of this resin solution. Dissolve 0.52 g of p-toluenesulfonic acid PGME, 0.07 g of PGMEA containing 1% by mass of surfactant, 13.95 g of PGMEA, and 6.73 g of PGME in the solution, and filter the solution using a microfilter made of polytetrafluoroethylene with a pore size of 0.1 μm to prepare a solution of the composition for forming the lower layer film of the resist.

[0280] <Comparative Example 6>

[0281] The resin obtained in Synthesis Example 6 was dissolved in PGMEA, and ion exchange was performed for 4 hours using both cation and anion exchange resins to obtain a 29.80% compound solution. 0.21 g of PL-LI containing 2% pyridine was added to 2.78 g of this resin solution. Dissolve 0.62 g of p-toluenesulfonic acid PGME, 0.08 g of PGMEA containing 1% by mass of surfactant, 7.73 g of PGMEA, and 3.58 g of PGME in the solution, and filter the solution using a micro-filter made of polytetrafluoroethylene with a pore size of 0.1 μm to prepare a solution of the composition for forming the lower layer film of the resist.

[0282] (Contact Angle Measurement)

[0283] Regarding the polymer solutions used in Comparative Examples 1-6 and Examples 1-9, they were each coated onto silicon wafers using a spin coater and then fired at 160°C for 60 seconds on a hot plate to form polymer films. The contact angles of the polymers relative to pure water were then measured using a contact angle meter manufactured by Kyowa Interface Science Co., Ltd. The contact angles of the polymers used in the examples were compared with those of the polymers used in the comparative examples, and cases where the contact angle of the polymer used in the examples was higher were defined as "0".

[0284] [Table 1]

[0285] Table 1

[0286] Comparative Example 1 Synthesis example 1 160℃ × Comparative Example 2 Synthesis example 2 160℃ × Comparative Example 3 Synthesis example 3 160℃ × Comparative Example 4 Synthesis example 4 160℃ × Comparative Example 5 Synthesis example 5 160℃ × Comparative Example 6 Synthesis example 6 160℃ × Example 1 Synthesis Example 7 160℃ ○ Example 2 Synthesis example 8 160℃ ○ Example 3 Synthesis example 9 160℃ ○ Example 4 Synthesis example 10 160℃ ○ Example 5 Synthesis Example 11 160℃ ○ Example 6 Synthesis example 12 160℃ ○ Example 7 Synthesis example 13 160℃ ○ Example 8 Synthesis Example 14 160℃ ○ Example 9 Synthesis Example 15 160℃ ○

[0287] If we compare Comparative Examples 1 (Examples 1 and 7), Comparative Examples 2 (Examples 2 and 8), Comparative Examples 3 (Example 3), Comparative Examples 4 (Example 4), Comparative Examples 5 (Example 5), Comparative Examples 6 (Example 6) and 9, the polymers used in the examples show a higher contact angle compared to the polymers used in the comparative examples.

[0288] (Dissolution test in resist solvent)

[0289] Solutions of the resist underlayer film forming compositions prepared in Comparative Examples 1-6 and Examples 1-9 were respectively coated onto silicon wafers using a spin coater and then fired at 240°C for 60 seconds or 350°C for 60 seconds on a hot plate to form resist underlayer films (film thickness 65 nm). These resist underlayer films were impregnated with PGME / PGMEA = 7 / 3 as a common diluent. The resist underlayer films were insoluble, confirming sufficient curability.

[0290] [Table 2]

[0291] Table 2

[0292] Comparative Example 1 Synthesis example 1 240℃ ○ Comparative Example 2 Synthesis example 2 240℃ ○ Comparative Example 3 Synthesis example 3 240℃ ○ Comparative Example 4 Synthesis example 4 240℃ ○ Comparative Example 5 Synthesis example 5 240℃ ○ Comparative Example 6 Synthesis example 6 240℃ ○ Example 1 Synthesis Example 7 240℃ ○ Example 2 Synthesis example 8 240℃ ○ Example 3 Synthesis example 9 240℃ ○ Example 4 Synthesis example 10 240℃ ○ Example 5 Synthesis Example 11 240℃ ○ Example 6 Synthesis example 12 240℃ ○

[0293] Comparative Example 1 Synthesis example 1 350℃ ○ Comparative Example 2 Synthesis example 2 350℃ ○ Comparative Example 6 Synthesis example 6 350℃ ○ Example 7 Synthesis example 13 350℃ ○ Example 8 Synthesis Example 14 350℃ ○ Example 9 Synthesis Example 15 350℃ ○

