Composition for forming protective film, protective film, method for manufacturing substrate, and method for manufacturing semiconductor device

Abstract

The present invention provides a composition for forming a protective film, with which it is possible to form a protective film that has excellent resistance to a wet etching liquid for a semiconductor and excellent resistance to a solvent that is contained in a resist composition. This composition for forming a protective film is capable of forming a flat protective film that has a high etching rate, good coverage even with respect to a substrate having a level difference, and a small difference in film thickness after embedment. The present invention also provides a compound which is suitable for use in the composition for forming a protective film.　The compound is obtained by reacting a reaction starting material that contains an epoxy compound having at least two epoxy groups and a dicarboxylic acid compound. The compound has a partial structure represented by formula (3) and a partial structure represented by formula (4) as structures derived from the dicarboxylic acid compound. (In formula (3), R11 represents an alkylene group having 1 to 10 carbon atoms. * represents an atomic bond.　In formula (4), Q11 represents a divalent organic group having at least one heteroatom that is selected from the group consisting of oxygen, sulfur, and nitrogen in the main chain.)

Description

Composition for forming protective film, protective film, method for manufacturing substrate, and method for manufacturing semiconductor device

[0001] The present invention relates to a composition for forming a protective film, particularly one that is highly resistant to semiconductor wet etching solutions, in a lithography process in semiconductor manufacturing. It also relates to a compound that can be suitably used in the protective film-forming composition. It also relates to a protective film formed from the composition, a method for producing a resist-patterned substrate using the protective film, and a method for producing a semiconductor device.

[0002] In semiconductor manufacturing, a lithography process is widely known in which a resist underlayer film is provided between a substrate and a resist film to be formed thereon, thereby forming a resist pattern of a desired shape. After the resist pattern is formed, the substrate is processed, and dry etching is mainly used as the process, but wet etching may also be used depending on the type of substrate. Patent Document 1 discloses a resist underlayer film material that is resistant to alkaline hydrogen peroxide solution.

[0003] Japanese Patent Application Laid-Open No. 2018-173520

[0004] When a protective film for a semiconductor substrate is formed using a protective film-forming composition and the underlying substrate is processed by wet etching using the protective film as an etching mask, the protective film is required to have a good masking function against a semiconductor wet etching solution (i.e., to be able to protect the masked portion of the substrate) and resistance to the solvent contained in the resist composition (solvent resistance). Furthermore, it is desired that a protective film with a high dry etching rate can be formed, that good coverage is also provided for uneven substrates, that the film thickness difference after filling is small, and that a flat protective film can be formed.

[0005] The present invention has been made in consideration of the above-mentioned circumstances, and aims to provide a protective film-forming composition that can form a protective film that has excellent resistance to semiconductor wet etching solutions and excellent resistance to solvents contained in resist compositions, and that can form a protective film with a fast etching rate, good coverage even on uneven substrates, small film thickness difference after filling, and a flat protective film. Another object of the present invention is to provide a compound that can be suitably used in the protective film-forming composition. Another object of the present invention is to provide a protective film formed from the protective film-forming composition, a method for manufacturing a resist-patterned substrate using the protective film, and a method for manufacturing a semiconductor device.

[0006] As a result of intensive research conducted by the inventors to solve the above-mentioned problems, they discovered that the above-mentioned problems can be solved by adding a specific compound to a composition for forming a protective film, and thus completed the present invention.

[0007] That is, the present invention encompasses the following aspects: [1] A compound obtained by reacting reaction raw materials containing an epoxy compound having at least two epoxy groups and a dicarboxylic acid compound, the compound having a partial structure represented by the following formula (3) and a partial structure represented by the following formula (4) as structures derived from the dicarboxylic acid compound: (In formula (3), R １１ represents an alkylene group having 1 to 10 carbon atoms. * represents a bond. In formula (4), Q １１ represents a divalent organic group having at least one heteroatom selected from the group consisting of oxygen, sulfur, and nitrogen in the main chain.) [2] The compound according to [1], having at least one of a partial structure represented by the following formula (1) and a partial structure represented by the following formula (2) as the structure derived from the epoxy compound: (In formula (1), X １ represents a divalent group represented by the following formula (1-1), (1-2), or (1-3): １ and Z ２ A each independently represents a direct bond or a divalent group represented by the following formula (1-4): １ , A２ , A ３ , A ４ , A ５ and A ６ Each of Q independently represents a hydrogen atom, a methyl group, or an ethyl group. * represents a bond. １ represents a divalent organic group having an aromatic hydrocarbon ring or an aliphatic hydrocarbon ring. １１ , A １２ , A １３ , A １４ , A １５ and A １６ each independently represents a hydrogen atom, a methyl group, or an ethyl group. n1 and n2 each independently represent 0 or 1. * represents a bond. (In formulas (1-1) to (1-3), R １ ~R ５ R each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms which may be interrupted by an oxygen atom or a sulfur atom, an alkenyl group having 2 to 10 carbon atoms which may be interrupted by an oxygen atom or a sulfur atom, an alkynyl group having 2 to 10 carbon atoms which may be interrupted by an oxygen atom or a sulfur atom, a benzyl group, or a phenyl group, and the phenyl group may be substituted with at least one monovalent group selected from the group consisting of an alkyl group having 1 to 6 carbon atoms, a halogen atom, an alkoxy group having 1 to 6 carbon atoms, a nitro group, a cyano group, and an alkylthio group having 1 to 6 carbon atoms. １ and R ２ may be bonded to each other to form a ring having 3 to 6 carbon atoms. ３ and R ４ may be bonded to each other to form a ring having 3 to 6 carbon atoms. * represents a bond. *1 represents a bond bonded to a carbon atom. *2 represents a bond bonded to a nitrogen atom. (In formula (1-4), m1 is an integer of 1 to 4, and m2 is 0 or 1. *3 represents a bond bonded to a nitrogen atom. *4 represents a bond bonded to a carbon atom.) [3] The compound according to [2], having a partial structure represented by formula (1) as a structure derived from the epoxy compound. [4] X in formula (1) １is represented by the formula (1-3). [5] The compound according to any one of [2] to [4], wherein the molar ratio [(M1 + M2):(M3 + M4)] of the sum of the partial structure (M1) represented by the formula (1) and the partial structure (M2) represented by the formula (2), which are related to the structure derived from the epoxy compound, to the sum of the partial structure (M3) represented by the formula (3) and the partial structure (M4) represented by the formula (4), which are related to the structure derived from the dicarboxy compound, is 55:45 to 38:62. [6] A composition for forming a protective film, for forming a protective film on a semiconductor substrate having an inorganic film formed on its surface, which protects the inorganic film from wet etching, the composition for forming a protective film, comprising: a compound having a partial structure represented by the following formula (3) and a partial structure represented by the following formula (4), and a solvent: (In formula (3), R １１ represents an alkylene group having 1 to 10 carbon atoms. * represents a bond. In formula (4), Q １１ represents a divalent organic group having at least one heteroatom selected from the group consisting of oxygen, sulfur, and nitrogen in the main chain.) [7] The composition for forming a protective film according to [6], wherein the compound is a compound obtained by reacting a reaction raw material containing an epoxy compound having at least two epoxy groups with a dicarboxylic acid compound, and has, as structures derived from the dicarboxylic acid compound, a partial structure represented by formula (3) and a partial structure represented by formula (4). [8] The composition for forming a protective film according to [7], wherein the compound has, as structures derived from the epoxy compound, at least one of a partial structure represented by formula (1) below and a partial structure represented by formula (2) below: (In formula (1), X １ represents a divalent group represented by the following formula (1-1), (1-2), or (1-3): １ and Z ２ A each independently represents a direct bond or a divalent group represented by the following formula (1-4): １ , A ２ , A ３ , A ４ , A ５ and A ６Each of Q independently represents a hydrogen atom, a methyl group, or an ethyl group. * represents a bond. １ represents a divalent organic group having an aromatic hydrocarbon ring or an aliphatic hydrocarbon ring. １１ , A １２ , A １３ , A １４ , A １５ and A １６ each independently represents a hydrogen atom, a methyl group, or an ethyl group. n1 and n2 each independently represent 0 or 1. * represents a bond. (In formulas (1-1) to (1-3), R １ ~R ５ R each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms which may be interrupted by an oxygen atom or a sulfur atom, an alkenyl group having 2 to 10 carbon atoms which may be interrupted by an oxygen atom or a sulfur atom, an alkynyl group having 2 to 10 carbon atoms which may be interrupted by an oxygen atom or a sulfur atom, a benzyl group, or a phenyl group, and the phenyl group may be substituted with at least one monovalent group selected from the group consisting of an alkyl group having 1 to 6 carbon atoms, a halogen atom, an alkoxy group having 1 to 6 carbon atoms, a nitro group, a cyano group, and an alkylthio group having 1 to 6 carbon atoms. １ and R ２ may be bonded to each other to form a ring having 3 to 6 carbon atoms. ３ and R ４ may be bonded to each other to form a ring having 3 to 6 carbon atoms. * represents a bond. *1 represents a bond bonded to a carbon atom. *2 represents a bond bonded to a nitrogen atom. (In formula (1-4), m1 is an integer of 1 to 4, and m2 is 0 or 1. *3 represents a bond bonded to a nitrogen atom. *4 represents a bond bonded to a carbon atom.) [9] The composition for forming a protective film according to any one of [6] to [8], further comprising at least one of a compound represented by the following formula (1a) and a compound represented by the following formula (1b): (In formulas (1a) and (1b), R １represents a single bond, an alkylene group having 1 to 4 carbon atoms, or an alkenylene group having 2 to 4 carbon atoms and one or two carbon-carbon double bonds, k represents 0 or 1, m represents an integer of 1 to 3, and n represents an integer of 2 to 4.

