Composition for forming resist underlayer film to reduce environmental impact

Abstract

A composition for forming a resist underlayer film contains a first component, a second component, and a solvent. The second component is a water-soluble polymer, the mass ratio of the first component and the second component (first component: second component) is 99:1 to 50:50, and the solvent contains water in an amount of 50% by mass or more relative to the solvent.

Description

Composition for forming resist underlayer film for reducing environmental impact

[0001] The present invention relates to a composition for forming a resist underlayer film, a resist underlayer film, a substrate for semiconductor processing, a method for manufacturing a semiconductor element, and a method for forming a pattern.

[0002] Conventionally, in the manufacture of semiconductor devices, microfabrication by lithography using a photoresist composition has been carried out. This microfabrication is a processing method in which a thin film of the photoresist composition is formed on a silicon wafer, and the thin film is irradiated with active energy rays such as ultraviolet light through a mask pattern on which a semiconductor device pattern is drawn, and then developed, and the silicon wafer is etched using the resulting resist pattern as a protective film.

[0003] However, in recent years, with the progress in the high integration of semiconductor devices, there has been a trend toward shorter wavelengths of active energy rays, from KrF excimer lasers (248 nm) to ArF excimer lasers (193 nm). As a result, the effects of diffuse reflection and standing waves of active energy rays from the substrate have become a major problem. Therefore, a method of providing an anti-reflective coating (Bottom Anti-Reflective Coating: BARC), which is a resist underlayer film, between the photoresist and the substrate has been widely studied.

[0004] For example, the present applicant has proposed an anti-reflective coating-forming composition that has a high anti-reflective light effect, does not cause intermixing with a resist layer, provides an excellent resist pattern and a wide focus depth margin, and can provide an anti-reflective coating for lithography that has a higher dry etching rate than a resist (see Patent Document 1).

[0005] International Publication No. 2003 / 017002

[0006] Resist underlayer film-forming compositions are generally organic solvent-based compositions in which a polymer is dissolved in an organic solvent. The replacement of organic solvent-based paints and the like with water-based paints is being actively considered due to the environmental impact of volatile organic solvents and the health of workers who handle the paints. Resist underlayer film-forming compositions are used in clean rooms, so volatile organic solvents are less likely to be released into the environment and workers are not exposed to organic solvents. However, in terms of waste liquid disposal and the need for caution in handling and transportation due to the flammability of organic solvent-based compositions, water-based compositions are preferred.

[0007] An object of the present invention is to provide a composition for forming a resist underlayer film, which uses water as a solvent, a resist underlayer film, a substrate for semiconductor processing, a method for producing a semiconductor element, and a method for forming a pattern.

[0008] The present inventors conducted extensive research to solve the above-mentioned problems, and as a result, found that the above-mentioned problems can be solved, and completed the present invention having the following gist. That is, the present invention includes the following: [1] A composition for forming a resist underlayer film, comprising a first component, a second component, and a solvent, wherein the second component is a water-soluble polymer, the mass ratio of the first component to the second component (first component:second component) is 99:1 to 50:50, and the solvent contains 50% by mass or more of water relative to the solvent. [2] A composition for forming a resist underlayer film, comprising a first component and a solvent, wherein the first component is a compound containing at least one selected from the group consisting of a structure represented by the following formula (1) and a structure represented by the following formula (2), and the solvent contains 50% by mass or more of water relative to the solvent. (In formula (1), X １ represents a group represented by any one of the following formulas (1-1) to (1-4): １ and Z ２ Each of Q independently represents a single bond or a divalent group represented by the following formula (1-5): １ represents a divalent organic group having at least one selected from an aromatic hydrocarbon ring and an aliphatic hydrocarbon ring. (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. ３ represents a single bond or a divalent group represented by the following formula (1-5). * represents a bond. *1 represents a bond bonded to a carbon atom in formula (1). *2 represents a bond bonded to a nitrogen atom in formula (1). (In formula (1-5), m1 is an integer of 0 to 4, m2 is 0 or 1, m3 is 0 or 1, and m4 is an integer of 0 to 2. However, when m3 is 1, m1 and m2 cannot be 0 at the same time. *3 represents a bond bonded to a nitrogen atom in formula (1) or formula (1-4). *4 represents a bond.) [3] The composition for forming a resist underlayer film according to [1], wherein the first component is a compound containing at least one selected from a structure represented by the following formula (1) and a structure represented by the following formula (2): (In formula (1), X １ represents a group represented by any one of the following formulas (1-1) to (1-4): １ and Z ２ Each of Q independently represents a single bond or a divalent group represented by the following formula (1-5): １ represents a divalent organic group having at least one selected from an aromatic hydrocarbon ring and an aliphatic hydrocarbon ring. (In formulas (1-1) to (1-3), R１ ~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. ３ represents a single bond or a divalent group represented by the following formula (1-5). * represents a bond. *1 represents a bond bonded to a carbon atom in formula (1). *2 represents a bond bonded to a nitrogen atom in formula (1). (In formula (1-5), m1 is an integer of 0 to 4, m2 is 0 or 1, m3 is 0 or 1, and m4 is an integer of 0 to 2. However, when m3 is 1, m1 and m2 cannot be 0 at the same time. *3 represents a bond bonded to a nitrogen atom in formula (1) or formula (1-4). *4 represents a bond.) [4] Q １ is represented by the following formula (2-1): (In formula (2-1), Q １１ represents a divalent organic group represented by any one of the following formulas (2-1-1) to (2-1-4). n1 and n2 each independently represent 0 or 1. * represents a bond. (In formulas (2-1-1) to (2-1-4), 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 (2-1-1), 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. ４ 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 may be the same or different. In formula (2-1-3), 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. ５ 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.) [5] The composition for forming a resist underlayer film according to any one of [1] to [3], wherein the first component includes at least one of a structure represented by the following formula (E-1) and a structure represented by the following formula (E-2): (In formulas (E-1) and (E-2), * represents a bond.) [6] The composition for forming a resist underlayer film according to [2], which contains a second component, and the second component is a water-soluble polymer. [7] The composition for forming a resist underlayer film according to [1] or [6], wherein the water-soluble polymer is at least one selected from polyvinyl alcohol, polystyrene sulfonic acid, and water-soluble cellulose. [8] The aqueous composition for forming a resist underlayer film according to [6] or [7], wherein a mass ratio of the first component to the second component (first component:second component) is 99:1 to 50:50. [9] The composition for forming a resist underlayer film according to any one of [1] to [8], further containing a crosslinking agent.

[10] The composition for forming a resist underlayer film according to any one of [1] to [9], further containing a curing catalyst.

[11] A resist underlayer film, which is a cured product of the composition for forming a resist underlayer film according to any one of [1] to

[10] .

[12] A semiconductor processing substrate comprising: a semiconductor substrate; and the resist underlayer film according to

[11] .

[13] A method for manufacturing a semiconductor device, comprising: forming a resist underlayer film on a semiconductor substrate using the composition for forming a resist underlayer film according to any one of [1] to

[10] , and forming a resist film on the resist underlayer film.

[14] A pattern formation method, comprising: forming a resist underlayer film on a semiconductor substrate using the composition for forming a resist underlayer film according to any one of [1] to

[10] , forming a resist film on the resist underlayer film, irradiating the resist film with light or an electron beam and then developing the resist film to obtain a resist pattern, and etching the resist underlayer film using the resist pattern as a mask.

[0009] According to the present invention, it is possible to provide a composition for forming a resist underlayer film, a resist underlayer film, a substrate for semiconductor processing, a method for manufacturing a semiconductor device, and a method for forming a pattern, which use water as a solvent. The amount of organic solvents used in the prior art in this field can be reduced, thereby contributing to reducing the environmental load.

[0010] FIG. 1 is an SEM photograph of an example of resist pattern formation.

[0011] (Composition for forming a resist underlayer film) One embodiment of the composition for forming a resist underlayer film of the present invention contains a first component and water. One embodiment of the composition for forming a resist underlayer film of the present invention contains the first component, a second component, and water.

[0012] <First Component> The first component is an organic compound. The first component is a component that may be used in combination with the second component in, for example, a composition for forming a resist underlayer film. The first component is an organic compound that dissolves in the above-mentioned solvent so as to be used as a composition for forming a resist underlayer film. The molecular weight of the first component is not particularly limited, and the first component may be a low-molecular-weight compound or a high-molecular-weight compound.

[0013] The first component is preferably a compound containing at least one selected from the structure represented by the following formula (1) and the structure represented by the following formula (2): When the first component is a compound containing at least one selected from the structure represented by the following formula (1) and the structure represented by the following formula (2), excellent solvent resistance and excellent antireflection performance are imparted to the resist underlayer film obtained from the composition for forming a resist underlayer film. (In formula (1), X １ represents a group represented by any one of the following formulas (1-1) to (1-4): １ and Z ２ Each of Q independently represents a single bond or a divalent group represented by the following formula (1-5): １ represents a divalent organic group having at least one selected from an aromatic hydrocarbon ring and an aliphatic hydrocarbon ring. (In formulas (1-1) to (1-3), R １ ~R ５R 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. ３ represents a single bond or a divalent group represented by the following formula (1-5). * represents a bond. *1 represents a bond bonded to a carbon atom in formula (1). *2 represents a bond bonded to a nitrogen atom in formula (1). (In formula (1-5), m1 is an integer of 0 to 4, m2 is 0 or 1, m3 is 0 or 1, and m4 is an integer of 0 to 2. However, when m3 is 1, m1 and m2 cannot be 0 at the same time. *3 represents a bond bonding to a nitrogen atom in formula (1) or formula (1-4). *4 represents a bond.)

