Chemical solution-resistant protective film

Abstract

Provided are a protective film forming composition for a semiconductor, which has a good mask (protection) function against a wet etching liquid, a low dry etching speed, further good coatability and embeddability for a high-low difference substrate, a small film thickness difference after embedding, and enables formation of a flat film, a protective film, a resist underlayer film, a substrate with a resist pattern, and a manufacturing method of a semiconductor device using the composition. A protective film forming composition for a semiconductor against a wet etching liquid, comprising: (A) a polymer having a unit structure represented by the following formula (1-1): (in formula (1-1), Ar represents a benzene ring, a naphthalene ring, or an anthracene ring, R 1 represents a hydroxyl group, a mercapto group which can be protected by a methyl group, an amino group which can be protected by a methyl group, a halogenated group, or an alkyl group having 1 to 10 carbon atoms which can be substituted or interrupted by a hetero atom and can be substituted by a hydroxyl group, n1 represents an integer of 0 to 3, L 1 represents a single bond or an alkylene group having 1 to 10 carbon atoms, E represents an epoxy group, T 1 represents a single bond or an alkylene group having 1 to 10 carbon atoms which can be interrupted by an ether bond, an ester bond, or an amide bond, T 1 represents a nitrogen atom or an amide bond) when n2 = 1; (B) a compound or a polymer having a phenolic hydroxyl group other than catechol; (C) a thermal acid generator; and (D) a solvent.

Description

TECHNICAL FIELD

[0001] The present application relates to a composition for forming a protective film, particularly excellent in resistance to a semiconductor wet etching liquid, in a lithography process in semiconductor manufacturing. Further, to a protective film formed from the above composition and a manufacturing method of a substrate with a resist pattern to which the protective film is applied, and a manufacturing method of a semiconductor device. BACKGROUND

[0002] In semiconductor manufacturing, a lithography process of forming a resist pattern of a desired shape by providing a resist underlayer film between a substrate and a resist film formed thereon is well known. After the resist pattern is formed, processing of the substrate is performed, and as this process, dry etching is mainly used, but depending on the type of substrate, wet etching is sometimes used. A resist underlayer film material having alkaline hydrogen peroxide water resistance is disclosed in Patent Literature 1.

[0003] PRIOR ART DOCUMENTS

[0004] PATENT LITERATURE

[0005] Patent Literature 1: Japanese Patent Application Laid-Open No. 2018-173520 SUMMARY

[0006] PROBLEMS TO BE SOLVED BY THE INVENTION

[0007] In a case where a protective film of a semiconductor substrate is formed using a protective film forming composition, and processing of a base substrate is performed by wet etching with the protective film as an etching mask, the protective film is required to have a good mask function against a semiconductor wet etching liquid (i.e., a portion to be masked can protect the substrate).

[0008] Further, a protective film forming composition that is also excellent in coatability for a so-called step difference substrate, has a small film thickness difference after embedding, and can form a flat film is also required.

[0009] In the past, in order to exhibit resistance to SC-1 (ammonia-hydrogen peroxide solution), which is one of wet etching chemicals, a method of applying a low molecular compound (e.g., gallic acid) as an additive has been used, but there are limitations in solving the above problems.

[0010] Further, it is desired that the protective film used for the above purpose has a function as a resist underlayer film for solving problems at the time of forming a resist pattern (shape defects, etc.).

[0011] An object of the present application is to solve the above problems.

[0012] MEANS FOR SOLVING THE PROBLEMS

[0013] The present application includes the following solutions.

[0014] [1] A protective film forming composition for a wet etching solution for semiconductors, comprising:

[0015] (A) a polymer having a unit structure represented by the following formula (1-1),

[0016]

[0017] (In formula (1-1), Ar represents a benzene ring, a naphthalene ring, or an anthracene ring, R 1 represents a hydroxyl group, a mercapto group which can be protected with a methyl group, an amino group which can be protected with a methyl group, a halogeno group, or an alkyl group having 1 to 10 carbon atoms which can be substituted or interrupted with a hetero atom and can be substituted with a hydroxyl group, n1 represents an integer of 0 to 3, L 1 represents a single bond or an alkylene group having 1 to 10 carbon atoms, E represents an epoxy group, T 1 represents a single bond, or an alkylene group having 1 to 10 carbon atoms which can be interrupted with an ether bond, an ester bond, or an amide bond, T 1 represents a nitrogen atom or an amide bond) when n2 = 2;

[0018] (B) a compound or a polymer having a phenolic hydroxyl group other than catechol;

[0019] (C) a thermal acid generator; and

[0020] (D) a solvent.

[0021] [2] The protective film forming composition according to [1], the compound or the polymer of the above-mentioned (B) having 2 or more phenolic hydroxyl groups.

[0022] [3] The protective film forming composition according to [1] or [2], the compound or the polymer of the above-mentioned (B) being represented by the following formula (2-1),

[0023]

[0024] (In formula (2-1), R 2 and T 2 each independently represent a halogeno 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 can 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 can be substituted with a halogeno group.A. 1 and A 2 each independently are an alkylene group having 1 to 10 carbon atoms, a 2-valent organic group derived from a bicyclic compound, a biphenylene group, or a 2-valent organic group represented by -CT 2 T 3 -CT 3 represents a hydrogen atom or a 1-valent group represented by formula 2-1-a).

[0025]

[0026] * in the formula (2-1-a) indicates a bonding site to T 3 a indicates an integer of 1 to 6.

[0027] n3 to n5 each independently indicate an integer of 0 to 2. r2 indicates an integer of 0 to 3. m1 and m2 each independently indicate a number of 0 to 10,000,000.

[0028] [4] The protective film-forming composition according to [3], wherein m1, n3 to n5, and r2 are 0, and m2 is 1.

[0029] [5] The protective film-forming composition according to [1] or [2], wherein the (B) compound or polymer is a compound represented by the following formula (2-2),

[0030]

[0031] (in the formula, R 3 indicates a halogeno 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 can 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 can be substituted with a halogeno group. r4 indicates an integer of 0 to 3. n7 indicates an integer of 0 to 2. a indicates an integer of 1 to 6. 1 indicates a single bond, an oxygen atom, a sulfur atom, a sulfonyl group, a carbonyl group, an imino group, an arylene group having 6 to 40 carbon atoms, an alkylene group having 1 to 10 carbon atoms which can be substituted with a halogeno group. a indicates an integer of 1 to 6. n6 indicates an integer of 0 to 2. r3 indicates an integer of 0 to 3.

[0032] [6] The protective film-forming composition according to [1] or [2], wherein the (B) compound or polymer is a polymer comprising a unit structure represented by the following formula (3-1),

[0033]

[0034] (in the formula, T 4 indicates an alkyl group having 1 to 10 carbon atoms which can be substituted with a halogeno group. R 4 indicates a halogeno 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 can 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 can be substituted with a halogeno group. r4 indicates an integer of 0 to 3. n7 indicates an integer of 0 to 2. a indicates an integer of 1 to 6.

[0035] [7] A protective film for a wet etching solution for semiconductors, characterized by being a fired product of a coated film formed from the protective film-forming composition described in any one of [1] to [6].

[0036] [8] A resist underlayer film-forming composition, comprising:

[0037] (A) a polymer having a unit structure represented by the following formula (1-1),

[0038]

[0039] (In formula (1-1), Ar represents a benzene ring, a naphthalene ring, or an anthracene ring, R 1 represents a hydroxyl group, a mercapto group which can be protected by a methyl group, an amino group which can be protected by a methyl group, a halogeno group, or an alkyl group having 1 to 10 carbon atoms which can be substituted or interrupted by a hetero atom and can be substituted by a hydroxyl group, n1 represents an integer of 0 to 3, L 1 represents a single bond or an alkylene group having 1 to 10 carbon atoms, E represents an epoxy group, T 1 represents a single bond, or an alkylene group having 1 to 10 carbon atoms which can be interrupted by an ether bond, an ester bond, or an amide bond, T 1 represents a nitrogen atom or an amide bond) when n2 = 2;

[0040] (B) a compound or a polymer having a phenolic hydroxyl group other than catechol;

[0041] (C) a thermal acid generator; and

[0042] (D) a solvent.

