Silicon-containing resist underlayer film-forming composition containing a protected phenol group and nitric acid

Abstract

To provide a resist underlayer film-forming composition for lithography that can be used for producing a semiconductor device, and for forming a resist underlayer film that can be used as a hard mask.SOLUTION: The resist underlayer film-forming composition for lithography includes: a hydrolysis condensate (c) of a hydrolyzable silane (a) as a silane; nitric acid ions; and a solvent. The hydrolyzable silane (a) includes a hydrolyzable silane of the formula (1) in the figure, where in the formula (1), R1 is an organic group of a specific formula and is bonded to a silicon atom via an Si-C bond]. The composition further includes the hydrolyzable silane (a) and / or a hydrolysate (b) thereof. The content of the nitric acid ions in the resist underlayer film-forming composition is in the range from 1 ppm to 1000 ppm. In the hydrolysis condensate (c), the functional group of the formula (2) in the hydrolyzable silane of the formula (1) is such that the molar ratio of (hydrogen atoms) / (hydrogen atoms+R5 groups) of 1% to 100%.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a composition for forming an underlayer film between a substrate and a resist (e.g., photoresist, electron beam resist) used in the manufacture of a semiconductor device. More specifically, the present invention relates to a resist underlayer film-forming composition for lithography for forming an underlayer film used as an underlayer of a photoresist in a lithography process for the manufacture of a semiconductor device. The present invention also relates to a method for forming a resist pattern using the underlayer film-forming composition.

[0002] Conventionally, in the manufacture of semiconductor devices, microfabrication by lithography using photoresist has been carried out. Siri This is a processing method in which a thin film of photoresist is formed on a semiconductor substrate such as a semiconductor wafer, and then the photoresist is irradiated with actinic rays such as ultraviolet light through a mask pattern on which a semiconductor device pattern is drawn, developed, and the substrate is then etched using the resulting photoresist pattern as a protective film, thereby forming fine irregularities on the substrate surface corresponding to the pattern. However, in recent years, with the increasing integration density of semiconductor devices, the actinic rays used have tended to be shorter in wavelength, from KrF excimer lasers (248 nm) to ArF excimer lasers (193 nm). As a result, the impact of actinic rays reflected from semiconductor substrates has become a major problem.

[0003] In addition, a film known as a hard mask containing a metal element such as silicon or titanium is used as an underlayer film between a semiconductor substrate and a photoresist. In this case, since the components of the resist and the hard mask differ significantly, the rate at which they are removed by dry etching depends greatly on the gas species used in the dry etching. By appropriately selecting the gas species, the hard mask can be removed by dry etching without significantly reducing the thickness of the photoresist. Thus, in recent semiconductor device manufacturing, a resist underlayer film has been placed between the semiconductor substrate and the photoresist to achieve various effects, including anti-reflection. While compositions for resist underlayer films have been investigated, the development of new materials for resist underlayer films is desired due to the variety of properties required.

[0004] For example, a resist underlayer film has been disclosed in which a silicon-containing resist underlayer film-forming composition having a phenyl group-containing chromophor is applied onto a semiconductor substrate in a lithography process and then baked (see Patent Document 1).

[0005] For example, a radiation-sensitive composition containing a polysiloxane exhibiting phenoplast crosslinking reactivity as a base resin has been disclosed (see Patent Document 2). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] International Publication No. 2015 / 194555 Brochure [Patent Document 2] International Publication No. 2016 / 199762 Brochure Summary of the Invention [Problem to be solved by the invention]

[0007] Highly polar polysiloxane solutions may contain a large amount of ionic impurities. These ionic impurities include polyvalent metal ions and charged colloidal particles of these metals or metal oxides, which may be difficult to remove even with ion exchange resins. In such cases, filters containing polar groups may be used. The solution is sometimes filtered through a filter. Filters containing polar groups can cause problems such as an increase in the molecular weight of the polysiloxane or gelation due to the polar groups reacting with the polysiloxane component. Furthermore, while volatile catalysts such as hydrochloric acid are removed during the solvent substitution process, which involves heating the polysiloxane solution, high-molecular-weight acids can be removed by the filter during filtration, potentially causing the polysiloxane to become unstable as it passes through the filter.

[0008] In view of the above circumstances, the present invention has been made, and an object of the present invention is to provide a resist underlayer film-forming composition for lithography that can be used in the manufacture of semiconductor devices. More specifically, an object of the present invention is to provide a resist underlayer film-forming composition for lithography that can be used to form a resist underlayer film that can be used as a hard mask. Another object of the present invention is to provide a resist underlayer film-forming composition containing a polysiloxane that remains stable even after undergoing a step of filtering out foreign matter through a filter. [Means for solving the problem]

[0009] As a result of extensive research aimed at solving the above problems, the present inventors discovered that a polysiloxane solution containing a specific amount of nitric acid can be stably filtered when passed through a polar group-containing filter that removes ionic impurities, and thus completed the present invention.