[0014] <<Formula (1)>> R in formulas (1-1) to (1-3) １ ~R ５ 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.

[0015] X in formula (1) １From the viewpoint of suitably obtaining the effects of the present invention, it is preferable that the compound be represented by formula (1-3) or formula (1-4).

[0016] Examples of formula (1) include the structures shown below. In the above structure, * represents a bond.

[0017] <<Formula (2)>> Q １ represents a divalent organic group having at least one selected from an aromatic hydrocarbon ring and an aliphatic hydrocarbon ring. The aromatic hydrocarbon ring may be monocyclic or polycyclic. The aromatic hydrocarbon ring is not particularly limited, and examples thereof include a benzene ring, a naphthalene ring, and an anthracene ring. The aliphatic hydrocarbon ring may be monocyclic or polycyclic. The aliphatic hydrocarbon ring is not particularly limited, and examples thereof include a cyclohexane ring.

[0018] Q １ is preferably represented by the following formula (2-1). (In formula (2-1), Q １１ represents a divalent organic group represented by any one of the following formulas (2-1-1) to (2-1-4). n1 and n2 each independently represent 0 or 1. * represents a bond. (In formulas (2-1-1) to (2-1-4), R ２１ ~R ２６ each 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 (2-1-1), 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 more２１ may be the same or different. ４ 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 may be the same or different. In formula (2-1-3), 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. ５ 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.)

[0019] 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.

[0020] Examples of the structure represented by formula (2-1) include the structures shown below. In the above structure, * represents a bond.

[0021] The first component is preferably a compound containing at least one selected from the structure represented by the following formula (11) and the structure represented by the following formula (12): The first component is preferably a compound containing at least one selected from the structure represented by the formula (1), the structure represented by the formula (2), the structure represented by the formula (11), and the structure represented by the formula (12). (In formula (11), X １ represents a group represented by any one of the above formulas (1-1) to (1-3) and the following formula (1-4A). １ and Z ２ each independently represents a single bond or a divalent group represented by the above formula (1-5) (wherein *3 in formula (1-5) represents a bond bonded to the nitrogen atom in formula (11)). A １ , A ２ , A ３ , A ４ , A ５ and A ６ each independently represents a hydrogen atom, a methyl group, or an ethyl group. * represents a bond. In formula (12), Q １１represents a divalent organic group represented by any one of the above formulas (2-1-1) to (2-1-4). n1 and n2 each independently represent 0 or 1. A 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. * represents a bond. (In formula (1-4A), Z ３ represents a single bond or a divalent group represented by the above formula (1-5) (wherein *3 in the above formula (1-5) represents a bond bonded to the nitrogen atom in formula (1-4A)). ７ , A ８ and A ９ each independently represents a hydrogen atom, a methyl group, or an ethyl group. * represents a bond. *1 represents a bond bonded to a carbon atom in formula (11). *2 represents a bond bonded to a nitrogen atom in formula (11).

[0022] The first component preferably contains at least one of a structure represented by the following formula (E-1) and a structure represented by the following formula (E-2): When the first component contains these structures, the solubility of the first component in water can be increased. (In formula (E-1) and formula (E-2), * represents a bond.)

[0023] The first component preferably contains a plurality of structures represented by formula (E-1) and a plurality of structures represented by formula (E-2), and more preferably contains 2 to 3 structures in the compound that is the first component.

[0024] The molecular weight of the first component is not particularly limited. From the viewpoint of solubility in water, the weight-average molecular weight of the first component is preferably small. The weight-average molecular weight of the first component is, for example, 300 to 100,000, preferably 300 to 50,000, more preferably 300 to 10,000, and particularly preferably 300 to 5,000.

[0025] An example of a method for producing the first component will be described below. An example of the first component can be obtained, for example, by the following reactions (I) to (III).

[0026] (I): A reaction of at least one of a compound represented by the following formula (11A) and a compound represented by the following formula (12A) with a compound represented by the following formula (EA). (In formula (11A), X １ represents a group represented by any one of the above formulas (1-1) to (1-3) and the following formula (1-4B). １ and Z ２ each independently represents a single bond or a divalent group represented by the above formula (1-5) (wherein *3 in formula (1-5) represents a bond bonded to the nitrogen atom in formula (11A)). A １ , A ２ , A ３ , A ４ , A ５ and A ６ each independently represents a hydrogen atom, a methyl group, or an ethyl group. １１ represents a divalent organic group represented by any one of the above formulas (2-1-1) to (2-1-4). n1 and n2 each independently represent 0 or 1. A 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. (In formula (1-4B), Z ３ represents a single bond or a divalent group represented by the above formula (1-5) (wherein *3 in formula (1-5) represents a bond bonded to the nitrogen atom in formula (1-4B)). A ７ , A ８ and A ９ each independently represents a hydrogen atom, a methyl group, or an ethyl group. *1 represents a bond bonded to a carbon atom in formula (11A). *2 represents a bond bonded to a nitrogen atom in formula (11A).

[0027] Examples of the compound represented by formula (11A) include the following compounds.

[0028] Examples of the compound represented by formula (12A) include the following compounds.

[0029] (II): A reaction of at least one of a compound represented by the following formula (11B) and a compound represented by the following formula (12A) with a compound represented by the following formula (EB). (In formula (11B), X １ represents a group represented by any one of the above formulas (1-1) to (1-3) and the following formula (1-4C). １ and Z ２ each independently represents a single bond or a divalent group represented by the above formula (1-5) (wherein *3 in formula (1-5) represents a bond bonded to the nitrogen atom in formula (11B)). １１ represents a divalent organic group represented by any one of the above formulas (2-1-1) to (2-1-4). n1 and n2 each independently represent 0 or 1. (In formula (1-4C), Z ３ represents a single bond or a divalent group represented by the above formula (1-5) (wherein *3 in formula (1-5) represents a bond bonded to the nitrogen atom in formula (1-4C)). *1 represents a bond bonded to the carbon atom in formula (11B). *2 represents a bond bonded to the nitrogen atom in formula (11B).

[0030] Examples of the compound represented by formula (11B) include the following compounds:

[0031] Examples of the compound represented by formula (12B) include the following compounds:

[0032] (III): A reaction of at least one of a compound represented by the formula (11A) and a compound represented by the formula (12A) with a compound represented by the following formula (EC): (In formula (EC), Q２１ represents a single bond or a divalent organic group.) The divalent organic group may be, for example, a divalent organic group having 1 to 20 carbon atoms, or a divalent organic group having 1 to 10 carbon atoms. The divalent organic group may have a heteroatom. Examples of the heteroatom include an oxygen atom and a sulfur atom. Examples of the divalent organic group include a hydrocarbon group having 1 to 10 carbon atoms. The hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. Examples of the divalent organic group include a hydrocarbon group having 1 to 10 carbon atoms substituted with a hydroxy group or a mercapto group. Examples of the hydrocarbon group include an aliphatic hydrocarbon group. Examples of the divalent organic group include a hydrocarbon group having 2 to 10 carbon atoms interrupted by an oxygen atom or a sulfur atom. Examples of the hydrocarbon group include an aliphatic hydrocarbon group.

[0033] Examples of the compound represented by formula (EC) include the following compounds.

[0034] Reactions (I) to (III) may be carried out in the presence of a catalyst, for example. Examples of the catalyst 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 polymer raw 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.

[0035] <Second Component> The second component is used to improve the coatability of the composition for forming a resist underlayer film. The second component is a water-soluble polymer. The second component is a compound different from the first component.

[0036] The water-soluble polymer is a polymer compound that dissolves 1 g or more in 100 g of water at 25°C, preferably 5 g or more in 100 g of water at 25°C, and more preferably 10 g or more in 100 g of water at 25°C.

[0037] The water-soluble polymer is not particularly limited, but examples thereof include polyvinyl alcohol, water-soluble cellulose, polyethylene glycol (PEG), polyethylene oxide (PEO), polyvinylpyrrolidone, polyacrylic acid, polystyrene sulfonic acid, and polyvinylacetamide.

