Resist underlayer film-forming composition containing diol structure

Abstract

Provided are a composition for forming a resist underlayer film that can fill the micropores on a semiconductor substrate that is being miniaturized without voids (gaps), produces less sublimates when the film is fired during film formation, and a liquid-resistant protective film composition that also functions as a protective film against wet etching liquid in semiconductor substrate processing. A composition for forming a resist underlayer film or a composition for forming a protective film, comprising: a compound represented by the following formula (1) with a theoretical molecular weight of 999 or less; and an organic solvent. [In formula (1), Z1 comprises a nitrogen-containing heterocyclic ring, U is a monovalent organic group represented by the following formula (2), and p represents an integer of 2 to 4. ][In formula (2), R1 represents an alkylene group having 1 to 4 carbon atoms, A1 to A3 each independently represent a hydrogen atom, a methyl group or an ethyl group, and X represents -COO-, -OCO-, -O-, -S- and -NR a ‑Any one of R a represents a hydrogen atom or a methyl group. Y represents a directly bonded or substituted alkylene group having 1 to 4 carbon atoms, R2, R3 and R4 are each a hydrogen atom, or an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 40 carbon atoms which may be substituted, R5 is a hydrogen atom or a hydroxyl group, n represents an integer of 0 or 1, m1 and m2 each independently represent an integer of 0 or 1, and * represents a portion bonded to Z1]

Description

[0001] The invention of this application is a divisional application of the application with application number 202180041796.3, invention name “Composition for forming a resist underlayer film containing a diol structure”, and application date June 11, 2021. Technical Field

[0002] The present invention relates to a composition for forming a resist underlayer film, which has excellent embedding properties in a microstructure substrate and produces less sublimates during film formation in a photolithography process in semiconductor manufacturing. It also relates to a method for manufacturing a substrate with a resist pattern using the resist underlayer film and a method for manufacturing a semiconductor device. It also relates to a protective film for substrate processing in semiconductor manufacturing using a wet etching solution. Background Art

[0003] In semiconductor manufacturing, a photolithography process is well known in which a resist underlayer film is provided between a substrate and a resist film formed thereon to form a resist pattern of a desired shape. Patent Document 1 discloses a composition for forming a resist underlayer film containing a reaction product of a compound having a triazine skeleton and having three epoxy groups and a dicarboxylic acid compound containing a disulfide bond.

[0004] In addition, in the photolithography process of semiconductor manufacturing, when the resist underlayer film is formed using the above-mentioned resist underlayer film forming composition, the sublimation components (sublimates) derived from low molecular weight compounds such as the above-mentioned polymer resin, crosslinking agent, and crosslinking catalyst during firing become a new problem. Such sublimates are attached and accumulated in the film forming device during the semiconductor device manufacturing process, thereby polluting the device, and they are attached to the wafer as foreign matter, thereby worrying that they will become a factor of defect (defect) etc. Therefore, it is required to propose a new underlayer film composition that suppresses such sublimates generated by the resist underlayer film as much as possible, and Patent Document 2 and the like have also conducted research on resist underlayer films showing such low sublimation properties.

[0005] Patent Document 3 discloses a protective film-forming composition for a semiconductor wet etching solution, comprising a compound having at least one set of two adjacent hydroxyl groups in a molecule, or a polymer thereof, and a solvent.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: International Publication No. 2019 / 151471

[0009] Patent Document 2: Japanese Patent Application Publication No. 2010-237491

[0010] Patent Document 3: International Publication No. 2019 / 124474 Summary of the invention

[0011] Problems to be solved by the invention

[0012] In order to solve the problems (such as poor shape) during the formation of the resist pattern required as the resist underlayer film, the previous resist underlayer film-forming composition also required to properly control the optical constants of the film itself, and at the same time, it was difficult to achieve these properties simultaneously in order to bury the fine pattern (for example, less than 10 nm in width) on the increasingly miniaturized semiconductor substrate without pores (voids).

[0013] Furthermore, the sublimates generated during the film firing when the resist underlayer film is formed are also required to be further reduced because they also cause device contamination and voids. Furthermore, in the semiconductor manufacturing process, the resist underlayer film is sometimes processed with a wet etching solution (such as SC-1 (ammonia-hydrogen peroxide solution) etc.) for substrate processing, and sometimes it is required to function as a protective film for the non-processed portion.

[0014] An object of the present invention is to solve the above-mentioned problems.

[0015] Methods for solving problems

[0016] The present invention includes the following aspects.

[0017] [1] A resist underlayer film-forming composition comprising: a compound represented by the following formula (1) and having a theoretical molecular weight of 999 or less; and an organic solvent.

[0018]

[0019] [In formula (1), Z1 includes a nitrogen-containing heterocyclic ring, U is a monovalent organic group represented by the following formula (2), and p represents an integer of 2 to 4.]

[0020]

[0021] [In formula (2), R1 represents an alkylene group having 1 to 4 carbon atoms, A1 to A3 each independently represent a hydrogen atom, a methyl group or an ethyl group, and X represents -COO-, -OCO-, -O-, -S- or -NR a -Any one of R a represents a hydrogen atom or a methyl group. Y represents a directly bonded or substituted alkylene group having 1 to 4 carbon atoms, R2, R3 and R4 are each a hydrogen atom, or an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 40 carbon atoms which may be substituted, R5 is a hydrogen atom or a hydroxyl group, n represents an integer of 0 or 1, m1 and m2 each independently represent an integer of 0 or 1, and * represents a portion bonded to Z1]

[0022] [2] The resist underlayer film forming composition according to [1], wherein the Z1 is represented by the following formula (3).

[0023]

[0024] [In formula (3), Q3 represents the following formula (4), formula (5) or formula (6).]

[0025]

[0026] [In formula (4), formula (5) and formula (6),

[0027] R 11 , R 12 , R 13 and R 14 Each independently represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms which may be interrupted by an oxygen atom or a sulfur atom, an alkenyl group having 2 to 10 carbon atoms which may be interrupted by an oxygen atom or a sulfur atom, an alkynyl group having 2 to 10 carbon atoms which may be interrupted by an oxygen atom or a sulfur atom, a benzyl group or a phenyl group, and the phenyl group may be substituted with at least one monovalent functional group selected from the group consisting of an alkyl group having 1 to 6 carbon atoms, a halogen atom, an alkoxy group having 1 to 10 carbon atoms, a nitro group, a cyano group and an alkylthio group having 1 to 6 carbon atoms.

[0028] R 15 represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms which may be interrupted by an oxygen atom or a sulfur atom and which may be substituted by a hydroxyl group, an alkenyl group having 3 to 10 carbon atoms which may be interrupted by an oxygen atom or a sulfur atom, an alkynyl group having 3 to 10 carbon atoms which may be interrupted by an oxygen atom or a sulfur atom, a benzyl group, or a phenyl group, wherein the phenyl group may be substituted by at least one monovalent functional group selected from an alkyl group having 1 to 6 carbon atoms, a halogen atom, an alkoxy group having 1 to 10 carbon atoms, a nitro group, a cyano group, an alkylthio group having 1 to 6 carbon atoms, and a monovalent organic group represented by U in formula (1). * represents a portion bonded to U. ]

[0029] [3] The resist underlayer film forming composition according to [2], wherein the R 15 It is an alkyl group having 1 to 10 carbon atoms or a monovalent organic group represented by U in the formula (1).

[0030] [4] The resist underlayer film forming composition according to [2] or [3], wherein the R 11 and R 12 Each independently represents an alkyl group having 1 to 10 carbon atoms.

[0031] [5] The resist underlayer film forming composition according to any one of [1] to [4], wherein X is -S-, and Y is a methylene group.

[0032] [6] The resist underlayer film forming composition according to [1], further comprising an acid compound.

[0033] [7] The resist underlayer film forming composition according to any one of [1] to [6], further comprising a surfactant.

[0034] [8] A resist underlayer film, characterized in that it is a fired product of a coating film formed from the resist underlayer film-forming composition according to any one of [1] to [7].

[0035] [9] A composition for forming a protective film for a semiconductor wet etching solution, comprising: a compound represented by the following formula (1), having a theoretical molecular weight of 999 or less and containing 2 or more nitrogen atoms and 6 or more oxygen atoms in the molecule; and an organic solvent.

