Chemical-resistant protective film

Abstract

The present invention provides a protective film-forming composition that provides good protection against wet etching solutions during semiconductor substrate processing, and a method for manufacturing a substrate with a protective film using the composition. [Solution] A protective film-forming composition for semiconductor wet etching solutions is used, comprising (A) a polymer having a unit structure represented by formula (1-1), (B) a compound or polymer having a phenolic hydroxyl group other than catechol, (C) a thermal acid generator, and (D) a solvent. TIFF2026108745000052.tif65161

Description

[Technical Field]

[0001] The present invention relates to a composition for forming a protective film with particularly excellent resistance to semiconductor wet etching solutions in a lithography process for semiconductor manufacturing. The invention also relates to a protective film formed from the composition, a method for manufacturing a substrate with a resist pattern to which the protective film is applied, and a method for manufacturing a semiconductor device. [Background technology]

[0002] In semiconductor manufacturing, the lithography process, which involves forming a resist underlayer film between a substrate and a resist film formed on it to create a resist pattern of a desired shape, is widely known. After forming the resist pattern, the substrate is processed, mainly using dry etching, although wet etching may be used depending on the type of substrate. Patent Document 1 discloses a resist underlayer film material that has resistance to alkaline hydrogen peroxide solution. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2018-173520 [Overview of the project] [Problems that the invention aims to solve]

[0004] When forming a protective film on a semiconductor substrate using a protective film-forming composition, and then processing the underlying substrate by wet etching using the protective film as an etching mask, the protective film is required to have good masking function against semiconductor wet etching solutions (i.e., the masked portion can protect the substrate).

[0005] Furthermore, there is a need for protective film-forming compositions that exhibit good coverage even on so-called stepped substrates, have small differences in film thickness after embedding, and can form a flat film.

[0006] Conventionally, in order to develop resistance to SC-1 (ammonia-hydrogen peroxide solution), which is a type of wet etching chemical solution, a method of applying a low molecular weight compound (for example, gallic acid) as an additive has been used, but there is a limit to solving the above problems.

[0007] Furthermore, the protective film used for the above purpose is expected to have a function as an underlayer film for the resist to solve troubles (such as defective shape) during the formation of a so-called resist pattern.

[0008] An object of the present invention is to solve the above problems.

Means for Solving the Problems

[0009] The present invention includes the following.

[0010] [1] (A) A polymer having a unit structure represented by the following formula (1-1):

Chemical formula

[0011] [2] The protective film-forming composition according to [1], wherein the (B) compound or polymer has two or more phenolic hydroxy groups.

[0012] [3] The protective film-forming composition according to [1] or [2], wherein the (B) compound or polymer is represented by the following formula (2-1): [Chemical formula] (In the formula, R 2 and T 2 each independently represent a halogeno group, a carboxy group, a nitro group, a cyano group, a methylenedioxy group, an acetoxy group, a methylthio group, an alkoxy group having 1 to 9 carbon atoms, an amino group optionally substituted with an alkyl group having 1 to 3 carbon atoms, a hydroxy group or an alkyl group having 1 to 10 carbon atoms optionally substituted with a halogeno group. A 1 and A 2 each independently represent an alkylene group having 1 1 to 10 carbon atoms, a divalent organic group derived from a bicyclic compound, a biphenylene group or a divalent organic group represented by -CT 2 T 3 - or a combination thereof, and T 3 represents a hydrogen atom or a monovalent group represented by the formula (2-1-a): [Chemical formula] (In the formula (2-1-a), * represents the bonding site with the carbon atom to which T 3 is bonded. a represents an integer of 1 to 6. n3 to n5 each independently represent an integer of 0 to 2. r2 represents an integer of 0 to 3. m1 and m2 each independently represent a number of 0 to 10,000,000.)

[0013] [4] The protective film-forming composition according to [3], wherein m1, n3 to n5 and r2 are 0 and m² is 1.

[0014] [5] The protective film-forming composition according to [1] or [2], wherein the compound or polymer of (B) is a compound represented by the following formula (2-2): [ka] (In the formula, R 3 This represents a halogen group, carboxyl group, nitro group, cyano group, methylenedioxy group, acetoxy group, methylthio group, alkoxy group having 1 to 9 carbon atoms, an amino group which may be substituted with an alkyl group having 1 to 3 carbon atoms, a hydroxyl group, or an alkyl group having 1 to 10 carbon atoms which may be substituted with a halogen group. 1 (The characters represent a single bond, an oxygen atom, a sulfur atom, a sulfonyl group, a carbonyl group, an imino group, an arylene group with 6 to 40 carbon atoms, or an alkylene group with 1 to 10 carbon atoms that may be substituted with a halogeno group. a represents an integer from 1 to 6. n6 represents an integer from 0 to 2. r3 represents an integer from 0 to 3.)

[0015] [6] The protective film-forming composition according to [1] or [2], wherein the compound (B) or polymer is a polymer containing a unit structure represented by the following formula (3-1): [ka] (In the formula, T 4 R represents an alkyl group having 1 to 10 carbon atoms, which may be substituted with a halogen group. 4 represents a halogen group, carboxyl group, nitro group, cyano group, methylenedioxy group, acetoxy group, methylthio group, alkoxy group with 1 to 9 carbon atoms, amino group which may be substituted with an alkyl group with 1 to 3 carbon atoms, hydroxyl group, or alkyl group with 1 to 10 carbon atoms which may be substituted with a halogen group. r4 represents an integer from 0 to 3. n7 represents an integer from 0 to 2. a represents an integer from 1 to 6.

[0016] A protective film for semiconductor wet etching solutions, characterized in that it is a fired product of a coating film made from any one of the protective film-forming compositions described in [7] [1] to [6].

[0017] [8] (A) Polymers having a unit structure represented by the following formula (1-1): [ka] (In formula (1-1), Ar represents a benzene ring, a naphthalene ring, or an anthracene ring, R 1 n1 represents a hydroxyl group, a mercapto group which may be protected by a methyl group, an amino group which may be protected by a methyl group, a halogeno group, or an alkyl group having 1 to 10 carbon atoms which may be substituted or interrupted by a heteroatom or substituted by a hydroxyl group, n1 represents an integer from 0 to 3, L 1 represents a single bond or an alkylene group with 1 to 10 carbon atoms, E represents an epoxy group, and T 1 When n2=1, it represents an alkylene group having 1 to 10 carbon atoms, which may be interrupted by a single bond, an ether bond, an ester bond, or an amide bond. 1 (When n²=2, it represents a nitrogen atom or an amide bond.) (B) Compounds or polymers having phenolic hydroxyl groups other than catechol, (C) Thermal acid generator, and (D) Solvent, A resist underlayer film forming composition comprising the above.

[0018] A resist underlayer film characterized by being a fired product of a coated film made from the resist underlayer film forming composition described in [9] [8].

[0019] A method for manufacturing a substrate with a protective film, characterized by being used in the manufacture of a semiconductor, comprising the step of applying a protective film-forming composition described in any one of items [1] to [6] onto a semiconductor substrate having steps and firing it to form a protective film.