[0010] That is, in a first aspect, the present invention provides a method for producing a silane-based compound comprising a hydrolysis condensate (c) of a hydrolyzable silane (a), nitrate ions, and a solvent, wherein the hydrolyzable silane (a) is represented by the formula (1): [ka] [In formula (1), R 1 is given by equation (2): [ka] (In formula (2), X represents an oxygen atom, a sulfur atom, or a nitrogen atom; R 4 represents a single bond or an alkylene group having 1 to 10 carbon atoms; R 5 represents an alkyl group having 1 to 10 carbon atoms which may contain an alkoxy group having 1 to 10 carbon atoms; R 6 represents an alkyl group having 1 to 10 carbon atoms, n1 is 1≦n1≦5, 0≦n2≦(5-n1), n3 is 0 or 1, and * indicates the bonding position to the silicon atom.) and is bonded to the silicon atom by a Si-C bond. 2 R is an organic group having an alkyl group, an aryl group, a halogenated alkyl group, a halogenated aryl group, an alkoxyaryl group, an alkenyl group, or an epoxy group, an acryloyl group, a methacryloyl group, a mercapto group, an amino group, or a cyano group, and is bonded to a silicon atom by a Si-C bond. 3 represents an alkoxy group, an acyloxy group, or a halogen group; a represents an integer of 1, b represents an integer of 0 to 2, and a+b represents an integer of 1 to 3. As a second aspect, the present invention relates to the resist underlayer film-forming composition according to the first aspect, further comprising a hydrolyzable silane (a) and / or a hydrolyzate thereof (b). According to a third aspect, the present invention relates to the resist underlayer film-forming composition according to the first or second aspect, which contains nitrate ions in the range of 1 ppm to 1000 ppm. As a fourth aspect, the hydrolysis condensation product (c) is a compound in which the functional group of the formula (2) in the hydrolyzable silane of the formula (1) is (hydrogen atom) / (hydrogen atom + R 5 The resist underlayer film-forming composition according to any one of the first to third aspects, wherein the molar ratio of the aryl group to the alkyl group is 1% to 100%. As a fifth aspect, the hydrolyzable silane (a) is a combination of the hydrolyzable silane of the formula (1) and another hydrolyzable silane, and the other hydrolyzable silane is a hydrolyzable silane of the formula (3): [ka] (In formula (3), R 7 is an organic group having an alkyl group, an aryl group, a halogenated alkyl group, a halogenated aryl group, an alkoxyaryl group, an alkenyl group, or an epoxy group, an acryloyl group, a methacryloyl group, a mercapto group, or a cyano group, and is bonded to a silicon atom by a Si-C bond; R 8 represents an alkoxy group, an acyloxy group, or a halogen atom, and c represents an integer of 0 to 3), and a compound represented by formula (4): [ka] (In formula (4), R 9 is an alkyl group bonded to a silicon atom by a Si-C bond, and R 10 represents an alkoxy group, an acyloxy group, or a halogen group; Y represents an alkylene group or an arylene group; d represents an integer of 0 or 1; and e represents an integer of 0 or 1. According to a sixth aspect, the present invention relates to a resist underlayer film-forming composition according to the fifth aspect, which comprises, as a polymer, a hydrolyzed condensate of hydrolyzable silanes, the hydrolyzable silane being a combination of the hydrolyzable silane of formula (1) according to the first aspect and the hydrolyzable silane of formula (3) according to the fifth aspect. As a seventh aspect, the present invention relates to the resist underlayer film-forming composition according to any one of the first to sixth aspects, further comprising an additive comprising water, an acid, a photoacid generator, a surfactant, a metal oxide, or a combination thereof. As an eighth aspect, the present invention relates to a method for producing a resist underlayer film-forming composition according to any one of the first to seventh aspects, comprising: a step (A) of filtering a polymer solution containing the hydrolyzed condensate (c) of a hydrolyzable silane, or the hydrolyzed condensate (c) of a hydrolyzable silane, the hydrolyzed silane (a) and / or a hydrolyzate (b) thereof, nitrate ions, and a solvent, through a filter including a polar group-containing filter. As a ninth aspect, the present invention relates to the method for producing a resist underlayer film-forming composition according to the eighth aspect, in which the polar group-containing filter is a nylon filter. According to a tenth aspect, the present invention relates to a method for producing a resist underlayer film-forming composition according to the eighth or ninth aspect, further comprising a step (B) of filtering a solution obtained by adding the additive according to the seventh aspect to a polymer solution through a filter. As an eleventh aspect, the present invention relates to a method for manufacturing a semiconductor device, the method including the steps of applying the resist underlayer film-forming composition according to any one of the first to seventh aspects onto a semiconductor substrate and baking the composition to form a resist underlayer film, applying a resist composition onto the underlayer film to form a resist layer, exposing the resist layer to light, developing the resist after exposure to obtain a resist pattern, etching the resist underlayer film using the resist pattern, and processing a semiconductor substrate using the patterned resist layer and resist underlayer film. As a twelfth aspect, the present invention relates to a method for manufacturing a semiconductor device, including the steps of: forming an organic underlayer film on a semiconductor substrate; applying the resist underlayer film-forming composition according to any one of the first to seventh aspects thereon and baking the composition to form a resist underlayer film; applying a resist composition on the resist underlayer film to form a resist layer; exposing the resist layer to light; developing the resist after exposure to obtain a resist pattern; etching the resist underlayer film using the resist pattern; etching the organic underlayer film using the patterned resist underlayer film; and processing a semiconductor substrate using the patterned organic underlayer film. In particular, the present invention provides a first aspect of a resist underlayer film-forming composition for lithography, which comprises a hydrolysis condensate (c) of a hydrolyzable silane (a) as a silane, nitrate ions, and a solvent, wherein the hydrolyzable silane (a) is represented by the formula (1): [ka] [In formula (1), R 1 is given by equation (2): [ka] (In formula (2), X represents an oxygen atom, a sulfur atom, or a nitrogen atom; R 4 represents a single bond or an alkylene group having 1 to 10 carbon atoms; R 5 represents an alkyl group having 1 to 10 carbon atoms; R 6 represents an alkyl group having 1 to 10 carbon atoms, n1 is 1≦n1≦5, 0≦n2≦(5-n1), n3 is 1, and * indicates the bonding position to the silicon atom.) and is bonded to the silicon atom by a Si-C bond. 2 R is an organic group having an alkyl group, an aryl group, a halogenated alkyl group, a halogenated aryl group, an alkoxyaryl group, an alkenyl group, or an epoxy group, an acryloyl group, a methacryloyl group, a mercapto group, an amino group, or a cyano group, and is bonded to a silicon atom by a Si-C bond. 3 represents an alkoxy group, an acyloxy group, or a halogen group; a represents an integer of 1, b represents an integer of 0 to 2, and a+b represents an integer of 1 to 3; The present invention relates to the resist underlayer film-forming composition for lithography, wherein the hydrolysis condensate (c) is represented by the following formula: [ka] [Effects of the Invention]

[0011] In the present invention, a resist underlayer film is formed on a substrate by a coating method, or an organic underlayer film is formed on a substrate by a coating method, and a resist film (e.g., photoresist, electron beam resist) is formed on the resist underlayer film. A resist pattern is then formed by exposure and development, and the resist underlayer film with the resist pattern formed thereon is dry-etched to transfer the pattern, and the substrate is processed using the patterned resist underlayer film, or the organic underlayer film is etched to transfer the pattern, and the substrate is processed using the organic underlayer film.

[0012] When forming a fine pattern on a resist film, the resist film thickness tends to be thin to prevent pattern collapse. When dry etching is performed to transfer the resist film pattern to a film existing below it due to the thinning of the resist, the pattern cannot be transferred unless the etching rate of the lower layer film is higher than that of the upper layer film. In the present invention, a resist underlayer film (containing an inorganic silicon-based compound) of the present invention is coated on a substrate, either via an organic underlayer film or without an organic underlayer film, and a resist film (organic resist film) is coated on top of that. The dry etching rates of films made of organic components and films made of inorganic components differ significantly depending on the etching gas selected; films made of organic components are dry-etched at a higher rate with oxygen-based gases, while films made of inorganic components are dry-etched at a higher rate with halogen-containing gases.

[0013] For example, a resist pattern is formed on a resist film, the resist underlayer film of the present invention existing below it is dry-etched with a halogen-containing gas to transfer the pattern to the resist underlayer film, and the resist underlayer film to which the pattern has been transferred is used to process a substrate with a halogen-containing gas. Alternatively, the resist underlayer film to which the pattern has been transferred is used to dry-etch the underlying organic underlayer film with an oxygen-based gas to transfer the pattern to the organic underlayer film, and the organic underlayer film to which the pattern has been transferred is used to process a substrate with a halogen-containing gas.

[0014] In recent years, the trend toward thinner resists has been remarkable in cutting-edge semiconductor devices, and improved lithography properties are required for silicon-containing resist underlayer films, even in tri-layer processes. In the present invention, the phenolic hydroxyl group or hydroxyalkyl group improves adhesion to the upper layer resist, resulting in the development of a good resist pattern and improved solvent resistance and developer resistance. When the upper layer resist is developed with an alkaline developer, it is effective in reducing scum during hole formation. Furthermore, when the upper layer resist is developed with an organic solvent, it is effective in suppressing collapse during line formation.