[0038] Polyvinyl alcohol is a polymer obtained by hydrolyzing polyvinyl acetate to convert the acetyl groups in the polyvinyl acetate molecule to hydroxyl groups. The proportion of these hydroxyl groups, expressed in mole percent, is called the degree of saponification. Polyvinyl alcohols are known to have various properties depending on their degree of saponification. For example, polyvinyl acetate (0 mole percent saponification) is generally water-insoluble, while polyvinyl alcohol with a degree of saponification of 100 mole percent is known to be water-soluble. Among polyvinyl alcohols, those with a degree of saponification of 60 mole percent or less have poor solubility in water, and those with a degree of saponification of 30 mole percent or less are virtually insoluble. Conversely, polyvinyl alcohols with a degree of saponification that is too high also have low solubility, with those with a degree of saponification of 85 to 90 mole percent being the most soluble. In the present invention, polyvinyl alcohols with a degree of saponification of 70 mole percent or more are preferred. Generally, a higher degree of saponification results in better developer resistance, so polyvinyl alcohols with a degree of saponification of 75 mole percent or more are preferred. However, conversely, if the degree of saponification is too high, the storage stability of the composition (generation of insoluble foreign matter) tends to deteriorate, so the degree of saponification of polyvinyl alcohol is preferably 99 mol % or less, more preferably 98 mol % or less.

[0039] The degree of polymerization of polyvinyl alcohol is usually expressed by the viscosity (20°C) of a 4% by mass aqueous solution, and is generally about 1 to 80 cps (mPa·s). The polyvinyl alcohol used in the present invention preferably has a viscosity of 1 cps or more, and more preferably has a viscosity of 2 cps or more. The upper limit of the viscosity is preferably 70 cps, and more preferably 65 cps, 50 cps, 40 cps, 30 cps, 20 cps, 10 cps, 8 cps, or 5 cps. The viscosity range is, for example, 1 to 20 cps, 2 to 10 cps, or 3 to 8 cps.

[0040] The polyvinyl alcohol may be modified by substituting some of its hydroxyl groups with alkyl ether groups, alkyloxymethyl groups, acetylacetate groups, or the like.

[0041] The water-soluble cellulose is not particularly limited, but examples thereof include alkyl celluloses such as methyl cellulose and ethyl cellulose, hydroxyalkyl celluloses such as hydroxyethyl cellulose and hydroxypropyl cellulose, and hydroxyalkyl alkyl celluloses such as hydroxyethyl methyl cellulose and hydroxypropyl methyl cellulose, etc. Among these, hydroxypropyl cellulose is more preferred.

[0042] Hydroxypropyl cellulose is commercially available from various companies with various viscosities, and all of them can be used in the present invention.The viscosity of 2% by mass aqueous solution (20 ° C) of hydroxypropyl cellulose is not particularly limited, and can be appropriately selected according to purpose, but is preferably 2.0 mPa s (centipoise, cps) or more and 4,000 mPa s (centipoise, cps) or less.In addition, the viscosity of hydroxypropyl cellulose is considered to depend on the weight-average molecular weight, degree of substitution and molecular weight of hydroxypropyl cellulose.

[0043] The weight-average molecular weight of hydroxypropyl cellulose is not particularly limited and can be appropriately selected depending on the purpose, but is preferably from 15,000 to 400,000. The weight-average molecular weight can be measured, for example, by gel permeation chromatography (GPC).

[0044] There are no particular limitations on the commercially available hydroxypropyl cellulose products, and they can be appropriately selected depending on the purpose, and examples thereof include the following commercially available products: HPC-SSL and the like (manufactured by Nippon Soda Co., Ltd.) having a molecular weight of 15,000 to 30,000 and a viscosity of 2.0 to 2.9 mPa·s; HPC-SL and the like (manufactured by Nippon Soda Co., Ltd.) having a molecular weight of 30,000 to 50,000 and a viscosity of 3.0 to 5.9 mPa·s; HPC-L and the like (manufactured by Nippon Soda Co., Ltd.) having a molecular weight of 55,000 to 70,000 and a viscosity of 6.0 to 10.0 mPa·s; HPC-M and the like (manufactured by Nippon Soda Co., Ltd.) having a molecular weight of 110,000 to 150,000 and a viscosity of 150 to 400 mPa·s. HPC-H and the like (manufactured by Nippon Soda Co., Ltd.) having a molecular weight of 250,000 to 400,000 and a viscosity of 1,000 to 4,000 mPa s. Of these, HPC-SSL having a molecular weight of 15,000 to 30,000 and a viscosity of 2.0 to 2.9 mPa s is preferred. In the above commercially available products, the molecular weight is measured using gel permeation chromatography (GPC), and the viscosity is measured using a 2% by mass aqueous solution (20°C).

[0045] The polystyrene sulfonic acid is not particularly limited as long as it is water-soluble, and its sulfonation rate may be 100% or less. The sulfonation rate is, for example, 80% or more and 100% or less. Here, the "sulfonation rate" refers to the molar proportion (%) of "styrene units having sulfonic acid groups" out of the total of "styrene units having sulfonic acid groups" and "styrene units" in the polystyrene sulfonic acid molecule. That is, the polystyrene sulfonic acid may be a homopolymer consisting only of repeating units represented by the following formula (SS), or may be a copolymer having repeating units represented by the following formula (SS) and repeating units represented by the following formula (St).

[0046] Examples of styrene sulfonic acids constituting polystyrene sulfonic acid include 4-styrene sulfonic acid.

[0047] The content of the second component (water-soluble polymer) in the composition for forming a resist underlayer film is not particularly limited.

[0048] Adding a small amount of the second component to the composition for forming a resist underlayer film can improve the coatability of the composition for forming a resist underlayer film. Therefore, the mass ratio of the first component to the second component (first component:second component) in the composition for forming a resist underlayer film is preferably 99:1 to 50:50, more preferably 99:1 to 75:25, and particularly preferably 99:1 to 90:10.

[0049] <Crosslinking Agent> The composition for forming a resist underlayer film preferably contains a crosslinking agent. The crosslinking agent contained as an optional component in the composition for forming a resist underlayer film has, for example, a functional group that reacts independently. Examples of crosslinking agents include hexamethoxymethylmelamine, tetramethoxymethylbenzoguanamine, 1,3,4,6-tetrakis(methoxymethyl)glycoluril (tetramethoxymethylglycoluril) (POWDERLINK [registered trademark] 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.

[0050] 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:

[0051] (In formula (1d), R １ represents a methyl group or an ethyl group. * represents a bond to the nitrogen atom.)

[0052] 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).

[0053] (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.

[0054] Examples of the glycoluril derivative represented by the formula (1E) include compounds represented by the following formulas (1E-1) to (1E-6).

[0055]

[0056] 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):

[0057] (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.)

[0058] 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).

[0059] 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).

[0060] (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.

[0061] 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.

[0062]

[0063] The entire disclosure of WO 2017 / 187969 is incorporated herein by reference with respect to the content of the nitrogen-containing compound having 2 to 6 substituents represented by formula (1d) bonded to a nitrogen atom per molecule.

[0064] The crosslinking agent may be a crosslinkable compound represented by the following formula (G-1) or formula (G-2), which is described in WO 2014 / 208542.

[0065] (In the formula, Q １ represents a single bond or m represents a monovalent organic group, and R １ and R ４ each represents an alkyl group having 2 to 10 carbon atoms or an alkyl group having 2 to 10 carbon atoms and an alkoxy group having 1 to 10 carbon atoms; R ２ and R ５ each represents a hydrogen atom or a methyl group, and R ３ and R ６ respectively represent an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 40 carbon atoms. n1 represents an integer of 1≦n1≦3, n2 represents an integer of 2≦n2≦5, n3 represents an integer of 0≦n3≦3, n4 represents an integer of 0≦n4≦3, or an integer of 3≦(n1+n2+n3+n4)≦6. n5 represents an integer of 1≦n5≦3, n6 represents an integer of 1≦n6≦4, n7 represents an integer of 0≦n7≦3, n8 represents an integer of 0≦n8≦3, or an integer of 2≦(n5+n6+n7+n8)≦5. m1 represents an integer of 2 to 10.

[0066] The crosslinkable compound represented by the above formula (G-1) or formula (G-2) may be obtained by reacting a compound represented by the following formula (G-3) or formula (G-4) with a hydroxyl group-containing ether compound or an alcohol having 2 to 10 carbon atoms.

[0067] (In the formula, Q ２ represents a single bond or a divalent organic group. ８ , R ９ , R １１ and R １２ each represents a hydrogen atom or a methyl group, and R ７ and R １０respectively represent an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 40 carbon atoms. n9 represents an integer of 1≦n9≦3, n10 represents an integer of 2≦n10≦5, n11 represents an integer of 0≦n11≦3, n12 represents an integer of 0≦n12≦3, or an integer of 3≦(n9+n10+n11+n12)≦6. n13 represents an integer of 1≦n13≦3, n14 represents an integer of 1≦n14≦4, n15 represents an integer of 0≦n15≦3, n16 represents an integer of 0≦n16≦3, or an integer of 2≦(n13+n14+n15+n16)≦5. m2 represents an integer of 2 to 10.

[0068] Examples of the compounds represented by the above formula (G-1) and formula (G-2) include the following.

[0069]

[0070]

[0071]

[0072]

[0073]

[0074] Examples of the compounds represented by formula (G-3) and formula (G-4) are as follows.