[10] The composition for forming a protective film according to any one of [6] to [9], further comprising an acid generator.

[11] A protective film against a semiconductor wet etching solution, which is a fired product of a coating film made of the composition for forming a protective film according to any one of [6] to

[10] .

[12] A method for producing a substrate with a protective film, which includes a step of applying the composition for forming a protective film according to any one of [6] to

[10] onto a semiconductor substrate having a step, and firing the composition to form a protective film.

[13] A method for manufacturing a substrate with a resist pattern, which is used in manufacturing a semiconductor, comprising the steps of: applying the composition for forming a protective film according to any one of [6] to

[10] onto a semiconductor substrate and baking the composition to form a protective film as a resist underlayer film; forming a resist film on the protective film directly or via another layer, and then exposing and developing the resist film to form a resist pattern.

[14] A method for manufacturing a semiconductor device, which comprises the steps of forming a protective film using the composition for forming a protective film according to any one of [6] to

[10] on a semiconductor substrate having an inorganic film formed on its surface, forming a resist pattern on the protective film directly or via another layer, dry-etching the protective film using the resist pattern as a mask to expose the surface of the inorganic film, and wet-etching the inorganic film using a semiconductor wet etching solution using the protective film after dry etching as a mask.

[0008] According to the present invention, there is provided a protective film-forming composition that can form a protective film that has excellent resistance to semiconductor wet etching solutions and excellent resistance to solvents contained in the resist composition, and that can form a protective film with a high etching rate, good coverage even on uneven substrates, small film thickness difference after filling, and a flat protective film. Furthermore, according to the present invention, there is provided a compound that can be suitably used in the protective film-forming composition. Furthermore, according to the present invention, there are provided a protective film formed from the protective film-forming composition, a method for manufacturing a resist-patterned substrate using the protective film, and a method for manufacturing a semiconductor device.

[0009] Fig. 1 is a schematic diagram for explaining the test outline of the chemical resistance test in the examples. Fig. 2 is a schematic diagram for explaining the test outline of the chemical resistance test in the examples. Fig. 3 is a schematic diagram for explaining the test outline of the chemical resistance test in the examples. Fig. 4 is a schematic diagram for explaining the test outline of the chemical resistance test in the examples.

[0010] (Composition for forming protective film) The composition for forming a protective film of the present invention is a composition for forming a protective film. The protective film is preferably a protective film that protects an inorganic film formed on a surface of a semiconductor substrate from wet etching. The composition for forming a protective film contains a compound having a specific partial structure and a solvent.

[0011] <Compound> The compound having the specific partial structure contained in the composition for forming a protective film has a partial structure represented by the following formula (3) and a partial structure represented by the following formula (4). Furthermore, a more preferred embodiment of the compound having the specific partial structure is a compound obtained by reacting a reaction raw material containing an epoxy compound having at least two epoxy groups and a dicarboxylic acid compound, and the compound has, as a structure derived from the dicarboxylic acid compound, a partial structure represented by the following formula (3) and a partial structure represented by the following formula (4). When the composition for forming a protective film contains this compound, it is possible to form a protective film that has excellent resistance to semiconductor wet etching solutions and solvents contained in the resist composition, and further a protective film with a high etching rate can be formed. In addition, it is possible to form a protective film that has good coverage even on uneven substrates, has a small film thickness difference after filling, and is a flat film.

[0012] (In formula (3), R １１ represents an alkylene group having 1 to 10 carbon atoms. * represents a bond. In formula (4), Q １１ represents a divalent organic group having at least one heteroatom selected from the group consisting of oxygen, sulfur, and nitrogen in the main chain.

[0013] R in formula (3) １１The alkylene group in the formula (I) is, for example, a non-cyclic alkylene group. Examples of such alkylene groups include linear alkylene groups and branched alkylene groups.

[0014] Q in formula (4) １１ Examples of the divalent organic group include linear, branched, or cyclic divalent organic groups having 2 to 20 carbon atoms and at least one heteroatom selected from the group consisting of oxygen, sulfur, and nitrogen. Among these, divalent organic groups having an oxygen atom or a sulfur atom are preferred.

[0015] Examples of the structure represented by formula (3) include the structures shown below. (* represents a bond.)

[0016] Examples of the structure represented by formula (4) include the structures shown below. (* represents a bond.)

[0017] In the compound having the specific partial structure, the molar ratio (M3:M4) of the partial structure (M3) represented by formula (3) to the partial structure (M4) represented by formula (4) is preferably 1:99 to 99:1, more preferably 20:80 to 80:20, and even more preferably 53:47 to 67:33.

[0018] <<Partial Structure Derived from Epoxy Compound>> A more preferred embodiment of the compound having the specific partial structure is a compound obtained by reacting a reaction raw material containing an epoxy compound having at least two epoxy groups with a dicarboxylic acid compound. In this case, the compound preferably has, as the structure derived from the dicarboxylic acid compound, the partial structure represented by the above-mentioned formula (3) and the partial structure represented by formula (4), and also preferably has, as the structure derived from the epoxy compound, at least one partial structure represented by the following formula (1) and the following partial structure represented by formula (2): (In formula (1), X １ represents a divalent group represented by the following formula (1-1), (1-2), or (1-3): １ and Z ２A each independently represents a direct bond or a divalent group represented by the following formula (1-4): １ , A ２ , A ３ , A ４ , A ５ and A ６ Each of Q independently represents a hydrogen atom, a methyl group, or an ethyl group. * represents a bond. １ represents a divalent organic group having an aromatic hydrocarbon ring or an aliphatic hydrocarbon ring. １１ , A １２ , A １３ , A １４ , A １５ and A １６ each independently represents a hydrogen atom, a methyl group, or an ethyl group. n1 and n2 each independently represent 0 or 1. * represents a bond. (In formulas (1-1) to (1-3), R １ ~R ５ R each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms which may be interrupted by an oxygen atom or a sulfur atom, an alkenyl group having 2 to 10 carbon atoms which may be interrupted by an oxygen atom or a sulfur atom, an alkynyl group having 2 to 10 carbon atoms which may be interrupted by an oxygen atom or a sulfur atom, a benzyl group, or a phenyl group, and the phenyl group may be substituted with at least one monovalent group selected from the group consisting of an alkyl group having 1 to 6 carbon atoms, a halogen atom, an alkoxy group having 1 to 6 carbon atoms, a nitro group, a cyano group, and an alkylthio group having 1 to 6 carbon atoms. １ and R ２ may be bonded to each other to form a ring having 3 to 6 carbon atoms. ３ and R ４ may be bonded to each other to form a ring having 3 to 6 carbon atoms. * represents a bond. *1 represents a bond bonded to a carbon atom. *2 represents a bond bonded to a nitrogen atom. (In formula (1-4), m1 is an integer of 1 to 4, m2 is 0 or 1, *3 represents a bond bonded to a nitrogen atom, and *4 represents a bond bonded to a carbon atom.)