[0015] In the present invention, the hydrolyzable silane includes a hydrolyzable silane having a protected phenol group. When a hydrolyzable silane is hydrolyzed and condensed without protecting the phenol group to produce a polysiloxane, dehydration condensation of the phenolic hydroxyl group occurs simultaneously, resulting in a gel-like structure. To avoid this, the phenol group is protected during hydrolysis and condensation. In the present invention, nitric acid is used as the hydrolysis catalyst.

[0016] The polysiloxane solution of the present invention contains nitric acid, which has the effect of allowing the polysiloxane solution to remain stable even after passing through a polar group-containing filter such as a nylon filter to remove ionic foreign matter. Polysiloxane is formed by condensing the hydrolyzed product of hydrolyzable silane. However, the hydrolysis catalyst used is nitric acid, which is a non-volatile acid and can pass through a nylon filter. DETAILED DESCRIPTION OF THE INVENTION

[0017] The present invention relates to a resist underlayer film-forming composition for lithography, which comprises a hydrolyzed condensate (c) of a hydrolyzable silane (a) as a silane, nitrate ions, and a solvent, wherein the hydrolyzable silane (a) comprises a hydrolyzable silane of formula (1).

[0018] In formula (1), R 1 is an organic group of formula (2) and is bonded to the silicon atom by a Si-C bond. 2 R is an organic group having an alkyl group, an aryl group, a halogenated alkyl group, a halogenated aryl group, an alkoxyaryl group, an alkenyl group, or an epoxy group, an acryloyl group, a methacryloyl group, a mercapto group, an amino group, or a cyano group, and is bonded to a silicon atom by a Si-C bond. 3 represents an alkoxy group, an acyloxy group, or a halogen group, a represents an integer of 1, b represents an integer of 0 to 2, and a+b represents an integer of 1 to 3.

[0019] In formula (2), X represents an oxygen atom, a sulfur atom, or a nitrogen atom; 4 represents a single bond or an alkylene group having 1 to 10 carbon atoms; R 5 represents an alkyl group having 1 to 10 carbon atoms which may contain an alkoxy group having 1 to 10 carbon atoms; R 6 represents an alkyl group having 1 to 10 carbon atoms, n1 represents 1≦n1≦5, 0≦n2≦(5−n1), n3 represents 0 or 1, and * represents the bonding position to the silicon atom.

[0020] The present invention may further comprise a hydrolyzable silane (a) and / or its hydrolyzate (b).

[0021] Of the total silanes, the silane of formula (1) can be used in the range of 50 mol% or less, or 1 to 50 mol%, or 3 to 50 mol%, or 5 to 50 mol%, or 7 to 50 mol%, or 7 to 40 mol%, or 7 to 35 mol%, or 7 to 30 mol%, or 7 to 20 mol%, or 10 to 50 mol%, or 10 to 45 mol%, or 10 to 40 mol%, or 10 to 35 mol%, or 10 to 30 mol%, or 7 to 20 mol%.

[0022] The resist underlayer film-forming composition of the present invention contains a hydrolyzable silane of formula (1), or a combination of a hydrolyzable silane of formula (1) with another hydrolyzable silane (e.g., a hydrolyzable silane of formula (3)), a hydrolyzate thereof, or a hydrolyzed condensate thereof, and a solvent, and may optionally contain an acid, water, an alcohol, a curing catalyst, an acid generator, another organic polymer, a light-absorbing compound, a metal oxide, a surfactant, etc.

[0023] The solids content of the resist underlayer film-forming composition of the present invention is, for example, 0.1 to 50% by mass, 0.1 to 30% by mass, or 0.1 to 25% by mass, where the solids content is the total content of all components of the resist underlayer film-forming composition excluding the solvent component.

[0024] The proportion of hydrolyzable silane, its hydrolysate, and its hydrolysis condensate in the solid content is 20% by mass or more, for example, 50% to 100% by mass, 60% to 99% by mass, or 70% to 99% by mass.

[0025] The alkyl group is a straight-chain or branched alkyl group having 1 to 10 carbon atoms, and examples thereof include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group, an s-butyl group, a t-butyl group, an n-pentyl group, a 1-methyl-n-butyl group, a 2-methyl-n-butyl group, a 3-methyl-n-butyl group, a 1,1-dimethyl-n-propyl group, a 1,2-dimethyl-n-propyl group, a 2,2-dimethyl-n-propyl group, a 1-ethyl-n-butyl group, a 2,2-dimethyl-n-propyl ...butyl group, a 2,2-dimethyl-n-butyl group, a 2,2-dimethyl-n-butyl group, a 2,2-dimethyl-n-butyl group, a 2,2-dimethyl-n-butyl group, a 2,2-dimethyl-n-butyl group, a 2,2-dimethyl-n-butyl group, a 2,2-dimethyl-n-butyl group, a 2,2-dimethyl-n-butyl group, a 2,2-dimethyl-n-butyl group, a 2,2-dimethyl-n-butyl group, a 2,2-dimethyl- n-propyl group, n-hexyl group, 1-methyl-n-pentyl group, 2-methyl-n-pentyl group, 3-methyl-n-pentyl group, 4-methyl-n-pentyl group, 1,1-dimethyl-n-butyl group, 1,2-dimethyl-n-butyl group, 1,3-dimethyl-n-butyl group, 2,2-dimethyl-n-butyl group, 2,3-dimethyl-n-butyl group, 3,3-dimethyl-n-butyl group, 1-ethyl-n-butyl group, 2-ethyl-n-butyl group, 1,1,2-trimethyl-n-propyl group, 1,2,2-trimethyl-n-propyl group, 1-ethyl-1-methyl-n-propyl group, and 1-ethyl-2-methyl-n-propyl group.

[0026] Cyclic alkyl groups can also be used, and examples of cyclic alkyl groups having 1 to 10 carbon atoms include cyclopropyl, cyclobutyl, 1-methylcyclopropyl, 2-methylcyclopropyl, cyclopentyl, 1-methylcyclobutyl, 2-methylcyclobutyl, 3-methylcyclobutyl, 1,2-dimethylcyclopropyl, 2,3-dimethylcyclopropyl, 1-ethylcyclopropyl, 2-ethylcyclopropyl, cyclohexyl, 1-methylcyclopentyl, 2-methylcyclopentyl, 3-methylcyclopentyl, 1-ethylcyclobutyl, 2-ethylcyclobutyl, 3-ethylcyclobutyl, 1,2-dimethylcyclopropyl, 2,3-dimethylcyclopropyl, 1-ethylcyclopropyl, 2-ethylcyclopropyl, cyclohexyl, 1-methylcyclopentyl, 2-methylcyclopentyl, 3-methylcyclopentyl, 1-ethylcyclobutyl, 2-ethylcyclobutyl, 3-ethylcyclobutyl, 1,2-dimethylcyclopropyl, 2,3-dimethylcyclopropyl, 1-ethylcyclopropyl, 2,3 ... butyl group, 1,3-dimethyl-cyclobutyl group, 2,2-dimethyl-cyclobutyl group, 2,3-dimethyl-cyclobutyl group, 2,4-dimethyl-cyclobutyl group, 3,3-dimethyl-cyclobutyl group, 1-n-propyl-cyclopropyl group, 2-n-propyl-cyclopropyl group, 1-i-propyl-cyclopropyl group, 2-i-propyl-cyclopropyl group, 1,2,2-trimethyl-cyclopropyl group, 1,2,3-trimethyl-cyclopropyl group, 2,2,3-trimethyl-cyclopropyl group, 1-ethyl-2-methyl-cyclopropyl group, 2-ethyl-1-methyl-cyclopropyl group, 2-ethyl-2-methyl-cyclopropyl group, and 2-ethyl-3-methyl-cyclopropyl group.