[0294] (Coating performance test)

[0295] Solutions of the resist underlayer film forming compositions prepared in Comparative Examples 1-6 and Examples 1-9 were respectively coated onto silicon wafers using a spin coater and fired at 240°C for 60 seconds or 350°C for 60 seconds on a hot plate to form a resist underlayer film. A coating-type silicon solution was then further coated onto the top layer and fired at 215°C for 60 seconds to form a silicon film. The film thickness was then measured and calculated as "film thickness deviation (maximum film thickness - minimum film thickness) / average film thickness × 100". A low value indicates good coatability. For the examples corresponding to the comparative examples, if the coatability is good, it is judged as "0".

[0296] [Table 3]

[0297] Table 3

[0298] Comparative Example 1 Synthesis example 1 240℃ × Comparative Example 2 Synthesis example 2 240℃ × Comparative Example 3 Synthesis example 3 240℃ × Comparative Example 4 Synthesis example 4 240℃ × Comparative Example 5 Synthesis example 5 240℃ × Comparative Example 6 Synthesis example 6 240℃ × Example 1 Synthesis Example 7 240℃ ○ Example 2 Synthesis example 8 240℃ ○ Example 3 Synthesis example 9 240℃ ○ Example 4 Synthesis example 10 240℃ ○ Example 5 Synthesis Example 11 240℃ ○ Example 6 Synthesis example 12 240℃ ○

[0299] Comparative Example 1 Synthesis example 1 350℃ × Comparative Example 2 Synthesis example 2 350℃ × Comparative Example 6 Synthesis example 6 350℃ × Example 7 Synthesis example 13 350℃ ○ Example 8 Synthesis Example 14 350℃ ○ Example 9 Synthesis Example 15 350℃ ○

[0300] Comparing Comparative Examples 1 (Examples 1 and 7), 2 (Examples 2 and 8), 3 (Example 3), 4 (Example 4), 5 (Example 5), 6 (Example 6), and 9, the examples show better coatability compared to the comparative examples. This is because the polymer is hydrophobic, thus improving coatability.

[0301] (Drug resistance test)

[0302] Solutions of the resist underlayer film forming compositions prepared in Comparative Examples 1-6 and Examples 1-9 were respectively coated onto SiON using a spin coater. A resist underlayer film (65 nm thick) was formed by firing at 240°C for 60 seconds or 350°C for 60 seconds on a hot plate. A silicon hard mask layer (20 nm thick) and a resist layer (AR2772JN-14, manufactured by JSR Corporation, 120 nm thick) were formed on top of this layer. The resist pattern was obtained by exposure and development using the mask at a wavelength of 193 nm. Then, the resist pattern was transferred onto the resist underlayer film by dry etching using a fluorine-based gas and an oxygen-based gas using an etching apparatus manufactured by Ramlissett Corporation. The pattern shape was verified using a Hitachi Technologie CG-4100, confirming the formation of a 50 nm line pattern.

[0303] The patterned wafers obtained here were cut and immersed in SARC-410 (manufactured by Integrities Japan Co., Ltd.) at a temperature of 30°C. After immersion, the wafers were removed, rinsed with water, and dried. They were then observed using a scanning electron microscope (Regulus 8240) to confirm whether the pattern shape formed by the resist underlayer had deteriorated or whether the pattern had collapsed. High resistivity was indicated when the pattern shape did not deteriorate and the pattern did not collapse, compared to a comparative example with a similar structure. A value of "0" was defined as the absence of pattern deterioration or collapse even after longer immersion in the resist solution.

[0304] [Table 4]

[0305] Table 4

[0306] Comparative Example 1 240℃ No peeling It is curved There was a collapse × Comparative Example 2 240℃ There is peeling - - × Comparative Example 3 240℃ There is peeling It is curved There was a collapse × Comparative Example 4 240℃ There is peeling - - × Comparative Example 5 240℃ There is peeling - - × Comparative Example 6 240℃ No peeling It is curved There was a collapse × Example 1 240℃ No peeling vertical No collapse ○ Example 2 240℃ No peeling vertical No collapse ○ Example 3 240℃ No peeling vertical No collapse ○ Example 4 240℃ No peeling vertical No collapse ○ Example 5 240℃ No peeling vertical No collapse ○ Example 6 240℃ No peeling vertical No collapse ○