[0019] R in formulas (1-1) to (1-3) １ ~R５ Examples of the alkyl group having 1 to 10 carbon atoms which may be interrupted by an oxygen atom or a sulfur atom in the formula (I) include an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkoxyalkyl group having 2 to 10 carbon atoms, an alkoxyalkoxyalkyl group having 3 to 10 carbon atoms, an alkylthio group having 1 to 10 carbon atoms, and an alkylthioalkyl group having 2 to 10 carbon atoms. The alkyl group having 1 to 10 carbon atoms which may be interrupted by an oxygen atom or a sulfur atom may contain two or more oxygen atoms or sulfur atoms.

[0020] <<<X １ >>> X in formula (1) １ From the viewpoint of suitably obtaining the effects of the present invention, it is preferable that the compound represented by formula (1-3) is used.

[0021] The structure represented by the following (1A) in formula (1) is (In formula (1A), Z １ , Z ２ and X １ respectively represent Z in formula (1). １ , Z ２ and X １ (The symbol * represents a bond.) For example, the following structures are given as examples. In the above structure, * represents a bond.

[0022] <<<Q １ >>> Q in formula (2) １ From the viewpoint of suitably obtaining the effects of the present invention, it is preferable that the compound be represented by any one of the following formulas (2-1) to (2-4). (In formulas (2-1) to (2-4), R ２１ ~R ２６each independently represents a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkenyloxy group having 2 to 6 carbon atoms, an alkynyloxy group having 2 to 6 carbon atoms, an acyl group having 2 to 6 carbon atoms, an aryloxy group having 6 to 12 carbon atoms, an arylcarbonyl group having 7 to 13 carbon atoms, or an aralkyl group having 7 to 13 carbon atoms. * represents a bond. In formula (2-1), n3 represents 0 or 1. When n3 is 0, n11 represents an integer of 0 to 4. When n3 is 1, n11 represents an integer of 0 to 6. R ２１ When is 2 or more, R is 2 or more ２１ may be the same or different. １ represents a single bond, an oxygen atom, a sulfur atom, a carbonyl group, a sulfonyl group, or an alkylene group having 1 to 6 carbon atoms. n12 and n13 each independently represent an integer of 0 to 4. R ２２ When is 2 or more, R is 2 or more ２２ may be the same or different. ２３ When is 2 or more, R is 2 or more ２３ In formula (2-3), Y may be the same or different. １ and Y ２ each independently represents a single bond or an alkylene group having 1 to 6 carbon atoms. n14 represents an integer of 0 to 4. R ２４ When is 2 or more, R is 2 or more ２４ may be the same or different. ２ represents a single bond, an oxygen atom, a sulfur atom, a carbonyl group, a sulfonyl group, or an alkylene group having 1 to 6 carbon atoms. n15 and n16 each independently represent an integer of 0 to 4. R ２５ When is 2 or more, R is 2 or more ２５ may be the same or different. ２６ When is 2 or more, R is 2 or more ２６ may be the same or different.)

[0023] As used herein, examples of halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms. As used herein, alkyl groups are not limited to linear ones, and may be branched or cyclic. Examples of linear or branched alkyl groups include methyl groups, ethyl groups, isopropyl groups, tert-butyl groups, and n-hexyl groups. Examples of cyclic alkyl groups (cycloalkyl groups) include cyclobutyl groups, cyclopentyl groups, and cyclohexyl groups. As used herein, examples of alkoxy groups include methoxy groups, ethoxy groups, n-pentyloxy groups, and isopropoxy groups. As used herein, examples of alkylthio groups include methylthio groups, ethylthio groups, n-pentylthio groups, and isopropylthio groups. As used herein, examples of alkenyl groups include ethenyl, 1-propenyl, 2-propenyl, 1-methyl-1-ethenyl, 1-butenyl, 2-butenyl, 3-butenyl, 2-methyl-1-propenyl, and 2-methyl-2-propenyl groups. As used herein, examples of alkynyl groups include groups in which the double bond of the alkenyl groups listed above for "alkenyl groups" is replaced with a triple bond. As used herein, examples of alkenyloxy groups include vinyloxy, 1-propenyloxy, 2-n-propenyloxy (allyloxy), 1-n-butenyloxy, and prenyloxy groups. As used herein, examples of alkynyloxy groups include 2-propynyloxy, 1-methyl-2-propynyloxy, 2-methyl-2-propynyloxy, 2-butynyloxy, and 3-butynyloxy groups. As used herein, examples of acyl groups include acetyl groups and propionyl groups. As used herein, examples of aryloxy groups include phenoxy groups and naphthyloxy groups. As used herein, examples of arylcarbonyl groups include phenylcarbonyl groups. As used herein, examples of aralkyl groups include benzyl groups and phenethyl groups.In this specification, examples of the alkylene group include a methylene group, an ethylene group, a 1,3-propylene group, a 2,2-propylene group, a 1-methylethylene group, a 1,4-butylene group, a 1-ethylethylene group, a 1-methylpropylene group, a 2-methylpropylene group, a 1,5-pentylene group, a 1-methylbutylene group, a 2-methylbutylene group, a 1,1-dimethylpropylene group, a 1,2-dimethylpropylene group, a 1-ethylpropylene group, a 2-ethylpropylene group, a 1,6-hexylene group, a 1,4-cyclohexylene group, a 1,8-octylene group, a 2-ethyloctylene group, a 1,9-nonylene group, and a 1,10-decylene group.

[0024] The structure represented by the following (2A) in formula (2) is (In formula (2A), Q １ , n1 and n2 are respectively Q in formula (2) １ , n1 and n2 are the same. * represents a bond.) For example, the following structures can be mentioned. In the above structure, * represents a bond.

[0025] From the viewpoint of suitably achieving the effects of the present invention, the compound having the specific partial structure preferably has the following partial structure. For example, when the structure derived from the epoxy compound has the partial structure represented by formula (1) above, it preferably has a partial structure represented by formula (A) below and a partial structure represented by formula (B) below. Alternatively, for example, when the structure derived from the epoxy compound has the partial structure represented by formula (2) above, it preferably has a partial structure represented by formula (C) below and a partial structure represented by formula (D) below. (In formula (A), X １ , Z １ , Z ２ , A １ , A ２ , A ３ , A ４ , A ５ and A ６ are X in formula (1), respectively. １ , Z１ , Z ２ , A １ , A ２ , A ３ , A ４ , A ５ and A ６ It is the same as R １１ is R in formula (3). １１ In formula (B), X １ , Z １ , Z ２ , A １ , A ２ , A ３ , A ４ , A ５ and A ６ are X in formula (1), respectively. １ , Z １ , Z ２ , A １ , A ２ , A ３ , A ４ , A ５ and A ６ It is the same as: １１ is Q in formula (4) １１ In formula (C), Q １ , A １１ , A １２ , A １３ , A １４ , A １５ , A １６ 、 n1 and n2 are respectively Q in formula (2) １ , A １１ , A １２ , A １３ , A １４ , A １５ , A １６ 、 Same as n1 and n2. R １１ is R in formula (3). １１ In formula (D), Q １ , A １１ , A １２ , A １３ , A １４ , A １５ , A １６ 、 n1 and n2 are respectively Q in formula (2) １ , A １１ , A１２ , A １３ , A １４ , A １５ , A １６ 、 Same as n1 and n2. Q １１ is Q in formula (4) １１ is the same as

[0026] In the compound containing a structure derived from a dicarboxylic acid compound and a structure derived from an epoxy compound, the molar ratio [(M1+M2):(M3+M4)] of the total of the partial structure (M1) represented by formula (1) and the partial structure (M2) represented by formula (2) to the total of the partial structure (M3) represented by formula (3) and the partial structure (M4) represented by formula (4) is preferably 55:45 to 38:62, and more preferably 50:50 to 40:60.