[0027] The alkylene group can be an alkylene group derived from the above alkyl groups, for example, a methylene group for a methyl group, an ethylene group for an ethyl group, and a propylene group for a propyl group.

[0028] The alkenyl group is an alkenyl group having 2 to 10 carbon atoms, and examples thereof include ethenyl, 1-propenyl, 2-propenyl, 1-methyl-1-ethenyl, 1-butenyl, 2-butenyl, 3-butenyl, 2-methyl-1-propenyl, 2-methyl-2-propenyl, 1-ethylethenyl, 1-methyl-1-propenyl, 1-methyl-2-propenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl, 1-n-propyleth ... 1-methyl-1-butenyl group, 1-methyl-2-butenyl group, 1-methyl-3-butenyl group, 2-ethyl-2-propenyl group, 2-methyl-1-butenyl group, 2-methyl-2-butenyl group, 2-methyl-3-butenyl group, 3-methyl-1-butenyl group, 3-methyl-2-butenyl group, 3-methyl-3-butenyl group, 1,1-dimethyl-2-propenyl group, 1-i-propylethenyl group, 1,2-dimethyl-1-propenyl group, 1,2-dimethyl-2-propenyl group cyclopentenyl, 1-cyclopentenyl, 2-cyclopentenyl, 3-cyclopentenyl, 1-hexenyl, 2-hexenyl, 3-hexenyl, 4-hexenyl, 5-hexenyl, 1-methyl-1-pentenyl, 1-methyl-2-pentenyl, 1-methyl-3-pentenyl, 1-methyl-4-pentenyl, 1-n-butylethenyl, 2-methyl-1-pentenyl, 2-methyl-2-pentenyl, 2-methyl-3-pentenyl, 2-methyl-4- pentenyl group, 2-n-propyl-2-propenyl group, 3-methyl-1-pentenyl group, 3-methyl-2-pentenyl group, 3-methyl-3-pentenyl group, 3-methyl-4-pentenyl group, 3-ethyl-3-butenyl group, 4-methyl-1-pentenyl group, 4-methyl-2-pentenyl group, 4-methyl-3-pentenyl group, 4-methyl-4-pentenyl group, 1,1-dimethyl-2-butenyl group, 1,1-dimethyl-3-butenyl group, 1,2-dimethyl-1-butenyl group, 1 ,2-dimethyl-2-butenyl group, 1,2-dimethyl-3-butenyl group, 1-methyl-2-ethyl-2-propenyl group, 1-s-butylethenyl group, 1,3-dimethyl-1-butenyl group, 1,3-dimethyl-2-butenyl group, 1,3-dimethyl-3-butenyl group, 1-i-butylethenyl group, 2,2-dimethyl-3-butenyl group, 2,3-dimethyl-1-butenyl group, 2,3-dimethyl-2-butenyl group, 2,3-dimethyl-3-butenyl group thenyl group, 2-i-propyl-2-propenyl group, 3,3-dimethyl-1-butenyl group, 1-ethyl-1-butenyl group, 1-ethyl-2-butenyl group, 1-ethyl-3-butenyl group, 1-n-propyl-1-propenyl group, 1-n-propyl-2-propenyl group, 2-ethyl-1-butenyl group, 2-ethyl-2-butenyl group, 2-ethyl-3-butenyl group, 1,1,2-trimethyl-2-propenyl group, 1-t-butylethenyl group, 1 -methyl-1-ethyl-2-propenyl group, 1-ethyl-2-methyl-1-propenyl group, 1-ethyl-2-methyl-2-propenyl group, 1-i-propyl-1-propenyl group, 1-i-propyl-2-propenyl group, 1-methyl-2-cyclopentenyl group, 1-methyl-3-cyclopentenyl group, 2-methyl-1-cyclopentenyl group, 2-methyl-2-cyclopentenyl group, 2-methyl-3-cyclopentenyl group, 2-methyl-4 cyclopentenyl group, 2-methyl-5-cyclopentenyl group, 2-methylene-cyclopentyl group, 3-methyl-1-cyclopentenyl group, 3-methyl-2-cyclopentenyl group, 3-methyl-3-cyclopentenyl group, 3-methyl-4-cyclopentenyl group, 3-methyl-5-cyclopentenyl group, 3-methylene-cyclopentyl group, 1-cyclohexenyl group, 2-cyclohexenyl group, and 3-cyclohexenyl group.

[0029] Examples of the aryl group include aryl groups having 6 to 20 carbon atoms, such as a phenyl group, an o-methylphenyl group, a m-methylphenyl group, a p-methylphenyl group, an o-chlorophenyl group, a m-chlorophenyl group, a p-chlorophenyl group, an o-fluorophenyl group, a p-mercaptophenyl group, an o-methoxyphenyl group, a p-methoxyphenyl group, a p-aminophenyl group, a p-cyanophenyl group, an α-naphthyl group, a β-naphthyl group, an o-biphenylyl group, an m-biphenylyl group, a p-biphenylyl group, a 1-anthryl group, a 2-anthryl group, a 9-anthryl group, a 1-phenanthryl group, a 2-phenanthryl group, a 3-phenanthryl group, a 4-phenanthryl group, and a 9-phenanthryl group.

[0030] Examples of the organic group having an epoxy group include a glycidoxymethyl group, a glycidoxyethyl group, a glycidoxypropyl group, a glycidoxybutyl group, and an epoxycyclohexyl group.

[0031] Examples of the organic group having an acryloyl group include an acryloylmethyl group, an acryloylethyl group, and an acryloylpropyl group.

[0032] Examples of the organic group having a methacryloyl group include a methacryloylmethyl group, a methacryloylethyl group, and a methacryloylpropyl group.

[0033] Examples of the organic group having a mercapto group include an ethyl mercapto group, a butyl mercapto group, a hexyl mercapto group, and an octyl mercapto group.

[0034] Examples of the organic group having a cyano group include a cyanoethyl group and a cyanopropyl group.