[0020] A method for manufacturing a resist-patterned substrate, comprising the steps of: applying a protective film composition described in any one of items [1] to [6] or a resist underlayer film forming composition described in [8] onto a semiconductor substrate and firing it to form a protective film as a resist underlayer film; forming a resist film on the protective film, and then exposing and developing it to form a resist pattern, the method being used in the manufacture of a semiconductor.

[0021]

[12] A method for manufacturing a semiconductor device, comprising the steps of forming a protective film on a semiconductor substrate which may have an inorganic film formed on its surface using a protective film forming composition according to any one of [1] 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 inorganic film or the surface of the semiconductor substrate, and wet etching and cleaning the inorganic film or the semiconductor substrate using a semiconductor wet etching solution, using the dry-etched protective film as a mask.

[0022]

[13] A method for manufacturing a semiconductor device, comprising the steps of forming a resist underlayer film on a semiconductor substrate which may have an inorganic film formed on its surface using the resist underlayer film forming composition described in [8], 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. [Effects of the Invention]

[0023] The protective film-forming composition of the present invention is required to have a good balance of the following properties in the lithography process of semiconductor manufacturing: (1) having good masking function against wet etching solution during substrate processing, (2) further reducing damage to the protective film or resist underlayer film during substrate processing by low dry etching rate, (3) excellent planarization of stepped substrates, and (4) excellent embedding properties in fine trench pattern substrates. By having a good balance of these properties (1) to (4), microfabrication of semiconductor substrates can be easily performed. [Modes for carrying out the invention]

[0024] <Protective film-forming composition for semiconductor wet etching solutions> The protective film-forming composition for semiconductor wet etching solutions of the present invention is (A) Polymers having a unit structure represented by the following formula (1-1): [ka] (In formula (1-1), Ar represents a benzene ring, a naphthalene ring, or an anthracene ring, R 1 n1 represents a hydroxyl group, a mercapto group which may be protected by a methyl group, an amino group which may be protected by a methyl group, a halogeno group, or an alkyl group having 1 to 10 carbon atoms which may be substituted or interrupted by a heteroatom or substituted by a hydroxyl group, n1 represents an integer from 0 to 3, L 1 represents a single bond or an alkylene group with 1 to 10 carbon atoms, E represents an epoxy group, and T 1 When n2=1, it represents an alkylene group having 1 to 10 carbon atoms, which may be interrupted by a single bond, an ether bond, an ester bond, or an amide bond. 1 (When n²=2, it represents a nitrogen atom or an amide bond.) (B) Compounds or polymers having phenolic hydroxyl groups other than catechol, (C) Thermal acid generator, and (D) Solvent, Includes.

[0025] <Polymer (A)> The polymer (A) used in the present invention is a polymer having a unit structure represented by the following formula (1-1): [ka] (In formula (1-1), Ar represents a benzene ring, a naphthalene ring, or an anthracene ring, R 1 n1 represents a hydroxyl group, a mercapto group which may be protected by a methyl group, an amino group which may be protected by a methyl group, a halogeno group, or an alkyl group having 1 to 10 carbon atoms which may be substituted or interrupted by a heteroatom or substituted by a hydroxyl group as a substituent on a hydrogen atom contained in the benzene ring, naphthalene ring, or anthracene ring, and n1 represents an integer from 0 to 3, L 1 represents a single bond or an alkylene group with 1 to 10 carbon atoms, E represents an epoxy group, and T 1 When n2=1, it represents an alkylene group having 1 to 10 carbon atoms, which may be interrupted by a single bond, an ether bond, an ester bond, or an amide bond. 1 (When n²=2, it represents a nitrogen atom or an amide bond.)

[0026] The alkyl groups having 1 to 10 carbon atoms include methyl group, ethyl group, n-propyl group, i-propyl group, cyclopropyl group, n-butyl group, i-butyl group, s-butyl group, t-butyl group, cyclobutyl group, 1-methyl-cyclopropyl group, 2-methyl-cyclopropyl group, n-pentyl group, 1-methyl-n-butyl group, 2-methyl-n-butyl group, 3-methyl-n-butyl group, 1,1-dimethyl-n-propyl group, 1,2-dimethyl-n-propyl group, 2,2-dimethyl-n-propyl group, and 1-ethyl-n-propyl group. Group, cyclopentyl group, 1-methyl-cyclobutyl group, 2-methyl-cyclobutyl group, 3-methyl-cyclobutyl group, 1,2-dimethyl-cyclopropyl group, 2,3-dimethyl-cyclopropyl group, 1-ethyl-cyclopropyl group, 2-ethyl-cyclopropyl group, n-hexyl group, 1-methyl-n-pentyl group, 2-methyl-n-pentyl group, 3-methyl-n-pentyl group, 4-methyl-n-pentyl group, 1,1-dimethyl-n-butyl group, 1,2-dimethyl-n-butyl group, 1,3-dimethyl-n-butyl group, 2,2 -dimethyl-n-butyl group, 2,3-dimethyl-n-butyl group, 3,3-dimethyl-n-butyl group, 1-ethyl-n-butyl group, 2-ethyl-n-butyl group, 1,1,2-trimethyl-n-propyl group, 1,2,2-trimethyl-n-propyl group, 1-ethyl-1-methyl-n-propyl group, 1-ethyl-2-methyl-n-propyl group, cyclohexyl group, 1-methyl-cyclopentyl group, 2-methyl-cyclopentyl group, 3-methyl-cyclopentyl group, 1-ethyl-cyclobutyl group, 2-ethyl-cyclobutyl group, 3-ethyl-cyclobutyl group, 1,2-dimethyl-cyclobutyl group, 1,3-dimethyl-cyclobutyl group, 2,2-dimethyl-cyclobutyl group, 2,3-dimethyl-cyclobutyl group, 2,4-dimethyl-cyclobutyl group, 3,3-dimethyl-cyclobutyl group, 1-n-propyl-cyclopropyl group, 2-n-propyl-cyclopropyl group, 1-i-propyl-cyclopropyl group, 2-i-propyl-cyclopropyl group, 1,2,2-trimethyl-cyclopropyl group, 1,2,3-trimethyl-cyclopropyl group, 2,2,Examples include 3-trimethylcyclopropyl group, 1-ethyl-2-methylcyclopropyl group, 2-ethyl-1-methylcyclopropyl group, 2-ethyl-2-methylcyclopropyl group, 2-ethyl-3-methylcyclopropyl group, decyl group, methoxy group, ethoxy group, methoxymethyl group, ethoxymethyl group, methoxyethyl group, ethoxyethyl group, hydroxymethyl group, 1-hydroxyethyl group, 2-hydroxyethyl group, methylamino group, dimethylamino group, diethylamino group, aminomethyl group, 1-aminoethyl group, 2-aminoethyl group, methylthio group, ethylthio group, mercaptomethyl group, 1-mercaptoethyl group, 2-mercaptoethyl group, etc.