[0043] [9] A resist underlayer film, characterized by being a fired product of a coated film formed from the resist underlayer film-forming composition described in [8].

[0044]

[10] A method for manufacturing a substrate with a protective film, characterized by being used for manufacturing a semiconductor, which comprises a step of applying the protective film-forming composition described in any one of [1] to [6] on a semiconductor substrate having a step difference and performing firing to form a protective film.

[0045]

[11] A method for manufacturing a substrate with a resist pattern, characterized by being used for manufacturing a semiconductor, which comprises a step of applying the protective film-forming composition described in any one of [1] to [6] or the resist underlayer film-forming composition described in [8] on a semiconductor substrate and performing firing to form a protective film as a resist underlayer film; and a step of forming a resist film on the protective film, followed by exposure, development, and formation of a resist pattern.

[0046]

[12] A method for manufacturing a semiconductor device, comprising the steps of: 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 [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 surface of the inorganic film or the semiconductor substrate, and wet-etching the inorganic film or the semiconductor substrate using a semiconductor wet etching liquid, with the dry-etched protective film as a mask, and washing.

[0047]

[13] A method for manufacturing a semiconductor device, comprising the steps of: 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 [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.

[0048] Effects of the Invention

[0049] The protective film forming composition of the present application is required to have, in a photolithography process in semiconductor manufacturing, good balance of properties such as the following (1) to (4). (1) Good mask function against a wet etching liquid at the time of substrate processing, (2) further reduction of damage to the protective film or resist underlayer film at the time of substrate processing by low dry etching speed, (3) excellent planarization property for a stepped substrate, and (4) excellent embedding property for a fine trench pattern substrate. By having these (1) to (4) in good balance, fine processing of a semiconductor substrate can be easily performed. DETAILED DESCRIPTION

[0050] <Protective film forming composition against a semiconductor wet etching liquid>

[0051] The protective film forming composition against a semiconductor wet etching liquid of the present application comprises:

[0052] (A) a polymer having a unit structure represented by the following formula (1-1),

[0053]

[0054] (In formula (1-1), Ar represents a benzene ring, a naphthalene ring, or an anthracene ring, R 1 represents a hydroxyl group, a mercapto group which can be protected with a methyl group, an amino group which can be protected with a methyl group, a halogeno group, or an alkyl group having 1 to 10 carbon atoms which can be substituted or interrupted with a hetero atom and can be substituted with a hydroxyl group, n1 represents an integer of 0 to 3, L 1represents a single bond or an alkylene group having 1 to 10 carbon atoms which can be interrupted by an ether bond, an ester bond or an amide bond, T 1 represents a single bond or an alkylene group having 1 to 10 carbon atoms which can be interrupted by an ether bond, an ester bond or an amide bond, T 1 represents a nitrogen atom or an amide bond) when n2=2.

[0055] (B) a compound or a polymer having a phenolic hydroxyl group other than catechol;

[0056] (C) a thermal acid generator; and

[0057] (D) a solvent.

[0058] (Polymer (A))

[0059] The polymer (A) used in the present application is a polymer having a unit structure represented by the following formula (1-1),

[0060]

[0061] (in formula (1-1), Ar represents a benzene ring, a naphthalene ring or an anthracene ring, R 1 represents a hydroxyl group, a mercapto group which can be protected by a methyl group, an amino group which can be protected by a methyl group, a halogenated group, or an alkyl group having 1 to 10 carbon atoms which can be substituted or interrupted by a hetero atom and can be substituted by a hydroxyl group, as a substituent of a hydrogen atom included in the above benzene ring, naphthalene ring or anthracene ring, n1 represents an integer of 0 to 3, L 1 represents a single bond or an alkylene group having 1 to 10 carbon atoms which can be interrupted by an ether bond, an ester bond or an amide bond, T 1 represents a single bond or an alkylene group having 1 to 10 carbon atoms which can be interrupted by an ether bond, an ester bond or an amide bond, T 1 represents a nitrogen atom or an amide bond) when n2=2.

[0062] As the alkyl group having 1 to 10 carbon atoms, there are, for example, methyl, ethyl, n-propyl, isopropyl, cyclopropyl, n-butyl, isobutyl, sec-butyl, t-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, 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, methoxy, ethoxy, methoxymethyl, ethoxymethyl, methoxyethyl, ethoxyethyl, hydroxymethyl, 1-hydroxyethyl, 2-hydroxyethyl, methylamino, dimethylamino, diethylamino, aminomethyl, 1-aminoethyl, 2-aminoethyl, methylthio, ethylthio, mercaptomethyl, 1-mercaptoethyl, 2-mercaptoethyl, and the like.

[0063] As the above-mentioned alkylene group having 1 to 10 carbon atoms, there are methylene, ethylene, n-propylene, iso-propylene, cyclopropylene, n-butylene, iso-butylene, sec-butylene, tert-butylene, cyclobutylene, 1-methyl-cyclopropylene, 2-methyl-cyclopropylene, 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, 1-ethyl-n-propylene, cyclopentylene, 1-methyl-cyclobutylene, 2-methyl-cyclobutylene, 3-methyl-cyclobutylene, 1,2-dimethyl-cyclopropylene, 2,3-dimethyl-cyclopropylene, 1-ethyl-cyclopropylene, 2-ethyl-cyclopropylene, n-hexylene, 1-methyl-n-pentylene, 2-methyl-n-pentylene, 3-methyl-n-pentylene, 4-methyl-n-pentylene, 1,1-dimethyl-n-butylene, 1,2-dimethyl-n-butylene, 1,3-dimethyl-n-butylene, 2,2-dimethyl-n-butylene, 2,3-dimethyl-n-butylene, 3,3-dimethyl-n-butylene, 1-ethyl-n-butylene, 2-ethyl-n-butylene, 1,1,2-trimethyl-n-propylene, 1,2,2-trimethyl-n-propylene, 1-ethyl-1-methyl-n-propylene, 1-ethyl-2-methyl-n-propylene, cyclohexylene, 1-methyl-cyclopentylene, 2-methyl-cyclopentylene, 3-methyl-cyclopentylene, 1-ethyl-cyclobutylene, 2-ethyl-cyclobutylene, 3-ethyl-cyclobutylene, 1,2-dimethyl-cyclobutylene, 1,3-dimethyl-cyclobutylene, 2,2-dimethyl-cyclobutylene, 2,3-dimethyl-cyclobutylene, 2,4-dimethyl-cyclobutylene, 3,3-dimethyl-cyclobutylene, 1-n-propyl-cyclopropylene, 2-n-propyl-cyclopropylene, 1-iso-propyl-cyclopropylene, 2-iso-propyl-cyclopropylene, 1,2,2-trimethyl-cyclopropylene, 1,2,3-trimethyl-cyclopropylene, 2,2,3-trimethyl-cyclopropylene, 1-ethyl-2-methyl-cyclopropylene, 2-ethyl-1-methyl-cyclopropylene, 2-ethyl-2-methyl-cyclopropylene, 2-ethyl-3-methyl-cyclopropylene, n-heptylene, n-octylene, n-nonylene or n-decylene.

[0064] The above-mentioned R 1 may be an alkoxy group having 1 to 10 carbon atoms.

[0065] Examples of alkoxy groups with 1 to 10 carbon atoms include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy, tert-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, 4-methyl- n-Pentyloxy, 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.