[0027] <<Method for Producing Compound>> The method for producing the compound having the specific partial structure is not particularly limited, but for example, when the compound is a compound obtained by reacting reaction raw materials including an epoxy compound having at least two epoxy groups and a dicarboxylic acid compound, a method of reacting at least one of a diepoxy compound represented by formula (A1) below and a diepoxy compound represented by formula (A2) below with a dicarboxylic acid represented by formula (A3) below and a dicarboxylic acid represented by formula (A4) below can be mentioned. Note that from the viewpoint of producing a protective film with a faster etching rate, it is preferable to use a diepoxy compound represented by formula (A1) below rather than a diepoxy compound represented by formula (A2) below that has an aromatic hydrocarbon ring. Therefore, a more preferred embodiment of the method for producing a compound having a specific partial structure can be a production method of reacting a diepoxy compound represented by formula (A1) below with a dicarboxylic acid represented by formula (A3) below and a dicarboxylic acid represented by formula (A4) below.

[0028] For example, a diepoxy compound represented by the following formula (A1), a dicarboxylic acid represented by the following formula (A3), and a diepoxy compound represented by the following formula (A4) are dissolved in an organic solvent in an appropriate molar ratio. Then, in the presence of a catalyst that activates the epoxy groups, polymerization is performed to obtain a compound. When producing the compound, a diepoxy compound other than the diepoxy compound represented by formula (A1) and the diepoxy compound represented by formula (A2) may be used in combination. When producing the compound, a dicarboxylic acid other than the dicarboxylic acid represented by formula (A3) and the dicarboxylic acid represented by formula (A4) may be used in combination.

[0029] Examples of catalysts that activate epoxy groups include quaternary phosphonium salts such as tetrabutylphosphonium bromide and ethyltriphenylphosphonium bromide, and quaternary ammonium salts such as benzyltriethylammonium chloride. The amount of catalyst used can be selected appropriately from the range of 0.1 to 10% by mass based on the total mass of the raw compound materials used in the reaction. Optimal conditions for the temperature and time of the polymerization reaction can be selected, for example, from the ranges of 80 to 160°C and 2 to 50 hours.

[0030] (In formula (A1), X １ , Z １ , Z ２ , A １ , A ２ , A ３ , A ４ , A ５ and A ６ are X in formula (1), respectively. １ , Z １ , Z ２ , A １ , A ２ , A ３ , A ４ , A ５ and A ６ is the same as

[0031] (In formula (A2), Q １ , A １１ , A １２ , A １３ , A １４ , A１５ , A １６ 、 n1 and n2 are respectively Q in formula (2) １ , A １１ , A １２ , A １３ , A １４ , A １５ , A １６ 、 Same as n1 and n2.)

[0032] (In formula (A3), R １１ is R in formula (3). １１ is the same as

[0033] (In formula (A4), Q １１ is Q in formula (4) １１ is the same as

[0034] Examples of the diepoxy compound represented by formula (A1) include the following diepoxy compounds.

[0035] Examples of the diepoxy compound represented by formula (A2) include the following diepoxy compounds.

[0036] Examples of the dicarboxylic acid represented by formula (A3) include the following compounds.

[0037] Examples of the dicarboxylic acid represented by formula (A4) include the following compounds.

[0038] The weight-average molecular weight Mw of the compound is not particularly limited, but the lower limit is, for example, preferably 900 or more, more preferably 960 or more, even more preferably 1,000 or more, even more preferably 1,500 or more, and particularly preferably 2,000 or more. The upper limit of the weight-average molecular weight Mw is also not particularly limited, but the weight-average molecular weight Mw is preferably 50,000 or less. The compound of the present invention is more preferably a polymer having a weight-average molecular weight of 1,000 to 50,000, even more preferably 1,500 to 30,000, and particularly preferably 2,000 to 10,000. In the present invention, the weight-average molecular weight Mw is a polystyrene-equivalent value measured by gel permeation chromatography (GPC).

[0039] <Solvent> The solvent used in the protective film-forming composition is not particularly limited as long as it can uniformly dissolve the solid components contained therein at room temperature, but organic solvents generally used in chemical solutions for semiconductor lithography processes are preferred. Specifically, 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, cyclohexane, cyclohexane-1, cyclohexane-2, cyclohexane-3, cyclohexane-4, cyclohexane-5, cyclohexane-6, cyclohexane-7, cyclohexane-8, cyclohexane-9, cyclohexane-10, cyclohexane-11, cyclohexane-12, cyclohexane-13, cyclohexane-14, cyclohexane-15, cyclohexane-16, cyclohexane-17, cyclohexane-18, cyclohexane-19, cyclohexane-20, cyclohexane-21, cyclohexane-22, cyclohexane-23, cyclohexane-24, cyclohexane-25, cyclohexane-26, cyclohexane-27, cyclohexane-28, cyclohexane-29, cyclohexane-30, cyclohexane-31, cyclohexane-32, cyclohexane-33, cyclohexane-34, cyclohexane-35, cyclohexane-36, cyclohexane-37, cyclohexane-38, cyclohexane-49, cyclohexane-49, cyclohexane-49, cyclohexane-49, cyclohexane-51, cyclohexane-52, cyclohexane-19, cyclohexane-19, cyclohexane-29, cyclohexane-19, cyclohexane Examples of suitable solvents include heptanone, 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 may be used alone or in combination of two or more.

[0040] Among these solvents, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, ethyl lactate, butyl lactate, and cyclohexanone are preferred, with propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate being particularly preferred.

[0041] <Additives> The composition for forming a protective film of the present invention may contain, as an optional component, at least one compound represented by the following formula (1a) or formula (1b) in order to improve adhesion between the protective film formed from the composition for forming a protective film and the substrate: (In formulas (1a) and (1b), R １ represents a single bond, an alkylene group having 1 to 4 carbon atoms, or an alkenylene group having 2 to 4 carbon atoms and one or two carbon-carbon double bonds, k represents 0 or 1, m represents an integer of 1 to 3, and n represents an integer of 2 to 4.

[0042] Examples of the compound represented by formula (1a) include compounds represented by the following formulas (1a-1) to (1a-19).

[0043] Examples of the compound represented by formula (1b) include compounds represented by the following formulae (1b-1) to (1b-31).

[0044] When at least one compound represented by formula (1a) or formula (1b) is used, the content of the compound is, for example, 1% by mass to 50% by mass, preferably 1% by mass to 30% by mass, and more preferably 1% by mass to 15% by mass, relative to the compound having the specific partial structure of the present invention.

[0045] <Curing Catalyst> The curing catalyst contained as an optional component in the protective film-forming composition may be either a thermal acid generator or a photoacid generator, but it is preferable to use a thermal acid generator.

[0046] Examples of the thermal acid generator include sulfonic acid compounds and carboxylic acid compounds such as p-toluenesulfonic acid, trifluoromethanesulfonic acid, pyridinium p-toluenesulfonate (pyridinium p-toluenesulfonic acid), pyridinium phenolsulfonic acid, pyridinium p-hydroxybenzenesulfonic acid (pyridinium p-phenolsulfonate salt), pyridinium trifluoromethanesulfonic acid, salicylic acid, camphorsulfonic acid, 5-sulfosalicylic acid, 4-chlorobenzenesulfonic acid, 4-hydroxybenzenesulfonic acid, benzenedisulfonic acid, 1-naphthalenesulfonic acid, citric acid, benzoic acid, and hydroxybenzoic acid.

[0047] Examples of the photoacid generator include an onium salt compound, a sulfonimide compound, and a disulfonyldiazomethane compound.

[0048] Examples of the onium salt compound include iodonium salt compounds such as diphenyliodonium hexafluorophosphate, diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoro-normal butanesulfonate, diphenyliodonium perfluoro-normal octanesulfonate, diphenyliodonium camphorsulfonate, bis(4-tert-butylphenyl)iodonium camphorsulfonate, and bis(4-tert-butylphenyl)iodonium trifluoromethanesulfonate; and sulfonium salt compounds such as triphenylsulfonium hexafluoroantimonate, triphenylsulfonium nonafluoro-normal butanesulfonate, triphenylsulfonium camphorsulfonate, and triphenylsulfonium trifluoromethanesulfonate.

[0049] Examples of sulfonimide compounds include N-(trifluoromethanesulfonyloxy)succinimide, N-(nonafluoronormalbutanesulfonyloxy)succinimide, N-(camphorsulfonyloxy)succinimide, and N-(trifluoromethanesulfonyloxy)naphthalimide.