[0036]

[0037] [In formula (1), Z1 includes a nitrogen-containing heterocyclic ring, U is a monovalent organic group represented by the following formula (2), and p represents an integer of 2 to 4.]

[0038]

[0039] [In formula (2), R1 represents an alkylene group having 1 to 4 carbon atoms, A1 to A3 each independently represent a hydrogen atom, a methyl group or an ethyl group, and X represents -COO-, -OCO-, -O-, -S- or -NR a -Any one of R a represents a hydrogen atom or a methyl group. Y represents a directly bonded or substituted alkylene group having 1 to 4 carbon atoms, R2, R3 and R4 are each a hydrogen atom, or an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 40 carbon atoms which may be substituted, R5 is a hydrogen atom or a hydroxyl group, n represents an integer of 0 or 1, m1 and m2 each independently represent an integer of 0 or 1, and * represents a portion bonded to Z1]

[0040]

[10] The composition according to [9], wherein the Z1 is represented by the following formula (3).

[0041]

[0042] [In formula (3), Q3 represents the following formula (4), formula (5) or formula (6).]

[0043]

[0044] [In formula (4), formula (5) and formula (6),

[0045] R 11 , R12 , R 13 and R 14 Each independently represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms which may be interrupted by an oxygen atom or a sulfur atom, an alkenyl group having 2 to 10 carbon atoms which may be interrupted by an oxygen atom or a sulfur atom, an alkynyl group having 2 to 10 carbon atoms which may be interrupted by an oxygen atom or a sulfur atom, a benzyl group or a phenyl group, and the phenyl group may be substituted with at least one monovalent functional group selected from the group consisting of an alkyl group having 1 to 6 carbon atoms, a halogen atom, an alkoxy group having 1 to 10 carbon atoms, a nitro group, a cyano group and an alkylthio group having 1 to 6 carbon atoms.

[0046] R 15 represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms which may be interrupted by an oxygen atom or a sulfur atom and which may be substituted by a hydroxyl group, an alkenyl group having 3 to 10 carbon atoms which may be interrupted by an oxygen atom or a sulfur atom, an alkynyl group having 3 to 10 carbon atoms which may be interrupted by an oxygen atom or a sulfur atom, a benzyl group, or a phenyl group, wherein the phenyl group may be substituted by at least one monovalent functional group selected from an alkyl group having 1 to 6 carbon atoms, a halogen atom, an alkoxy group having 1 to 10 carbon atoms, a nitro group, a cyano group, an alkylthio group having 1 to 6 carbon atoms, and a monovalent organic group represented by U in formula (1). * represents a portion bonded to U. ]

[0047]

[11] The protective film-forming composition according to [9] or

[10] , further comprising an acid compound and / or a crosslinking agent.

[0048]

[12] A protective film characterized by being a fired product of a coating film formed from the protective film-forming composition according to any one of [9] to

[11] .

[0049]

[13] A method for manufacturing a substrate with a resist pattern, characterized in that it comprises the following steps: a step of applying the resist underlayer film forming composition described in any one of [1] to [7] on a semiconductor substrate and firing it to form a resist underlayer film; a step of forming a resist film on the resist underlayer film, followed by exposing and developing it to form a resist pattern, wherein the above-mentioned method for manufacturing a substrate with a resist pattern is used to manufacture semiconductors.

[0050]

[14] A method for manufacturing a semiconductor device, comprising the following steps: forming a resist underlayer film on a semiconductor substrate on which an inorganic film can be formed using the resist underlayer film forming composition described in any one of [1] to [7], forming a resist pattern on the resist underlayer film, dry-etching the resist underlayer film using the resist pattern as a mask to expose the surface of the inorganic film or the semiconductor substrate, and etching the inorganic film or the semiconductor substrate using the dry-etched resist underlayer film as a mask.

[0051]

[15] A method for manufacturing a semiconductor device, comprising the following steps: forming a protective film on a semiconductor substrate on which an inorganic film can be formed using the protective film forming composition described in [9] to

[11] , forming a resist pattern on the protective film, dry-etching the protective film using the resist pattern as a mask to expose the surface of the inorganic film or the semiconductor substrate, and wet-etching and washing the inorganic film or the semiconductor substrate using a semiconductor wet etching solution using the dry-etched protective film as a mask.

[0052] Effects of the Invention

[0053] The resist underlayer film-forming composition of the present invention can solve the problems (such as poor shape) in forming a resist pattern required as a resist underlayer film, and can embed a fine pattern (for example, a width of 10 nm or less) on a semiconductor substrate whose miniaturization is increasingly being advanced without voids. Furthermore, compared with conventional resist underlayer films, less sublimates are generated during film firing when forming the resist underlayer film.

[0054] Furthermore, the present invention has resistance to wet etching solutions used for substrate processing in semiconductor manufacturing processes. Furthermore, compared with conventional wet etching protective films, the dry etching rate is high, so when the present resist underlayer film and protective film are removed, damage to the substrate can be reduced.

[0055] The larger the molecular weight of the polymer, the larger the molecular size and the higher the viscosity, so it is considered that embedding into fine patterns becomes difficult. Therefore, the resist underlayer film-forming composition of the present invention uses a compound with a theoretical molecular weight of 999 or less, so it can be embedded into a fine structure compared to a composition using a high molecular polymer. Furthermore, by having a large number of hydroxyl groups in the compound, the boiling point of the compound is increased, sublimation is suppressed, and the adhesion is improved by interaction with a part of the substrate, and resistance can be obtained even when treated with a wet etching solution. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 It is a schematic cross-sectional view of the embedding property evaluation substrate of the example.

[0057] Figure 2 This is a cross-sectional SEM photograph of the evaluation of embedding property of the resist underlayer film-forming composition of Example 2 into an uneven substrate. DETAILED DESCRIPTION

[0058] <Resist underlayer film forming composition>

[0059] The resist underlayer film-forming composition according to the present invention comprises: a compound represented by the following formula (1) and having a theoretical molecular weight of 999 or less; and an organic solvent.

[0060] The theoretical molecular weight is a molecular weight calculated based on the chemical structure of the compound represented by formula (1).

[0061] From the viewpoint of improving the dry etching rate, the compound preferably contains 2 or more, 3 or more, 4 or more nitrogen atoms and 6 or more, 8 or more, 9 or more, 10 or more, or 15 or more oxygen atoms in the molecule. It is further preferred that the compound contains 2 or more, 3 or more, 4 or more, 5 or more, or 6 or more sulfur atoms in the molecule.

[0062] <Compound represented by formula (1) having a theoretical molecular weight of 999 or less>

[0063] The compound having a theoretical molecular weight of 999 or less contained in the resist underlayer film-forming composition of the present application is represented by the following formula (1).

[0064]

[0065] [In formula (1), Z1 includes a nitrogen-containing heterocyclic ring, U is a monovalent organic group represented by the following formula (2), and p represents an integer of 2 to 4.]

[0066]

[0067] [In formula (2), R1 represents an alkylene group having 1 to 4 carbon atoms, A1 to A3 each independently represent a hydrogen atom, a methyl group or an ethyl group, and X represents -COO-, -OCO-, -O-, -S- or -NR a -Any one of R a represents a hydrogen atom or a methyl group. Y represents an alkylene group having 1 to 4 carbon atoms which is directly bonded or may be substituted, R2, R3 and R4 are each a hydrogen atom, or an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 40 carbon atoms which may be substituted, R5 is a hydrogen atom or a hydroxyl group, n represents an integer of 0 or 1, m1 and m2 each independently represent an integer of 0 or 1, and * represents a portion bonded to Z1].

[0068] Preferably, m2 is 1, and more preferably, m1 is 1.

[0069] Most preferably, m1 is 0 when m2 is 1.

[0070] In formula (1), Z1 is preferably represented by the following formula (3).

[0071]

[0072] [In formula (3), Q3 represents the following formula (4), formula (5) or formula (6).]