[0066] The unit structure shown in formula (1-1) above can be one type or a combination of two or more types. For example, it can be a copolymer of multiple unit structures having Ar of the same type, such as a unit structure having Ar containing a benzene ring and a unit structure having a naphthalene ring, or a copolymer of multiple unit structures having different types of Ar, which are not excluded from the scope of this application.

[0067] The phrase "can be interrupted" as used above, in the case of alkylene groups with 2 to 10 carbon atoms, means that any carbon-carbon atom in the alkylene group is interrupted by a heteroatom (i.e., an ether bond in the case of oxygen, and a thioether bond in the case of sulfur), an ester bond, or an amide bond. For alkylene groups with 1 carbon atom (i.e., methylene), it means that there is a heteroatom (i.e., an ether bond in the case of oxygen, and a thioether bond in the case of sulfur), an ester bond, or an amide bond on either side of the carbon atom in the methylene group.

[0068] The above T 1 When n2 = 1, it represents a single bond, or an alkylene group with 1 to 10 carbon atoms that can be interrupted by an ether bond, ester bond, or amide bond, but preferably a combination of an ether bond and a methylene group (i.e., "-T" in formula (1-1)). 1 -(E)n2” is the case of glycidyl ether group, or the combination of ester bond and methylene group, or the combination of amide bond and methylene group.

[0069] The term "alkyl group with 1 to 10 carbon atoms that can be replaced by heteroatoms" refers to an alkyl group with 1 to 10 carbon atoms in which one or more hydrogen atoms are replaced by heteroatoms (preferably halogenated groups).

[0070] The above L 1represents a single bond or an alkylene group having 1 to 10 carbon atoms, but is preferably represented by the following formula (1-2).

[0071] -CR 2 R 3 - Formula (1-2)

[0072] (in formula (1-2), R 2 , R 3 independently of one another represent a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, a cyclopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a t-butyl group, a cyclobutyl group, R 2 , R 3 may combine with one another to form a ring having 3 to 6 carbon atoms). Among them, R 2 , R 3 are both hydrogen atoms (i.e., -(CR 2 R 3 )- is a methylene group).

[0073] The above-mentioned so-called halogenated group is a halogen -X (F, Cl, Br, I) in which a hydrogen is replaced.

[0074] The above-mentioned polymer (A) is not particularly limited as long as it satisfies the unit structure of the above-mentioned formula (1-1). It can be produced by a method known per se. Commercial products can also be used. As the commercial products, there are, for example, heat-resistant epoxy novolak resins EOCN (registered trademark) series (manufactured by Nikka Chemical Co., Ltd.), epoxy novolak resins D.E.N (registered trademark) series (manufactured by Dow Chemical Japan Co., Ltd.), and the like.

[0075] The weight average molecular weight of the above-mentioned polymer (A) is 100 or more, 500 to 200,000, 600 to 50,000, or 700 to 10,000.

[0076] As the polymer (A) of the present application, there are, for example, substances having the following unit structure.

[0077]

[0078] <(B) a compound or polymer having a phenolic hydroxyl group other than catechol>

[0079] The above-mentioned compound or polymer (B) having a phenolic hydroxyl group other than catechol is not particularly limited as long as it is a compound or polymer which does not impair the effects of the present application. Needless to say, the above-mentioned compound or polymer (B) having a phenolic hydroxyl group other than catechol is different from the above-mentioned polymer (A).

[0080] The weight average molecular weight of the compound or polymer (B) having a phenolic hydroxyl group other than catechol is not particularly limited, but is, for example, 300 to 50,000.

[0081] The compound or polymer (B) preferably has two or more phenolic hydroxyl groups.

[0082] [1] a compound or polymer represented by formula (2-1)

[0083] The compound (B) is preferably represented by the following formula (2-1).

[0084]

[0085] (In the formula, R 2 and T 2 each independently represents a halogeno 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 can 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 can be substituted with a halogeno group.A 1 and A 2 each independently is an alkylene group having 1 to 10 carbon atoms, a 2-valent organic group derived from a bicyclic compound, a biphenylene group, or -CT 2 T 3 a 2-valent organic group represented by -CT 3 represents a hydrogen atom or a 1-valent group represented by formula (2-1-a). The * in formula (2-1-a) indicates a bonding site to the carbon atom of T 3 . a indicates an integer of 1 to 6. n3 to n5 each independently indicates an integer of 0 to 2. r2 indicates an integer of 0 to 3. m1 and m2 each independently indicates 0 to 10,000,000.

[0086] The above m1, n3 to n5, and r2 are preferably 0, and m2 is preferably 1.

[0087] The halogeno group, the alkoxy group, and the alkyl group involved in the above formula (2-1) are as described above.

[0088] As the above-mentioned bicyclic compound, mention can be made of bicyclopentadiene, substituted bicyclopentadiene, 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 above-mentioned so-called substitution means that one or two or more hydrogen atoms of the above-mentioned bicyclic compound are each independently substituted with a halogeno group, a nitro group, an amino group, or a hydroxyl group, or an alkyl group having 1 to 10 carbon atoms which can be substituted with these groups, or an aryl group having 6 to 40 carbon atoms. The so-called divalent organic group derived from a bicyclic compound means a group having two binding sites which is derived by removing any two hydrogen atoms from the above-mentioned bicyclic compound.

[0089] As the above-mentioned aryl group having 6 to 40 carbon atoms, mention can be made of 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.

[0090] As a specific example of the above-mentioned compound represented by formula (2-1), mention can be made of the compounds described below.

[0091]

[0092] The above-mentioned compound (B) which is a compound having a phenolic hydroxyl group other than catechol is not particularly limited as long as it is a compound which does not impair the effects of the present application, but is preferably represented by the following formula (2-2).

[0093]

[0094] [2] Compound represented by formula (2-2)

[0095] The above-mentioned compound (B) which is a compound having a phenolic hydroxyl group other than catechol is not particularly limited as long as it is a compound which does not impair the effects of the present application, but is preferably represented by the following formula (2-2).

[0096]

[0097] (In the formula, R 3 represents a halogeno 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 can 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 can be substituted with a halogeno group. Q 1a single bond, an oxygen atom, a sulfur atom, a sulfonyl group, a carbonyl group, an imino group, an arylene group having 6 to 40 carbon atoms, an alkylene group having 1 to 10 carbon atoms which can be substituted with a halogen atom. a represents an integer of 1 to 6. n6 represents an integer of 0 to 2. r3 represents an integer of 0 to 3.

[0098] The alkyl group, the alkoxy group and the halogen atom of formula (2-2) are as described above.

[0099] As the arylene group having 6 to 40 carbon atoms, there can be mentioned phenylene, o-methylphenylene, m-methylphenylene, p-methylphenylene, o-chlorophenylene, m-chlorophenylene, p-chlorophenylene, o-fluorophenylene, p-fluorophenylene, o-methoxyphenylene, p-methoxyphenylene, p-nitrophenylene, p-cyanophenylene, α-naphthylene, β-naphthylene, o-biphenylene, m-biphenylene, p-biphenylene, 1-anthrylene, 2-anthrylene, 9-anthrylene, 1-phenanthrylene, 2-phenanthrylene, 3-phenanthrylene, 4-phenanthrylene and 9-phenanthrylene.