[0050] Examples of the disulfonyldiazomethane compound include bis(trifluoromethylsulfonyl)diazomethane, bis(cyclohexylsulfonyl)diazomethane, bis(phenylsulfonyl)diazomethane, bis(p-toluenesulfonyl)diazomethane, bis(2,4-dimethylbenzenesulfonyl)diazomethane, and methylsulfonyl-p-toluenesulfonyldiazomethane.

[0051] The curing catalyst may be used alone or in combination of two or more.

[0052] When a curing catalyst is used, the content of the curing catalyst is, for example, 0.1% by mass to 50% by mass, and preferably 1% by mass to 30% by mass, based on the compound of the present invention.

[0053] <Crosslinking Agent> The protective film-forming composition may further contain the crosslinking agent described below as an optional component. Examples of crosslinking agents include melamine-based crosslinkers having an alkoxymethyl group, substituted urea-based crosslinkers, and compounds thereof. Examples of the alkoxy group include alkoxy groups having 1 to 10 carbon atoms, such as methoxy, ethoxy, propoxy, and butoxy. Examples of methyl groups having such alkoxy groups include methoxymethyl, ethoxymethyl, propoxymethyl, and butoxymethyl groups. Preferred are cross-linking agents having at least two bridge-forming substituents, such as hexamethoxymethylmelamine, tetramethoxymethylbenzoguanamine, 1,3,4,6-tetrakis(methoxymethyl)glycoluril (tetramethoxymethylglycoluril) (POWDERLINK® 1174), 1,3,4,6-tetrakis(butoxymethyl)glycoluril, 1,3,4,6-tetrakis(hydroxymethyl)glycoluril, 1,3-bis(hydroxymethyl)urea, 1,1,3,3-tetrakis(butoxymethyl)urea, and 1,1,3,3-tetrakis(methoxymethyl)urea.

[0054] Furthermore, a crosslinking agent having high heat resistance can be used as the crosslinking agent, such as a compound containing a crosslink-forming substituent having an aromatic ring (e.g., a benzene ring or a naphthalene ring) in the molecule.

[0055] This compound may be a compound having a partial structure of the following formula (H-1), or a polymer or oligomer having a repeating unit of the following formula (H-2).

[0056] R １１ , R １２ , R １３ , and R １４ is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and the alkyl groups mentioned above can be used.

[0057] m1 is 1≦m1≦(6-m2). m2 is 1≦m2≦5. m3 is 1≦m3≦(4-m2). m4 is 1≦m4≦3.

[0058] Examples of the compounds, polymers and oligomers of formula (H-1) and formula (H-2) are shown below.

[0059] (In the formula, Me represents a methyl group.)

[0060] (In the formula, Me represents a methyl group.)

[0061] The above compounds are available as products of Asahi Organic Chemicals Co., Ltd. and Honshu Chemical Industry Co., Ltd. For example, among the above crosslinking agents, the compound of formula (H-1-23) is available from Honshu Chemical Industry Co., Ltd. under the trade name TMOM-BP. The compound of formula (H-1-20) is available from Asahi Organic Chemicals Co., Ltd. under the trade name TM-BIP-A.

[0062] The crosslinking agent may also be a nitrogen-containing compound having 2 to 6 substituents bonded to nitrogen atoms and represented by the following formula (1d) per molecule, as described in WO 2017 / 187969:

[0063] (In formula (1d), R １ represents a methyl group or an ethyl group. * represents a bond to the nitrogen atom.)

[0064] The nitrogen-containing compound having 2 to 6 substituents represented by the formula (1d) in one molecule may be a glycoluril derivative represented by the following formula (1E).

[0065] (In formula (1E), four R １ each independently represents a methyl group or an ethyl group, R ２ and R ３ each independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a phenyl group.

[0066] Examples of the glycoluril derivative represented by the formula (1E) include compounds represented by the following formulas (1E-1) to (1E-6).

[0067]

[0068] The nitrogen-containing compound having 2 to 6 substituents represented by the formula (1d) in one molecule can be obtained by reacting a nitrogen-containing compound having 2 to 6 substituents bonded to a nitrogen atom in one molecule, represented by the following formula (2d), with at least one compound represented by the following formula (3d):

[0069] (In formula (2d) and formula (3d), R １ represents a methyl group or an ethyl group, R ４ represents an alkyl group having 1 to 4 carbon atoms. * represents a bond to a nitrogen atom.)

[0070] The glycoluril derivative represented by the formula (1E) can be obtained by reacting a glycoluril derivative represented by the following formula (2E) with at least one compound represented by the formula (3d).

[0071] The nitrogen-containing compound having 2 to 6 substituents represented by the formula (2d) in one molecule is, for example, a glycoluril derivative represented by the following formula (2E).

[0072] (In formula (2E), R ２ and R ３ each independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a phenyl group; R ４ each independently represents an alkyl group having 1 to 4 carbon atoms.

[0073] Examples of glycoluril derivatives represented by formula (2E) include compounds represented by formulas (2E-1) to (2E-4) below. Furthermore, examples of compounds represented by formula (3d) include compounds represented by formulas (3d-1) and (3d-2) below.

[0074]

[0075] The entire disclosure of WO 2017 / 187969 is incorporated herein by reference with respect to the content of a nitrogen-containing compound having 2 to 6 substituents bonded to a nitrogen atom and represented by formula (1d) per molecule.

[0076] When a crosslinking agent is used, the content of the crosslinking agent is, for example, 1% by mass to 50% by mass, and preferably 1% by mass to 30% by mass, based on the compound of the present invention.

[0077] <Other Components> A surfactant may be further added to the protective film-forming composition to prevent pinholes, striations, etc., and further improve application properties for surface unevenness. Examples of surfactants include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, and polyoxyethylene oleyl ether; polyoxyethylene alkylaryl ethers such as polyoxyethylene octylphenol ether and polyoxyethylene nonylphenol ether; polyoxyethylene-polyoxypropylene block copolymers; sorbitan fatty acid esters such as sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, sorbitan trioleate, and sorbitan tristearate; polyoxyethylene sorbitan monolaurate; and polyoxyethylene sorbitan monopalmitate. nonionic surfactants such as polyoxyethylene sorbitan fatty acid esters, such as polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, and polyoxyethylene sorbitan tristearate; fluorine-based surfactants such as Eftop EF301, EF303, and EF352 (trade names, manufactured by Tochem Products Co., Ltd.), Megafac F171, F173, R-30, and R-40 (trade names, manufactured by DIC Corporation), Fluorad FC430 and FC431 (trade names, manufactured by Sumitomo 3M Limited), Asahiguard AG710, Surflon S-382, SC101, SC102, SC103, SC104, SC105, and SC106 (trade names, manufactured by Asahi Glass Co., Ltd.); and organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.). The amount of these surfactants to be added is usually 2.0% by mass or less, and preferably 1.0% by mass or less, based on the total solid content of the protective film-forming composition. These surfactants may be added alone or in combination of two or more.

[0078] The nonvolatile content of the protective film-forming composition, that is, the content of components excluding the solvent, is, for example, 0.01% by mass to 10% by mass.

[0079] (Compound) The present invention specifies a compound that can be suitably used in the above-described protective film-forming composition. The compound of the present invention is a compound obtained by reacting a reaction raw material containing an epoxy compound having at least two epoxy groups and a dicarboxylic acid compound, which is described as a particularly preferred embodiment among the compounds having the specific partial structure described in the <Compound> section of the above (Protective Film-Forming Composition). The compound of the present invention has, as structures derived from the dicarboxylic acid compound, a partial structure represented by the above formula (3) and a partial structure represented by the above formula (4). Furthermore, a preferred embodiment of the compound of the present invention includes a compound having, as structures derived from the epoxy compound, at least one of the partial structure represented by the above formula (1) and the partial structure represented by the above formula (2). The partial structures represented by formulas (1) to (4) in the compound of the present invention and the method for producing the compound are as described in the <Compound> section of the above (Protective Film-Forming Composition).

[0080] (Protective film, method for manufacturing a substrate with a protective film, method for manufacturing a substrate with a resist pattern, and method for manufacturing a semiconductor device) The protective film of the present invention is a fired product of a coating film made of a composition for forming a protective film. The method for manufacturing a substrate with a protective film of the present invention includes a step of applying the composition for forming a protective film of the present invention to a semiconductor substrate having a step and firing the composition to form a protective film.