[0027] The alkylene groups having 1 to 10 carbon atoms include methylene, ethylene, n-propylene, isopropylene, cyclopropylene, n-butylene, isobutylene, s-butylene, t-butylene, cyclobutylene, 1-methylcyclopropylene, 2-methylcyclopropylene, n-pentylene, 1-methyl-n-butylene, 2-methyl-n-butylene, 3-methyl-n-butylene, 1,1-dimethyl-n-propylene, 1,2-dimethyl-n-propylene, 2,2-dimethyl-n-propylene, and 1-ethyl-n-propylene. Polyethylene group, cyclopentylene group, 1-methyl-cyclobutylene group, 2-methyl-cyclobutylene group, 3-methyl-cyclobutylene group, 1,2-dimethyl-cyclopropylene group, 2,3-dimethyl-cyclopropylene group, 1-ethyl-cyclopropylene group, 2-ethyl-cyclopropylene group, n-hexylene group, 1-methyl-n-pentylene group, 2-methyl-n-pentylene group, 3-methyl-n-pentylene group, 4-methyl-n-pentylene group, 1,1-dimethyl-n-butylene group, 1,2-dimethyl-n-butylene group, 1,3-dimethyl-n-butylene group , 2,2-dimethyl-n-butylene group, 2,3-dimethyl-n-butylene group, 3,3-dimethyl-n-butylene group, 1-ethyl-n-butylene group, 2-ethyl-n-butylene group, 1,1,2-trimethyl-n-propylene group, 1,2,2-trimethyl-n-propylene group, 1-ethyl-1-methyl-n-propylene group, 1-ethyl-2-methyl-n-propylene group, cyclohexylene group, 1-methyl-cyclopentylene group, 2-methyl-cyclopentylene group, 3-methyl-cyclopentylene group, 1-ethyl-cyclobutylene group, 2-ethyl-cyclobutylene n group, 3-ethyl-cyclobutylene group, 1,2-dimethyl-cyclobutylene group, 1,3-dimethyl-cyclobutylene group, 2,2-dimethyl-cyclobutylene group, 2,3-dimethyl-cyclobutylene group, 2,4-dimethyl-cyclobutylene group, 3,3-dimethyl-cyclobutylene group, 1-n-propyl-cyclopropylene group, 2-n-propyl-cyclopropylene group, 1-isopropyl-cyclopropylene group, 2-isopropyl-cyclopropylene group, 1,2,2-trimethyl-cyclopropylene group, 1,2,3-trimethyl-cyclopropylene group, 2,2,Examples include 3-trimethylcyclopropylene group, 1-ethyl-2-methylcyclopropylene group, 2-ethyl-1-methylcyclopropylene group, 2-ethyl-2-methylcyclopropylene group, 2-ethyl-3-methylcyclopropylene group, n-heptylene group, n-octylene group, n-nonylene group, or n-decanylene group.

[0028] The aforementioned R 1 This may be an alkoxy group having 1 to 10 carbon atoms.

[0029] Examples of alkoxy groups with 1 to 10 carbon atoms include methoxy, ethoxy, n-propoxy, i-propoxy, n-butoxy, i-butoxy, s-butoxy, t-butoxy, 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, n-hexyloxy, 1-methyl-n-pentyloxy, 2-methyl-n-pentyloxy, 3-methyl-n-pentyloxy, and 4-methyl-n-pentyloxy. Examples include ethyl-n-pentyloxy group, 1,1-dimethyl-n-butoxy group, 1,2-dimethyl-n-butoxy group, 1,3-dimethyl-n-butoxy group, 2,2-dimethyl-n-butoxy group, 2,3-dimethyl-n-butoxy group, 3,3-dimethyl-n-butoxy group, 1-ethyl-n-butoxy group, 2-ethyl-n-butoxy group, 1,1,2-trimethyl-n-propoxy group, 1,2,2-trimethyl-n-propoxy group, 1-ethyl-1-methyl-n-propoxy group, 1-ethyl-2-methyl-n-propoxy group, n-heptyloxy group, n-octyloxy group, and n-nonyloxy group.

[0030] The unit structure represented by formula (1-1) above may be one type or a combination of two or more types. For example, it may be a copolymer having multiple unit structures in which Ar is of the same type, and copolymers having multiple unit structures in which Ar is of different types, such as a unit structure in which Ar contains a benzene ring and a unit structure in which Ar contains a naphthalene ring, are not excluded from the scope of the present invention.

[0031] The phrase "may be interrupted" means that, in the case of an alkylene group having 2 to 10 carbon atoms, any carbon-carbon bond in the alkylene group is interrupted by a heteroatom (i.e., an ether bond in the case of oxygen, a sulfide bond in the case of sulfur), an ester bond, or an amide bond; and in the case of a methylene group having 1 carbon atom, it means that one of the carbon atoms of the methylene group has a heteroatom (i.e., an ether bond in the case of oxygen, a sulfide bond in the case of sulfur), an ester bond, or an amide bond.

[0032] Said T 1 When n2=1, it represents an alkylene group with 1 to 10 carbon atoms, which may be interrupted by a single bond, an ether bond, an ester bond, or an amide bond, but the combination of an ether bond and a methylene group (i.e., "-T" in formula (1-1)) 1 When -(E)n2 is a glycidyl ether group, it is preferable that it is a combination of an ester bond and a methylene group, or a combination of an amide bond and a methylene group.

[0033] A C1-C10 alkyl group that may be substituted with a heteroatom means that one or more hydrogen atoms of the C1-C10 alkyl group are substituted with a heteroatom (preferably a halogen group).

[0034] Said L 1 represents a single bond or an alkylene group with 1 to 10 carbon atoms, as shown in formula (1-2): [ka] (In formula (1-2), R 2, R 3 R independently represents a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an i-propyl group, a cyclopropyl group, an n-butyl group, an i-butyl group, an s-butyl group, a t-butyl group, and a cyclobutyl group. 2 , R 3 It is preferable that these be represented as R (which may be bonded to each other to form a ring with 3 to 6 carbon atoms). 2 , R 3 Both are hydrogen atoms (that is, CR) 2 R 3 It is preferable that the group is a methylene group.

[0035] The aforementioned halogen group refers to a halogen-X (F, Cl, Br, I) substituted with hydrogen.

[0036] The polymer (A) is not particularly limited as long as it satisfies the unit structure of formula (1-1). It may be manufactured by a method known to the public. Commercial products may also be used. Examples of commercial products include the heat-resistant epoxy novolac resin EOCN® series (manufactured by Nippon Kayaku Co., Ltd.) and the epoxy novolac resin DEN® series (manufactured by Dow Chemical Japan Ltd.).

[0037] The weight-average molecular weight of the polymer (A) is 100 or more, 500 to 200,000, 600 to 50,000, or 700 to 10,000.

[0038] Examples of polymers (A) of the present invention include those having the following unit structure.

[0039] [ka]

[0040] <(B) Compounds or polymers having phenolic hydroxyl groups other than catechol> The compound or polymer (B) having a phenolic hydroxyl group other than catechol is not particularly limited as long as it does not impair the effects of the present invention. Needless to say, the compound or polymer (B) having a phenolic hydroxyl group other than catechol is different from polymer (A).

[0041] The weight-average molecular weight of the compound or polymer (B) having a phenolic hydroxyl group other than the aforementioned catechol is not particularly limited, but is, for example, 300 to 50,000.

[0042] It is preferable that the compound (B) or polymer has two or more phenolic hydroxyl groups.