[0100] Examples of alkylene groups having 1 to 10 carbon atoms include methylene, ethylene, n-propylene, isopropylene, cyclopropylene, n-butylene, isobutylene, secondary butylene, tert-butylene, cyclobutylene, 1-methyl-cyclopropylene, 2-methyl-cyclopropylene, 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, 1-ethyl-n-propylene, cyclopentylene, 1-methyl-cyclobutylene, 2-methyl-cyclopropylene, etc. Butylene, 3-methyl-cyclobutylene, 1,2-dimethyl-cyclopropylene, 2,3-dimethyl-cyclopropylene, 1-ethyl-cyclopropylene, 2-ethyl-cyclopropylene, n-hexylene, 1-methyl-n-pentylene, 2-methyl-n-pentylene, 3-methyl-n-pentylene, 4-methyl-n-pentylene, 1,1-dimethyl-n-butylene, 1,2-dimethyl-n-butylene, 1,3-dimethyl-n-butylene, 2,2-dimethyl-n-butylene, 2,3-dimethyl-n-butylene, 3,3-dimethyl-n-butylene, 1-ethyl-n-butylene 2-Ethyl-n-butylene, 1,1,2-trimethyl-n-propylene, 1,2,2-trimethyl-n-propylene, 1-ethyl-1-methyl-n-propylene, 1-ethyl-2-methyl-n-propylene, cyclohexylene, 1-methyl-cyclopentane, 2-methyl-cyclopentane, 3-methyl-cyclopentane, 1-ethyl-cyclobutylene, 2-ethyl-cyclobutylene, 3-ethyl-cyclobutylene, 1,2-dimethyl-cyclobutylene, 1,3-dimethyl-cyclobutylene, 2,2-dimethyl-cyclobutylene, 2,3-dimethyl-cyclobutylene, 2,4- -Dimethyl-cyclobutylene, 3,3-dimethyl-cyclobutylene, 1-n-propyl-cyclopropylene, 2-n-propyl-cyclopropylene, 1-isopropyl-cyclopropylene, 2-isopropyl-cyclopropylene, 1,2,2-trimethyl-cyclopropylene, 1,2,3-trimethyl-cyclopropylene, 2,2,3-trimethyl-cyclopropylene, 1-ethyl-2-methyl-cyclopropylene, 2-ethyl-1-methyl-cyclopropylene, 2-ethyl-2-methyl-cyclopropylene, 2-ethyl-3-methyl-cyclopropylene, n-heptylene, n-octylene, n-nonylene, or n-decylene.

[0101] As specific examples of the compounds shown in the above formula (2-2), the following compounds can be cited.

[0102]

[0103] The above-mentioned compound (B) can also be represented by the following formula (4-1):

[0104]

[0105] (where R is in the formula) 5halogen, carboxyl, nitro, cyano, methylenedioxy, acetoxy, methylthio, an alkoxy group having 1 to 9 carbon atoms, an amino group which can 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 can be substituted with a halogen. In the formula, n8 represents an integer of 4, 5, 6, or 8.

[0106] The above-mentioned terms are as described above.

[0107] Specific examples of the compound represented by formula (4-1) are shown below.

[0108]

[0109] The above-mentioned compound (B) can also be a compound represented by the following formula (5-1) and formula (5-1-a):

[0110]

[0111] (In the formula, n9 and n10 each represent an integer of 0 or 1, R 6 halogen, carboxyl, nitro, cyano, methylenedioxy, acetoxy, methylthio, an alkoxy group having 1 to 9 carbon atoms, an amino group which can 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 can be substituted with a halogen. a represents an integer of 1 to 6. n11 represents an integer of 1 or 2. r5 represents an integer of 0 to 3. * represents the binding site of the compound of formula (5-1) and the compound of formula (5-1-a).

[0112] The above-mentioned terms are as described above.

[0113] Specific examples of the compound represented by the following formula (5-1) and formula (5-1-a) are shown below.

[0114]

[0115] The above-mentioned compound (B) having a phenolic hydroxyl group other than catechol can be a compound represented by the following formula.

[0116]

[0117] [3] Polymer having a phenolic hydroxyl group other than catechol

[0118] The above-mentioned compound (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 which does not impair the effects of the present application.

[0119] The above-mentioned polymer (B) preferably has at least 3 or more repeating unit structures.

[0120] The weight average molecular weight of the above-mentioned (B) polymer is not particularly limited, but is, for example, 1,000 to 50,000.

[0121] Preferably, the above-mentioned (B) polymer contains a unit structure represented by the following formula (3-1):

[0122]

[0123] (In the formula, T 4 represents an alkyl group having 1 to 10 carbon atoms which can be substituted with a halogen group. R 4 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 can 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 can be substituted with a halogen group. r4 represents an integer of 0 to 3. n7 represents an integer of 0 to 2. a represents an integer of 1 to 6.)

[0124] The above-mentioned halogen group, alkyl group, and alkoxy group are as described above.

[0125] The polymer represented by the above-mentioned formula (3-1) can be a polymer containing one kind of unit structure represented by formula (3-1), or can be a copolymer containing two or more kinds.

[0126] As a specific example of the above-mentioned (B) polymer represented by formula (3-1), a polymer containing the unit structures described below can be given.

[0127]

[0128] (In the above-mentioned formula, m and n written beside the repeating unit represent the molar ratio of copolymerization)

[0129] <Thermal acid generator>

[0130] The protective film-forming composition of the present application can further contain a thermal acid generator.

[0131] As the thermal acid generator, for example, pyridinium - p-toluenesulfonate, pyridinium - trifluoromethanesulfonate, pyridinium - p-phenolsulfonic acid salt, K-PURE (registered trademark) CXC-1612, K-PURE (registered trademark) CXC-1614, K-PURE (registered trademark) TAG-2172, K-PURE (registered trademark) TAG-2179, K-PURE (registered trademark) TAG-2678, K-PURE (registered trademark) TAG2689 (all of which are manufactured by King Industries), and SI-45, SI-60, SI-80, SI-100, SI-110, SI-150 (all of which are manufactured by Sanwa Chemical Industry Co., Ltd.).

[0132] These thermal acid generators can be used in combination of one or two or more.

[0133] In the case where the protective film-forming composition of the present application contains a thermal acid generator, the content thereof is 0.0001 to 20 mass% with respect to the total solid content of the protective film-forming composition, preferably 0.01 to 15 mass%, and further preferably 0.1 to 10 mass%.

[0134] <solvent>

[0135] The protective film-forming composition of the present application can be prepared by dissolving each of the above components in a solvent, preferably an organic solvent, and used in a uniform solution state.

[0136] As the organic solvent of the protective film-forming composition of the present application, any organic solvent can be used without particular limitation as long as it can dissolve the above-mentioned compounds, the solid components described below, and the like. In particular, since the protective film-forming composition of the present application is used in a uniform solution state, if the coating properties thereof are considered, it is recommended to use an organic solvent that is generally used in a photolithography process.

[0137] As the above-mentioned organic solvent, for example, 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, 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 can be mentioned. These solvents can be used alone or in combination of two or more.

[0138] Among these solvents, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, ethyl lactate, butyl lactate, and cyclohexanone are preferable. Propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate are particularly preferable.

[0139] The solid content of the protective film-forming composition according to the present application is usually 0.1 to 70 mass%, and preferably 0.1 to 60 mass%. The solid content is the proportion of the total content of all components after removal of the solvent from the protective film-forming composition. The proportion of the polymer represented by the above formula (1-1) in the solid content is preferably in the order of 1 to 100 mass%, 1 to 99.9 mass%, 50 to 99.9 mass%, 50 to 95 mass%, and 50 to 90 mass%.

[0140] <Resist underlayer film-forming composition>

[0141] The resist underlayer film-forming composition according to the present application contains:

[0142] (A) a polymer having a unit structure represented by the following formula (1-1):

[0143]

[0144] (In formula (1-1), Ar represents a benzene ring, a naphthalene ring, or an anthracene ring, R 1 represents a hydroxyl group, a mercapto group which can be protected with a methyl group, an amino group which can be protected with a methyl group, a halogenated group, or an alkyl group having 1 to 10 carbon atoms which can be substituted or interrupted with a hetero atom and can be substituted with a hydroxyl group, n1 represents an integer of 0 to 3, L 1 represents a single bond or an alkylene group having 1 to 10 carbon atoms, E represents an epoxy group, T 1 represents a single bond, or an alkylene group having 1 to 10 carbon atoms which can be interrupted with an ether bond, an ester bond, or an amide bond, T 1 represents a nitrogen atom or an amide bond) when n2 = 2;

[0145] (B) a compound or a polymer having a phenolic hydroxyl group other than catechol;

[0146] (C) a thermal acid generator; and

[0147] (D) a solvent.