[0075]

[0076] In the formula, Me represents a methyl group.

[0077] The entire disclosure of WO 2014 / 208542 is incorporated herein by reference.

[0078] When the crosslinking agent is used, the content of the crosslinking agent in the composition for forming a resist underlayer film is, for example, 1% by mass to 50% by mass, and preferably 5% by mass to 40% by mass, relative to the total of the first component and the second component. When the crosslinking agent is used, the content of the crosslinking agent in the composition for forming a resist underlayer film is, for example, 1% by mass to 50% by mass, and preferably 5% by mass to 40% by mass, relative to the total of the first component.

[0079] <Curing Catalyst> The curing catalyst contained as an optional component in the composition for forming a resist underlayer film may be either a thermal acid generator or a photoacid generator, but it is preferable to use a thermal acid generator.

[0080] 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.

[0081] Examples of the photoacid generator include an onium salt compound, a sulfonimide compound, and a disulfonyldiazomethane compound.

[0082] 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.

[0083] Examples of the sulfonimide compound include N-(trifluoromethanesulfonyloxy)succinimide, N-(nonafluoronormalbutanesulfonyloxy)succinimide, N-(camphorsulfonyloxy)succinimide, and N-(trifluoromethanesulfonyloxy)naphthalimide.

[0084] 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.

[0085] The curing catalyst may be used alone or in combination of two or more.

[0086] 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, relative to the crosslinking agent.

[0087] <Solvent> The composition for forming a resist underlayer film contains a solvent. The solvent includes water. The solvent may include an organic solvent in addition to water.

[0088] The solvent preferably contains 50% by mass or more of water relative to the solvent, more preferably 70% by mass or more of water relative to the solvent, even more preferably 80% by mass or more of water relative to the solvent, and particularly preferably 90% by mass or more of water relative to the solvent.

[0089] The organic solvent is preferably an organic solvent generally used in chemical solutions for semiconductor lithography processes, 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-39, cyclohexane-40, cyclohexane-41, cyclohexane-42, cyclohexane-43, cyclohexane-44, cyclohexane-45, cyclohexane-46, cyclohexane-47, cyclohexane-48, cyclohexane-49, cyclohexane-51, cyclohexane-52, cyclohexane-53, cyclohexane-54, 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.

[0090] 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.

[0091] <Other Components> A surfactant may be further added to the composition for forming a resist underlayer film in order to prevent pinholes, striations, and the like from occurring and to further improve the coatability against surface irregularities.

[0092] Examples of surfactants include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, and polyoxyethylene oleyl ether; polyoxyethylene alkyl aryl 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; 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-containing surfactants such as EFTOP EF301, EF303, and EF352 (trade names, manufactured by Tochem Products Co., Ltd.), Megafac F171, F173, and R-30 (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 not particularly limited, but is usually 2.0 mass % or less, and preferably 1.0 mass % or less, based on the total solid content of the composition for forming a resist underlayer film. These surfactants may be added alone or in combination of two or more.

[0093] The film-constituting components contained in the composition for forming a resist underlayer film, that is, the components excluding the solvent, are, for example, 0.01% by mass to 10% by mass of the composition for forming a resist underlayer film.

[0094] The resist underlayer film-forming composition of the present invention is produced, for example, by mixing the first component, a solvent, and the like by a known method. To be used as a resist underlayer film-forming composition, the composition must be in a homogeneous solution state. The produced composition is preferably filtered through a filter or the like to remove metal impurities, foreign matter, and the like present in the composition. One measure for evaluating whether a resist underlayer film-forming composition is in a homogeneous solution state is to observe its passability through a specific microfilter. The resist underlayer film-forming composition of the present invention preferably passes through microfilters with pore sizes of 0.1 μm, 0.05 μm, 0.03 μm, 0.02 μm, and 0.01 μm, and exhibits a homogeneous solution state.

[0095] Examples of materials for the microfilter include fluorine-based resins such as PTFE (polytetrafluoroethylene) and PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer), PE (polyethylene), UPE (ultra-high molecular weight polyethylene), PP (polypropylene), PSF (polysulfone), PES (polyethersulfone), and nylon, with PTFE (polytetrafluoroethylene) being preferred. Because the resist underlayer film-forming composition contains water as a solvent, the filter used to filter the resist underlayer film-forming composition is preferably a filter that has been subjected to a hydrophilization treatment.

[0096] (Resist Underlayer Film) The resist underlayer film of the present invention is a cured product of the composition for forming a resist underlayer film described above. The resist underlayer film can be produced, for example, by applying the composition for forming a resist underlayer film described above onto a semiconductor substrate and baking the applied composition.

[0097] Examples of semiconductor substrates onto which the resist underlayer film-forming composition 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.

[0098] When using a semiconductor substrate having an inorganic film formed on its surface, 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, BPSG (Boro-Phospho Silicate Glass) films, titanium nitride films, titanium nitride oxide films, tungsten films, gallium nitride films, and gallium arsenide films. The inorganic film may be a single layer or a multilayer structure consisting of two or more layers. In the case of a multilayer structure or more, each layer may be the same type of inorganic film or different types of inorganic films. The thickness of the inorganic film is not particularly limited.

[0099] The resist underlayer film-forming composition of the present invention is applied to such a semiconductor substrate by a suitable application method such as a spinner or coater. The composition is then baked using a heating means such as a hot plate to form a resist underlayer film. The 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. A baking temperature of 120°C to 350°C and a baking time of 0.5 to 30 minutes are preferred, and a baking temperature of 150°C to 300°C and a baking time of 0.8 to 10 minutes are more preferred.

[0100] The thickness of the resist underlayer film may be, for example, 0.001 μm (1 nm) to 10 μm, 0.002 μm (2 nm) to 1 μm, 0.005 μm (5 nm) to 0.5 μm (500 nm), 0.001 μm (1 nm) to 0.05 μm (50 nm), 0.002 μm (2 nm) to 0.05 μm (50 nm), 0.003 μm (3 nm) to 0.05 μm (50 nm), 0.004 μm (4 nm) to 0.05 μm (50 nm), 0.005 μm (5 nm) to 0.05 μm (5 0 nm), 0.003 μm (3 nm) to 0.03 μm (30 nm), 0.003 μm (3 nm) to 0.02 μm (20 nm), 0.005 μm (5 nm) to 0.02 μm (20 nm), 0.005 μm (5 nm) to 0.02 μm (20 nm), 0.003 μm (3 nm) to 0.01 μm (10 nm), 0.005 μm (5 nm) to 0.01 μm (10 nm), 0.003 μm (3 nm) to 0.006 μm (6 nm), or 0.005 μm (5 nm).

[0101] The method for measuring the film thickness of the resist underlayer film in this specification is as follows: Name of measuring device: Optical interference film thickness meter (product name: Nanospec 6100, manufactured by Nanometrics Japan Co., Ltd.) Arithmetic mean of four points (for example, measurement at four points at 1 cm intervals in the X direction of the wafer)

[0102] (Substrate for semiconductor processing) The substrate for semiconductor processing of the present invention includes a semiconductor substrate and the resist underlayer film of the present invention. Examples of the semiconductor substrate include the semiconductor substrates described above. The resist underlayer film is disposed on, for example, the semiconductor substrate.

[0103] (Method for manufacturing a semiconductor element, method for forming a pattern) The method for manufacturing a semiconductor element of the present invention includes at least the following steps: forming a resist underlayer film on a semiconductor substrate using the composition for forming a resist underlayer film of the present invention, and forming a resist film on the resist underlayer film.

[0104] The pattern forming method of the present invention includes at least the following steps: forming a resist underlayer film on a semiconductor substrate using the composition for forming a resist underlayer film of the present invention, forming a resist film on the resist underlayer film, irradiating the resist film with light or an electron beam and then developing the resist film to obtain a resist pattern, and etching the resist underlayer film using the resist pattern as a mask.

[0105] Typically, a resist film is formed on the resist underlayer film. The thickness of the resist film is preferably 200 nm or less, more preferably 150 nm or less, even more preferably 100 nm or less, and particularly preferably 80 nm or less. The thickness of the resist film is preferably 10 nm or more, more preferably 20 nm or more, and particularly preferably 30 nm or more.