[0035] The alkoxy group having 1 to 10 carbon atoms includes an alkoxy group having a linear, branched or cyclic alkyl moiety having 1 to 10 carbon atoms, such as a methoxy group, an ethoxy group, an n-propoxy group, an i-propoxy group, an n-butoxy group, an i-butoxy group, an s-butoxy group, a t-butoxy group, an n-pentyloxy group, a 1-methyl-n-butoxy group, a 2-methyl-n-butoxy group, an ... n-butoxy, 3-methyl-n-butoxy, 1,1-dimethyl-n-propoxy, 1,2-dimethyl-n-propoxy, 2,2-dimethyl-n-propoxy, 1-ethyl-n-propoxy, n-hexyloxy, 1-methyl-n-pentyloxy, 2-methyl-n-pentyloxy, 3-methyl-n-pentyloxy, 4-methyl-n-pentyloxy, 1,1-dimethyl-n-butoxy, 1,2-dimethyl-n-butoxy, 1,3-dimethyl-n-butoxy, 2,2-dimethyl-n Examples of cyclic alkoxy groups include cyclopropoxy, cyclobutoxy, 1-methylcyclopropoxy, 2-methylcyclopropoxy, cyclopentyl ... oxy group, 1-methyl-cyclobutoxy group, 2-methyl-cyclobutoxy group, 3-methyl-cyclobutoxy group, 1,2-dimethyl-cyclopropoxy group, 2,3-dimethyl-cyclopropoxy group, 1-ethyl-cyclopropoxy group, 2-ethyl-cyclopropoxy group, cyclohexyloxy group, 1-methyl-cyclopentyloxy group, 2-methyl-cyclopentyloxy group, 3-methyl-cyclopentyloxy group, 1-ethyl-cyclobutoxy group, 2-ethyl-cyclobutoxy group, 3-ethyl-cyclobutoxy group, 1,2 -dimethylcyclobutoxy group, 1,3-dimethylcyclobutoxy group, 2,2-dimethylcyclobutoxy group, 2,3-dimethylcyclobutoxy group, 2,4-dimethylcyclobutoxy group, 3,3-dimethylcyclobutoxy group, 1-n-propylcyclopropoxy group, 2-n-propylcyclopropoxy group, 1-i-propylcyclopropoxy group, 2-i-propylcyclopropoxy group, 1,2,2-trimethylcyclopropoxy group, 1,2,3-trimethylcyclopropoxy group, 2,2,Examples include a 3-trimethyl-cyclopropoxy group, a 1-ethyl-2-methyl-cyclopropoxy group, a 2-ethyl-1-methyl-cyclopropoxy group, a 2-ethyl-2-methyl-cyclopropoxy group, and a 2-ethyl-3-methyl-cyclopropoxy group.

[0036] Examples of the acyloxy group having 2 to 20 carbon atoms include a methylcarbonyloxy group, an ethylcarbonyloxy group, an n-propylcarbonyloxy group, an i-propylcarbonyloxy group, an n-butylcarbonyloxy group, an i-butylcarbonyloxy group, an s-butylcarbonyloxy group, a t-butylcarbonyloxy group, an n-pentylcarbonyloxy group, a 1-methyl-n-butylcarbonyloxy group, a 2-methyl-n-butylcarbonyloxy group, a 3-methyl-n-butylcarbonyloxy group, a 1,1-dimethyl-n-propylcarbonyloxy group, a 1,2-dimethyl-n-propylcarbonyloxy group, a 2,2-dimethyl-n-propylcarbonyloxy group, a 1-ethyl-n-propylcarbonyloxy group, an n-hexylcarbonyloxy group, a 1-methyl-n-pentylcarbonyloxy group, and a 2-methyl-n-pentylcarbonyloxy group. , 3-methyl-n-pentylcarbonyloxy group, 4-methyl-n-pentylcarbonyloxy group, 1,1-dimethyl-n-butylcarbonyloxy group, 1,2-dimethyl-n-butylcarbonyloxy group, 1,3-dimethyl-n-butylcarbonyloxy group, 2,2-dimethyl-n-butylcarbonyloxy group, 2,3-dimethyl-n-butylcarbonyloxy group, 3,3-dimethyl-n-butylcarbonyloxy group, 1-ethyl-n-butylcarbonyloxy group, 2-ethyl-n-butylcarbonyloxy group, 1,1,2-trimethyl-n-propylcarbonyloxy group, 1,2,2-trimethyl-n-propylcarbonyloxy group, 1-ethyl-1-methyl-n-propylcarbonyloxy group, 1-ethyl-2-methyl-n-propylcarbonyloxy group, phenylcarbonyloxy group, and tosylcarbonyloxy group.

[0037] The halogen atoms include fluorine, chlorine, bromine, iodine, and the like.

[0038] Examples of hydrolyzable silanes of formula (1) include the following: [ka] [ka] [ka] [ka]

[0039] The above T is an alkoxy group, an acyloxy group, or a hydrolyzable group consisting of a halogen atom, and for example, a methoxy group or an ethoxy group can be suitably used.

[0040] In the present invention, the hydrolyzable silane (a) is a combination of the hydrolyzable silane of the formula (1) and another hydrolyzable silane, and the other hydrolyzable silane can be at least one hydrolyzable silane selected from the group consisting of the formulas (3) and (4). Cut.

[0041] In formula (3), R 7 is an organic group having an alkyl group, an aryl group, a halogenated alkyl group, a halogenated aryl group, an alkoxyaryl group, an alkenyl group, or an epoxy group, an acryloyl group, a methacryloyl group, a mercapto group, or a cyano group, and is bonded to a silicon atom by a Si-C bond; R 8 represents an alkoxy group, an acyloxy group, or a halogen group; c represents an integer of 0 to 3.

[0042] In formula (4), R 9 is an alkyl group bonded to a silicon atom by a Si-C bond, and R 10 represents an alkoxy group, an acyloxy group, or a halogen group; Y represents an alkylene group or an arylene group; d represents an integer of 0 or 1; and e represents an integer of 0 or 1.

[0043] The alkyl group, aryl group, halogenated alkyl group, halogenated aryl group, alkenyl group, or organic group having an epoxy group, an acryloyl group, a methacryloyl group, a mercapto group, or a cyano group, alkoxy group, acyloxy group, and halogen group can be the same as those described above.