[0148] The terms used in the resist underlayer film-forming composition according to the present application are the same as those described above in the protective film-forming composition.

[0149] <Manufacturing method of protective film, resist underlayer film, substrate with resist pattern, and semiconductor device>

[0150] Next, a method for manufacturing a substrate with a resist pattern using the protective film-forming composition (resist underlayer film-forming composition) according to the present application and a method for manufacturing a semiconductor device will be described.

[0151] A substrate with a resist pattern according to the present application can be manufactured by applying the above-mentioned protective film-forming composition (resist underlayer film-forming composition) to a semiconductor substrate and performing baking.

[0152] As the semiconductor substrate to which the protective film-forming composition (resist underlayer film-forming composition) according to the present application is applied, for example, a silicon wafer, a germanium wafer, and compound semiconductor wafers such as gallium arsenide, indium phosphide, gallium nitride, indium nitride, and aluminum nitride can be mentioned.

[0153] In the case where the semiconductor substrate has an inorganic film formed on the surface, the inorganic film is formed, for example, by an ALD (atomic layer deposition) method, a CVD (chemical vapor deposition) method, a reactive sputtering method, an ion plating method, a vacuum evaporation method, or a spin coating method (spin on glass: SOG). As the inorganic film, for example, a polysilicon film, a silicon oxide film, a silicon nitride film, a silicon oxynitride film, a BPSG (Boro-Phospho Silicate Glass) film, a titanium nitride film, a titanium oxynitride film, a tungsten nitride film, a gallium nitride film, and a gallium arsenide film can be mentioned. The semiconductor substrate can be a step substrate in which a so-called via (hole), a trench (groove), or the like is formed. For example, the via has a substantially circular shape when viewed from above, and the diameter of the substantially circular shape is, for example, 2 nm to 20 nm, and the depth is 50 nm to 500 nm. The trench has, for example, a groove (a recess of the substrate) having 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) according to the present application can be embedded in the step substrate without defects such as voids because the weight average molecular weight and the average particle diameter of the compound contained in the composition are small. The absence of defects such as voids is an important characteristic for the next process of semiconductor manufacturing (wet etching / dry etching of the semiconductor substrate, resist pattern formation).

[0154] On such a semiconductor substrate, the protective film-forming composition (resist underlayer film-forming composition) of the present application is applied by a suitable application method such as a spin coater, a coater, or the like. Then, baking is performed using a heating means such as a hot plate or the like to form a protective film (resist underlayer film). As the baking conditions, a baking temperature of 100°C to 400°C and a baking time of 0.3 minutes to 60 minutes are appropriately selected. It is preferable that the baking temperature be 120°C to 350°C and the baking time be 0.5 minutes to 30 minutes, and more preferable that the baking temperature be 150°C to 300°C and the baking time be 0.8 minutes to 10 minutes. The film thickness of the protective film formed 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. In the case where the temperature at the time of baking is lower than the above range, crosslinking becomes insufficient, and sometimes the protective film formed (resist underlayer film-forming composition) does not easily obtain resistance to a resist solvent or an alkaline hydrogen peroxide aqueous solution. On the other hand, in the case where the temperature at the time of baking is higher than the above range, sometimes the protective film (resist underlayer film) is decomposed by heat.

[0155] Exposure is performed through a mask (reticle) for forming a prescribed pattern using, for example, i-ray, a KrF excimer laser, an ArF excimer laser, EUV (extreme ultraviolet), or EB (electron beam). Development is performed using an alkaline developer, and a development temperature of 5°C to 50°C and a development time of 10 seconds to 300 seconds are appropriately selected. As the alkaline developer, an aqueous solution of an inorganic base such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, or the like, a primary amine such as ethylamine, n-propylamine, or the like, a secondary amine such as diethylamine, di-n-butylamine, or the like, a tertiary amine such as triethylamine, methyldiethylamine, or the like, an alcohol amine such as dimethyl ethanolamine, triethanolamine, or the like, a quaternary ammonium salt such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, choline, or the like, a cyclic amine such as pyrrole, piperidine, or the like, or the like can be used. Further, an appropriate amount of an alcohol such as isopropyl alcohol, a surfactant such as a nonionic surfactant, or the like can be added to the above-mentioned aqueous solution of a base and used. Among them, a preferable developer is a quaternary ammonium salt, and further preferable are tetramethylammonium hydroxide and choline. Further, a surfactant or the like can be added to these developers. Instead of the alkaline developer, a method of developing a portion of the photoresist in which the alkali dissolution rate is not increased using an organic solvent such as butyl acetate or the like can be used.

[0156] Next, dry etching is performed on the above-mentioned protective film (resist underlayer film-forming composition) using the resist pattern formed as a mask. At this time, in the case where the inorganic film is formed on the surface of the semiconductor substrate used, the surface of the inorganic film is exposed, and in the case where the inorganic film is not formed on the surface of the semiconductor substrate used, the surface of the semiconductor substrate is exposed.

[0157] Further, by using a semiconductor wet etching liquid with the dry-etched protective film (composition for resist underlayer film formation) (in the case where a resist pattern remains on the protective film / resist underlayer film, also with the resist pattern) as a mask, wet etching is performed, thereby forming a desired pattern.

[0158] As the semiconductor wet etching liquid, a general chemical solution for etching processing of a semiconductor wafer can be used, and both an acidic substance and an alkaline substance can be used.

[0159] As the acidic substance, for example, hydrogen peroxide, hydrofluoric acid, ammonium fluoride, acidic ammonium fluoride, ammonium bifluoride, buffered hydrofluoric acid, hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, or a mixed solution thereof can be given.

[0160] As the alkaline substance, alkaline hydrogen peroxide water in which ammonia, sodium hydroxide, potassium hydroxide, sodium cyanide, potassium cyanide, triethanolamine, or the like is mixed with hydrogen peroxide water so as to be alkaline at pH can be given. As a specific example, SC-1 (ammonia-hydrogen peroxide solution) can be given. In addition, a substance which is alkaline at pH, for example, a substance in which urea is mixed with hydrogen peroxide water, and ammonia is generated by heat decomposition of urea by heating, and finally becomes alkaline at pH can also be used as a wet etching chemical solution.

[0161] Among them, acidic hydrogen peroxide water or alkaline hydrogen peroxide water is preferable.

[0162] These chemical solutions can contain an additive such as a surfactant.

[0163] The use temperature of the semiconductor wet etching liquid is desirably 25°C to 90°C, and further desirably 40°C to 80°C. As the wet etching time, 0.5 minutes to 30 minutes is desirable, and further 1 minute to 20 minutes is desirable.

[0164] Examples

[0165] Next, the content of the present application will be specifically described by giving examples, but the present application is not limited to them.

[0166] The weight average molecular weight of the compounds shown in the following Synthesis Example 1 to Synthesis Example 8 of the present specification was measured as a result of gel permeation chromatography (hereinafter, abbreviated as GPC). The measurement used a GPC device manufactured by Tosoh Corporation, and the measurement conditions and the like were as described below.

[0167] GPC column: Shodex KF803L, Shodex KF802, Shodex KF801 (registered trademark) (Showa Denko Co., Ltd.)

[0168] Column temperature: 40°C

[0169] Solvent: tetrahydrofuran (THF)

[0170] Flow rate: 1.0 ml / min

[0171] Standard sample: polystyrene (manufactured by Toho Chemical Industry Co., Ltd.)