[0106] The resist film formed on the resist underlayer film by a known method (e.g., coating and baking) is not particularly limited as long as it is responsive to light or electron beam (EB) used for irradiation. Either negative or positive photoresist can be used. The light or electron beam is not particularly limited, but examples include i-line (365 nm), KrF excimer laser (248 nm), ArF excimer laser (193 nm), EUV (extreme ultraviolet; 13.5 nm), and EB (electron beam). In this specification, resists responsive to EB are also referred to as photoresists. Examples of photoresists include positive photoresists made of novolac resin and 1,2-naphthoquinone diazide sulfonic acid ester, chemically amplified photoresists made of a binder having a group that decomposes in the presence of acid to increase the alkaline dissolution rate and a photoacid generator, chemically amplified photoresists made of a low molecular weight compound that decomposes in the presence of acid to increase the alkaline dissolution rate of the photoresist, an alkali-soluble binder, and a photoacid generator, and chemically amplified photoresists made of a binder having a group that decomposes in the presence of acid to increase the alkaline dissolution rate of the photoresist, a low molecular weight compound that decomposes in the presence of acid to increase the alkaline dissolution rate of the photoresist, and a photoacid generator, and resists containing metal elements. Examples include V146G (trade name) manufactured by JSR Corporation, APEX-E (trade name) manufactured by Shipley Chemical Co., Ltd., PAR710 (trade name) manufactured by Sumitomo Chemical Co., Ltd., and AR2772 and SEPR430 (trade names) manufactured by Shin-Etsu Chemical Co., Ltd. Further, for example, the photoresists described in Proc. SPIE, Vol. 3999, 330-334 (2000), Proc. SPIE, Vol. 3999, 357-364 (2000), and Proc. SPIE, Vol. 3999, 365-374 (2000).

[0107] Also, WO2019 / 188595, WO2019 / 187881, WO2019 / 187803, WO2019 / 167737, WO2019 / 167725, WO2019 / 187445, WO2019 / 167419, WO2019 / 123842, WO2019 / 054282, WO2019 / 058945, WO2019 / 058890, WO2019 / 039290, WO2019 / 044259, WO2019 / 044231, WO2019 / 026549, WO2018 / 193954, WO201 9 / 172054, WO2019 / 021975, WO2018 / 230334, WO2018 / 194123, JP 2018-180525, WO2018 / 190088, JP 2018-070596, JP 2018-028090, JP 2016-153409, JP 2016-130240, JP 2016-108325, JP 2016-047920, JP 2016-035570, JP 2016-035567, JP 2016-035565, JP 2019-101417, JP 2019-117373, JP 2019-052294, JP 2019-008280, JP 2019-008279, JP 2019-003176, JP 2019-003175, JP 2018-197853, JP 2019-191298, JP 2019-061217, JP 2018-045152, JP 2018-022039, JP 2016-090441, JP 2015-10878, JP 2012-168279, JP 2012-022261, JP 2012-022258, JP 2011-043749, JP 2010-18 1857, JP 2010-128369, WO2018 / 031896, JP 2019-113855, WO2017 / 156388, WO2017 / 066319, JP 2018-41099, WO2016 / 065120, WO2015 / 026482, JP 2016-29498, JP 2011-253185, etc., radiation-sensitive resin compositions, so-called resist compositions such as high-resolution patterning compositions based on organometallic solutions, and metal-containing resist compositions can be used, but are not limited to these.

[0108] Examples of the resist composition include the following compositions.

[0109] An actinic ray-sensitive or radiation-sensitive resin composition comprising: Resin A having a repeating unit having an acid-decomposable group in which a polar group is protected with a protecting group that is cleaved by the action of an acid; and a compound represented by the following general formula (21):

[0110] In the general formula (21), m represents an integer of 1 to 6. １ and R ２ each independently represents a fluorine atom or a perfluoroalkyl group. １ is -O-, -S-, -COO-, -SO ２ - or -SO ３ - represents. ２ represents an alkylene group which may have a substituent or a single bond. １ represents a cyclic organic group which may have a substituent. ＋ represents a cation.

[0111] A metal-containing film-forming composition for extreme ultraviolet or electron beam lithography, comprising a compound having a metal-oxygen covalent bond and a solvent, wherein the metal element constituting the compound belongs to Periods 3 to 7 of Groups 3 to 15 of the periodic table.

[0112] A radiation-sensitive resin composition comprising: a polymer having a first structural unit represented by the following formula (31) and a second structural unit represented by the following formula (32) containing an acid-dissociable group; and an acid generator.

[0113] In formula (31), Ar is a group obtained by removing (n+1) hydrogen atoms from an arene having 6 to 20 carbon atoms. １ is a hydroxy group, a sulfanyl group, or a monovalent organic group having 1 to 20 carbon atoms. n is an integer of 0 to 11. When n is 2 or more, multiple R １ are the same or different. ２ is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. ３ is a monovalent group having 1 to 20 carbon atoms containing the above acid-dissociable group. Z is a single bond, an oxygen atom, or a sulfur atom. R ４ is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0114] A resist composition comprising: a resin (A1) containing a structural unit having a cyclic carbonate structure, a structural unit represented by the following formula, and a structural unit having an acid labile group; and an acid generator.

[0115] [In the formula, R ２ represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom; X １ represents a single bond, —CO—O—*, or —CO—NR ４ -*, * represents a bond to -Ar, R ４ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and Ar represents an aromatic hydrocarbon group having 6 to 20 carbon atoms which may have one or more groups selected from the group consisting of a hydroxy group and a carboxyl group.]

[0116] Examples of the resist film include the following.

[0117] A resist film comprising a base resin comprising a repeating unit represented by the following formula (a1) and / or a repeating unit represented by the following formula (a2), and a repeating unit that generates an acid bonded to a polymer main chain upon exposure:

[0118] (In formula (a1) and formula (a2), R Ａ are each independently a hydrogen atom or a methyl group. １ and R ２ are each independently a tertiary alkyl group having 4 to 6 carbon atoms. ３ are each independently a fluorine atom or a methyl group, and m is an integer of 0 to 4. １ X is a single bond, a phenylene group, or a naphthylene group, or a linking group having 1 to 12 carbon atoms and containing at least one selected from an ester bond, a lactone ring, a phenylene group, and a naphthylene group. ２ is a single bond, an ester bond, or an amide bond.

[0119] Examples of resist materials include the following:

[0120] A resist material comprising a polymer having a repeating unit represented by the following formula (b1) or (b2):

[0121] (In formula (b1) and formula (b2), R Ａ is a hydrogen atom or a methyl group. １ is a single bond or an ester group. ２ is a linear, branched or cyclic alkylene group having 1 to 12 carbon atoms or an arylene group having 6 to 10 carbon atoms, and some of the methylene groups constituting the alkylene group may be substituted with an ether group, an ester group or a lactone ring-containing group; and X ２ At least one hydrogen atom contained in X is substituted with a bromine atom. ３ Rf is a single bond, an ether group, an ester group, or a linear, branched, or cyclic alkylene group having 1 to 12 carbon atoms, and some of the methylene groups constituting the alkylene group may be substituted with an ether group or an ester group. １ ~Rf ４ are each independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group, but at least one is a fluorine atom or a trifluoromethyl group. １ and Rf ２ may combine to form a carbonyl group. １ ~R ５ are each independently a linear, branched, or cyclic alkyl group having 1 to 12 carbon atoms, a linear, branched, or cyclic alkenyl group having 2 to 12 carbon atoms, an alkynyl group having 2 to 12 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, or an aryloxyalkyl group having 7 to 12 carbon atoms, in which some or all of the hydrogen atoms may be substituted with a hydroxy group, a carboxy group, a halogen atom, an oxo group, a cyano group, an amide group, a nitro group, a sultone group, a sulfone group, or a sulfonium salt-containing group, and in which some of the methylene groups constituting these groups may be substituted with an ether group, an ester group, a carbonyl group, a carbonate group, or a sulfonate ester group. １ and R ２may be bonded to form a ring together with the sulfur atom to which they are attached.

[0122] A resist material comprising a base resin containing a polymer containing a repeating unit represented by the following formula (a):

[0123] (In formula (a), R Ａ is a hydrogen atom or a methyl group. １ is a hydrogen atom or an acid labile group. ２ is a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms, or a halogen atom other than bromine. １ X is a single bond, a phenylene group, or a linear, branched or cyclic alkylene group having 1 to 12 carbon atoms which may contain an ester group or a lactone ring. ２ is -O-, -O-CH ２ - or -NH-. m is an integer of 1 to 4. u is an integer of 0 to 3. However, m+u is an integer of 1 to 4.

[0124] A resist composition that generates an acid upon exposure, and whose solubility in a developer changes due to the action of the acid, comprising: a base component (A) whose solubility in a developer changes due to the action of the acid; and a fluorine additive component (F) that exhibits decomposition in an alkaline developer, wherein the fluorine additive component (F) comprises a fluororesin component (F1) that has a structural unit (f1) that includes a base dissociable group, and a structural unit (f2) that includes a group represented by the following general formula (f2-r-1):

[0125] [In formula (f2-r-1), Rf ２１ are each independently a hydrogen atom, an alkyl group, an alkoxy group, a hydroxyl group, a hydroxyalkyl group, or a cyano group; n" is an integer of 0 to 2; * is a bond.

[0126] The structural unit (f1) includes a structural unit represented by the following general formula (f1-1) or a structural unit represented by the following general formula (f1-2).

[0127] [In formulas (f1-1) and (f1-2), each R is independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. X is a divalent linking group that does not have an acid-dissociable site. A ａｒｙｌ represents a divalent aromatic cyclic group which may have a substituent. ０１ is a single bond or a divalent linking group. ２ are each independently an organic group having a fluorine atom.

[0128] Coatings, coating solutions, and coating compositions include, for example:

[0129] A coating comprising a metal oxo-hydroxo network having organic ligands with metal carbon and / or metal carboxylate bonds.