[0073]

[0074] [In formula (4), formula (5) and formula (6),

[0075] R 11 , R 12 , R 13 and R 14 Each independently represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms which may be interrupted by an oxygen atom or a sulfur atom, an alkenyl group having 2 to 10 carbon atoms which may be interrupted by an oxygen atom or a sulfur atom, an alkynyl group having 2 to 10 carbon atoms which may be interrupted by an oxygen atom or a sulfur atom, a benzyl group or a phenyl group, and the phenyl group may be substituted with at least one monovalent functional group selected from the group consisting of an alkyl group having 1 to 6 carbon atoms, a halogen atom, an alkoxy group having 1 to 10 carbon atoms, a nitro group, a cyano group and an alkylthio group having 1 to 6 carbon atoms.

[0076] Examples of the alkyl group include methyl, ethyl, n-propyl, isopropyl, cyclopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, cyclobutyl, 1-methyl-cyclopropyl, 2-methyl-cyclopropyl, 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, cyclopentyl, 1-methyl-cyclobutyl, 2-methyl-cyclobutyl, 3-methyl -cyclobutyl, 1,2-dimethyl-cyclopropyl, 2,3-dimethyl-cyclopropyl, 1-ethyl-cyclopropyl, 2-ethyl-cyclopropyl, n-hexyl, 1-methyl-n-pentyl, 2-methyl-n-pentyl, 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, 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 Butyl, 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, 2-ethyl-3-methyl-cyclopropyl, decyl, etc.

[0077] Examples of the alkenyl group include 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-cyclopentenyl cyclopentenyl, 2-methyl-3-cyclopentenyl, 2-methyl-4-cyclopentenyl, 2-methyl-5-cyclopentenyl, 2-methylene-cyclopentyl, 3-methyl-1-cyclopentenyl, 3-methyl-2-cyclopentenyl, 3-methyl-3-cyclopentenyl, 3-methyl-4-cyclopentenyl, 3-methyl-5-cyclopentenyl, 3-methylene-cyclopentyl, 1-cyclohexenyl, 2-cyclohexenyl and 3-cyclohexenyl, etc.

[0078] Examples of the alkynyl group include ethynyl, 1-propynyl, 2-propynyl, 1-butynyl, 2-butynyl, and 3-butynyl.

[0079] The phenyl group may be substituted with at least one monovalent functional group selected from the group consisting of an alkyl group having 1 to 6 carbon atoms, a halogen atom, an alkoxy group having 1 to 10 carbon atoms, a nitro group, a cyano group, and an alkylthio group having 1 to 6 carbon atoms.

[0080] The above-mentioned alkyl group is as exemplified above.

[0081] Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.

[0082] Examples of the alkoxy group include a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, an isobutoxy group, a sec-butoxy group, a tert-butoxy group, an n-pentoxy group, a 1-methyl-n-butoxy group, a 2-methyl-n-butoxy group, a 3-methyl-n-butoxy group, a 1,1-dimethyl-n-propoxy group, a 1,2-dimethyl-n-propoxy group, a 2,2-dimethyl-n-propoxy group, a 1-ethyl-n-propoxy group, an n-hexyloxy group, a 1-methyl-n-pentoxy group, a 2-methyl-n-pentoxy group, a 3-methyl-n-pentoxy group, a 4-methyl-n-pentoxy group Oxy, 1,1-dimethyl-n-butoxy, 1,2-dimethyl-n-butoxy, 1,3-dimethyl-n-butoxy, 2,2-dimethyl-n-butoxy, 2,3-dimethyl-n-butoxy, 3,3-dimethyl-n-butoxy, 1-ethyl-n-butoxy, 2-ethyl-n-butoxy, 1,1,2-trimethyl-n-propoxy, 1,2,2,-trimethyl-n-propoxy, 1-ethyl-1-methyl-n-propoxy, 1-ethyl-2-methyl-n-propoxy, n-heptyloxy, n-octyloxy and n-nonyloxy, etc.

[0083] Examples of the alkylthio group include a methylthio group, an ethylthio group, and a butylthio group.

[0084] Preferably, in the above formula (3), when Q3 represents the formula (4), R in the formula (4) 11 and R 12 Each independently represents an alkyl group having 1 to 10 carbon atoms.

[0085] Preferably, in the above formula (3), when Q3 represents the formula (5), R in the formula (5) 13 and R 14 Each independently represents an alkyl group having 1 to 10 carbon atoms.

[0086] In the above formula (3), when Q3 represents formula (6), R in formula (6) 15 represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms which may be interrupted by an oxygen atom or a sulfur atom and which may be substituted by a hydroxyl group, an alkenyl group having 3 to 10 carbon atoms which may be interrupted by an oxygen atom or a sulfur atom, an alkynyl group having 3 to 10 carbon atoms which may be interrupted by an oxygen atom or a sulfur atom, a benzyl group, or a phenyl group, wherein the phenyl group may be substituted by at least one monovalent functional group selected from an alkyl group having 1 to 6 carbon atoms, a halogen atom, an alkoxy group having 1 to 10 carbon atoms, a nitro group, a cyano group, an alkylthio group having 1 to 6 carbon atoms, and the monovalent organic group represented by U in the formula (1).

[0087] The alkyl group, alkenyl group, alkynyl group, halogen atom, alkoxy group and alkylthio group are as exemplified above.

[0088] Preferably, the above R 15 It is an alkyl group having 1 to 10 carbon atoms or a monovalent organic group represented by U in the formula (1); and p represents an integer of 2 to 4.

[0089]

[0090] In the formula (2), R1 represents an alkylene group having 1 to 4 carbon atoms.

[0091] Examples of the alkylene group include methylene, ethylene, n-propylene, isopropylene, cyclopropylene, n-butylene, isobutylene, sec-butylene, tert-butylene, cyclobutylene, 1-methyl-cyclopropylene, and 2-methyl-cyclopropylene.

[0092] A1 to A3 each independently represent a hydrogen atom, a methyl group or an ethyl group, and X represents any one of -COO-, -OCO-, -O-, -S- and -NR1-. a -, R a represents a hydrogen atom or a methyl group. Preferably, X is -S-.

[0093] In formula (2), Y represents a directly bonded or optionally substituted alkylene group having 1 to 4 carbon atoms. The alkylene group is as exemplified above, and Y is preferably a methylene group.

[0094] R2, R3 and R4 are each a hydrogen atom, or an optionally substituted alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 40 carbon atoms.

[0095] The term "may be substituted by the above substituents" means that part or all of the hydrogen atoms present in the substituted functional group may be substituted by, for example, a hydroxyl group, a halogen atom, a carboxyl group, a nitro group, a cyano group, a methylenedioxy group, an acetoxy group, a methylthio group, an amino group, or an alkoxy group having 1 to 9 carbon atoms. R5 is a hydrogen atom or a hydroxyl group.

[0096] Examples of the aryl group include phenyl, o-methylphenyl, m-methylphenyl, p-methylphenyl, o-chlorophenyl, m-chlorophenyl, p-chlorophenyl, o-fluorophenyl, p-fluorophenyl, o-methoxyphenyl, p-methoxyphenyl, p-nitrophenyl, p-cyanophenyl, α-naphthyl, β-naphthyl, o-biphenyl, m-biphenyl, p-biphenyl, 1-anthryl, 2-anthryl, 9-anthryl, 1-phenanthryl, 2-phenanthryl, 3-phenanthryl, 4-phenanthryl and 9-phenanthryl.

[0097] m1 and m2 each independently represent an integer of 0 or 1, but m2 is preferably 1, and m1 is more preferably 1.

[0098] Most preferably, m1 is 0 when m2 is 1.

[0099] The compound represented by formula (1) of the present application can be obtained by, for example, reacting the epoxy group or allyl group of the compound represented by the following formula (a) to (ak) with 1-thioglycerol (3-mercapto-1,2-propanediol, CAS No. 96-27-5) by a known method, but is not limited thereto. Furthermore, it may include a diol structure obtained by hydrolysis of the epoxy group possessed by the above compound. Preferably, it is a diol structure derived from the reaction of the above epoxy group or allyl group with 1-thioglycerol, and more preferably, it is a diol structure derived from the reaction of the above epoxy group with 1-thioglycerol.