[0043] [1] Compound or polymer represented by formula (2-1) The compound (B) is preferably represented by the following formula (2-1): [ka] [ka] (In the formula, R 2 and T 2 Each of these independently represents a halogen group, a carboxyl group, a nitro group, a cyano group, a methylenedioxy group, an acetoxy group, a methylthio group, an alkoxy group having 1 to 9 carbon atoms, an amino group which may be substituted with an alkyl group having 1 to 3 carbon atoms, a hydroxyl group, or an alkyl group having 1 to 10 carbon atoms which may be substituted with a halogen group. 1 and A 2 Each of these is independently an alkylene group having 1 to 10 carbon atoms, a divalent organic group derived from a bicyclocyclic compound, a biphenylene group, or -CT 2 T 3 - is a divalent organic group or a combination thereof, T 3 * represents a hydrogen atom or a monovalent group represented by (Formula 2-1-a). * in (Formula 2-1-a) represents T 3This represents the bonding site with the carbon atom to which it is bonded. 'a' represents an integer from 1 to 6. 'n3' to 'n5' each independently represent an integer from 0 to 2. 'r2' represents an integer from 0 to 3. 'm1' and 'm2' each independently represent an integer from 0 to 10,000,000. It is preferable that m1, n3 to n5 and r2 are 0, and m2 is 1.

[0044] The explanations of the halogeno group, alkoxy group, and alkyl group related to formula (2-1) are as described above.

[0045] Examples of the bicyclocyclic ring compound include dicyclopentadiene, substituted dicyclopentadiene, tetracyclo[4.4.0.12,5.17,10]dodeca-3,8-diene, or substituted tetracyclo[4.4.0.12,5.17,10]dodeca-3,8-diene. The substitution means that one or more hydrogen atoms of the bicyclocyclic ring compound are independently substituted with a halogen group, a nitro group, an amino group, or a hydroxyl group, or with an alkyl group having 1 to 10 carbon atoms, or with an aryl group having 6 to 40 carbon atoms, which may be substituted with these groups. A divalent organic group derived from a bicyclocyclic ring compound means a group having two bonds, derived by removing any two hydrogen atoms from the bicyclocyclic ring compound.

[0046] Examples of the aryl group having 6 to 40 carbon atoms include phenyl group, o-methylphenyl group, m-methylphenyl group, p-methylphenyl group, o-chlorophenyl group, m-chlorophenyl group, p-chlorophenyl group, o-fluorophenyl group, p-fluorophenyl group, o-methoxyphenyl group, p-methoxyphenyl group, p-nitrophenyl group, p-cyanophenyl group, α-naphthyl group, β-naphthyl group, o-biphenylyl group, m-biphenylyl group, p-biphenylyl group, 1-anthryl group, 2-anthryl group, 9-anthryl group, 1-phenanthryl group, 2-phenanthryl group, 3-phenanthryl group, 4-phenanthryl group, and 9-phenanthryl group.

[0047] Specific examples of compounds represented by formula (2-1) are listed below.

[0048] [ka] The compounds having a phenolic hydroxyl group other than (B) catechol mentioned above may be the compounds shown below.

[0049] [ka]

[0050] [2] Compound represented by formula (2-2) The compound (B) is a compound having a phenolic hydroxyl group other than (B)catechol, and is not particularly limited as long as it does not impair the effects of the present invention, but it is preferable that the compound (B) is represented by the following formula (2-2): [ka] (In the formula, R 3 This represents a halogen group, carboxyl group, nitro group, cyano group, methylenedioxy group, acetoxy group, methylthio group, alkoxy group having 1 to 9 carbon atoms, an amino group which may be substituted with an alkyl group having 1 to 3 carbon atoms, a hydroxyl group, or an alkyl group having 1 to 10 carbon atoms which may be substituted with a halogen group. 1 (The characters represent a single bond, an oxygen atom, a sulfur atom, a sulfonyl group, a carbonyl group, an imino group, an arylene group with 6 to 40 carbon atoms, or an alkylene group with 1 to 10 carbon atoms that may be substituted with a halogeno group. a represents an integer from 1 to 6. n6 represents an integer from 0 to 2. r3 represents an integer from 0 to 3.) The explanations of the alkoxy group, alkyl group, and halogeno group in formula (2-2) are as described above.

[0051] Arylene groups having 6 to 40 carbon atoms include phenylene group, o-methylphenylene group, m-methylphenylene group, p-methylphenylene group, o-chlorphenylene group, m-chlorphenylene group, p-chlorphenylene group, o-fluorophenylene group, p-fluorophenylene group, o-methoxyphenylene group, p-methoxyphenylene group, p-nitrophenylene group, p-cyanophenylene group, α-naphthylene group, β-naphthylene group, o-biphenylylene group, m-biphenylylene group, p-biphenylylene group, 1-antrylene group, 2-antrylene group, 9-antrylene group, 1-phenanthrylene group, 2-phenanthrylene group, 3-phenanthrylene group, 4-phenanthrylene group, and 9-phenanthrylene group.

[0052] Alkylene groups with 1 to 10 carbon atoms include methylene, ethylene, n-propylene, isopropylene, cyclopropylene, n-butylene, isobutylene, s-butylene, t-butylene, cyclobutylene, 1-methylcyclopropylene, 2-methylcyclopropylene, n-pentylene, 1-methyl-n-butylene, 2-methyl-n-butylene, 3-methyl-n-butylene, 1,1-dimethyl-n-propylene, 1,2-dimethyl-n-propylene, 2,2-dimethyl-n-propylene, and 1-ethyl-n-propylene. Pyrene group, cyclopentylene group, 1-methylcyclobutylene group, 2-methylcyclobutylene group, 3-methylcyclobutylene group, 1,2-dimethylcyclopropylene group, 2,3-dimethylcyclopropylene group, 1-ethylcyclopropylene group, 2-ethylcyclopropylene group, n-hexylene group, 1-methyl-n-pentylene group, 2-methyl-n-pentylene group, 3-methyl-n-pentylene group, 4-methyl-n-pentylene group, 1,1-dimethyl-n-butylene group, 1,2-dimethyl-n-butylene group, 1,3-dimethyl-n-butylene group , 2,2-dimethyl-n-butylene group, 2,3-dimethyl-n-butylene group, 3,3-dimethyl-n-butylene group, 1-ethyl-n-butylene group, 2-ethyl-n-butylene group, 1,1,2-trimethyl-n-propylene group, 1,2,2-trimethyl-n-propylene group, 1-ethyl-1-methyl-n-propylene group, 1-ethyl-2-methyl-n-propylene group, cyclohexylene group, 1-methyl-cyclopentylene group, 2-methyl-cyclopentylene group, 3-methyl-cyclopentylene group, 1-ethyl-cyclobutylene group, 2-ethyl-cyclobutylene n group, 3-ethyl-cyclobutylene group, 1,2-dimethyl-cyclobutylene group, 1,3-dimethyl-cyclobutylene group, 2,2-dimethyl-cyclobutylene group, 2,3-dimethyl-cyclobutylene group, 2,4-dimethyl-cyclobutylene group, 3,3-dimethyl-cyclobutylene group, 1-n-propyl-cyclopropylene group, 2-n-propyl-cyclopropylene group, 1-isopropyl-cyclopropylene group, 2-isopropyl-cyclopropylene group, 1,2,2-trimethyl-cyclopropylene group, 1,2,3-trimethyl-cyclopropylene group, 2,2,Examples include 3-trimethylcyclopropylene group, 1-ethyl-2-methylcyclopropylene group, 2-ethyl-1-methylcyclopropylene group, 2-ethyl-2-methylcyclopropylene group, 2-ethyl-3-methylcyclopropylene group, n-heptylene group, n-octylene group, n-nonylene group, or n-decanylene group.