[0130] Inorganic oxo / hydroxo-based compositions.

[0131] a coating solution comprising an organic solvent; a first organometallic composition having the formula R ｚ SnO （２－（ｚ／２）－（ｘ／２）） (OH) ｘ (where 0<z≦2 and 0<(z+x)≦4), formula R′ ｎ SnX ４－ｎ wherein n=1 or 2, or mixtures thereof, where R and R′ are independently hydrocarbyl groups having 1 to 31 carbon atoms, and X is a ligand having a hydrolyzable bond to Sn, or a combination thereof; and a hydrolyzable metal compound having the formula MX′ ｖ wherein M is a metal selected from groups 2 to 16 of the periodic table of the elements, v is a number from 2 to 6, and X' is a ligand having a hydrolyzable M-X bond or a combination thereof.

[0132] an organic solvent and a solution of the formula RSnO （３／２－ｘ／２） (OH) ｘand a first organometallic compound of the formula: wherein 0<x<3, wherein the solution contains from about 0.0025M to about 1.5M tin, and R is an alkyl or cycloalkyl group having from 3 to 31 carbon atoms, the alkyl or cycloalkyl group being bonded to the tin at a secondary or tertiary carbon atom.

[0133] An aqueous inorganic patterning precursor solution comprising a mixture of water, metal suboxide cations, polyatomic inorganic anions, and radiation-sensitive ligands comprising peroxide groups.

[0134] The irradiation with light or electron beams is carried out, for example, through a mask (reticle) for forming a predetermined pattern. The exposure dose and irradiation energy of the electron beam are not particularly limited.

[0135] After irradiation with light or electron beams and before development, baking (PEB: Post Exposure Bake) may be performed. The baking temperature is not particularly limited, but is preferably 60° C. to 150° C., more preferably 70° C. to 120° C., and particularly preferably 75° C. to 110° C. The baking time is not particularly limited, but is preferably 1 second to 10 minutes, more preferably 10 seconds to 5 minutes, and particularly preferably 30 seconds to 3 minutes.

[0136] For example, an alkaline developer is used for development. The development temperature can be, for example, 5°C to 50°C. The development time can be, for example, 10 seconds to 300 seconds. Examples of alkaline developers that can be used include aqueous solutions of alkalis such as inorganic alkalis (e.g., sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia); primary amines (e.g., ethylamine and n-propylamine); secondary amines (e.g., diethylamine and di-n-butylamine); tertiary amines (e.g., triethylamine and methyldiethylamine); alcohol amines (e.g., dimethylethanolamine and triethanolamine); quaternary ammonium salts (e.g., tetramethylammonium hydroxide, tetraethylammonium hydroxide, and choline); and cyclic amines (e.g., pyrrole and piperidine). Furthermore, the aqueous solutions of the alkalis can be used by adding an appropriate amount of alcohols (e.g., isopropyl alcohol) or a nonionic surfactant. Among these, preferred developers are aqueous solutions of quaternary ammonium salts, more preferably aqueous solutions of tetramethylammonium hydroxide and choline. Furthermore, surfactants and the like can also be added to these developers. Alternatively, development may be carried out with an organic solvent such as butyl acetate instead of an alkaline developer, and the portions of the photoresist where the alkaline dissolution rate is not improved may be developed.

[0137] Next, the resist underlayer film is etched using the formed resist pattern as a mask. The etching may be dry etching or wet etching, but dry etching is preferred. If the inorganic film is formed on the surface of the semiconductor substrate used, the surface of the inorganic film is exposed. If the inorganic film is not formed on the surface of the semiconductor substrate used, the surface of the semiconductor substrate is exposed. Thereafter, the semiconductor substrate is processed by a known method (e.g., dry etching), thereby manufacturing a semiconductor device.

[0138] 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.

[0139] The weight-average molecular weights of the polymers shown in Synthesis Examples 1 to 10 below were measured by gel permeation chromatography (hereinafter abbreviated as GPC). A GPC device manufactured by Tosoh Corporation was used for the measurements, and the measurement conditions were as follows: Column temperature: 40°C, Flow rate: 0.35 ml / min, Eluent: tetrahydrofuran (THF), Standard sample: polystyrene (Tosoh Corporation).

[0140] Synthesis Example 1 16.00 g of MeDGIC (Shikoku Chemical Industry Co., Ltd., 28.8% by mass propylene glycol monomethyl ether solution), 3.88 g of 1-thioglycerol (Fujifilm Wako Pure Chemical Industries, Ltd.), and 0.45 g of tetrabutylphosphonium bromide (Hokuko Chemical Industry Co., Ltd.) were added to a reaction flask, and the mixture was heated and stirred at 105°C for 18 hours under a nitrogen atmosphere. The resulting reaction product corresponded to the following formula (X-1), and had a weight-average molecular weight Mw of 330 as measured by GPC in terms of polystyrene. Thereafter, the solution of the reaction product was added dropwise to a hexane solution, and the resulting precipitate was separated by filtration and dried in vacuo at 40°C. The resulting compound was dissolved in ultrapure water to a concentration of 10% by mass.

[0141] Synthesis Example 2 5.00 g of TEPIC (Nissan Chemical Industries, Ltd.), 5.45 g of 1-thioglycerol (Fujifilm Wako Pure Chemical Industries, Ltd.), and 0.21 g of tetrabutylphosphonium bromide (Hokuko Chemical Industry Co., Ltd.) were added to a reaction flask, which was heated and stirred at 105°C for 23 hours under a nitrogen atmosphere. The resulting reaction product corresponded to the following formula (X-2), and had a weight-average molecular weight Mw of 470 as measured by GPC in terms of polystyrene. Thereafter, a solution of the reaction product was added dropwise to a hexane solution, and the resulting precipitate was separated by filtration and dried at 40°C under vacuum. The resulting compound was dissolved in ultrapure water to a concentration of 10% by mass.

[0142] Synthesis Example 3 2.50 g of EX-201 (manufactured by Nagase ChemteX Corporation), 2.31 g of 1-thioglycerol (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), and 0.26 g of tetrabutylphosphonium bromide (manufactured by Hokko Chemical Co., Ltd.) were added to a reaction flask, and the mixture was heated and stirred at 105°C for 18 hours under a nitrogen atmosphere. The resulting reaction product corresponded to the following formula (X-3), and had a weight-average molecular weight Mw of 500 as measured by GPC in terms of polystyrene. Thereafter, the solution of the reaction product was added dropwise to a hexane solution, and the resulting precipitate was separated by filtration and dried at 40°C under vacuum. The resulting compound was dissolved in ultrapure water to a concentration of 10% by mass.

[0143] Synthesis Example 4 5.00 g of HP-4032D (DIC Corporation), 3.96 g of 1-thioglycerol (FUJIFILM Wako Pure Chemical Industries, Ltd.), and 0.31 g of tetrabutylphosphonium bromide (Hokuko Chemical Industry Co., Ltd.) were added to a reaction flask, and the mixture was heated and stirred at 105°C for 18 hours under a nitrogen atmosphere. The resulting reaction product corresponded to the following formula (X-4), and had a weight-average molecular weight Mw of 700 as measured by GPC in terms of polystyrene. Thereafter, the reaction product solution was added dropwise to a hexane solution, and the resulting precipitate was separated by filtration and dried at 40°C under vacuum. The resulting compound was dissolved in ultrapure water to a concentration of 10% by mass.

[0144] Synthesis Example 5 2.30 g of TEPIC (Nissan Chemical Industries, Ltd.), 2.74 g of succinic acid (Tokyo Chemical Industry Co., Ltd.), and 0.04 g of tetrabutylphosphonium bromide (Hokuko Chemical Industry Co., Ltd.) were added to a reaction flask containing 20.36 g of propylene glycol monomethyl ether, and the mixture was heated and stirred at 90°C for 21 hours under a nitrogen atmosphere. The resulting reaction product corresponded to the following formula (X-5), and had a weight average molecular weight Mw of 800 as measured by GPC in terms of polystyrene. Thereafter, a solution of the reaction product was added dropwise to a hexane solution, and the resulting precipitate was separated by filtration and dried at 40°C under vacuum. The resulting compound was dissolved in ultrapure water to a concentration of 10% by mass.

[0145] Synthesis Example 6 2.20 g of MAICA (manufactured by Shikoku Chemical Industry Co., Ltd.), 2.00 g of glycidol (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), and 0.16 g of tetrabutylphosphonium bromide (manufactured by Hokko Chemical Industry Co., Ltd.) were added to a reaction flask, which was heated and stirred at 105°C for 22 hours under a nitrogen atmosphere. The resulting reaction product corresponded to the following formula (X-6), and had a weight-average molecular weight Mw of 400 as measured by GPC in terms of polystyrene. Thereafter, the solution of the reaction product was added dropwise to a hexane solution, and the resulting precipitate was separated by filtration and dried at 40°C under vacuum. The resulting compound was dissolved in ultrapure water to a concentration of 10% by mass.