[0100]

[0101]

[0102] If we give some specific examples of the compounds represented by formula (1), they are as follows. The synthesis method is described in detail in the embodiment. (Theoretical molecular weight of the compound represented by formula (X-1): 799, the theoretical molecular weight of the compound represented by formula (X-2): 621, the theoretical molecular weight of the compound represented by formula (X-3): 471, the theoretical molecular weight of the compound represented by formula (X-4): 456, the theoretical molecular weight of the compound represented by formula (X-5): 573, the theoretical molecular weight of the compound represented by formula (X-6): 795)

[0103]

[0104]

[0105] The theoretical molecular weight of the compound represented by formula (1) is 400 to 999, preferably 450 to 800.

[0106] <Organic solvents>

[0107] The resist underlayer film-forming composition of the present invention can be prepared by dissolving the above-mentioned components in an organic solvent and used in a uniform solution state.

[0108] As the organic solvent of the resist underlayer film forming composition according to the present invention, any organic solvent that can dissolve the above-mentioned compound, the acid catalyst described below and other solid components can be used without particular limitation. In particular, since the protective film forming composition according to the present invention is used in a uniform solution state, it is recommended to use an organic solvent generally used in a photolithography process in combination in consideration of its coating performance.

[0109] Examples of the organic solvent include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, methyl cellosolve acetate, ethyl cellosolve acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monomethyl ether acetate, propylene glycol propyl ether acetate, toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, cycloheptanone, 4-methyl-2-pentanol, and 2-hydroxyisobutyric acid. Methyl ester, ethyl 2-hydroxyisobutyrate, ethyl ethoxylate, 2-hydroxyethyl acetate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl 3-ethoxypropionate, methyl pyruvate, ethyl pyruvate, ethyl acetate, butyl acetate, ethyl lactate, butyl lactate, 2-heptanone, methoxycyclopentane, anisole, γ-butyrolactone, N-methylpyrrolidone, N,N-dimethylformamide, and N,N-dimethylacetamide. These solvents can be used alone or in combination of two or more.

[0110] Preferred among these solvents are propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, ethyl lactate, butyl lactate, and cyclohexanone, etc. Propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate are particularly preferred.

[0111] The resist underlayer film forming composition of the present application may further include an acid catalyst (acid compound). As the acid catalyst, in addition to an acidic compound and a basic compound, a compound that generates an acid or a base by heat can also be used. As the acidic compound, a sulfonic acid compound or a carboxylic acid compound can be used, and as a compound that generates an acid by heat, a thermal acid generator can be used.

[0112] Examples of the sulfonic acid compound or carboxylic acid compound include p-toluenesulfonic acid, trifluoromethanesulfonic acid, pyridine Trifluoromethanesulfonate (=pyridine Trifluoromethanesulfonic acid), pyridine - p-Toluenesulfonate, pyridine -4-Hydroxybenzenesulfonate, salicylic acid, camphorsulfonic acid, 5-sulfosalicylic acid, 4-chlorobenzenesulfonic acid, 4-phenolsulfonic acid, pyridine -4-Phenolsulfonate, benzene disulfonic acid, 1-naphthalenesulfonic acid, 4-nitrobenzenesulfonic acid, citric acid, benzoic acid, hydroxybenzoic acid.

[0113] Examples of the thermal acid generator include K-PURE [registered trademark] CXC-1612, K-PURE CXC-1614, K-PURE TAG-2172, K-PURE TAG-2179, K-PURE TAG-2678, and K-PURE TAG2689 (all manufactured by King Industries), and SI-45, SI-60, SI-80, SI-100, SI-110, and SI-150 (all manufactured by Sanshin Chemical Industry Co., Ltd.).

[0114] These acid catalysts may be used alone or in combination of two or more. In addition, as the basic compound, an amine compound or an ammonium hydroxide compound may be used, and as the compound that generates a base by heat, urea may be used.

[0115] As the amine compound, for example, tertiary amines such as triethanolamine, tributanolamine, trimethylamine, triethylamine, tri-n-propylamine, triisopropylamine, tri-n-butylamine, tri-tert-butylamine, tri-n-octylamine, triisopropanolamine, phenyldiethanolamine, stearyldiethanolamine, and diazabicyclooctane, and aromatic amines such as pyridine and 4-dimethylaminopyridine can be mentioned. In addition, primary amines such as benzylamine and n-butylamine, and secondary amines such as diethylamine and di-n-butylamine can also be mentioned as the amine compound. These amine compounds can be used alone or in combination of two or more.

[0116] Examples of the ammonium hydroxide compound include tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, benzyltrimethylammonium hydroxide, benzyltriethylammonium hydroxide, cetyltrimethylammonium hydroxide, phenyltrimethylammonium hydroxide, and phenyltriethylammonium hydroxide.

[0117] In addition, as the compound that generates a base by heat, for example, a compound having a thermally unstable group such as an amide group, a carbamate group or an aziridine group, which generates an amine by heating, can be used. In addition, urea, benzyltrimethylammonium chloride, benzyltriethylammonium chloride, benzyldimethylphenylammonium chloride, benzyldodecyldimethylammonium chloride, benzyltributylammonium chloride, and choline chloride can also be cited as the compound that generates a base by heat.

[0118] When the resist underlayer film forming composition of the present application contains an acid catalyst, the content thereof is 0.0001 to 20 mass %, preferably 0.01 to 15 mass %, and more preferably 0.1 to 10 mass % based on the total solid content of the resist underlayer film forming composition.

[0119] The solid content of the resist underlayer film forming composition of the present invention is usually 0.1 to 70% by mass, preferably 0.1 to 60% by mass. The solid content is the content ratio of all components from the resist underlayer film forming composition excluding the solvent. The proportion of the polymer in the solid content is preferably in the order of 1 to 100% by mass, 1 to 99.9% by mass, 50 to 99.9% by mass, 50 to 95% by mass, and 50 to 90% by mass.

[0120] <Cross-linking agent>

[0121] The resist underlayer film forming composition of the present invention may include a crosslinking agent. As the crosslinking agent, melamine system, substituted urea system, or polymer system thereof, etc. may be cited. Preferably, the crosslinking agent has at least two crosslinking substituents, such as methoxymethylated glycoluril, butoxymethylated glycoluril, methoxymethylated melamine, butoxymethylated melamine, methoxymethylated benzoguanamine, butoxymethylated benzoguanamine, methoxymethylated urea, butoxymethylated urea, methoxymethylated thiourea, or methoxymethylated thiourea. In addition, condensates of these compounds may also be used.

[0122] As the crosslinking agent, a crosslinking agent with high heat resistance can be used. As the crosslinking agent with high heat resistance, a compound containing a crosslinking-forming substituent having an aromatic ring (for example, a benzene ring or a naphthalene ring) in the molecule can be used.

[0123] Examples of such a compound include a compound having a partial structure of the following formula (5-1) and a polymer or oligomer having a repeating unit of the following formula (5-2).

[0124]

[0125] The above R 11 , R 12 , R 13 , and R 14It is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. Specific examples of these alkyl groups are as described above.

[0126] m1 is 1≤m1≤6-m2, m2 is 1≤m2≤5, m3 is 1≤m3≤4-m2, and m4 is 1≤m4≤3.

[0127] The compounds, polymers and oligomers of formula (5-1) and formula (5-2) are exemplified below.

[0128]

[0129] The above compounds can be obtained as products of Asahi Organic Materials Industries, Ltd. and Honshu Chemical Industries, Ltd. For example, among the above crosslinking agents, the compound of formula (6-22) can be obtained as TMOM-BP from Honshu Chemical Industries, Ltd.

[0130] The amount of the crosslinking agent added varies depending on the coating solvent used, the base substrate used, the required solution viscosity, the required film shape, etc., but is usually 0.001 to 80% by mass, preferably 0.01 to 50% by mass, and more preferably 0.1 to 40% by mass relative to the total solid content of the resist underlayer film-forming composition. These crosslinking agents sometimes undergo a crosslinking reaction caused by self-condensation, but when there is a crosslinkable substituent in the above-mentioned polymer of the present invention, a crosslinking reaction can occur with these crosslinkable substituents.