[0307] Comparative Example 1 350℃ No peeling It is curved There was a collapse × Comparative Example 2 350℃ No peeling It is curved There was a collapse × Comparative Example 6 350℃ No peeling It is curved There was a collapse × Example 7 350℃ No peeling vertical No collapse ○ Example 8 350℃ No peeling vertical No collapse ○ Example 9 350℃ No peeling vertical No collapse ○

[0308] When fired at 240°C, as can be seen from Comparative Examples 1-Example 1, 2-Example 2, 3-Example 3, 4-Example 4, 5-Example 5, and 6-Example 6, modification with amino and hydroxyl groups can improve the resistance to alkaline solutions. Furthermore, the resistance to solutions is similarly improved when fired at a high temperature of 350°C. Therefore, this material can also be applied to processes using pharmaceutical solutions.

[0309] Industry availability

[0310] According to the present invention, a new composition for forming a resist underlayer film is provided, which addresses the requirements of obtaining a hydrophobic underlayer film that exhibits a high pure water contact angle, high adhesion to the upper film, is not easily peeled off, and has good coatability, and also exhibits other good properties such as sufficient resistance to the solution also used in the resist underlayer film.

Claims

1. A composition for forming a resist underlayer film, comprising: a solvent; and a polymer comprising a unit structure (A) as shown in formula (1) below. In the formula, Ar 1 and Ar 2 Each represents a benzene ring or a naphthalene ring, Ar 1 and Ar 2 They can be linked via a single bond, where, In Ar 1 and Ar 2 When each represents a benzene ring, Ar 1 and Ar 2 They combine without using a single bond. R 1 and R 2 Each to replace Ar 1 And Ar 2 The group consisting of hydrogen atoms on the ring is selected from halogen, nitro, amino, cyano, alkyl with 1 to 10 carbon atoms, alkenyl with 2 to 10 carbon atoms, alkynyl with 2 to 10 carbon atoms, aryl with 6 to 40 carbon atoms, and combinations thereof. Furthermore, the alkyl, alkenyl, alkenyl, and aryl groups may contain ether bonds, ketone bonds, or ester bonds. R 3 It is an alkynyl group with 2 to 10 carbon atoms. R 4 It is an aryl group with 6 to 40 carbon atoms. R 5 It is a hydrogen atom; n1 and n2 are both integers from 0 to 3.

2. The composition for forming a resist underlayer film according to claim 1, wherein Ar in formula (1) 1 and Ar 2 It is a benzene ring.

3. The composition for forming a resist underlayer film according to claim 1 or 2, wherein in formula (1), R 4 It is an aromatic hydrocarbon group with 6 to 16 carbon atoms.

4. The composition for forming a resist underlayer film according to claim 1 or 2, further comprising a crosslinking agent.

5. The composition for forming a resist underlayer film according to claim 1 or 2, further comprising an acid and / or an acid-generating agent.

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

7. A resist underlayer film, which is a sintered product of a coating film formed by the resist underlayer film forming composition according to any one of claims 1 to 6.

8. A method for manufacturing a semiconductor device, comprising the following steps: A process of forming a photoresist underlayer film by using the photoresist underlayer film forming composition according to any one of claims 1 to 6 on a semiconductor substrate; The process of forming a resist film on the formed resist underlayer film; The process of irradiating the formed resist film with light or electron beams and developing it to form a resist pattern; The process of etching the underlying resist film through the formed resist pattern to perform patterning; and The process of processing a semiconductor substrate through a patterned resist underlayer.

9. A method for manufacturing a semiconductor device, comprising the following steps: A process of forming a photoresist underlayer film by using the photoresist underlayer film forming composition according to any one of claims 1 to 6 on a semiconductor substrate; The process of forming a hard mask on the formed resist underlayer film; The process of forming a resist film on the hard mask; The process of irradiating the formed resist film with light or electron beams and developing it to form a resist pattern; The process of etching a hard mask through the formed resist pattern; The process of etching the underlying resist film through an etched hard mask; as well as The process of removing the hard mask.

10. The method for manufacturing a semiconductor device according to claim 9, further comprising the following steps: The process of forming a vapor-deposited film, or spacer, on the lower film after the hard mask has been removed; The process of etching the formed vapor-deposited film, i.e., the spacer, is a process of processing. The process of removing the lower film; and The process of processing a semiconductor substrate using spacers.

11. The method for manufacturing a semiconductor device according to any one of claims 8 to 10, wherein the semiconductor substrate is a substrate with a high-low gradient.

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