[0081] The method for producing a substrate having a resist pattern of the present invention includes the following steps (1) and (2): Step (1): A step of applying the composition for forming a protective film of the present invention onto a semiconductor substrate and baking the composition to form a protective film as a resist underlayer film; Step (2): A step of forming a resist film on the protective film directly or via another layer, followed by exposure and development to form a resist pattern.

[0082] The method for manufacturing a semiconductor device of the present invention includes the following steps (A) to (D): step (A): forming a protective film on a semiconductor substrate having an inorganic film formed on its surface using the protective film-forming composition of the present invention; step (B): forming a resist pattern on the protective film directly or via another layer; step (C): dry-etching the protective film using the resist pattern as a mask to expose the surface of the inorganic film; step (D): wet-etching the inorganic film using a semiconductor wet etching solution using the protective film after dry etching as a mask.

[0083] Examples of semiconductor substrates onto which the protective film-forming composition of the present invention can be applied include silicon wafers, germanium wafers, and wafers of compound semiconductors such as gallium arsenide, indium phosphide, gallium nitride, indium nitride, and aluminum nitride.

[0084] When a semiconductor substrate having an inorganic film formed on its surface is used, the inorganic film can be 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, borophosphosilicate glass (BPSG) films, titanium nitride films, titanium oxynitride films, tungsten nitride films, gallium nitride films, and gallium arsenide films. The semiconductor substrate may be a stepped substrate having vias (holes), trenches (grooves), or the like formed therein. For example, the via has a substantially circular shape when viewed from above, with a diameter of, for example, 2 nm to 20 nm and a depth of, for example, 50 nm to 500 nm, and the trench has a groove (recess in the substrate) with a width of, for example, 2 nm to 20 nm and a depth of, for example, 50 nm to 500 nm. The composition for forming a protective film of the present invention has a small weight-average molecular weight and average particle size of the compounds contained in the composition, and therefore, the composition can be used to fill uneven substrates such as those described above without defects such as voids (gaps), etc. The absence of defects such as voids is an important characteristic for the subsequent steps in semiconductor manufacturing (wet etching / dry etching of the semiconductor substrate, and resist pattern formation).

[0085] The protective film-forming composition of the present invention is applied to such a semiconductor substrate using an appropriate application method such as a spinner or coater. A protective film is then formed by baking using a heating means such as a hot plate. Baking conditions are appropriately selected from a baking temperature of 100°C to 400°C and a baking time of 0.3 to 60 minutes. Preferably, the baking temperature is 120°C to 350°C, the baking time is 0.5 to 30 minutes, and more preferably, the baking temperature is 150°C to 300°C, and the baking time is 0.8 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 above range, crosslinking may be insufficient, and the formed protective film may not be resistant to resist solvents or basic hydrogen peroxide aqueous solutions. On the other hand, if the baking temperature is higher than the above range, the protective film may be thermally decomposed.

[0086] A resist film is formed on the protective film formed as described above, either directly or via another layer, followed by exposure and development to form a resist pattern. Exposure is performed through a mask (reticle) for forming a predetermined pattern, and for example, i-line, KrF excimer laser, ArF excimer laser, EUV (extreme ultraviolet), or EB (electron beam) is used. An alkaline developer is used for development, with the development temperature selected from 5°C to 50°C and the development time selected from 10 seconds to 300 seconds. Examples of alkaline developers that can be used include aqueous solutions of inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia; primary amines such as ethylamine and n-propylamine; secondary amines such as diethylamine and di-n-butylamine; tertiary amines such as triethylamine and methyldiethylamine; alcohol amines such as dimethylethanolamine and triethanolamine; quaternary ammonium salts such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, and choline; and cyclic amines such as pyrrole and piperidine. Furthermore, an appropriate amount of an alcohol such as isopropyl alcohol or a nonionic surfactant can be added to the aqueous alkali solution. Among these, preferred developers are quaternary ammonium salts, more preferably tetramethylammonium hydroxide and choline. Furthermore, surfactants can be added to these developers. A method can also be used in which development is carried out with an organic solvent such as butyl acetate instead of an alkaline developer, and the parts of the photoresist where the alkaline dissolution rate is not improved are developed.

[0087] Next, the protective film is dry-etched using the formed resist pattern as a mask, to expose the surface of the inorganic film if the inorganic film is formed on the surface of the semiconductor substrate used, or to expose the surface of the semiconductor substrate if the inorganic film is not formed on the surface of the semiconductor substrate used.

[0088] Furthermore, the protective film after dry etching (and the resist pattern, if any, remaining on the protective film) is used as a mask to perform wet etching using a semiconductor wet etching solution, thereby forming a desired pattern.

[0089] As the wet etching solution for semiconductors, a general chemical solution for etching semiconductor wafers can be used, and for example, either an acidic substance or a basic substance can be used.

[0090] Examples of substances that exhibit acidity include hydrogen peroxide, hydrofluoric acid, ammonium fluoride, acidic ammonium fluoride, ammonium hydrogen fluoride, buffered hydrofluoric acid, hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, and mixtures thereof.

[0091] Examples of substances that exhibit basicity include basic hydrogen peroxide solution, which is obtained by mixing ammonia, sodium hydroxide, potassium hydroxide, sodium cyanide, potassium cyanide, or an organic amine such as triethanolamine with hydrogen peroxide solution to make the pH basic. A specific example is SC-1 (ammonia-hydrogen peroxide solution). Other substances that can make the pH basic, such as a solution obtained by mixing urea with hydrogen peroxide solution and heating to cause thermal decomposition of the urea to generate ammonia, which ultimately makes the pH basic, can also be used as a wet etching chemical.

[0092] Among these, acidic hydrogen peroxide solution or basic hydrogen peroxide solution is preferred.

[0093] These chemical solutions may contain additives such as surfactants.

[0094] The temperature at which the semiconductor wet etching solution is used is preferably 25° C. to 90° C., and more preferably 40° C. to 80° C. The wet etching time is preferably 0.5 to 30 minutes, and more preferably 1 to 20 minutes.

[0095] Next, the present invention will be explained in detail with reference to synthesis examples and examples, but the present invention is not limited to these.

[0096] The weight average molecular weight (Mw) of the polymers shown in the following synthesis examples is the result of measurement by gel permeation chromatography (GPC). A GPC device manufactured by Tosoh Corporation was used for the measurement, and the measurement conditions are as follows: Measurement device: HLC-8020GPC (trade name) (manufactured by Tosoh Corporation) Column temperature: 40°C Solvent: tetrahydrofuran (THF) Flow rate: 1.0 mL / min Standard sample: polystyrene (manufactured by Tosoh Corporation)

[0097] Synthesis Example 1 In a reaction flask was added 80.0 g of diglycidyl methylisocyanurate (product name: MeDGIC, manufactured by Shikoku Chemical Industry Co., Ltd., 29.9 wt% propylene glycol monomethyl ether solution), 15.2 g of succinic acid (Tokyo Chemical Industry Co., Ltd.), 0.6 g of diglycolic acid (Tokyo Chemical Industry Co., Ltd.), and 2.4 g of tetrabutylphosphonium bromide (Hokuko Chemical Industry Co., Ltd.), and 112.7 g of propylene glycol monomethyl ether was added. The resulting mixture was heated and stirred in a nitrogen atmosphere at 100°C for 16 hours in a reaction flask. The resulting reaction product corresponded to formula (x-1), and had a weight average molecular weight Mw of 960 as measured by GPC in terms of polystyrene.

[0098] Synthesis Example 2 In a reaction flask was added 80.0 g of diglycidyl methylisocyanurate (product name: MeDGIC, manufactured by Shikoku Chemical Industry Co., Ltd., 29.9 wt% propylene glycol monomethyl ether solution), 14.3 g of succinic acid (Tokyo Chemical Industry Co., Ltd.), 2.9 g of diglycolic acid (Tokyo Chemical Industry Co., Ltd.), and 2.4 g of tetrabutylphosphonium bromide (Hokuko Chemical Industry Co., Ltd.), and 118.3 g of propylene glycol monomethyl ether was added. The resulting mixture was heated and stirred in a nitrogen atmosphere at 100°C for 16 hours in a reaction flask. The resulting reaction product corresponded to formula (x-2), and had a weight average molecular weight Mw of 984 as measured by GPC in terms of polystyrene.