[0131] <Surfactant>

[0132] The resist film-forming composition of the present invention may contain a surfactant in order to improve the coating property on the semiconductor substrate. Examples of the surfactant include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, polyoxyethylene oleyl ether and other polyoxyethylene alkyl ethers, polyoxyethylene octylphenyl ether, polyoxyethylene nonylphenyl ether and other polyoxyethylene alkyl aryl ethers, polyoxyethylene / polyoxypropylene block copolymers, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, Sorbitan fatty acid esters such as sorbitan trioleate and sorbitan tristearate, polyoxyethylene sorbitan fatty acid esters such as polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate and polyoxyethylene sorbitan tristearate, etc., nonionic surfactants, EFTOP (registered trademark) EF30 1. EFT EF303, EFT EF352 (Mitsubishi Mitsubishi Electronics Co., Ltd. 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-30N、メガファックR-40、メガファックR-40-L M (manufactured by DIC Co., Ltd.), Fluoro FC430, Fluoro FC431 (Sumitomo Solar Fluorine-based surfactants such as SURFLUO® (manufactured by Asahi Glass Co., Ltd.), ASHIGADO (registered trademark) AG710, S-382 (registered trademark), S-101, S-102, S-103, S-104, S-105, and S-106 (manufactured by Asahi Glass Co., Ltd.), and organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.). These surfactants may be used alone or in combination of two or more. When the protective film-forming composition contains a surfactant, the content thereof is 0.0001 to 10% by weight, preferably 0.01 to 5% by weight, relative to the total solid content of the protective film-forming composition.

[0133] <Protective film forming composition>

[0134] The protective film forming composition of the present application is characterized in that it comprises: a compound represented by the following formula (1), having a theoretical average molecular weight of 999 or less, and containing 2 or more, 3 or more, or 4 or more nitrogen atoms, and 6 or more, 8 or more, 9 or more, 10 or more, or 15 or more oxygen atoms in the molecule; and an organic solvent.

[0135] Furthermore, the above compound preferably contains 2 or more, 3 or more, 4 or more, 5 or more, or 6 or more sulfur atoms.

[0136] The reason why a certain number or more of the above-mentioned specific atoms are contained is to increase the dry etching rate of the protective film.

[0137]

[0138] [In formula (1), Z1 includes a nitrogen-containing heterocyclic ring, U is a monovalent organic group represented by the following formula (2), and p represents an integer of 2 to 4.]

[0139]

[0140] [In formula (2), R1 represents a single bond or an alkylene group having 1 to 4 carbon atoms, A1 to A3 each independently represent a hydrogen atom, a methyl group or an ethyl group, and X represents -COO-, -OCO-, -O-, -S- or -NR a -Any one of R a represents a hydrogen atom or a methyl group. Y represents a directly bonded or substituted alkylene group having 1 to 4 carbon atoms, R2, R3 and R4 are each a hydrogen atom, or an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 40 carbon atoms which may be substituted, R5 is a hydrogen atom or a hydroxyl group, n represents an integer of 0 or 1, m1 and m2 each independently represent an integer of 0 or 1, and * represents a portion bonded to Z1]

[0141] Preferably, m2 is 1, and more preferably, m1 is 1.

[0142] Most preferably, m1 is 0 when m2 is 1.

[0143] It is preferred that the above Z1 is represented by the following formula (3).

[0144]

[0145] [In formula (3), Q3 represents the following formula (4), formula (5) or formula (6).]

[0146]

[0147] [In formula (4), formula (5) and formula (6),

[0148] R 11 , R 12 , R 13 and R 14Each independently represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms which may be interrupted by an oxygen atom or a sulfur atom, an alkenyl group having 2 to 10 carbon atoms which may be interrupted by an oxygen atom or a sulfur atom, an alkynyl group having 2 to 10 carbon atoms which may be interrupted by an oxygen atom or a sulfur atom, a benzyl group or a phenyl group, and the phenyl group may be substituted with at least one monovalent functional group selected from the group consisting of an alkyl group having 1 to 6 carbon atoms, a halogen atom, an alkoxy group having 1 to 10 carbon atoms, a nitro group, a cyano group and an alkylthio group having 1 to 6 carbon atoms.

[0149] R 15 represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms which may be interrupted by an oxygen atom or a sulfur atom and which may be substituted by a hydroxyl group, an alkenyl group having 3 to 10 carbon atoms which may be interrupted by an oxygen atom or a sulfur atom, an alkynyl group having 3 to 10 carbon atoms which may be interrupted by an oxygen atom or a sulfur atom, a benzyl group, or a phenyl group, wherein the phenyl group may be substituted by at least one monovalent functional group selected from an alkyl group having 1 to 6 carbon atoms, a halogen atom, an alkoxy group having 1 to 10 carbon atoms, a nitro group, a cyano group, an alkylthio group having 1 to 6 carbon atoms, and a monovalent organic group represented by U in formula (1). * represents a portion bonded to U. ]

[0150] Preferably, the above R 15 It is an alkyl group having 1 to 10 carbon atoms or a monovalent organic group represented by U in the formula (1).

[0151] Preferably, the above R 11 and R 12 Each independently represents an alkyl group having 1 to 10 carbon atoms.

[0152] Preferably, X is -S-. Preferably, Y is a methylene group.

[0153] It is preferred that the protective film-forming composition further contain an acid compound and / or a cross-linking agent.

[0154] It is preferred that the protective film-forming composition further contain a surfactant.

[0155] The acid catalyst, the content of the acid catalyst, and the organic solvent are the same as those of the above-mentioned resist underlayer film-forming composition.

[0156] The solid content of the protective film forming composition of the present invention is usually 0.1 to 70% by mass, preferably 0.1 to 60% by mass. The solid content is the content ratio of all components after removing the solvent from the protective film forming composition. The proportion of the polymer in the solid content is preferably in the order of 1 to 100% by mass, 1 to 99.9% by mass, 50 to 99.9% by mass, 50 to 95% by mass, and 50 to 90% by mass.

[0157] <Cross-linking agent>

[0158] The protective film-forming composition of the present invention may contain a crosslinking agent. The crosslinking agent is the same as that of the resist underlayer film-forming composition described above.

[0159] <Surfactant>

[0160] The protective film forming composition of the present invention may contain a surfactant in order to improve the coating properties on a semiconductor substrate. The surfactant is the same as that of the resist underlayer film forming composition.

[0161] <Resist underlayer film, protective film, substrate with resist pattern, and method for manufacturing semiconductor device>

[0162] Hereinafter, a method for producing a substrate with a resist pattern and a method for producing a semiconductor device using the resist underlayer film-forming composition (protective film-forming composition) according to the present invention will be described.

[0163] The substrate with a resist pattern according to the present invention can be produced by applying the resist underlayer film-forming composition (protective film-forming composition) described above on a semiconductor substrate and firing the coating.

[0164] Examples of semiconductor substrates to which the resist underlayer film-forming composition (protective film-forming composition) of the present invention is applied include silicon wafers, germanium wafers, and compound semiconductor wafers such as gallium arsenide, indium phosphide, gallium nitride, indium nitride, and aluminum nitride.

[0165] In the case of using a semiconductor substrate having an inorganic film formed on the surface, the inorganic film is formed, for example, by ALD (atomic layer deposition) method, CVD (chemical vapor deposition) method, reactive sputtering method, ion plating method, vacuum evaporation method, spin coating method (spin-on glass: SOG). Examples of the inorganic film include polysilicon film, silicon oxide film, silicon nitride film, silicon oxynitride film, borophosphosilicate glass (BPSG, Boro-Phospho Silicate Glass) film, titanium nitride film, titanium oxynitride film, tungsten nitride film, gallium nitride film, and gallium arsenide film. The semiconductor substrate may be a height difference substrate having so-called through holes (holes), grooves (grooves), etc. For example, if the through hole is viewed from above, it is roughly circular in shape, and the diameter of the roughly circular circle is, for example, 1nm to 20nm, and the depth is 50nm to 500nm. The groove, such as the groove (the concave part of the substrate), has a width of 2nm to 20nm and a depth of 50nm to 500nm. The resist underlayer film forming composition (protective film forming composition) of the present application has a small theoretical average molecular weight and average particle size of the compound contained in the composition, so the composition can be embedded without defects such as voids in the above-mentioned high-height substrate. For the next step of semiconductor manufacturing (wet etching / dry etching of semiconductor substrates, resist pattern formation), the absence of defects such as voids is an important characteristic.