[0172] <Explanation of terms>

[0173] PGME: propylene glycol monomethyl ether

[0174] PGMEA: propylene glycol monomethyl ether acetate

[0175] <Example 1>

[0176] To 5.92 g (30 mass% PGMEA solution, weight average molecular weight: 3,100) of epoxy novolac resin EOCN-104S (manufactured by Japan Epoxy Resin Co., Ltd., corresponding to formula (a-1)), were added 5.91 g (6 mass% PGME solution) of TrisP-HAP (manufactured by Hokuriku Chemical Industry Co., Ltd., corresponding to formula (a-2)), 3.55 g (0.5 mass% PGME solution) of K-PURE [registered trademark] TAG-2689 (manufactured by King Industries, Inc.) as a thermal acid generator, 0.18 g of R-40-LM (DIC Corporation) (1 mass% PGMEA solution), 29.18 g of PGMEA, and 5.26 g of PGME, to prepare a 4.3 mass% solid content solution. The solution was filtered using a polytetrafluoroethylene microfilter having a pore size of 0.2 μm to prepare a protective film-forming composition.

[0177]

[0178] <Example 2>

[0179] To 5.32 g (30 mass% PGMEA solution, weight average molecular weight: 3,100) of epoxy novolac resin EOCN-104S (manufactured by Japan Epoxy Resin Co., Ltd., corresponding to formula (a-1)), were added 10.63 g (6 mass% PGME solution) of TrisP-HAP (manufactured by Hokuriku Chemical Industry Co., Ltd., corresponding to formula (a-2)), 3.19 g (0.5 mass% PGME solution) of K-PURE [registered trademark] TAG-2689 (manufactured by King Industries, Inc.) as a thermal acid generator, 0.18 g of R-40-LM (DIC Corporation) (1 mass% PGMEA solution), 29.55 g of PGMEA, and 1.16 g of PGME, to prepare a 4.5 mass% solid content solution. The solution was filtered using a polytetrafluoroethylene microfilter having a pore size of 0.2 μm to prepare a protective film-forming composition.

[0180]

[0181] Example 3

[0182] To 2.40 g (30 mass% PGMEA solution, weight average molecular weight: 3,100) of epoxy novolac resin EOCN-104S (product of Japan Epoxy Resins Co., Ltd., corresponding to formula (a-1)) was added 0.24 g (30 mass% PGMEA solution) of VP-8000 (product of Japan Cabot Co., Ltd., corresponding to formula (a-3), weight average molecular weight: 10,257), 0.72 g (1 mass% PGME solution) of K-PURE [registered trademark] TAG-2689 (product of King Industries, Inc.) as a thermal acid generator, 0.072 g of R-40-LM (DIC Corporation) (1 mass% PGMEA solution), 11.52 g of PGMEA, and 5.05 g of PGME, to prepare a 4.0 mass% solid content solution. This solution was filtered using a polytetrafluoroethylene-made microfilter having a pore size of 0.2 μm to prepare a protective film-forming composition.

[0183]

[0184] Example 4

[0185] To 2.03 g (30 mass% PGMEA solution, weight average molecular weight: 3,100) of epoxy novolac resin EOCN-104S (product of Japan Epoxy Resins Co., Ltd., corresponding to formula (a-1)) was added 0.61 g (30 mass% PGMEA solution) of VP-8000 (product of Japan Cabot Co., Ltd., corresponding to formula (a-3), weight average molecular weight: 10,257), 0.61 g (1 mass% PGME solution) of K-PURE [registered trademark] TAG-2689 (product of King Industries, Inc.) as a thermal acid generator, 0.061 g of R-40-LM (DIC Corporation) (1 mass% PGMEA solution), 11.53 g of PGMEA, and 5.16 g of PGME, to prepare a 4.0 mass% solid content solution. This solution was filtered using a polytetrafluoroethylene-made microfilter having a pore size of 0.2 μm to prepare a protective film-forming composition.

[0186]

[0187]

[0188] Example 5

[0189] To 3.60 g (30 mass% PGMEA solution, weight average molecular weight: 3,100) of an epoxy novolac resin EOCN-104S (product of Japan Epoxy Resins Co., Ltd., corresponding to formula (a-1)), 2.70 g (4 mass% PGME solution) of TEP-DF (product of Asahi Organic Chemicals Industry Co., Ltd., corresponding to formula (a-4)), 1.08 g (1 mass% PGME solution) of K-PURE [Trade Name] TAG-2689 (product of King Industries, Inc.) as a thermal acid generator, 0.11 g of R-40-LM (product of DIC Corporation) (1 mass% PGMEA solution), 17.53 g of PGMEA, and 4.98 g of PGME were mixed to prepare a 4.0 mass% solution of solid content. This solution was filtered using a polytetrafluoroethylene-made microfilter having a pore size of 0.2 μm to prepare a composition for protective film formation.

[0190]

[0191] Example 6

[0192] To 3.05 g (30 mass% PGMEA solution, weight average molecular weight: 3,100) of an epoxy novolac resin EOCN-104S (product of Japan Epoxy Resins Co., Ltd., corresponding to formula (a-1)), 6.87 g (4 mass% PGME solution) of TEP-DF (product of Asahi Organic Chemicals Industry Co., Ltd., corresponding to formula (a-4)), 0.92 g (1 mass% PGME solution) of K-PURE [Trade Name] TAG-2689 (product of King Industries, Inc.) as a thermal acid generator, 0.092 g of R-40-LM (product of DIC Corporation) (1 mass% PGMEA solution), 17.93 g of PGMEA, and 1.14 g of PGME were mixed to prepare a 4.0 mass% solution of solid content. This solution was filtered using a polytetrafluoroethylene-made microfilter having a pore size of 0.2 μm to prepare a composition for protective film formation.

[0193]

[0194] Example 7

[0195] To 3.60 g (30 mass% PGMEA solution, weight average molecular weight: 3,100) of an epoxy novolac resin EOCN-104S (product of Japan Epoxy Resins Co., Ltd., corresponding to formula (a-1)), 2.70 g (4 mass% PGME solution) of TEP-TPA (product of Asahi Organic Chemicals Industry Co., Ltd., corresponding to formula (a-5)), 1.08 g (1 mass% PGME solution) of K-PURE [registered trademark] TAG-2689 (product of King Industries, Inc.) as a thermal acid generator, 0.108 g of R-40-LM (product of DIC Corporation) (1 mass% PGMEA solution), 17.53 g of PGMEA, and 4.98 g of PGME were mixed to prepare a 4.0 mass% solution of solid content. This solution was filtered using a polytetrafluoroethylene-made microfilter having a pore diameter of 0.2 μm to prepare a composition for protective film formation.

[0196]

[0197] Example 8

[0198] To 3.05 g (30 mass% PGMEA solution, weight average molecular weight: 3,100) of an epoxy novolac resin EOCN-104S (product of Japan Epoxy Resins Co., Ltd., corresponding to formula (a-1)), 6.87 g (4 mass% PGME solution) of TEP-TPA (product of Asahi Organic Chemicals Industry Co., Ltd., corresponding to formula (a-5)), 0.92 g (1 mass% PGME solution) of K-PURE [registered trademark] TAG-2689 (product of King Industries, Inc.) as a thermal acid generator, 0.092 g of R-40-LM (product of DIC Corporation) (1 mass% PGMEA solution), 17.93 g of PGMEA, and 1.14 g of PGME were mixed to prepare a 4.0 mass% solution of solid content. This solution was filtered using a polytetrafluoroethylene-made microfilter having a pore diameter of 0.2 μm to prepare a composition for protective film formation.