[0099] Synthesis Example 3 In a reaction flask was added 40.0 g of diglycidyl methylisocyanurate (product name: MeDGIC, manufactured by Shikoku Chemical Industry Co., Ltd., 29.9 wt% propylene glycol monomethyl ether solution), 6.6 g of succinic acid (Tokyo Chemical Industry Co., Ltd.), 1.4 g of 2,2'-thiodiglycolic acid (Tokyo Chemical Industry Co., Ltd.), and 1.2 g of tetrabutylphosphonium bromide (Hokuko Chemical Industry Co., Ltd.), and 50.9 g of propylene glycol monomethyl ether was added. The resulting mixture was heated and stirred in a nitrogen atmosphere at 100°C for 16 hours in a reaction flask. The resulting reaction product corresponded to formula (x-3), and had a weight average molecular weight Mw of 1008 as measured by GPC in terms of polystyrene.

[0100] Synthesis Example 4 In a reaction flask was added 110.0 g of diglycidyl methylisocyanurate (product name: MeDGIC, manufactured by Shikoku Chemical Industry Co., Ltd., 29.9 wt% propylene glycol monomethyl ether solution), 17.0 g of succinic acid (Tokyo Chemical Industry Co., Ltd.), 9.5 g of dithiodiglycolic acid (Tokyo Chemical Industry Co., Ltd.), and 3.3 g of tetrabutylphosphonium bromide (Hokuko Chemical Industry Co., Ltd.), and 69.4 g of propylene glycol monomethyl ether was added. The resulting mixture was heated and stirred in a nitrogen atmosphere at 100°C for 16 hours in a reaction flask. The resulting reaction product corresponded to formula (x-4), and had a weight average molecular weight Mw of 1213 as measured by GPC in terms of polystyrene.

[0101] Synthesis Example 5 In a reaction flask was added 30.0 g of diglycidyl methylisocyanurate (product name: MeDGIC, manufactured by Shikoku Chemical Industry Co., Ltd., 29.9 wt% propylene glycol monomethyl ether solution), 2.5 g of succinic acid (Tokyo Chemical Industry Co., Ltd.), 4.5 g of 3,3'-dithiodipropionic acid (Tokyo Chemical Industry Co., Ltd.), and 0.9 g of tetrabutylphosphonium bromide (Hokuko Chemical Industry Co., Ltd.), and 18.5 g of propylene glycol monomethyl ether was added. The resulting mixture was heated and stirred in a nitrogen atmosphere at 100°C for 16 hours in a reaction flask. The resulting reaction product corresponded to formula (x-5), and had a weight average molecular weight Mw of 1840 as measured by GPC in terms of polystyrene.

[0102] Example 1 0.033 g of pyridinium trifluoromethanesulfonate (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.088 g of gallic acid represented by the following formula (a) (manufactured by Tokyo Chemical Industry Co., Ltd.), and 14.1 g of propylene glycol monomethyl ether were added to 5.5 g of a solution (solids content: 16.0% by mass) of the reaction product corresponding to formula (x-1) obtained by the method described in Synthesis Example 1. The solution was filtered using a polyethylene microfilter having a pore size of 0.02 μm to prepare a protective film-forming composition.

[0103] Example 2 0.033 g of pyridinium trifluoromethanesulfonate (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.088 g of gallic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), and 14.1 g of propylene glycol monomethyl ether were added to 5.5 g of a solution (solids content: 16.1% by mass) of the reaction product corresponding to formula (x-2) obtained by the method described in Synthesis Example 2. The solution was filtered using a polyethylene microfilter having a pore size of 0.02 μm to prepare a protective film-forming composition.

[0104] Example 3 0.033 g of pyridinium trifluoromethanesulfonate (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.088 g of gallic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), and 14.7 g of propylene glycol monomethyl ether were added to 5.1 g of a solution of the reaction product corresponding to formula (x-3) (solid content: 17.1% by mass) obtained by the method described in Synthesis Example 3. The solution was filtered using a polyethylene microfilter having a pore size of 0.02 μm to prepare a protective film-forming composition.

[0105] Example 4 0.033 g of pyridinium trifluoromethanesulfonate (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.088 g of gallic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), and 16.1 g of propylene glycol monomethyl ether were added to 3.8 g of a solution (solids content: 23.1% by mass) of the reaction product corresponding to formula (x-4) obtained by the method described in Synthesis Example 4. The solution was filtered using a polyethylene microfilter having a pore size of 0.02 μm to prepare a protective film-forming composition.

[0106] Example 5 0.033 g of pyridinium trifluoromethanesulfonate (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.088 g of gallic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), and 16.0 g of propylene glycol monomethyl ether were added to 3.9 g of a solution (solids content: 22.7% by mass) of the reaction product corresponding to formula (x-5) obtained by the method described in Synthesis Example 5. The solution was filtered using a polyethylene microfilter having a pore size of 0.02 μm to prepare a protective film-forming composition.

[0107] Comparative Example 1 To 4.78 g of a solution (solids content: 16.5% by mass) of a reaction product (a copolymer represented by the following formula (1n) and having a weight-average molecular weight of 4,500 as measured by GPC relative to polystyrene standards) obtained by the method described in Japanese Patent No. 7,029,112 (Synthesis Example 7), 0.030 g of pyridinium trifluoromethanesulfonate (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.040 g of gallic acid hydrate (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.00079 g of a surfactant (product name: Megafac R-40, manufactured by DIC Corporation), 13.2 g of propylene glycol monomethyl ether, and 1.9 g of propylene glycol monomethyl ether acetate were added to obtain a solution. The solution was filtered using a polyethylene microfilter having a pore size of 0.02 μm to prepare a composition for forming a protective film.

[0108] [Resistance Test to Basic Hydrogen Peroxide Aqueous Solution (Chemical Solution Resistance Test)] Protective films (coating films) were formed using each of the protective film-forming compositions prepared in Examples 1 to 5 and Comparative Example 1, and a resistance test to a basic hydrogen peroxide aqueous solution was performed. An outline of the resistance test is shown in FIGS. 1A to 1D. As shown in FIG. 1A, a silicon substrate 1 having a 5-nm-thick titanium nitride (TiN) film formed on its surface and having a step (width 37 nm, depth 240 nm) was used as the semiconductor substrate. FIG. 1A shows a portion of the silicon substrate, and multiple steps are provided. Next, as shown in FIG. 1B, each of the protective film-forming compositions prepared in Examples 1 to 5 and Comparative Example 1 was applied to the silicon substrate 1, and heated at 220°C for 60 seconds to form a coating film (protective film 2). Next, as shown in FIG. 1C, the formed protective film 2 was subjected to a dry etching process using a RIE-200NL (manufactured by Samco Inc.) to remove N ２ / O ２ Mixed gas (N ２ / O ２ The protective film 2 was dry-etched for 60 seconds using a 200 / 10 volume ratio solution. The protective film 2 was dry-etched so that the TiN on the wall surface within the step was exposed. Next, a basic hydrogen peroxide solution was prepared by mixing 20 mL of a 28% by mass ammonia solution, 80 mL of a 33% by mass hydrogen peroxide solution, and 400 mL of ultrapure water. The silicon substrate 1 dry-etched as described above was immersed in the basic hydrogen peroxide solution heated to 60°C for 100 seconds for wet etching. The protective film 2 was then rinsed with water and dried. The state of the protective film 2 after drying was observed using a field-emission scanning electron microscope (Regulus® 8240) manufactured by Hitachi High-Technologies Corporation. As shown in FIG. 1D, the TiN was removed deeper within the step than the protective film by the wet etching. The results of the resistance test to the basic hydrogen peroxide solution are shown in Table 1 below. In Table 1, "◯" indicates that no peeling was observed in the protective film after immersion, and "×" indicates that peeling was observed in part or all of the protective film after immersion, resulting in a worsening condition.

[0109]

[0110] [Evaluation of Etching Selectivity] To evaluate the etching selectivity, each of the resist underlayer film-forming compositions (protective film-forming compositions) prepared in Examples 1 to 5 and Comparative Example 1 was applied to a silicon wafer and heated at 220°C for 1 minute to form a protective film with a thickness of 100 nm. Next, the formed protective film was dry-etched using a dry etching apparatus (product name: Lam2300, Lam Research) with a mixed gas of nitrogen gas and hydrogen gas, and the dry etching rate ratio (dry etching rate selectivity) of the protective film was measured. The measurement results of the etching selectivity are shown in Table 2 below. It can be said that the higher the etching selectivity, the faster the dry etching rate.