[0053] Specific examples of compounds represented by formula (2-2) are listed below.

[0054] [ka] The compound (B) may be represented by the following formula (4-1): [ka] (In the formula, R 5 n8 represents a halogen group, carboxyl group, nitro group, cyano group, methylenedioxy group, acetoxy group, methylthio group, alkoxy group having 1 to 9 carbon atoms, an amino group which may be substituted with an alkyl group having 1 to 3 carbon atoms, a hydroxyl group, or an alkyl group having 1 to 10 carbon atoms which may be substituted with a halogen group. In the formula, n8 represents an integer of 4, 5, 6, or 8. The explanations of the above terms are as stated above.

[0055] Specific examples of compounds represented by formula (4-1) are shown below.

[0056] [ka] The compound (B) may be of the following formulas (5-1) and (5-1-a): [ka] (In the formula, n9 and n10 represent integers of 0 or 1, respectively, R 6represents a halogen group, carboxyl group, nitro group, cyano group, methylenedioxy group, acetoxy group, methylthio group, alkoxy group with 1 to 9 carbon atoms, an amino group which may be substituted with an alkyl group with 1 to 3 carbon atoms, a hydroxyl group, or an alkyl group with 1 to 10 carbon atoms which may be substituted with a halogen group. a represents an integer from 1 to 6. n11 represents an integer of 1 or 2. r5 represents an integer from 0 to 3. * represents the bonding site between the compound of formula (5-1) and the compound of formula (5-1-a). The explanations of the above terms are as stated above.

[0057] Specific examples of compounds represented by formulas (5-1) and (5-1-a) are shown below.

[0058] [ka] The compounds having a phenolic hydroxyl group other than (B) catechol may be the compounds listed below.

[0059] [ka] [ka]

[0060] [3] Polymers having phenolic hydroxyl groups other than catechol The compound or polymer (B) having a phenolic hydroxyl group other than catechol can be a polymer (B) having a phenolic hydroxyl group other than catechol, and is not particularly limited as long as it is a polymer that does not impair the effects of the present invention.

[0061] The polymer (B) preferably has at least three or more repeating unit structures.

[0062] The weight-average molecular weight of the polymer (B) is not particularly limited, but is, for example, between 1,000 and 50,000.

[0063] The polymer (B) preferably contains a unit structure represented by the following formula (3-1): [ka] (In the formula, T 4 R represents an alkyl group having 1 to 10 carbon atoms, which may be substituted with a halogen group. 4 represents a halogen group, carboxyl group, nitro group, cyano group, methylenedioxy group, acetoxy group, methylthio group, alkoxy group with 1 to 9 carbon atoms, amino group which may be substituted with an alkyl group with 1 to 3 carbon atoms, hydroxyl group, or alkyl group with 1 to 10 carbon atoms which may be substituted with a halogen group. r4 represents an integer from 0 to 3. n7 represents an integer from 0 to 2. a represents an integer from 1 to 6. The explanations of the halogeno group, alkyl group, and alkoxy group are as described above.

[0064] The polymer represented by formula (3-1) may be a polymer containing one unit structure represented by formula (3-1), or a copolymer containing two or more such units.

[0065] Specific examples of the polymer (B) represented by formula (3-1) include polymers containing the unit structures described below.

[0066] [ka]

[0067] <Heat acid generator> The protective film-forming composition of the present invention may further contain a thermal acid generator.

[0068] Examples of thermal acid generating agents include pyridinium-p-toluenesulfonate, pyridinium-trifluoromethanesulfonate, pyridium-p-phenolsulfonate, K-PURE® CXC-1612, CXC-1614, TAG-2172, TAG-2179, TAG-2678, TAG2689 (all manufactured by King Industries), and SI-45, SI-60, SI-80, SI-100, SI-110, SI-150 (all manufactured by Sanshin Chemical Industry Co., Ltd.).

[0069] These thermal acid generators can be used individually or in combination of two or more types.

[0070] If the protective film-forming composition of the present invention contains a thermal acid generator, its content is 0.0001 to 20% by mass, preferably 0.01 to 15% by mass, and more preferably 0.1 to 10% by mass, based on the total solid content of the protective film-forming composition.

[0071] <Solvent> The protective film-forming composition of the present invention can be prepared by dissolving each of the above components in a solvent, preferably an organic solvent, and is used in a homogeneous solution state.

[0072] The organic solvent used in the protective film-forming composition according to the present invention is not particularly limited, as long as it is an organic solvent capable of dissolving the compound or solid components such as the acid catalyst described below. 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 commonly used in lithography processes in combination, considering its coating performance.

[0073] Examples of the aforementioned organic solvents 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, and cyclohexanoyl ether. Examples of solvents include cycloheptanone, 4-methyl-2-pentanol, methyl 2-hydroxyisobutyrate, ethyl 2-hydroxyisobutyrate, ethyl ethoxyacetate, 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 individually or in combination of two or more.

[0074] Among these solvents, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, ethyl lactate, butyl lactate, and cyclohexanone are preferred. Propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate are particularly preferred.

[0075] The solid content of the protective film-forming composition according to the present invention is usually 0.1 to 70% by mass, preferably 0.1 to 60% by mass. The solid content is the percentage of all components in the protective film-forming composition excluding the solvent. The percentage of the polymer represented by formula (1-1) 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.

[0076] <Resist Underlayer Film Forming Composition> The resist underlayer film forming composition of the present invention is (A) a polymer having a unit structure represented by the following formula (1-1): [ka] (In formula (1-1), Ar represents a benzene ring, a naphthalene ring, or an anthracene ring, R 1 n1 represents a hydroxyl group, a mercapto group which may be protected by a methyl group, an amino group which may be protected by a methyl group, a halogeno group, or an alkyl group having 1 to 10 carbon atoms which may be substituted or interrupted by a heteroatom or substituted by a hydroxyl group, n1 represents an integer from 0 to 3, L 1 represents a single bond or an alkylene group with 1 to 10 carbon atoms, E represents an epoxy group, and T 1 When n2=1, it represents an alkylene group having 1 to 10 carbon atoms, which may be interrupted by a single bond, an ether bond, an ester bond, or an amide bond. 1 (When n²=2, it represents a nitrogen atom or an amide bond.) (B) Compounds or polymers having phenolic hydroxyl groups other than catechol, (C) Thermal acid generator, and (D) Solvent, This includes the following. The explanations of terms relating to the resist underlayer film forming composition of this application are the same as those explained for the protective film forming composition described above.

[0077] <Method for manufacturing protective film, resist underlayer film, resist patterned substrate, and semiconductor device> The following describes a method for manufacturing a substrate with a resist pattern and a method for manufacturing a semiconductor device using the protective film forming composition (resist underlayer film forming composition) according to the present invention.