[0044] Examples of the silicon-containing compound represented by formula (3) include tetramethoxysilane, tetrachlorosilane, tetraacetoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetraisopropoxysilane, tetra-n-butoxysilane, methyltrimethoxysilane, methyltrichlorosilane, methyltriacetoxysilane, methyltrippropoxysilane, methyltriacetoxysilane, methyltributoxysilane, methyltrippropoxysilane, methyltriamyloxysilane, methyltriphenoxysilane, methyltribenzyloxysilane, and methyltrimethylsilane. ethyltriphenethyloxysilane, glycidoxymethyltrimethoxysilane, glycidoxymethyltriethoxysilane, α-glycidoxyethyltrimethoxysilane, α-glycidoxyethyltriethoxysilane, β-glycidoxyethyltrimethoxysilane, β-glycidoxyethyltriethoxysilane, α-glycidoxypropyltrimethoxysilane, α-glycidoxypropyltriethoxysilane, β-glycidoxypropyltrimethoxysilane, β-glycidoxypropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-Glycidoxypropyltriethoxysilane, γ-glycidoxypropyltripropoxysilane, γ-glycidoxypropyltributoxysilane, γ-glycidoxypropyltriphenoxysilane, α-glycidoxybutyltrimethoxysilane, α-glycidoxybutyltriethoxysilane, β-glycidoxybutyltriethoxysilane, γ-glycidoxybutyltrimethoxysilane, γ-glycidoxybutyltriethoxysilane, δ-glycidoxybutyltrimethoxysilane, δ-glycidoxybutyltriethoxysilane, (3,4-epoxysilane (3,4-epoxycyclohexyl)methyltrimethoxysilane, (3,4-epoxycyclohexyl)methyltriethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltriethoxysilane, β-(3,4-epoxycyclohexyl)ethyltripropoxysilane, β-(3,4-epoxycyclohexyl)ethyltributoxysilane, β-(3,4-epoxycyclohexyl)ethyltriphenoxysilane, γ-(3,4-epoxycyclohexyl)propyltrimethoxysilane, γ-(3,4-epoxycyclohexyl)propyltriethoxysilane, δ-(3,4-epoxycyclohexyl)butyltrimethoxysilane, δ-(3,4-epoxycyclohexyl)butyltriethoxysilane, glycidoxymethylmethyldimethoxysilane, glycidoxymethylmethyldiethoxysilane, α-glycidoxyethylmethyldimethoxysilane, α-glycidoxyethylmethyldiethoxysilane, β-glycidoxyethylmethyldimethoxysilane, β-glycidoxyethylethyldimethoxysilane, α-glycidoxypropylmethyldimethoxysilane, α-glycidoxypropylmethyldiethoxysilane, β-glycidoxypropyl Methyldimethoxysilane, β-glycidoxypropylethyldimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropylmethyldipropoxysilane, γ-glycidoxypropylmethyldibutoxysilane, γ-glycidoxypropylmethyldiphenoxysilane, γ-glycidoxypropylethyldimethoxysilane, γ-glycidoxypropylethyldiethoxysilane, γ-glycidoxypropylvinyldimethoxysilane, γ-glycidoxypropylvinyldiethoxysilane Sisilane, ethyltrimethoxysilane, ethyltriethoxysilane, vinyltrimethoxysilane, vinyltrichlorosilane, vinyltriacetoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane, methoxyphenyltrimethoxysilane, methoxyphenyltriethoxysilane, methoxyphenyltriacetoxysilane, methoxyphenyltrichlorosilane, methoxybenzyltrimethoxysilane, methoxybenzyltriethoxysilane, methoxybenzyltriacetoxysilane, methoxybenzyltrichlorosilane, methoxyphenethyl Trimethoxysilane, Methoxyphenethyltriethoxysilane, Methoxyphenethyltriacetoxysilane, Methoxyphenethyltrichlorosilane, Ethoxyphenyltrimethoxysilane, Ethoxyphenyltriethoxysilane, Ethoxyphenyltriacetoxysilane, Ethoxyphenyltrichlorosilane, Ethoxybenzyltrimethoxysilane, Ethoxybenzyltriethoxysilane, Ethoxybenzyltriacetoxysilane, Ethoxybenzyltrichlorosilane, Isopropoxyphenyltrimethoxysilane, Isopropoxyphenyltriethoxy Silane, isopropoxyphenyltriacetoxysilane, isopropoxyphenyltrichlorosilane, isopropoxybenzyltrimethoxysilane, isopropoxybenzyltriethoxysilane, isopropoxybenzyltriacetoxysilane, isopropoxybenzyltrichlorosilane, t-butoxyphenyltrimethoxysilane, t-butoxyphenyltriethoxysilane, t-butoxyphenyltriacetoxysilane, t-butoxyphenyltrichlorosilane, t-butoxybenzyltrimethoxysilane, t-butoxybenzyltriethoxysilane,t-Butoxybenzyltriacetoxysilane, t-Butoxybenzyltrichlorosilane, Methoxynaphthyltrimethoxysilane, Methoxynaphthyltriethoxysilane, Methoxynaphthyltriacetoxysilane, Methoxynaphthyltrichlorosilane, Ethoxynaphthyltrimethoxysilane, Ethoxynaphthyltriethoxysilane, Ethoxynaphthyltriacetoxysilane, Ethoxynaphthyltrichlorosilane, γ-Chloropropyltrimethoxysilane, γ-Chloropropyltriethoxysilane, γ-Chloropropyltriacetoxysilane, 3,3,3-Trifluoropropyltrimethoxysilane, γ-Methacryloxypropyltrimethoxysilane, γ-Mercaptopropyltrimethoxysilane, γ -mercaptopropyltriethoxysilane, β-cyanoethyltriethoxysilane, chloromethyltrimethoxysilane, chloromethyltriethoxysilane, dimethyldimethoxysilane, phenylmethyldimethoxysilane, dimethyldiethoxysilane, phenylmethyldiethoxysilane, γ-chloropropylmethyldimethoxysilane, γ-chloropropylmethyldiethoxysilane, dimethyldiacetoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-mercaptopropylmethyldimethoxysilane, γ-mercaptomethyldiethoxysilane, methylvinyldimethoxysilane, methylvinyldiethoxysilane, and the like.

[0045] Examples of the silicon-containing compound represented by formula (4) include methylenebistrimethoxysilane, methylenebistrichlorosilane, methylenebistriacetoxysilane, ethylenebistriethoxysilane, ethylenebistrichlorosilane, ethylenebistriacetoxysilane, propylenebistriethoxysilane, butylenebistrimethoxysilane, phenylenebistrimethoxysilane, phenylenebistriethoxysilane, phenylenebismethyldiethoxysilane, phenylenebismethyldimethoxysilane, naphthylenebistrimethoxysilane, bistrimethoxydisilane, bistriethoxydisilane, bisethyldiethoxydisilane, and bismethyldimethoxydisilane.

[0046] In the present invention, silanes having a sulfone group or a sulfonamide group can be used as the hydrolyzable silane (a), and examples of such silanes include those listed below. [ka] [ka] [ka]

[0047] Specific examples of the hydrolysis condensate (polysiloxane) (c) used in the present invention are given below. [ka] [ka]

[0048] The hydrolysis condensation product (polysiloxane) used in the present invention is produced by hydrolyzing a hydrolyzable silane using nitric acid as a hydrolysis catalyst. After the hydrolysis and condensation proceed, refluxing is performed, during which the phenol protecting group is eliminated at a rate of approximately 1% to 100%, resulting in the conversion to phenol. The hydrolysis condensation product (c) is a product of the hydrolyzable silane of formula (1) in which the functional group of formula (2) is (hydrogen atom) / (hydrogen atom + R 5 The molar ratio of the hydroxyl group is 1% to 100%.

[0049] Nitrate ions derived from nitric acid are added to the resist underlayer film-forming composition at a concentration of 1 ppm to 1000 ppm. The hydrolysis condensation product (polysiloxane) after the phenol protecting group is eliminated changes to the following structure: [ka] [ka]

[0050] The hydrolysis condensate (polyorganosiloxane) (c) of the hydrolyzable silane can be obtained as a condensate having a weight average molecular weight (Mw) of 1,000 to 1,000,000, or 1,000 to 100,000. These weight average molecular weights (Mw) are molecular weights obtained by GPC analysis in terms of polystyrene.