[0146] Synthesis Example 7 3.37 g of monomethyldicarboxymethyldiisocyanuric acid, 2.00 g of glycidol (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), and 0.55 g of tetrabutylphosphonium bromide (manufactured by Hokko Chemical Co., Ltd.) were added to a reaction flask containing 21.73 g of propylene glycol monomethyl ether, and the mixture was heated and stirred at 105°C for 22 hours under a nitrogen atmosphere. The resulting reaction product corresponded to the following formula (X-7), and had a weight-average molecular weight Mw of 460 as measured by GPC in terms of polystyrene. Thereafter, the reaction product solution was added dropwise to a hexane solution, and the resulting precipitate was separated by filtration and dried at 40°C under vacuum. The resulting compound was dissolved in ultrapure water to a concentration of 10% by mass.

[0147] Synthesis Example 8 2.90 g of tricarboxymethyl isocyanuric acid, 2.40 g of glycidol (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), and 0.08 g of tetrabutylphosphonium bromide (manufactured by Hokko Chemical Co., Ltd.) were added to a reaction flask containing 21.56 g of propylene glycol monomethyl ether, and the mixture was heated and stirred at 105°C for 21 hours under a nitrogen atmosphere. The resulting reaction product corresponded to the following formula (X-8), and had a weight-average molecular weight Mw of 550 as measured by GPC in terms of polystyrene. Thereafter, the solution of the reaction product was added dropwise to a hexane solution, and the resulting precipitate was separated by filtration and dried at 40°C under vacuum. The resulting compound was dissolved in ultrapure water to a concentration of 10% by mass.

[0148] Synthesis Example 9 2.16 g of isophthalic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 2.00 g of glycidol (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), and 0.22 g of tetrabutylphosphonium bromide (manufactured by Hokko Chemical Industry Co., Ltd.) were added to a reaction flask, and the mixture was heated and stirred at 105°C for 22 hours under a nitrogen atmosphere. The resulting reaction product corresponded to formula (x-9), and had a weight-average molecular weight Mw of 450 as measured by GPC in terms of polystyrene. Thereafter, the solution of the reaction product was added dropwise to a hexane solution, and the resulting precipitate was separated by filtration and dried at 40°C under vacuum. The resulting compound was dissolved in ultrapure water to a concentration of 10% by mass.

[0149] Synthesis Example 10 3.00 g of TEPIC (Nissan Chemical Industries, Ltd.), 3.29 g of 1-thioglycerol (Fujifilm Wako Pure Chemical Industries, Ltd.), and 0.13 g of tetrabutylphosphonium bromide (Hokuko Chemical Industry Co., Ltd.) were added to a reaction flask containing 25.7 g of ultrapure water, and the mixture was heated and stirred at 100° C. for 14 hours under a nitrogen atmosphere. The resulting reaction product was represented by the following formula (X-2), and had a weight average molecular weight Mw of 530 as measured by GPC in terms of polystyrene.

[0150] Example 1 0.18 g of tetramethoxymethyl glycoluril, 0.02 g of pyridinium p-toluenesulfonate (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.03 g of hydroxypropyl cellulose (HPC-SSL, Nippon Soda Co., Ltd.), and 92.41 g of ultrapure water were added to 7.33 g of the aqueous solution (solids content: 10% by mass) of the reaction product obtained in Synthesis Example 1 to prepare a solution. The solution was filtered using a hydrophilized PTFE syringe filter having a pore size of 0.02 μm, thereby preparing a composition for forming a resist underlayer film.

[0151] Example 2 0.18 g of tetramethoxymethyl glycoluril, 0.02 g of pyridinium p-toluenesulfonate (Tokyo Chemical Industry Co., Ltd.), 0.03 g of hydroxypropyl cellulose (HPC-SSL, Nippon Soda Co., Ltd.), and 92.41 g of ultrapure water were added to 7.33 g of the aqueous solution (solid content: 10% by mass) of the reaction product obtained in Synthesis Example 2 to prepare a solution. The solution was filtered using a hydrophilized PTFE syringe filter having a pore size of 0.02 μm, thereby preparing a composition for forming a resist underlayer film.

[0152] Example 3 0.18 g of tetramethoxymethyl glycoluril, 0.02 g of pyridinium p-toluenesulfonate (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.03 g of hydroxypropyl cellulose (HPC-SSL, Nippon Soda Co., Ltd.), and 92.41 g of ultrapure water were added to 7.33 g of the aqueous solution (solid content: 10% by mass) of the reaction product obtained in Synthesis Example 3 to prepare a solution. The solution was filtered using a hydrophilized PTFE syringe filter having a pore size of 0.02 μm, thereby preparing a composition for forming a resist underlayer film.

[0153] Example 4 0.18 g of tetramethoxymethyl glycoluril, 0.02 g of pyridinium p-toluenesulfonate (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.03 g of hydroxypropyl cellulose (HPC-SSL, Nippon Soda Co., Ltd.), and 92.41 g of ultrapure water were added to 7.33 g of the aqueous solution of the reaction product obtained in Synthesis Example 4 (solid content: 10% by mass) to prepare a solution. The solution was filtered using a hydrophilized PTFE syringe filter having a pore size of 0.02 μm, thereby preparing a composition for forming a resist underlayer film.

[0154] Example 5 0.18 g of tetramethoxymethyl glycoluril, 0.02 g of pyridinium p-toluenesulfonate (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.03 g of hydroxypropyl cellulose (HPC-SSL, Nippon Soda Co., Ltd.), and 92.41 g of ultrapure water were added to 7.33 g of the aqueous solution of the reaction product obtained in Synthesis Example 5 (solid content: 10% by mass) to prepare a solution. The solution was filtered using a hydrophilized PTFE syringe filter having a pore size of 0.02 μm, thereby preparing a composition for forming a resist underlayer film.

[0155] Example 6 0.18 g of tetramethoxymethyl glycoluril, 0.02 g of pyridinium p-toluenesulfonate (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.03 g of hydroxypropyl cellulose (HPC-SSL, Nippon Soda Co., Ltd.), and 92.41 g of ultrapure water were added to 7.33 g of the aqueous solution of the reaction product obtained in Synthesis Example 6 (solid content: 10% by mass) to prepare a solution. The solution was filtered using a hydrophilized PTFE syringe filter having a pore size of 0.02 μm, thereby preparing a composition for forming a resist underlayer film.

[0156] Example 7 0.18 g of tetramethoxymethyl glycoluril, 0.02 g of pyridinium p-toluenesulfonate (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.03 g of hydroxypropyl cellulose (HPC-SSL, Nippon Soda Co., Ltd.), and 92.41 g of ultrapure water were added to 7.33 g of the aqueous solution of the reaction product obtained in Synthesis Example 7 (solid content: 10% by mass) to prepare a solution. The solution was filtered using a hydrophilized PTFE syringe filter having a pore size of 0.02 μm, thereby preparing a composition for forming a resist underlayer film.

[0157] Example 8 0.18 g of tetramethoxymethyl glycoluril, 0.02 g of pyridinium p-toluenesulfonate (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.03 g of hydroxypropyl cellulose (HPC-SSL, Nippon Soda Co., Ltd.), and 92.41 g of ultrapure water were added to 7.33 g of the aqueous solution of the reaction product obtained in Synthesis Example 8 (solid content: 10% by mass) to prepare a solution. The solution was filtered using a hydrophilized PTFE syringe filter having a pore size of 0.02 μm, thereby preparing a composition for forming a resist underlayer film.

[0158] Example 9 0.18 g of tetramethoxymethyl glycoluril, 0.02 g of pyridinium p-toluenesulfonate (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.03 g of hydroxypropyl cellulose (HPC-SSL, Nippon Soda Co., Ltd.), and 92.41 g of ultrapure water were added to 7.33 g of the aqueous solution of the reaction product obtained in Synthesis Example 9 (solid content: 10% by mass) to prepare a solution. The solution was filtered using a hydrophilized PTFE syringe filter having a pore size of 0.02 μm, thereby preparing a composition for forming a resist underlayer film.

[0159] Example 10 0.18 g of tetramethoxymethyl glycoluril, 0.02 g of pyridinium p-toluenesulfonate (Tokyo Chemical Industry Co., Ltd.), 0.03 g of polyvinyl alcohol (PXP-05, Nippon Vinyl Acetate & Poval Corporation), and 92.41 g of ultrapure water were added to 7.33 g of the aqueous solution (solids content: 10% by mass) of the reaction product obtained in Synthesis Example 2 to prepare a solution. The solution was filtered using a hydrophilized PTFE syringe filter with a pore size of 0.02 μm, to prepare a composition for forming a resist underlayer film.

[0160] Example 11 0.03 g of pyridinium trifluoromethanesulfonate (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.05 g of hydroxypropyl cellulose (HPC-SSL, Nippon Soda Co., Ltd.), and 90.72 g of ultrapure water were added to 9.19 g of the aqueous solution (solid content: 10% by mass) of the reaction product obtained in Synthesis Example 2 to prepare a solution. The solution was filtered using a hydrophilized PTFE syringe filter having a pore size of 0.02 μm, thereby preparing a composition for forming a resist underlayer film.