[0078] A resist patterned substrate according to the present invention can be manufactured by applying the protective film forming composition (resist underlayer film forming composition) described above onto a semiconductor substrate and firing it.

[0079] Examples of semiconductor substrates to which the protective film-forming composition (resist underlayer 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.

[0080] When a semiconductor substrate with an inorganic film formed on its surface is used, the inorganic film is formed by, for example, ALD (atomic layer deposition), CVD (chemical vapor deposition), reactive sputtering, ion plating, vacuum deposition, or spin coating (spin-on-glass: SOG). Examples of the inorganic film include polysilicon films, silicon oxide films, silicon nitride films, silicon oxynitride films, BPSG (Boro-PhosphoSilicate Glass) films, titanium nitride films, titanium oxynitride films, tungsten nitride films, gallium nitride films, and gallium arsenide films. The semiconductor substrate may also be a stepped substrate with so-called vias (holes), trenches (grooves), etc. formed on it. For example, a via has a roughly circular shape when viewed from above, with a diameter of approximately 2 nm to 20 nm and a depth of 50 nm to 500 nm, while a trench has a width of 2 nm to 20 nm and a depth of 50 nm to 500 nm. The protective film-forming composition (resist underlayer film-forming composition) of this application has a small weight-average molecular weight and average particle size of the compounds contained in the composition, so it can be embedded in stepped substrates like the one described above without defects such as voids. The absence of defects such as voids is an important characteristic for subsequent processes in semiconductor manufacturing (wet etching / dry etching of semiconductor substrates, resist pattern formation).

[0081] The protective film-forming composition (resist underlayer-forming composition) of the present invention is applied to such a semiconductor substrate by an appropriate coating method such as a spinner or coater. Subsequently, a protective film (resist underlayer-forming film) is formed by baking using a heating means such as a hot plate. The baking conditions are appropriately selected from a bake temperature of 100°C to 400°C and a bake time of 0.3 minutes to 60 minutes. Preferably, the bake temperature is 120°C to 350°C and the bake time is 0.5 minutes to 30 minutes, more preferably, the bake temperature is 150°C to 300°C and the bake time is 0.8 minutes to 10 minutes. The thickness of the formed protective film is, for example, 0.001 μm to 10 μm, preferably 0.002 μm to 1 μm, and more preferably 0.005 μm to 0.5 μm. If the baking temperature is lower than the aforementioned range, crosslinking may be insufficient, and the protective film (resist underlayer forming composition) formed may not be able to obtain resistance to the resist solvent or basic hydrogen peroxide aqueous solution. On the other hand, if the baking temperature is higher than the aforementioned range, the protective film (resist underlayer) may decompose due to heat.

[0082] Exposure is performed through a mask (reticle) to form a predetermined pattern, and examples of such lasers used include i-rays, KrF excimer lasers, ArF excimer lasers, EUV (extreme ultraviolet), or EB (electron beam). For development, an alkaline developer is used, with a development temperature of 5°C to 50°C and a development time of 10 to 300 seconds, which are appropriately selected. As the alkaline developer, aqueous solutions of alkalis such as inorganic alkalis like sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia, primary amines like ethylamine and n-propylamine, secondary amines like diethylamine and di-n-butylamine, tertiary amines like triethylamine and methyldiethylamine, alcohol amines like dimethylethanolamine and triethanolamine, quaternary ammonium salts like tetramethylammonium hydroxide, tetraethylammonium hydroxide, and choline, and cyclic amines like pyrrole and piperidine can be used. Furthermore, an appropriate amount of alcohols such as isopropyl alcohol and nonionic surfactants can be added to the aqueous solution of the alkalis. Among these, preferred developers are quaternary ammonium salts, more preferably tetramethylammonium hydroxide and choline. Furthermore, surfactants and other additives can be added to these developers. Alternatively, instead of an alkaline developer, development can be performed using an organic solvent such as butyl acetate, developing the portions of the photoresist where the alkaline dissolution rate has not improved.

[0083] Next, the protective film (resist underlayer film forming composition) 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; if the inorganic film is not formed on the surface of the semiconductor substrate used, the surface of the semiconductor substrate is exposed.

[0084] Furthermore, the desired pattern is formed by wet etching using a semiconductor wet etching solution, with the protective film (resist underlayer forming composition) after dry etching (and the resist pattern if one remains on the protective film / resist underlayer) as a mask.

[0085] For semiconductor wet etching solutions, general chemicals used for etching semiconductor wafers can be used, including substances that exhibit both acidic and basic properties.

[0086] Examples of acidic substances include hydrogen peroxide, hydrofluoric acid, ammonium fluoride, acidic ammonium fluoride, ammonium hydrogen fluoride, buffered hydrofluoric acid, hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, or mixtures thereof.

[0087] Substances exhibiting basicity include ammonia, sodium hydroxide, potassium hydroxide, sodium cyanide, potassium cyanide, and basic hydrogen peroxide solution obtained by mixing hydrogen peroxide with organic amines such as triethanolamine to make the pH basic. A specific example is SC-1 (ammonia-hydrogen peroxide solution). In addition, other substances that can make the pH basic, such as a solution obtained by mixing urea with hydrogen peroxide and generating ammonia by thermal decomposition of urea through heating, which ultimately makes the pH basic, can also be used as a chemical solution for wet etching.

[0088] Among these, acidic hydrogen peroxide solution or basic hydrogen peroxide solution is preferred.

[0089] These chemical solutions may contain additives such as surfactants.

[0090] The operating temperature for semiconductor wet etching solutions is preferably 25°C to 90°C, and more preferably 40°C to 80°C. The wet etching time is preferably 0.5 minutes to 30 minutes, and more preferably 1 minute to 20 minutes. [Examples]

[0091] The present invention will now be specifically described with reference to examples, but the present invention is not limited to these examples.

[0092] The weight-average molecular weights of the compounds shown in Synthesis Examples 1 to 8 below in this specification were obtained by gel permeation chromatography (hereinafter abbreviated as GPC). A GPC instrument manufactured by Tosoh Corporation was used for the measurements, and the measurement conditions were as follows.

[0093] GPC columns: Shodex KF803L, Shodex KF802, Shodex KF801 [registered trademark] (Showa Denko K.K.) Column temperature: 40℃ Solvent: Tetrahydrofuran (THF) Flow rate: 1.0ml / min Standard sample: Polystyrene (manufactured by Tosoh Corporation)

[0094] <Explanation of Terms> PGME: Propylene glycol monomethyl ether PGMEA: Propylene glycol monomethyl ether acetate

[0095] <Example 1> 5.92 g of epoxy novolac resin EOCN-104S (product of Nippon Kayaku Co., Ltd., corresponding to formula (a-1)) (30% by mass PGMEA solution, weight-average molecular weight 3,100) was mixed with 5.91 g of TrisP-HAP (product of Honshu Chemical Industry Co., Ltd., corresponding to formula (a-2)) (6% by mass PGME solution), 3.55 g of K-PURE [trademark registered] TAG-2689 (product of King Industries) (0.5% by mass PGME solution) as a thermal acid generator, 0.18 g of R-40-LM (DIC Corporation) (1% by mass PGMEA solution), 29.18 g of PGMEA, and 5.26 g of PGME to obtain a 4.3% by mass solids solution. This solution was filtered using a polytetrafluoroethylene microfilter with a pore size of 0.2 μm to prepare a protective film-forming composition.