[0111]

[0112] The results in the above table show that the coating films prepared using the protective film-forming compositions prepared in Examples 1 to 5 can be protective films that have excellent resistance to semiconductor wet etching solutions and solvents contained in resist compositions. They also have a high etching rate.

[0113] 1 Silicon substrate 2 Protective film

Claims

1. A compound obtained by reacting reaction raw materials including an epoxy compound having at least two epoxy groups and a dicarboxylic acid compound, the compound having a partial structure represented by the following formula (3) and a partial structure represented by the following formula (4) as structures derived from the dicarboxylic acid compound: (In formula (3), R １１ represents an alkylene group having 1 to 10 carbon atoms. * represents a bond. In formula (4), Q １１ represents a divalent organic group having at least one heteroatom selected from the group consisting of oxygen, sulfur, and nitrogen in the main chain.

2. The compound according to claim 1, having at least one of a partial structure represented by the following formula (1) and a partial structure represented by the following formula (2) as a structure derived from the epoxy compound: (In formula (1), X １ represents a divalent group represented by the following formula (1-1), (1-2), or (1-3): １ and Z ２ A each independently represents a direct bond or a divalent group represented by the following formula (1-4): １ , A ２ , A ３ , A ４ , A ５ and A ６ Each of Q independently represents a hydrogen atom, a methyl group, or an ethyl group. * represents a bond. １ represents a divalent organic group having an aromatic hydrocarbon ring or an aliphatic hydrocarbon ring. １１ , A １２ , A １３ , A １４ , A １５ and A １６ each independently represents a hydrogen atom, a methyl group, or an ethyl group. n1 and n2 each independently represent 0 or 1. * represents a bond. (In formulas (1-1) to (1-3), R １ ~R ５ R each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms which may be interrupted by an oxygen atom or a sulfur atom, an alkenyl group having 2 to 10 carbon atoms which may be interrupted by an oxygen atom or a sulfur atom, an alkynyl group having 2 to 10 carbon atoms which may be interrupted by an oxygen atom or a sulfur atom, a benzyl group, or a phenyl group, and the phenyl group may be substituted with at least one monovalent group selected from the group consisting of an alkyl group having 1 to 6 carbon atoms, a halogen atom, an alkoxy group having 1 to 6 carbon atoms, a nitro group, a cyano group, and an alkylthio group having 1 to 6 carbon atoms. １ and R ２ may be bonded to each other to form a ring having 3 to 6 carbon atoms. ３ and R ４ may be bonded to each other to form a ring having 3 to 6 carbon atoms. * represents a bond. *1 represents a bond bonded to a carbon atom. *2 represents a bond bonded to a nitrogen atom. (In formula (1-4), m1 is an integer of 1 to 4, m2 is 0 or 1, *3 represents a bond bonded to a nitrogen atom, and *4 represents a bond bonded to a carbon atom.) 3. The compound according to claim 2, which has a partial structure represented by formula (1) as a structure derived from the epoxy compound.

4. X in the formula (1) １ The compound according to claim 3, wherein the compound is represented by formula (1-3).

5. The compound according to claim 2, wherein the molar ratio [(M1+M2):(M3+M4)] of the sum of the partial structure (M1) represented by formula (1) and the partial structure (M2) represented by formula (2), which are related to the structure derived from the epoxy compound, to the sum of the partial structure (M3) represented by formula (3) and the partial structure (M4) represented by formula (4), which are related to the structure derived from the dicarboxy compound, is 55:45 to 38:

62.

6. A composition for forming a protective film for forming a protective film that protects an inorganic film formed on a surface of a semiconductor substrate from wet etching, the composition comprising a compound having a partial structure represented by the following formula (3) and a partial structure represented by the following formula (4), and a solvent. (In formula (3), R １１ represents an alkylene group having 1 to 10 carbon atoms. * represents a bond. In formula (4), Q １１ represents a divalent organic group having at least one heteroatom selected from the group consisting of oxygen, sulfur, and nitrogen in the main chain.

7. The composition for forming a protective film according to claim 6, wherein the compound is obtained by reacting reaction raw materials including an epoxy compound having at least two epoxy groups and a dicarboxylic acid compound, and has a partial structure represented by formula (3) and a partial structure represented by formula (4) as structures derived from the dicarboxylic acid compound.

8. The composition for forming a protective film according to claim 7, wherein the compound has, as a structure derived from the epoxy compound, at least one of a partial structure represented by the following formula (1) and a partial structure represented by the following formula (2): (In formula (1), X １ represents a divalent group represented by the following formula (1-1), (1-2), or (1-3): １ and Z ２ A each independently represents a direct bond or a divalent group represented by the following formula (1-4): １ , A ２ , A ３ , A ４ , A ５ and A ６ Each of Q independently represents a hydrogen atom, a methyl group, or an ethyl group. * represents a bond. １ represents a divalent organic group having an aromatic hydrocarbon ring or an aliphatic hydrocarbon ring. １１ , A １２ , A １３ , A １４ , A １５ and A １６ each independently represents a hydrogen atom, a methyl group, or an ethyl group. n1 and n2 each independently represent 0 or 1. * represents a bond. (In formulas (1-1) to (1-3), R １ ~R ５ R each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms which may be interrupted by an oxygen atom or a sulfur atom, an alkenyl group having 2 to 10 carbon atoms which may be interrupted by an oxygen atom or a sulfur atom, an alkynyl group having 2 to 10 carbon atoms which may be interrupted by an oxygen atom or a sulfur atom, a benzyl group, or a phenyl group, and the phenyl group may be substituted with at least one monovalent group selected from the group consisting of an alkyl group having 1 to 6 carbon atoms, a halogen atom, an alkoxy group having 1 to 6 carbon atoms, a nitro group, a cyano group, and an alkylthio group having 1 to 6 carbon atoms. １ and R ２ may be bonded to each other to form a ring having 3 to 6 carbon atoms. ３ and R ４ may be bonded to each other to form a ring having 3 to 6 carbon atoms. * represents a bond. *1 represents a bond bonded to a carbon atom. *2 represents a bond bonded to a nitrogen atom. (In formula (1-4), m1 is an integer of 1 to 4, m2 is 0 or 1, *3 represents a bond bonded to a nitrogen atom, and *4 represents a bond bonded to a carbon atom.) 9. The composition for forming a protective film according to any one of claims 6 to 8, further comprising at least one of a compound represented by the following formula (1a) and a compound represented by the following formula (1b): (In formulas (1a) and (1b), R １ represents a single bond, an alkylene group having 1 to 4 carbon atoms, or an alkenylene group having 2 to 4 carbon atoms and one or two carbon-carbon double bonds, k represents 0 or 1, m represents an integer of 1 to 3, and n represents an integer of 2 to 4.

10. The composition for forming a protective film according to any one of claims 6 to 8, further comprising an acid generator.

11. A protective film against a wet etching solution for semiconductors, which is a fired product of a coating film made of the composition for forming a protective film according to any one of claims 6 to 8.

12. A method for producing a substrate with a protective film, comprising the steps of applying the composition for forming a protective film according to any one of claims 6 to 8 onto a semiconductor substrate having a step and baking the composition to form a protective film.

13. A method for producing a substrate with a resist pattern, for use in the production of semiconductors, comprising the steps of: applying the composition for forming a protective film according to any one of claims 6 to 8 onto a semiconductor substrate and baking the composition to form a protective film as a resist underlayer film; and forming a resist film on the protective film directly or via another layer, and then exposing and developing the resist film to form a resist pattern.

14. A method for manufacturing a semiconductor device, comprising the steps of forming a protective film on a semiconductor substrate having an inorganic film formed on its surface using the protective film-forming composition according to any one of claims 6 to 8, forming a resist pattern on the protective film directly or via another layer, dry-etching the protective film using the resist pattern as a mask to expose the surface of the inorganic film, and wet-etching the inorganic film using a semiconductor wet etching solution using the protective film after dry etching as a mask.

Images