[0161] Example 12 0.04 g of polystyrene sulfonic acid (manufactured by Sigma-Aldrich Co.) and 86.36 g of ultrapure water were added to 13.59 g of the aqueous solution (solid content: 10% by mass) of the reaction product obtained in Synthesis Example 2. The solution was filtered using a hydrophilized PTFE syringe filter having a pore size of 0.02 μm to prepare a composition for forming a resist underlayer film.

[0162] [Resist Solvent Resistance Test] Each of the resist underlayer film-forming compositions prepared in Examples 1 to 12 was applied (spin coated) onto a silicon wafer using a spin coater. The coated silicon wafer was heated on a hot plate at 205°C for 1 minute to form a coating (underlayer film) with a thickness of 25 nm. Next, to confirm the solvent resistance of the underlayer film, the silicon wafer on which the underlayer film had been formed was immersed for 1 minute in a mixed solvent of propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate in a mass ratio of 7:3, spin-dried, and then baked at 100°C for 30 seconds. The thickness of the protective film before and after immersion in the mixed solvent was measured using an optical interference film thickness meter (product name: Nanospec 6100, manufactured by Nanometrics Japan Co., Ltd.).

[0163] The solvent resistance was evaluated by calculating the film thickness reduction rate (%) of the underlayer film removed by solvent immersion using the following formula: Film thickness reduction rate (%) = ((A - B) ÷ A) × 100 A: Film thickness before solvent immersion B: Film thickness after solvent immersion The results are shown in Table 1. A film thickness reduction rate of approximately 1% or less can be said to have sufficient solvent resistance.

[0164]

[0165] From the above results, the films formed from the compositions for forming resist underlayer films of Examples 1 to 12 showed very little change in film thickness even after immersion in a solvent. Therefore, the films formed from the compositions for forming resist underlayer films of Examples 1 to 12 have sufficient solvent resistance to function as underlayer films. Note that although the film thickness reduction rates were negative in Examples 1, 3, 6, 9, and 11, this does not pose any particular problems.

[0166] [Evaluation of Optical Parameters] The resist underlayer film-forming compositions prepared in Examples 2, 10, 11, and 12 were each coated onto a silicon wafer using a spin coater. The coated silicon wafer was heated on a hot plate at 205°C for 1 minute to form a resist underlayer film (film thickness 30 nm). The n value (refractive index) and k value (extinction coefficient or absorption coefficient) of these resist underlayer films at a wavelength of 193 nm were then measured using a spectroscopic ellipsometer (product name: VUV-VASE VU-302, manufactured by J.A. Woollam Co.). The measurement results of the optical parameters are shown in Table 2.

[0167]

[0168] [Resist Pattern Formation] An example of forming a resist underlayer film and then forming a resist pattern thereon is described below. The resist underlayer film forming composition prepared in Example 2 was applied using a spin coater to a substrate having a silicon wafer on which a SiON film (nitrogen-containing silicon oxide film) was formed to a thickness of 50 nm. The coating was then baked on a hot plate (205°C, 1 minute) to form a resist underlayer film with a thickness of 20 to 30 nm. A commercially available photoresist solution (manufactured by JSR Corporation, product name: AR2772) was applied to the resist underlayer film using a spin coater and baked on a hot plate (e.g., 110°C, 90 seconds) to form a photoresist film with a thickness of 100 nm. Next, using a scanner [Nikon Corporation, NSRS307E (wavelength 193 nm, NA: 0.85, σ: 0.85 / 0.93 (dipole)], exposure was performed through a photomask set so that after development, the photoresist line width and the width between the photoresist lines would be 0.065 μm, i.e., 0.065 μmL / S (dense line), and nine such lines would be formed. Thereafter, post-exposure baking (PEB) was performed on a hot plate at 110°C for 90 seconds, and after cooling, development was performed using a 0.26N aqueous tetramethylammonium hydroxide solution as the developer in an industry standard 60-second single puddle process. Through the above process, a resist pattern was formed.

[0169] The cross section of the obtained photoresist pattern perpendicular to the substrate, i.e., silicon wafer, was observed using a scanning electron microscope (SEM). As a result, it was observed that the cross section of the obtained photoresist pattern was generally rectangular with a good straight bottom shape. An SEM image of the cross section of the photoresist pattern finally formed on the substrate using the composition for forming a resist underlayer film of Example 2 is shown in Figure 1.

Claims

1. A composition for forming a resist underlayer film, comprising a first component, a second component, and a solvent, wherein the second component is a water-soluble polymer, the mass ratio of the first component to the second component (first component:second component) is 99:1 to 50:50, and the solvent contains 50% or more by mass of water relative to the solvent.

2. A composition for forming a resist underlayer film, comprising a first component and a solvent, wherein the first component is a compound containing at least one selected from the group consisting of a structure represented by the following formula (1) and a structure represented by the following formula (2), and the solvent contains 50% by mass or more of water relative to the solvent. (In formula (1), X １ represents a group represented by any one of the following formulas (1-1) to (1-4): １ and Z ２ Each of Q independently represents a single bond or a divalent group represented by the following formula (1-5): １ represents a divalent organic group having at least one selected from an aromatic hydrocarbon ring and an aliphatic hydrocarbon ring. (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. ３ represents a single bond or a divalent group represented by the following formula (1-5). * represents a bond. *1 represents a bond bonded to a carbon atom in formula (1). *2 represents a bond bonded to a nitrogen atom in formula (1). (In formula (1-5), m1 is an integer of 0 to 4, m2 is 0 or 1, m3 is 0 or 1, and m4 is an integer of 0 to 2. However, when m3 is 1, m1 and m2 cannot be 0 at the same time. *3 represents a bond bonding to a nitrogen atom in formula (1) or formula (1-4). *4 represents a bond.) 3. The composition for forming a resist underlayer film according to claim 1, wherein the first component is a compound containing at least one selected from the group consisting of a structure represented by the following formula (1) and a structure represented by the following formula (2): (In formula (1), X １ represents a group represented by any one of the following formulas (1-1) to (1-4): １ and Z ２ Each of Q independently represents a single bond or a divalent group represented by the following formula (1-5): １ represents a divalent organic group having at least one selected from an aromatic hydrocarbon ring and an aliphatic hydrocarbon ring. (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. ３ represents a single bond or a divalent group represented by the following formula (1-5). * represents a bond. *1 represents a bond bonded to a carbon atom in formula (1). *2 represents a bond bonded to a nitrogen atom in formula (1). (In formula (1-5), m1 is an integer of 0 to 4, m2 is 0 or 1, m3 is 0 or 1, and m4 is an integer of 0 to 2. However, when m3 is 1, m1 and m2 cannot be 0 at the same time. *3 represents a bond bonding to a nitrogen atom in formula (1) or formula (1-4). *4 represents a bond.) 4. Q １ The composition for forming a resist underlayer film according to claim 2 or 3, wherein is represented by the following formula (2-1): (In formula (2-1), Q １１ represents a divalent organic group represented by any one of the following formulas (2-1-1) to (2-1-4). n1 and n2 each independently represent 0 or 1. * represents a bond. (In formulas (2-1-1) to (2-1-4), R ２１ ~R ２６ each 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 (2-1-1), 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. ４ 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 may be the same or different. In formula (2-1-3), 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. ５ 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.) 5. The composition for forming a resist underlayer film according to claim 1 or 2, wherein the first component contains at least one of a structure represented by the following formula (E-1) and a structure represented by the following formula (E-2): (In formula (E-1) and formula (E-2), * represents a bond.) 6. The composition for forming a resist underlayer film according to claim 2, further comprising a second component, said second component being a water-soluble polymer.

7. The composition for forming a resist underlayer film according to claim 1 or 6, wherein the water-soluble polymer is at least one selected from the group consisting of polyvinyl alcohol, polystyrene sulfonic acid, and water-soluble cellulose.

8. The aqueous composition for forming a resist underlayer film according to claim 6, wherein the mass ratio of the first component to the second component (first component:second component) is 99:1 to 50:

50.

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

10. The composition for forming a resist underlayer film according to claim 1 or 2, further comprising a curing catalyst.

11. A resist underlayer film, which is a cured product of the composition for forming a resist underlayer film according to claim 1 or 2.

12. A substrate for semiconductor processing, comprising: a semiconductor substrate; and the resist underlayer film according to claim 11.

13. A method for manufacturing a semiconductor device, comprising: a step of forming a resist underlayer film on a semiconductor substrate using the composition for forming a resist underlayer film according to claim 1 or 2; and a step of forming a resist film on the resist underlayer film.

14. A pattern forming method comprising: a step of forming a resist underlayer film on a semiconductor substrate using the composition for forming a resist underlayer film according to claim 1 or 2; a step of forming a resist film on the resist underlayer film; a step of irradiating the resist film with light or an electron beam and then developing the resist film to obtain a resist pattern; and a step of etching the resist underlayer film using the resist pattern as a mask.

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