[0096] [ka] [ka]

[0097] <Example 2> 5.32 g of epoxy novolac resin EOCN-104S (product of Nippon Kayaku Co., Ltd., corresponding to formula (a-1)) (30% by mass PGMEA solution, weight-average molecular weight 3,100) was mixed with 10.63 g of TrisP-HAP (product of Honshu Chemical Industry Co., Ltd., corresponding to formula (a-2)) (6% by mass PGME solution), 3.19 g of K-PURE [trademark registered] TAG-2689 (product of King Industries) (0.5% by mass PGME solution) as a thermal acid generator, 0.18 g of R-40-LM (DIC Corporation) (1% by mass PGMEA solution), 29.55 g of PGMEA, and 1.16 g of PGME to prepare a 4.5% by mass solids solution. This solution was filtered using a polytetrafluoroethylene microfilter with a pore size of 0.2 μm to prepare a protective film-forming composition.

[0098] [ka] [ka]

[0099] <Example 3> 2.40 g of epoxy novolac resin EOCN-104S (product of Nippon Kayaku Co., Ltd., corresponding to formula (a-1)) (30% by mass PGMEA solution, weight-average molecular weight 3,100) was mixed with 0.24 g of VP-8000 (product of Nippon Soda Co., Ltd., corresponding to formula (a-3), weight-average molecular weight 10,257) (30% by mass PGMEA solution), and as a thermoacid generator, 0.72 g of K-PURE [trademark registered] TAG-2689 (product of King Industries) (1% by mass PGME solution), 0.072 g of R-40-LM (DIC Co., Ltd.) (1% by mass PGMEA solution), 11.52 g of PGMEA, and 5.05 g of PGME were mixed to obtain a 4.0% by mass solids solution. This solution was filtered using a polytetrafluoroethylene microfilter with a pore size of 0.2 μm to prepare a protective film-forming composition.

[0100] [ka] [ka]

[0101] <Example 4> 2.03 g of epoxy novolac resin EOCN-104S (product of Nippon Kayaku Co., Ltd., corresponding to formula (a-1)) (30% by mass PGMEA solution, weight-average molecular weight 3,100) was mixed with 0.61 g of VP-8000 (product of Nippon Soda Co., Ltd., corresponding to formula (a-3), weight-average molecular weight 10,257) (30% by mass PGMEA solution), and as a thermoacid generator, 0.61 g of K-PURE [trademark registered] TAG-2689 (product of King Industries Co., Ltd.) (1% by mass PGME solution), 0.061 g of R-40-LM (DIC Co., Ltd.) (1% by mass PGMEA solution), 11.53 g of PGMEA, and 5.16 g of PGME were mixed to obtain a 4.0% by mass solids solution. This solution was filtered using a polytetrafluoroethylene microfilter with a pore size of 0.2 μm to prepare a protective film-forming composition.

[0102] [ka] [ka]

[0103] <Example 5> 3.60 g of epoxy novolac resin EOCN-104S (product of Nippon Kayaku Co., Ltd., corresponding to formula (a-1)) (30% by mass PGMEA solution, weight-average molecular weight 3,100) was mixed with 2.70 g of TEP-DF (product of Asahi Organic Chemicals Co., Ltd., corresponding to formula (a-4)) (4% by mass PGME solution), 1.08 g of K-PURE [trademark registered] TAG-2689 (product of King Industries) (1% by mass PGME solution) as a thermal acid generator (1% by mass PGME solution), 0.11 g of R-40-LM (DIC Corporation) (1% by mass PGMEA solution), 17.53 g of PGMEA, and 4.98 g of PGME to prepare a 4.0% by mass solids solution. This solution was filtered using a polytetrafluoroethylene microfilter with a pore size of 0.2 μm to prepare a protective film-forming composition.

[0104] [ka] [ka]

[0105] <Example 6> 3.05 g of epoxy novolac resin EOCN-104S (product of Nippon Kayaku Co., Ltd., corresponding to formula (a-1)) (30% by mass PGMEA solution, weight-average molecular weight 3,100) was mixed with 6.87 g of TEP-DF (product of Asahi Organic Chemicals Co., Ltd., corresponding to formula (a-4)) (4% by mass PGME solution), and as a thermal acid generator, 0.92 g of K-PURE [trademark registered] TAG-2689 (product of King Industries) (1% by mass PGME solution), 0.092 g of R-40-LM (DIC Corporation) (1% by mass PGMEA solution), 17.93 g of PGMEA, and 1.14 g of PGME were mixed to obtain a 4.0% by mass solids solution. This solution was filtered using a polytetrafluoroethylene microfilter with a pore size of 0.2 μm to prepare a protective film-forming composition.

[0106] [ka] [ka]

[0107] <Example 7> 3.60 g of epoxy novolac resin EOCN-104S (product of Nippon Kayaku Co., Ltd., corresponding to formula (a-1)) (30% by mass PGMEA solution, weight-average molecular weight 3,100) was mixed with 2.70 g of TEP-TPA (product of Asahi Organic Chemicals Co., Ltd., corresponding to formula (a-5)) (4% by mass PGME solution), 1.08 g of K-PURE [trademark registered] TAG-2689 (product of King Industries) (1% by mass PGME solution) as a thermal acid generator, 0.108 g of R-40-LM (DIC Corporation) (1% by mass PGMEA solution), 17.53 g of PGMEA, and 4.98 g of PGME to obtain a 4.0% by mass solids solution. This solution was filtered using a polytetrafluoroethylene microfilter with a pore size of 0.2 μm to prepare a protective film-forming composition.

[0108] [ka] [ka]

[0109] <Example 8> 3.05 g of epoxy novolac resin EOCN-104S (product of Nippon Kayaku Co., Ltd., corresponding to formula (a-1)) (30% by mass PGMEA solution, weight-average molecular weight 3,100) was mixed with 6.87 g of TEP-TPA (product of Asahi Organic Chemicals Co., Ltd., corresponding to formula (a-5)) (4% by mass PGME solution), and as a thermal acid generator, 0.92 g of K-PURE [trademark registered] TAG-2689 (product of King Industries) (1% by mass PGME solution), 0.092 g of R-40-LM (DIC Corporation) (1% by mass PGMEA solution), 17.93 g of PGMEA, and 1.14 g of PGME were mixed to obtain a 4.0% by mass solids solution. This solution was filtered using a polytetrafluoroethylene microfilter with a pore size of 0.2 μm to prepare a protective film-forming composition.