[0166] On such a semiconductor substrate, the resist lower film forming composition (protective film forming composition) of the present invention is applied by a suitable coating method such as a spin coater or a coater. Then, the resist lower film (protective film) is formed by baking using a heating means such as a hot plate. As baking conditions, it is appropriately selected from a baking temperature of 100°C to 400°C and a baking time of 0.3 minutes to 60 minutes. Preferably, the baking temperature is 120°C to 350°C, and the baking time is 0.5 minutes to 30 minutes, and more preferably, the baking temperature is 150°C to 300°C, and the baking time is 0.8 minutes to 10 minutes. The thickness of the protective film formed is, for example, 0.001 μm to 10 μm, preferably 0.002 μm to 1 μm, more preferably 0.005 μm (5 nm) to 0.5 μm (500 nm), 0.05 μm (50 nm) to 0.3 μm (300 nm), 0.05 μm (50 nm) to 0.2 μm (200 nm). When the temperature during baking is lower than the above range, crosslinking sometimes becomes insufficient, and it is difficult to obtain the resistance of the formed resist lower film (protective film) to the resist solvent or alkaline hydrogen peroxide solution. On the other hand, when the temperature during baking is higher than the above range, the resist lower film (protective film) is sometimes decomposed by heat.

[0167] Exposure is performed through a mask (intermediate mask) for forming a predetermined pattern, using, for example, i-rays, KrF excimer lasers, ArF excimer lasers, EUV (extreme ultraviolet rays) or EB (electron beams). An alkaline developer is used for development, and is appropriately selected from a development temperature of 5°C to 50°C and a development time of 10 seconds to 300 seconds. As an alkaline developer, for example, an aqueous solution of an inorganic base such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, ammonia water, a primary amine such as ethylamine, n-propylamine, a secondary amine such as diethylamine, di-n-butylamine, a tertiary amine such as triethylamine, methyldiethylamine, an alcohol amine such as dimethylethanolamine, triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, a quaternary ammonium salt such as choline, a cyclic amine such as pyrrole and piperidine, etc. can be used. Furthermore, an appropriate amount of an alcohol such as isopropyl alcohol, a nonionic surfactant, etc. can also be added to the aqueous solution of the above-mentioned alkali and used. Among them, preferred developer is quaternary ammonium salt, more preferably tetramethylammonium hydroxide and choline. Further, surfactants etc. may be added to these developers. Alternatively, an organic solvent such as butyl acetate may be used instead of an alkaline developer to develop the portion of the photoresist where the alkali dissolution rate is not increased.

[0168] Next, the resist underlayer film (protective film) is dry-etched using the formed resist pattern as a mask. At this time, if the inorganic film is formed on the surface of the semiconductor substrate used, the surface of the inorganic film is exposed, and if the inorganic film is not formed on the surface of the semiconductor substrate used, the surface of the semiconductor substrate is exposed.

[0169] Furthermore, by using the resist underlayer film (protective film) after dry etching (when a resist pattern remains on the resist underlayer film / protective film, the resist pattern is also used) as a mask, wet etching is performed using a semiconductor wet etching solution to form a desired pattern.

[0170] As the semiconductor wet etching solution, a general chemical solution used for etching a semiconductor wafer can be used, and for example, either an acidic substance or an alkaline substance can be used.

[0171] Examples of the acidic substance include hydrogen peroxide, hydrofluoric acid, ammonium fluoride, acidic ammonium fluoride, ammonium hydrogen fluoride, buffered hydrofluoric acid, hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, and a mixed solution thereof.

[0172] As a substance showing alkalinity, an alkaline hydrogen peroxide solution obtained by mixing an organic amine such as ammonia, sodium hydroxide, potassium hydroxide, sodium cyanide, potassium cyanide, triethanolamine with hydrogen peroxide solution to make the pH alkaline can be cited. As a specific example, SC-1 (ammonia-hydrogen peroxide solution) can be cited. In addition, a substance capable of making the pH alkaline, for example, a substance capable of making the pH alkaline by mixing urea with hydrogen peroxide solution, causing thermal decomposition of urea by heating to generate ammonia, and finally making the pH alkaline can also be used as a wet etching solution.

[0173] Among them, acidic hydrogen peroxide water or alkaline hydrogen peroxide water is preferred.

[0174] These liquids may contain additives such as surfactants.

[0175] The use temperature of the semiconductor wet etching solution is preferably 25° C. to 90° C., more preferably 40° C. to 80° C. The wet etching time is preferably 0.5 minute to 30 minutes, more preferably 1 minute to 20 minutes.

[0176] Example

[0177] Next, the present invention will be specifically described with reference to synthesis examples and working examples, but the present invention is not limited thereto.

[0178] The weight average molecular weight of the polymers shown in the following synthesis examples of this specification is the measurement result obtained by gel permeation chromatography (hereinafter, abbreviated as GPC). The measurement was performed using a GPC apparatus manufactured by Tosoh Corporation, and the measurement conditions and the like are as follows.

[0179] Column temperature: 40°C

[0180] Flow rate: 0.6mL / min

[0181] Eluent: N,N-dimethylformamide (DMF)

[0182] Standard sample: Polystyrene (Tosoh Corporation)

[0183] <Synthesis example 1>

[0184] 4.00 g of 1,3,4,6-(tetraglycidyl) glycoluril (product name: TG-G, manufactured by Shikoku Chemical Industry Co., Ltd.), 6.26 g of 1-thioglycerol (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), and tetrabutyl bromide were added. A reaction flask containing 43.26 g of propylene glycol monomethyl ether was added to 0.54 g of propylene glycol monomethyl ether (manufactured by Hokko Chemical Co., Ltd.) and heated and stirred at 105° C. for 22 hours under a nitrogen atmosphere. The obtained reaction product corresponds to formula (X-1), has a theoretical molecular weight of 799, and a weight average molecular weight Mw measured by GPC in terms of polystyrene is 980.

[0185]

[0186] <Synthesis example 2>

[0187] 5.00 g of triglycidyl isocyanuric acid (product name TEPIC, manufactured by Nissan Chemical Co., Ltd.), 5.45 g of 1-thioglycerol (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), and tetrabutyl bromide were added. A reaction flask containing 42.68 g of propylene glycol monomethyl ether was added to 0.21 g of propylene glycol monomethyl ether (manufactured by Hokko Chemical Co., Ltd.) and heated and stirred at 105° C. for 23 hours under a nitrogen atmosphere. The obtained reaction product corresponds to formula (X-2), has a theoretical molecular weight of 621, and a weight average molecular weight Mw measured by GPC in terms of polystyrene is 870.

[0188]

[0189] <Synthesis example 3>

[0190] 16.00 g of methyl isocyanurate diglycidyl (product name: MeDGIC, manufactured by Shikoku Chemical Industry Co., Ltd., 28.8 wt% propylene glycol monomethyl ether solution), 3.88 g of 1-thioglycerol (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), and tetrabutyl bromide were added. A reaction flask containing 24.52 g of propylene glycol monomethyl ether was added to 0.45 g of propylene glycol monomethyl ether (manufactured by Hokko Chemical Co., Ltd.) and heated and stirred at 105° C. for 18 hours under a nitrogen atmosphere. The obtained reaction product corresponds to formula (X-3), has a theoretical molecular weight of 471, and a weight average molecular weight Mw measured by GPC in terms of polystyrene is 600.

[0191]

[0192] <Synthesis example 4>

[0193] A solution of 3.00 g of glycerol monomethacrylate (product name: Brenma GLM, manufactured by NOF Corporation), 0.90 g of 2,2'-azobis(methyl isobutyrate) (manufactured by Fujifilm Wako Pure Chemicals Co., Ltd.), and 16.44 g of propylene glycol monomethyl ether was added to a dropping funnel, and added dropwise to a reaction flask containing 4.11 g of propylene glycol monomethyl ether at 100° C. under a nitrogen atmosphere, and heated and stirred for 15 hours. The resulting reaction product corresponds to formula (X-7), and the weight average molecular weight Mw measured by GPC in terms of polystyrene is 4160.