[0199]

[0200] Example 9

[0201] To 2.40 g (30 mass% PGMEA solution, weight average molecular weight: 3,100) of an epoxy novolac resin EOCN-104S (product of Japan Epoxy Resins Co., Ltd., corresponding to formula (a-1)) was added 0.24 g (30 mass% PGMEA solution) of NM8280G (product of Asahi Organic Chemicals Industry Co., Ltd., corresponding to formula (a-6), weight average molecular weight: 6,819), 0.72 g (1 mass% PGME solution) of K-PURE [registered trademark] TAG-2689 (product of King Industries, Inc.) as a thermal acid generator, 0.072 g of R-40-LM (product of DIC Corporation) (1 mass% PGMEA solution), 11.52 g of PGMEA, and 5.05 g of PGME, to prepare a 4.0 mass% solid content solution. This solution was filtered using a polytetrafluoroethylene-made microfilter having a pore size of 0.2 μm, to prepare a protective film-forming composition.

[0202]

[0203] Example 10

[0204] To 2.03 g (30 mass% PGMEA solution, weight average molecular weight: 3,100) of an epoxy novolac resin EOCN-104S (product of Japan Epoxy Resins Co., Ltd., corresponding to formula (a-1)) was added 0.60 g (30 mass% PGMEA solution) of NM8280G (product of Asahi Organic Chemicals Industry Co., Ltd., corresponding to formula (a-6), weight average molecular weight: 6,819), 0.61 g (1 mass% PGME solution) of K-PURE [registered trademark] TAG-2689 (product of King Industries, Inc.) as a thermal acid generator, 0.061 g of R-40-LM (product of DIC Corporation) (1 mass% PGMEA solution), 11.53 g of PGMEA, and 5.76 g of PGME, to prepare a 4.0 mass% solid content solution. This solution was filtered using a polytetrafluoroethylene-made microfilter having a pore size of 0.2 μm, to prepare a protective film-forming composition.

[0205]

[0206] Comparative Example 1

[0207] A solution having a solid content of 4.5 mass% was prepared by mixing epoxy novolac resin EOCN-104S (product of Japan Epoxy Resin Co., Ltd., corresponding to formula (a-1)), 7.46 g (30 mass% PGMEA solution, weight average molecular weight 3,100), K-PURE [registered trademark] TAG-2689 (product of King Industries, Inc.) as a thermal acid generator, 2.68 g (0.5 mass% PGME solution), PGMEA, 28.21 g, and PGME, 11.65 g. The solution was filtered using a polytetrafluoroethylene-made microfilter having a pore size of 0.2 μm to prepare a protective film-forming composition.

[0208]

[0209] (Formation of coated film)

[0210] A coated film having a thickness of 100 nm was prepared by coating each of the protective film-forming compositions prepared in Examples 1 to 10 and the film-forming composition prepared in Comparative Example 1 on a silicon substrate on which a titanium nitride film was formed by spin coating and baking at 250°C for 60 seconds.

[0211] (Resistance test to alkaline hydrogen peroxide aqueous solution)

[0212] The coated films prepared on a silicon substrate on which a titanium nitride film was formed using each of the protective film-forming compositions prepared in Examples 1 to 10 and the protective film-forming composition prepared in Comparative Example 1 were immersed in an alkaline hydrogen peroxide aqueous solution having the composition shown in Table 1 below at the temperature shown in the table, and then washed with water and dried, and the state of the coated films after drying was observed visually. The results are shown in Table 2 below. The values in Table 2 represent the ratio of the time at which peeling was observed based on Comparative Example 1.

[0213] [Table 1]

[0214] (Table 1)

[0215]

[0216] [Table 2]

[0217] (Table 2)

[0218]

[0219] As is clear from the results in Table 2 above, the coated films prepared using the protective film-forming compositions prepared in Examples 1 to 10 had improved resistance to alkaline hydrogen peroxide aqueous solution compared to Comparative Example 1.

[0220] (Test of optical parameters)

[0221] The protective film forming compositions prepared in Examples 1 to 10 and Comparative Example 1 described in the present specification were each applied to a silicon wafer by a spin coater. An antireflective underlayer film (film thickness: 50 nm) was formed by baking on a hot plate at 250°C for 1 minute. Further, the n value (refractive index) and k value (attenuation coefficient or light absorption coefficient) at a wavelength of 193 nm and a wavelength of 248 nm were measured using a spectroscopic ellipsometer (J. A. Woollam Co., VUV-VASE VU-302) for these films. The results are shown in Table 3.

[0222] [Table 3]

[0223] (Table 3)

[0224]

[0225] Industrial applicability

[0226] The protective film forming composition according to the present application has excellent resistance to application of a wet etching solution in substrate processing, has a low dry etching rate, and thus provides a protective film having low damage to the protective film during substrate processing. The antireflective underlayer film forming composition according to the present application has excellent resistance to application of a wet etching solution in substrate processing, has a low dry etching rate, and has excellent resistance to application of a wet etching solution in substrate processing.

Claims

1. A protective film forming composition for a wet etching solution for semiconductors, comprising: (A) a polymer having a unit structure represented by the following 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, wherein the (B) compound or polymer has a weight average molecular weight of 300 to 50,000 and is a compound represented by the following formula (2-1) or a compound represented by the following formula (2-2) or a polymer containing a unit structure represented by the following formula (3-1), ###0001### ###0002### ###0003### 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.

2. The protective film forming composition according to claim 1, wherein the (B) compound or polymer has 2 or more phenolic hydroxyl groups. In formula (1-1), Ar represents a benzene ring, a naphthalene ring, or an anthracene ring, R 1 represents a hydroxyl group, a mercapto group which can be protected with a methyl group, an amino group which can be protected with a methyl group, a halogeno group, or an alkyl group having 1 to 10 carbon atoms which can be substituted or interrupted with a hetero atom and can be substituted with a hydroxyl group, n1 represents an integer of 0 to 3, n2 is 1 or 2, L 1 represents a single bond or an alkylene group having 1 to 10 carbon atoms, E represents an epoxy group, T 1 represents a single bond, or an alkylene group having 1 to 10 carbon atoms which can be interrupted with an ether bond, an ester bond, or an amide bond, T 1 represents a nitrogen atom or an amide bond when n2 = 2; 3. The protective film forming composition according to claim 1, wherein m1, n3 to n5 and r2 are 0, and m2 is 1.