[0051] The GPC measurement conditions are, for example, a GPC apparatus (trade name HLC-8220GPC, manufactured by Tosoh Corporation), a GPC column (trade names Shodex KF803L, KF802, KF801, manufactured by Showa Denko K.K.), a column temperature of 40°C, an eluent (elution solvent) of tetrahydrofuran, a flow rate (flow rate) of 1.0 ml / min, and a standard sample of polystyrene (manufactured by Showa Denko K.K.).

[0052] For the hydrolysis of an alkoxysilyl group, an acyloxysilyl group, or a halogenated silyl group, 0.5 to 100 moles, preferably 1 to 10 moles, of water is used per mole of the hydrolyzable group.

[0053] Also, the amount of the compound is 0.001 to 10 moles, preferably 0.00 From 1 mole to 1 mole of hydrolysis catalyst can be used.

[0054] The reaction temperature for carrying out the hydrolysis and condensation is usually 20°C to 80°C.

[0055] The hydrolysis may be complete or partial, that is, the hydrolyzed product may contain residual hydrolyzates or monomers.

[0056] A catalyst can be used during the hydrolysis and condensation. Nitric acid is used as the hydrolysis catalyst. In addition to nitric acid, a metal chelate compound, an organic acid, an inorganic acid, an organic base, or an inorganic base can also be used in combination.

[0057] Examples of organic solvents used in hydrolysis include aliphatic hydrocarbon solvents such as n-pentane, i-pentane, n-hexane, i-hexane, n-heptane, i-heptane, 2,2,4-trimethylpentane, n-octane, i-octane, cyclohexane, and methylcyclohexane; aromatic hydrocarbon solvents such as benzene, toluene, xylene, ethylbenzene, trimethylbenzene, methylethylbenzene, n-propylbenzene, i-propylbenzene, diethylbenzene, i-butylbenzene, triethylbenzene, di-i-propylbenzene, n-amylnaphthalene, and trimethylbenzene; and methanol, ethanol, n-propanol, i-propanol, n-butanol, i-butanol, sec-butanol, t-butanol, n-pentanol, i-pentanol, 2-methylbutanol, sec-pentanol, t-pentanol, 3-methoxybutanol, n-hexanol, 2-methylpentanol, sec-hexanol, and 2-ethylbutanol. monoalcohol solvents such as ethanol, sec-heptanol, heptanol-3, n-octanol, 2-ethylhexanol, sec-octanol, n-nonyl alcohol, 2,6-dimethylheptanol-4, n-decanol, sec-undecyl alcohol, trimethylnonyl alcohol, sec-tetradecyl alcohol, sec-heptadecyl alcohol, phenol, cyclohexanol, methylcyclohexanol, 3,3,5-trimethylcyclohexanol, benzyl alcohol, phenylmethylcarbinol, diacetone alcohol, and cresol; polyalcohol solvents such as ethylene glycol, propylene glycol, 1,3-butylene glycol, pentanediol-2,4, 2-methylpentanediol-2,4, hexanediol-2,5, heptanediol-2,4, 2-ethylhexanediol-1,3, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol, and glycerin;Ketone solvents such as acetone, methyl ethyl ketone, methyl n-propyl ketone, methyl n-butyl ketone, diethyl ketone, methyl i-butyl ketone, methyl n-pentyl ketone, ethyl n-butyl ketone, methyl n-hexyl ketone, di-i-butyl ketone, trimethylnonanone, cyclohexanone, methylcyclohexanone, 2,4-pentanedione, acetonylacetone, diacetone alcohol, acetophenone, and fenchone; ethyl ether, i-propyl ether, n-butyl ether, n-hexyl ether, 2-ethylhexyl ether, ethylene oxide, 1,2-propylene oxide, dioxolane, 4-methyldioxolane, dioxane, dimethyldioxane, ethylene glycol monomethyl ether, and ethylene glycol monoethyl ether. ter, ethylene glycol diethyl ether, ethylene glycol mono-n-butyl ether, ethylene glycol mono-n-hexyl ether, ethylene glycol monophenyl ether, ethylene glycol mono-2-ethylbutyl ether, ethylene glycol dibutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol diethyl ether, diethylene glycol mono-n-butyl ether, diethylene glycol di-n-butyl ether, diethylene glycol mono-n-hexyl ether, ethoxytriglycol, tetraethylene glycol di-n-butyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl; ether solvents such as dipropylene glycol ether, propylene glycol monobutyl ether, propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monobutyl ether, tripropylene glycol monomethyl ether, tetrahydrofuran, and 2-methyltetrahydrofuran; diethyl carbonate, methyl acetate, ethyl acetate, γ-butyrolactone, γ-valerolactone, n-propyl acetate, i-propyl acetate, n-butyl acetate, i-butyl acetate, sec-butyl acetate, n-pentyl acetate, sec-pentyl acetate, 3-methoxybutyl acetate, methylpentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, benzyl acetate, cyclohexyl acetate, methylcyclohexyl acetate, n-nonyl acetate, methyl acetoacetate, ethyl acetoacetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, and diethyl acetate propylene glycol mono-n-butyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether acetate, dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether acetate, glycol diacetate, methoxytriglyceride, ethyl propionate, n-butyl propionate, i-amyl propionate, diethyl oxalate, di-n-butyl oxalate, methyl lactate, ethyl lactate, milk Examples of suitable solvents include ester-based solvents such as n-butyl lactate, n-amyl lactate, diethyl malonate, dimethyl phthalate, and diethyl phthalate; nitrogen-containing solvents such as N-methylformamide, N,N-dimethylformamide, N,N-diethylformamide, acetamide, N-methylacetamide, N,N-dimethylacetamide, N-methylpropionamide, and N-methylpyrrolidone (NMP); and sulfur-containing solvents such as dimethyl sulfide, diethyl sulfide, thiophene, tetrahydrothiophene, dimethyl sulfoxide, sulfolane, and 1,3-propane sultone.These solvents can be used alone or in combination of two or more.

[0058] In particular, ketone solvents such as acetone, methyl ethyl ketone, methyl-n-propyl ketone, methyl-n-butyl ketone, diethyl ketone, methyl-i-butyl ketone, methyl-n-pentyl ketone, ethyl-n-butyl ketone, methyl-n-hexyl ketone, di-i-butyl ketone, trimethylnonanone, cyclohexanone, methylcyclohexanone, 2,4-pentanedione, acetonylacetone, diacetone alcohol, acetophenone, and fenchone are preferred in terms of storage stability of the solution.

[0059] Furthermore, bisphenol S or a bisphenol S derivative can be added as an additive in an amount of 0.01 to 20 parts by mass, or 0.01 to 10 parts by mass, or 0.01 to 5 parts by mass per 100 parts by mass of the hydrolysis condensate of the hydrolyzable silane (polyorganosiloxane) (c).

[0060] Preferred examples of bisphenol S or bisphenol S derivatives are shown below. [ka]

[0061] The resist underlayer film-forming composition of the present invention may contain a curing catalyst, which acts as a curing catalyst when a coating film containing the polyorganosiloxane (c) formed from a hydrolysis condensate is heated and cured.

[0062] As the curing catalyst, ammonium salts, phosphines, phosphonium salts, and sulfonium salts can be used.