[0194]

[0195] <Synthesis example 5>

[0196] 11.00 g of diglycidyl methyl isocyanurate (product name: MeDGIC, manufactured by Shikoku Chemical Industry Co., Ltd., 28.8 wt% propylene glycol monomethyl ether solution), 1.16 g of succinic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.53 g of 1-thioglycerol (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), ethyltriphenylphosphine bromide, and 1.5 g of succinic acid (manufactured by Fujifilm Wako Pure Chemical Industry Co., Ltd.) were added to the mixture. A reaction flask containing 12.85 g of propylene glycol monomethyl ether was added to 0.29 g of propylene glycol monomethyl ether (manufactured by Tokyo Chemical Industry Co., Ltd.) and heated and stirred at 100° C. for 18 hours under a nitrogen atmosphere. The obtained reaction product corresponded to the formula (X-8), and the weight average molecular weight Mw measured by GPC in terms of polystyrene was 2800.

[0197]

[0198] <Example 1>

[0199] Pyridine was added to 8.22 g of a solution (solid content: 15.5 wt%) of the reaction product of the above formula (X-1). 0.06 g of trifluoromethanesulfonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.01 g of a surfactant (product name: Megafac R-40, manufactured by DIC Corporation), 18.84 g of propylene glycol monomethyl ether, and 2.87 g of propylene glycol monomethyl ether acetate were prepared into a solution. The solution was filtered using a polyethylene microfilter with a pore size of 0.02 μm to prepare a composition for forming a resist underlayer film (protective film).

[0200] <Example 2>

[0201] Pyridine was added to 7.12 g of a solution (solid content: 17.8 wt%) of the reaction product of the above formula (X-2). 0.06 g of trifluoromethanesulfonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.01 g of a surfactant (product name: Megafac R-40, manufactured by DIC Corporation), 19.90 g of propylene glycol monomethyl ether, and 2.87 g of propylene glycol monomethyl ether acetate were prepared into a solution. The solution was filtered using a polyethylene microfilter with a pore size of 0.02 μm to prepare a composition for forming a resist underlayer film (protective film).

[0202] <Example 3>

[0203] Pyridine was added to 7.12 g of a solution (solid content: 17.9 wt%) of the reaction product of the above formula (X-3). 0.06 g of trifluoromethanesulfonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.01 g of a surfactant (product name: Megafac R-40, manufactured by DIC Corporation), 19.94 g of propylene glycol monomethyl ether, and 2.87 g of propylene glycol monomethyl ether acetate were prepared into a solution. The solution was filtered using a polyethylene microfilter with a pore size of 0.02 μm to prepare a composition for forming a resist underlayer film (protective film).

[0204] <Example 4>

[0205] To 6.32 g of a solution (solid content: 17.8 wt%) of the reaction product of the above formula (X-2), 0.17 g of 3,3',5,5'-tetrakis(methoxymethyl)-4,4'-dihydroxybiphenyl (product name: TMOM-BP, manufactured by Honshu Chemical Industry Co., Ltd.), pyridine 0.06 g of trifluoromethanesulfonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.01 g of a surfactant (product name: Megafac R-40, manufactured by DIC Corporation), 19.47 g of propylene glycol monomethyl ether, and 2.87 g of propylene glycol monomethyl ether acetate were prepared into a solution. The solution was filtered using a polyethylene microfilter with a pore size of 0.02 μm to prepare a composition for forming a resist underlayer film (protective film).

[0206] <Comparative Example 1>

[0207] Pyridine was added to 4.32 g of a solution (solid content: 13.1 wt%) of the reaction product of the above formula (X-7). 0.03 g of trifluoromethanesulfonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.01 g of a surfactant (product name: Megafac R-40, manufactured by DIC Corporation), 9.21 g of propylene glycol monomethyl ether, and 1.44 g of propylene glycol monomethyl ether acetate were prepared into a solution. The solution was filtered using a polyethylene microfilter with a pore size of 0.02 μm to prepare a composition for forming a resist underlayer film (protective film).

[0208] <Comparative Example 2>

[0209] To 6.09 g of a solution (solid content: 17.5 wt%) of the reaction product of the above formula (X-8), 0.21 g of 3,3',5,5'-tetrakis(methoxymethyl)-4,4'-dihydroxybiphenyl (product name: TMOM-BP, manufactured by Honshu Chemical Industry Co., Ltd.), pyridine 0.01 g of 4-hydroxybenzenesulfonate, 0.01 g of a surfactant (product name: Megafac R-40, manufactured by DIC Corporation), 20.82 g of propylene glycol monomethyl ether, and 2.87 g of propylene glycol monomethyl ether acetate were mixed to prepare a solution. The solution was filtered using a polyethylene microfilter having a pore size of 0.02 μm to prepare a composition for forming a resist underlayer film (protective film).

[0210] [Resist solvent resistance test]

[0211] The compositions for forming the resist underlayer film (protective film) prepared in Examples 1 to 4 and Comparative Examples 1 to 2 were each applied (spin-coated) on a silicon wafer using a spin coater. The coated silicon wafer was heated on a hot plate at 220°C for 1 minute to form a film (protective film) with a thickness of 100 nm. Next, in order to confirm the resist solvent resistance of the protective film, the silicon wafer after the protective film was formed was immersed in a solvent obtained by mixing propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate in a weight ratio of 7:3 for 1 minute, and then baked at 100°C for 30 seconds after spin drying. The film thickness of the protective film before and after immersion in the mixed solvent was measured using an optical interference film thickness meter (product name: Nanospec 6100, manufactured by Nanometriks Japan Co., Ltd.).

[0212] The evaluation of the resist solvent resistance was performed by calculating the film thickness reduction rate (%) of the protective film removed by solvent immersion using the calculation formula ((film thickness before solvent immersion) - (film thickness after solvent immersion)) ÷ (film thickness before solvent immersion) × 100. The results are shown in Table 1. In addition, if the film thickness reduction rate is about 1% or less, it can be said that the resist solvent resistance is sufficient.

[0213] [Table 1]

[0214] Table 1

[0215]

[0216] According to the above results, the film thickness change of the resist underlayer film (protective film) of Examples 1 to 4 and Comparative Examples 1 and 2 after immersion in the resist solvent is also very small. Therefore, the protective film-forming composition of Examples 1 to 4 has sufficient resist solvent resistance to function as a resist underlayer film.

[0217] [Resistance test to alkaline hydrogen peroxide solution]

[0218] As an evaluation of resistance to alkaline hydrogen peroxide water, the resist underlayer film forming composition (protective film forming composition) prepared in Examples 1 to 4 and Comparative Examples 1 to 2 was applied to a titanium nitride (TiN) vapor-deposited substrate with a film thickness of 50 nm, and heated at 220°C for 1 minute to form a protective film with a film thickness of 100 nm. Next, 28% ammonia water, 33% hydrogen peroxide, and water were mixed in a weight ratio of 1:4:20 to prepare alkaline hydrogen peroxide water. The TiN vapor-deposited substrate coated with the resist underlayer film forming composition (protective film forming composition) was immersed in the alkaline hydrogen peroxide water heated to 50°C, and the time from just after immersion to when the protective film was completely peeled off from the substrate (peeling time) was measured. The results of the resistance test to alkaline hydrogen peroxide water are shown in Table 2. In addition, the longer the peeling time, the higher the resistance to the wet etching solution using alkaline hydrogen peroxide water.

[0219] [Table 2]

[0220] Table 2

[0221]

[0222] The results in the above table show that the coating films produced using the resist underlayer film-forming compositions (protective film-forming compositions) prepared in Examples 1 to 4 have sufficient resistance to alkaline aqueous hydrogen peroxide solutions. That is, it is known that these coating films can serve as protective films against alkaline aqueous hydrogen peroxide solutions. In addition, Examples 1 to 4 can be said to have good resistance to wet etching solutions using alkaline aqueous hydrogen peroxide solutions compared to Comparative Examples 1 to 2. Therefore, Examples 1 to 4 are more useful as protective films against wet etching solutions for semiconductors because they have good resistance to alkaline aqueous hydrogen peroxide solutions compared to Comparative Examples 1 to 2.