[0110] [ka] [ka]

[0111] <Example 9> 2.40 g of epoxy novolac resin EOCN-104S (product of Nippon Kayaku Co., Ltd., corresponding to formula (a-1)) (30% by mass PGMEA solution, weight-average molecular weight 3,100) was mixed with 0.24 g of NM8280G (product of Asahi Organic Chemicals Co., Ltd., corresponding to formula (a-6), weight-average molecular weight 6,819) (30% by mass PGMEA solution), and as a thermal acid generator, 0.72 g of K-PURE [trademark registered] TAG-2689 (product of King Industries Co., Ltd.) (1% by mass PGME solution), 0.072 g of R-40-LM (DIC Co., Ltd.) (1% by mass PGMEA solution), 11.52 g of PGMEA, and 5.05 g of PGME were mixed to obtain a 4.0% by mass solids solution. This solution was filtered using a polytetrafluoroethylene microfilter with a pore size of 0.2 μm to prepare a protective film-forming composition.

[0112] [ka] [ka]

[0113] <Example 10> 2.03 g of epoxy novolac resin EOCN-104S (product of Nippon Kayaku Co., Ltd., corresponding to formula (a-1)) (30% by mass PGMEA solution, weight-average molecular weight 3,100) was mixed with 0.60 g of NM8280G (product of Asahi Organic Chemicals Co., Ltd., corresponding to formula (a-6), weight-average molecular weight 6,819) (30% by mass PGMEA solution), and as a thermal acid generator, 0.61 g of K-PURE [trademark registered] TAG-2689 (product of King Industries Co., Ltd.) (1% by mass PGME solution), 0.061 g of R-40-LM (DIC Co., Ltd.) (1% by mass PGMEA solution), 11.53 g of PGMEA, and 5.76 g of PGME were mixed to obtain a 4.0% by mass solids solution. This solution was filtered using a polytetrafluoroethylene microfilter with a pore size of 0.2 μm to prepare a protective film-forming composition.

[0114] [ka] [ka]

[0115] <Comparative Example 1> 7.46 g of epoxy novolac resin EOCN-104S (a product of Nippon Kayaku Co., Ltd., corresponding to formula (a-1)) (30% by mass PGMEA solution, weight-average molecular weight 3,100), 2.68 g of K-PURE [trademark registered] TAG-2689 (a product of King Industries) (0.5% by mass PGME solution) as a thermal acid generator, 28.21 g of PGMEA, and 11.65 g of PGME were mixed to obtain a 4.5% by mass solids solution. This solution was filtered using a polytetrafluoroethylene microfilter with a pore size of 0.2 μm to prepare a protective film-forming composition.

[0116] [ka]

[0117] (Formation of coating film) On a silicon substrate with a titanium nitride film formed on its surface, the protective film-forming compositions prepared in Examples 1 to 10 and the film-forming composition prepared in Comparative Example 1 were each applied by spin coating, and a coating film with a thickness of 100 nm was fabricated by baking at 250°C for 60 seconds.

[0118] (Resistance test to basic hydrogen peroxide solution) The protective film-forming compositions prepared in Examples 1 to 10 and the protective film-forming composition prepared in Comparative Example 1 were used to create coatings on silicon substrates on which titanium nitride films were formed on the surface. These coatings were then immersed in basic hydrogen peroxide aqueous solutions of the composition shown in Table 1 at the temperatures shown in the same table, followed by rinsing with water and drying. The condition of the coatings after drying was then visually observed. The results are shown in Table 2. The values ​​in Table 2 represent the ratio of the time over which peeling was observed, relative to the comparative example.

[0119] [Table 1] [Table 2] From the results in Table 2 above, it was found that the coatings prepared using the protective film-forming compositions prepared in Examples 1 to 10 showed improved resistance to basic hydrogen peroxide aqueous solution compared to Comparative Example 1.

[0120] (Testing of optical parameters) The protective film-forming compositions prepared in Examples 1-10 and Comparative Example 1 described herein were each coated onto silicon wafers using a spinner. A resist underlayer film (50 nm thick) was formed by baking on a hot plate at 250°C for 1 minute. The n-value (refractive index) and k-value (attenuation coefficient or absorption coefficient) of these films were then measured at wavelengths of 193 nm and 248 nm using a spectroscopic ellipsometer (JAWoollam, VUV-VASE VU-302). The results are shown in Table 3.

[0121] [Table 3] [Industrial applicability]

[0122] The protective film-forming composition according to the present invention provides a protective film that exhibits excellent resistance when a wet etching solution is applied to the substrate during processing and has a low dry etching rate, thereby reducing damage to the protective film during substrate processing. The resist underlayer-forming composition according to the present invention exhibits excellent resistance when a wet etching solution is applied to the substrate during processing and has a low dry etching rate, and also exhibits excellent resistance when a wet etching solution is applied to the substrate during processing.

Claims

1. A method for manufacturing a substrate with a protective film, characterized by being used in the manufacture of a semiconductor, comprising the step of applying a protective film-forming composition onto a semiconductor substrate and firing it to form a protective film against semiconductor wet etching solutions, The protective film-forming composition is (A) a polymer having a unit structure represented by the following formula (1-1): 【Chemistry 47】 (In formula (1-1), Ar represents a benzene ring, a naphthalene ring, or an anthracene ring, R １ n1 represents a hydroxyl group, a mercapto group which may be protected by a methyl group, an amino group which may be protected by a methyl group, a halogeno group, or an alkyl group having 1 to 10 carbon atoms which may be substituted or interrupted by a heteroatom or substituted by a hydroxyl group, n1 represents an integer from 0 to 3, L １ represents a single bond or an alkylene group having 1 to 10 carbon atoms, E represents an epoxy group, and T １ When n² = 1, it represents an alkylene group having 1 to 10 carbon atoms, which may be interrupted by a single bond, an ether bond, an ester bond, or an amide bond. １ (where n² = 2 represents a nitrogen atom or an amide bond.) (B) Compounds or polymers having phenolic hydroxyl groups other than catechol, (C) Thermal acid generator, and (D) Solvent, Includes, A method for manufacturing a substrate with a protective film, wherein the compound or polymer (B) is represented by the following formula (2-1). 【Chemistry 48】 (In the formula, R ２ and T ２ Each of these independently represents a halogen group, a carboxyl group, a nitro group, a cyano group, a methylenedioxy group, an acetoxy group, a methylthio group, an alkoxy group having 1 to 9 carbon atoms, an amino group which may be substituted with an alkyl group having 1 to 3 carbon atoms, a hydroxyl group, or an alkyl group having 1 to 10 carbon atoms which may be substituted with a halogen group. １ and A ２ Each of these is independently an alkylene group having 1 to 10 carbon atoms, a divalent organic group derived from a bicyclocyclic compound, or a combination thereof. n3 to n5 each independently represent integers from 0 to 2. r2 represents an integer from 0 to 3. m1 and m2 each independently represent numbers from 0 to 10,000,000.

2. The method for producing a protective film-coated substrate according to claim 1, wherein the compound (B) or polymer has two or more phenolic hydroxyl groups.

3. A method for manufacturing a substrate with a resist pattern, comprising the steps of forming a resist film on a protective film according to claim 1 or 2, and then exposing and developing it to form a resist pattern, characterized in that it is used in the manufacture of a semiconductor.

4. A method for manufacturing a semiconductor device, comprising the steps of forming a protective film according to claim 1 or 2 on a semiconductor substrate which may have an inorganic film formed on its surface; 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 cleaning the inorganic film or the semiconductor substrate using a semiconductor wet etching solution, with the dry-etched protective film as a mask.

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