4. The protective film forming composition according to claim 1 or 2, wherein the (B) compound or polymer is a polymer containing a unit structure represented by any one of the following formulas (3-1-a) to (3-1-o), ###0004### ###0005### ###0006### ###0007### ###0008### ###0009### ###0010### ###0011### ###0012### ###0013### ###0014### ###0015### ###0016### ###0017### ###0018### ###0019### ###0020### ###0021### ###0022### ###0023### ###0024### ###0025### ###0026### ###0027### ###0028### ###0029### ###0030### ###0031### ###0032### ###0033### ###0034### ###0035### ###0036### ###0037### ###0038### ###0039### ###0040### ###0041### ###0042### ###0043### ###0044### ###0045### ###0046### ###0047### ###0048### ###0049### ###0050### ###0051### ###0052### ###0053### ###0054### ###0055### ###0056### ###0057### ###0058### ###0059### ###0060### ###0061### ###0062### ###0063### ###0064### ###0065### ###0066### ###0067### ###0068### ###0069### ###0070### ###0071### ###0072### ###0073### ###0074### ###0075### ###0076### ###0077### ###0078### ###0079### ###0080### ###0081### ###0082### ###0083### ###0084### ###0085### ###0086### ###0087### ###0088### ###0089### ###0090### ###0091### ###0092### ###0093### ###0094### ###0095### ###0096### ###0097### ###0098### ###0099### ###0100### ###0101### ###0102### ###0103### ###0104### ###0105### ###0106### ###0107### ###0108### ###0109### ###0110### ###0111### ###0112### ###0113### ###0114### ###0115### ###0116### ###0117### ###0118### ###0119### ###0120### ###0121### ###0122### ###0123### ###0124### ###0125### ###0126### ###0127### ###0128### ###0129### ###0130### ###0131### ###0132### ###0133### ###0134### ###0135### ###0136### ###0137### ###0138### ###0139### ###0140### ###0141### ###0142### ###0143### ###0144### ###0145### ###0146### ###0147### ###0148### ###0149### ###0150### ###0151### ###0152### ###0153### ###0154### ###0155### ###0156### ###0157### ###0158### ###0159### ###0160### ###0161### ###0162### ###0163### ###0164### ###0165### ###0166### ###0167### ###0168### ###0169### ###0170### ###0171### ###0172### ###0173### ###0174### ###0175### ###0176### ###0177### ###0178### ###0179### ###0180### ###0181### ###0182### ###0183### ###0184### ###0185### ###0186### ###0187### ###0188### ###0189### ###0190### ###0191### ###0192### ###0193### ###0194### ###0195### ###0196### ###0197### ###0198### ###0199### ###0200### ###0201### ###0202### ###0203### ###0204### ###0205### ###0206### ###0207### ###0208### ###0209### ###0210### ###0211### ###0212### ###0213### ###0214### ###0215### ###0216### ###0217### ###0218### ###0219### ###0220### ###0221### ###0222### ###0223### ###0224### ###0225### ###0226### ###0227### ###0228### ###0229### ###0230### ###0231### ###0232### ###0233### ###0234### ###0235### ###0236### ###0237### ###0238### ###0239### ###0240### ###0241### ###0242### ###0243### ###0244### ###0245### ###0246### ###0247### ###0248### ###0249### ###0250### ###0251### ###0252### ###0253### ###0254### ###0255### ###0256### ###0257### ###0258### ###0259### ###0260### ###0261### ###0262### ###0263### ###0264### ###0265### ###0266### ###0267### ###0268### ###0269### ###0270### ###0271### ###0272### ###0273### ###0274### ###0275### ###0276### ###0277### ###0278### ###0279### ###0280### ###0281### ###0282### ###0283### ###0284### ###0285### ###0286### ###0287### ###0288### ###0289### ###0290### ###0291### ###0292### ###0293### ###0294### ###0295### ###0296### ###0297### ###0298### ###0299### ###0300### ###0301### ###0302### ###0303### ###0304### ###0305### ###0306### ###0307### ###0308### ###0309### ###0310### ###0311### ###0312### ###0313### ###0314### ###0315### ###0316### ###0317### ###0318### ###0319### ###0320### ###0321### ###0322### ###0323### ###0324### ###0325### ###0326### ###0327### ###0328### ###0329### ###0330### ###0331### ###0332### ###0333### ###0334### ###0335### ###0336### ###0337### ###0338### ###0339### ###0340### ###0341### ###0342### ###0343### ###0344### ###0345### ###0346### ###0347### ###0348### ###0349### ###0350### ###0351### ###0352### ###0353### ###0354### ###0355### ###0356### ###0357### ###0358### ###0359### ###0360### ###0361### ###0362### ###0363### ###0364### ###0365### ###0366### ###0367### ###0368### ###0369### ###0370### ###0371### ###0372### ###0373### ###0374### ###0375### ###0376### ###0377### ###0378### ###0379### ###0380### ###0381### ###0382### ###0383### ###0384### ###0385### ###0386### ###0387### ###0388### ###0389### ###0390### ###0391### ###0392### ###0393### ###0394### ###0395### ###0396### ###0397### ###0398### ###0399### ###0400### ###0401### ###0402### ###0403### ###0404### ###0405### ###0406### ###0407### ###0408### ###0409### ###0410### ###0411### ###0412### ###0413### ​ wherein, ​ wherein R 2 and T 2 each independently represents a halogeno 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 can 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 can be substituted with a halogeno group; A 1 and A 2 each independently is an alkylene group having 1 to 10 carbon atoms, a 2-valent organic group derived from a bicyclic compound, a biphenylene group, or -CT 2 T 3 a 2-valent organic group represented by -T 3 represents a hydrogen atom or a 1-valent group represented by formula 2-1-a, * in the formula 2-1-a represents a bond with T 3 the bonding site of the bonded carbon atom; a represents an integer of 1 to 6; ​ wherein R 3 represents a halogeno 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 can 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 can be substituted with a halogeno group; Q 1 represents a single bond, an oxygen atom, a sulfur atom, a sulfonyl group, a carbonyl group, an imino group, an arylene group having 6 to 40 carbon atoms, an alkylene group having 1 to 10 carbon atoms which can be substituted with a halogeno group; a represents an integer of 1 to 6; n6 represents an integer of 0 to 2; r3 represents an integer of 0 to 3, wherein T 4 represents an alkyl group having 1 to 10 carbon atoms which can be substituted with a halogen group; R 4 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 can 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 can be substituted with a halogen group; r4 represents an integer of 0 to 3; n7 represents an integer of 0 to 2; and a represents an integer of 1 to 6. ​ ​ ​ ​ 5. A protective film for a wet etching solution for a semiconductor, characterized by ​ ​ ​ In formula (1-1), Ar represents a benzene ring, a naphthalene ring, or an anthracene ring, R 1 represents a hydroxyl group, a mercapto group which can be protected with a methyl group, an amino group which can be protected with a methyl group, a halogeno group, or an alkyl group having 1 to 10 carbon atoms which can be substituted or interrupted with a hetero atom and can be substituted with a hydroxyl group, n1 represents an integer of 0 to 3, n2 is 1 or 2, L 1 represents a single bond or an alkylene group having 1 to 10 carbon atoms, E represents an epoxy group, T 1 represents a single bond, or an alkylene group having 1 to 10 carbon atoms which can be interrupted with an ether bond, an ester bond, or an amide bond, T 1 represents a nitrogen atom or an amide bond when n2 = 2; ​ ​ ​ wherein ​ wherein R 2 and T 2 each independently represents a halogeno 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 can 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 can be substituted with a halogeno group; A 1 and A 2 each independently is an alkylene group having 1 to 10 carbon atoms, a 2-valent organic group derived from a bicyclic compound, a biphenylene group, or -CT 2 T 3 a 2-valent organic group represented by -T 3 represents a hydrogen atom or a 1-valent group represented by formula 2-1-a, * in the formula 2-1-a represents a bond with T 3 the bonding site of the bonded carbon atom; a represents an integer of 1 to 6; ​ wherein R 3 represents a halogeno group, a carboxyl group, a nitro group, a cyano group, a methylene dioxy group, an acetoxy group, a methylthio group, an alkoxy group having 1 to 9 carbon atoms, an amino group which can 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 can be substituted with a halogeno group; Q 1 represents a single bond, an oxygen atom, a sulfur atom, a sulfonyl group, a carbonyl group, an imino group, an arylene group having 6 to 40 carbon atoms, an alkylene group having 1 to 10 carbon atoms which can be substituted with a halogeno group; a represents an integer of 1 to 6; n6 represents an integer of 0 to 2; r3 represents an integer of 0 to 3, wherein T 4 represents an alkyl group having 1 to 10 carbon atoms which can be substituted with a halogen group; R 4 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 can 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 can be substituted with a halogen group; r4 represents an integer of 0 to 3; n7 represents an integer of 0 to 2; and a represents an integer of 1 to 6.

7. A resist underlayer film characterized by comprising: ​ ​ ​ ​ ​ ​ ​ 10. A method for manufacturing a semiconductor device, comprising the steps of: forming a protective film on a semiconductor substrate on which an inorganic film can be formed, using the composition for forming a protective film according to any one of claims 1 to 4, 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 the inorganic film or the semiconductor substrate using a semiconductor wet-etching solution using the protective film after dry-etching as a mask, and washing.

11. A method for manufacturing a semiconductor device, comprising the steps of: forming a resist underlayer film on a semiconductor substrate on which an inorganic film can be formed, using the composition for forming a resist underlayer film according to claim 6, 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 resist underlayer film after dry-etching as a mask.

Images