[0223] [Evaluation of etching selectivity]

[0224] As an evaluation of the etching selectivity, the resist underlayer film forming composition (protective film forming composition) prepared in the above-mentioned Examples 1 to 4 and Comparative Example 1 was coated on a silicon wafer and heated at 220°C for 1 minute to form a protective film with a film thickness of 100 nm. Next, the formed protective film was dry-etched using a dry etching device (product name: RIE-10NR, manufactured by Samco Co., Ltd.) using chlorine gas and a mixed gas of nitrogen and hydrogen, thereby measuring the dry etching rate ratio of the protective film (dry etching rate selectivity). The results of the etching selectivity are shown in Table 3. In addition, the larger the etching selectivity, the faster the dry etching rate.

[0225] [Table 3]

[0226] Table 3

[0227]

[0228] According to the above results, Examples 1 to 4 have a higher dry etching selectivity than Comparative Example 1, so it can be said that the dry etching speed is fast. That is, Examples 1 to 4 can shorten the dry etching time required to remove the protective film, thereby reducing damage to the base substrate and are therefore useful.

[0229] That is, Examples 1 to 4 have better resistance to semiconductor wet etching solutions using alkaline hydrogen peroxide solution than Comparative Examples 1 and 2, and have faster etching rates than Comparative Example 1. Therefore, according to the present invention, a protective film-forming composition having both high resistance to wet etching solutions and high etching rates can be provided.

[0230] [Evaluation of optical parameters]

[0231] The resist underlayer film-forming composition (protective film-forming composition) prepared in Examples 1 to 3 and Comparative Examples 1 to 2 described in this specification was applied (spin-coated) on a silicon wafer using a spin coater. The coated silicon wafer was heated on a hot plate at 220° C. for 1 minute to form a protective film-forming composition (film thickness 100 nm). Furthermore, the protective film-forming composition was measured for n value (refractive index) and k value (attenuation coefficient or absorption coefficient) at a wavelength of 193 nm using a spectroscopic ellipsometer (product name: VUV-VASE VU-302, manufactured by JA Woollam). The results of the measurement of optical parameters are shown in Table 4.

[0232] [Table 4]

[0233] Table 4

[0234]

[0235] [Determination of the amount of sublimated material]

[0236] The determination of the amount of sublimation is carried out using the sublimation amount measuring device described in the pamphlet of International Publication No. 2007 / 111147. First, the resist underlayer film-forming composition prepared in Examples 1 to 3 and Comparative Examples 1 to 2 is applied to a silicon wafer substrate having a diameter of 4 inches using a spin coater in a manner such that the film thickness becomes 100 nm. The wafer coated with the resist underlayer film is placed on the above-mentioned sublimation amount measuring device integrated with a hot plate, baked for 120 seconds, and the sublimation is captured in a QCM (Quartz Crystal Microbalance) sensor, i.e., a crystal resonator with electrodes formed. The QCM sensor can measure minute mass changes by utilizing the property that if sublimation is attached to the surface (electrode) of the crystal resonator, the frequency of the crystal resonator changes (decreases) according to its mass.

[0237] The detailed measurement procedure is as follows. The heating plate of the sublimation amount measuring device is heated to the measurement temperature listed in Table 5, and the pump flow rate is set to 2.4 m 3 / s, and the first 60 seconds were left for stabilization of the device. Then, the wafer coated with the resist lower film was quickly placed on the hot plate from the slide port, and the sublimation was captured from the 60-second moment to the 180-second moment (120 seconds). In addition, the flow attachment (detection part) connecting the QCM sensor and the capture funnel part of the sublimation amount measuring device was used without a nozzle, so the air flow flowed in from the flow path (diameter: 32mm) of the chamber unit with a distance of 30mm from the sensor (crystal resonator) without squeezing the air flow. In addition, the QCM sensor used a material (AlSi) with silicon and aluminum as the main components as the electrode, the diameter of the crystal resonator (sensor diameter) was 14mm, the diameter of the electrode on the surface of the crystal resonator was 5mm, and the resonance frequency was 9MHz.

[0238] The obtained frequency change is converted into grams from the inherent value of the crystal resonator used for the measurement, so that the relationship between the amount of sublimation of a wafer coated with a resist lower film and the passage of time is clarified. In addition, the first 60 seconds is a time band for placing the device for stabilization (without placing the wafer), and the measured value from the moment of 60 seconds to the moment of 180 seconds when the wafer is placed on the hot plate is a measured value related to the amount of sublimation of the wafer. The amount of sublimation of the resist lower film quantified from the device is shown in Table 5 as a sublimation amount ratio. In addition, the sublimation amount is expressed by converting the value of Comparative Example 1 to 1.

[0239] [Table 5]

[0240] Table 5

[0241]

[0242] [Evaluation of embedding performance of embedding performance evaluation substrate]

[0243] A silicon substrate having a 50nm groove (L(line) / S(gap)) formed thereon was coated with a composition for forming an anti-etching lower film, which was prepared by depositing a silicon oxide film of about 20nm by the CVD method and forming a silicon oxide film on the surface of the groove (after deposition of the silicon oxide film: 10nm groove (L(line) / S(gap)). Then, the composition was heated at 220°C on a hot plate for 1 minute to form an anti-etching lower film with a film thickness of about 100nm. The cross-sectional shape of the substrate having a groove coated with the composition for forming an anti-etching lower film obtained in Example 2 was observed using a scanning electron microscope (SEM). Figure 1 ), thereby evaluating the embedding property. It is known that in the resist underlayer film forming composition of the embodiment, the composition embeds into the 10nm groove (L (line) / S (gap)) substrate as the gap of the silicon oxide film without generating pores (voids, etc.) ( Figure 2 ).

[0244] Industrial Availability

[0245] The resist underlayer film-forming composition or protective film-forming composition of the present invention is useful as a resist underlayer film in a semiconductor photolithography process and further as a protective film when a semiconductor substrate is subjected to wet etching.

Claims

1. A resist underlayer film-forming composition comprising: a compound having a theoretical molecular weight of 999 or less, which is a reaction product of any one of the compounds represented by the following formulae (a) and (c) to (aj) and 1-thioglycerol; and an organic solvent, 2 . The resist underlayer film-forming composition according to claim 1 , further comprising at least one of an acid compound and a cross-linking agent. 3 . The resist underlayer film forming composition according to claim 1 , further comprising a surfactant.

4. A resist underlayer film, characterized in that: A fired product of a coating film formed from the resist underlayer film forming composition according to any one of claims 1 to 3.

5. A composition for forming a protective film for a semiconductor wet etching solution, comprising: a compound which is a reaction product of any one of the compounds represented by the following formulas (a) and (c) to (aj) and 1-thioglycerol, having a theoretical molecular weight of 999 or less and containing 2 or more nitrogen atoms and 6 or more oxygen atoms in the molecule; and an organic solvent, 6 . The protective film-forming composition according to claim 5 , further comprising at least one of an acid compound and a crosslinking agent.

7. A protective film, characterized in that: A fired product of a coating film formed from the protective film-forming composition according to any one of claims 5 to 6.

8. A method for manufacturing a substrate with a resist pattern, characterized in that: The method comprises the following steps: a step of applying the composition for forming an anti-etching underlayer film according to any one of claims 1 to 3 on a semiconductor substrate and firing it to form a anti-etching underlayer film; a step of forming a resist film on the resist underlayer film, and then exposing and developing it to form a resist pattern. The method for manufacturing a substrate with a resist pattern is used for manufacturing semiconductors.

9. A method for manufacturing a semiconductor device, comprising the following steps: forming a resist underlayer film on a semiconductor substrate whose surface can form an inorganic film using the resist underlayer film forming composition described in any one of claims 1 to 3, forming a resist pattern on the resist underlayer film, dry-etching the resist underlayer film using the resist pattern as a mask to expose the surface of the inorganic film or the semiconductor substrate, and etching the inorganic film or the semiconductor substrate using the dry-etched resist underlayer film as a mask.

10. A method for manufacturing a semiconductor device, comprising the following steps: forming a protective film on a semiconductor substrate on which an inorganic film can be formed using the protective film-forming composition described in any one of claims 5 to 6, forming a resist pattern on the protective film, dry-etching the protective film using the resist pattern as a mask to expose the surface of the inorganic film or the semiconductor substrate, and wet-etching and washing the inorganic film or the semiconductor substrate using a semiconductor wet etching solution using the dry-etched protective film as a mask.

Images