[0063] The ammonium salt includes those of formula (D-1): [ka] (where m is an integer from 2 to 11, n is an integer from 2 to 3, R 21 represents an alkyl group or an aryl group, Y - represents an anion.) a quaternary ammonium salt having a structure represented by the formula: Formula (D-2): [ka] (However, R 22 , R 23 , R 24 and R 25 represents an alkyl or aryl group, N represents a nitrogen atom, Y - indicates an anion, and R 22 , R 23 , R 24 , and R 25 are bonded to the nitrogen atom by a C-N bond), Formula (D-3): [ka] (However, R 26 and R 27 represents an alkyl group or an aryl group, Y - represents an anion), Formula (D-4): [ka] (However, R 28 represents an alkyl group or an aryl group, Y - represents an anion), Formula (D-5): [ka] (However, R 29 and R 30 represents an alkyl group or an aryl group, Y - represents an anion), Formula (D-6): [ka] (wherein m is an integer of 2 to 11, n is an integer of 2 to 3, H is a hydrogen atom, Y - represents an anion) are tertiary ammonium salts.

[0064] Furthermore, the phosphonium salt includes a compound of the formula (D-7): [ka] (However, R 31 , R 32 , R 33 , and R 34 represents an alkyl or aryl group, P represents a phosphorus atom, and Y - indicates an anion, and R 31 , R 32 , R 33 , and R 34 are bonded to the phosphorus atom by a C—P bond).

[0065] As the sulfonium salt, there is a compound represented by the formula (D-8): [ka] (However, R 35 , R 36 , and R 37 represents an alkyl or aryl group, S represents a sulfur atom, and Y - indicates an anion, and R 35 , R 36 , and R 37 are bonded to the sulfur atom by a C—S bond).

[0066] The compound represented by the above formula (D-1) is a quaternary ammonium salt derived from an amine, where m is an integer of 2 to 11 and n is an integer of 2 to 3. R of this quaternary ammonium salt 21represents an alkyl group or an aryl group having 1 to 18 carbon atoms, preferably 2 to 10 carbon atoms, and examples thereof include linear alkyl groups such as ethyl, propyl, and butyl groups, as well as benzyl, cyclohexyl, cyclohexylmethyl, and dicyclopentadienyl groups. - ) is a chloride ion (Cl - ), bromide ion (Br - ), iodide ion (I - ) and carboxylate ions (-COO - ), sulfonato (-SO3 - ), alcoholate (-O - ) and other acid groups can be mentioned.

[0067] The compound represented by the above formula (D-2) is R 22 R 23 R 24 R 25 N + Y - The R of this quaternary ammonium salt is 22 , R 23 , R 24 and R 25 is a silane compound bonded to a silicon atom by an alkyl or aryl group having 1 to 18 carbon atoms, or a Si-C bond. - ) is a chloride ion (Cl - ), bromide ion (Br - ), iodide ion (I - ) and carboxylate ions (-COO - ), sulfonato (-SO3 - ), alcoholate (-O - The quaternary ammonium salt can be commercially available, and examples thereof include tetramethylammonium acetate, tetrabutylammonium acetate, triethylbenzylammonium chloride, triethylbenzylammonium bromide, trioctylmethylammonium chloride, tributylbenzylammonium chloride, and trimethylbenzylammonium chloride.

[0068] The compound represented by the above formula (D-3) is a quaternary ammonium salt derived from a 1-substituted imidazole, and R 26 and R 27 has 1 to 18 carbon atoms, and R 26 and R 27 It is preferable that the total number of carbon atoms in R is 7 or more. 26 represents methyl, ethyl, propyl, phenyl, and benzyl groups, and R 27 Examples of the anion (Y - ) is a chloride ion (Cl - ), bromide ion (Br - ), iodide ion (I - ) and carboxylate ions (-COO - ), sulfonato (-SO3 - ), alcoholate (-O - Although this compound is commercially available, it can also be produced by reacting an imidazole compound such as 1-methylimidazole or 1-benzylimidazole with an alkyl halide or aryl halide such as benzyl bromide or methyl bromide.

[0069] The compound represented by the above formula (D-4) is a quaternary ammonium salt derived from pyridine, and R 28 is an alkyl group or aryl group having 1 to 18 carbon atoms, preferably 4 to 18 carbon atoms, and examples thereof include a butyl group, an octyl group, a benzyl group, and a lauryl group. - ) is a chloride ion (Cl - ), bromide ion (Br - ), iodide ion (I - ) and carboxylate ions (-COO - ), sulfonato (-SO3 - ), alcoholate (-O -This compound is commercially available, but it can also be prepared by, for example, combining pyridine with an alkyl halide such as lauryl chloride, benzyl chloride, benzyl bromide, methyl bromide, or octyl bromide, or can be produced by reacting an aryl halide. Examples of this compound include N-laurylpyridinium chloride and N-benzylpyridinium bromide.

[0070] The compound represented by the above formula (D-5) is a quaternary ammonium salt derived from a substituted pyridine, such as picoline, and R 29 R is an alkyl group or aryl group having 1 to 18 carbon atoms, preferably 4 to 18 carbon atoms, and examples thereof include a methyl group, an octyl group, a lauryl group, and a benzyl group. 30 is an alkyl group or an aryl group having 1 to 18 carbon atoms, and when it is a quaternary ammonium derived from, for example, picoline, R 30 is a methyl group. - ) is a chloride ion (Cl - ), bromide ion (Br - ), iodide ion (I - ) and carboxylate ions (-COO - ), sulfonato (-SO3 - ), alcoholate (-O - ) and other acid groups. This compound is commercially available, but can also be produced by reacting a substituted pyridine such as picoline with an alkyl halide or aryl halide such as methyl bromide, octyl bromide, lauryl chloride, benzyl chloride, or benzyl bromide. Examples of this compound include N-benzylpicolinium chloride, N-benzylpicolinium bromide, and N-laurylpicolinium chloride.

[0071] The compound represented by the above formula (D-6) is a tertiary ammonium salt derived from an amine, where m is an integer of 2 to 11 and n is an integer of 2 to 3. - ) is a chloride ion (Cl -), bromide ion (Br - ), iodide ion (I - ) and carboxylate (-COO - ), sulfonato (-SO3 - ), alcoholate (-O - ) and other acid groups. They can be produced by reacting an amine with a weak acid such as a carboxylic acid or phenol. Examples of carboxylic acids include formic acid and acetic acid. When formic acid is used, an anion (Y - ) is (HCOO - ) and when acetic acid is used, the anion (Y - ) is (CH3COO - ) and when phenol is used, the anion (Y - ) is (C6H5O - )

[0072] The compound represented by the above formula (D-7) is R 31 R 32 R 33 R 34 P + Y - It is a quaternary phosphonium salt having the structure: R 31 , R 32 , R 33 , and R 34 is an alkyl group having 1 to 18 carbon atoms, an aryl group, or a silane compound bonded to a silicon atom by a Si-C bond, preferably R 31 ~R 34 Three of the four substituents are phenyl groups or substituted phenyl groups, such as phenyl groups and tolyl groups, and the remaining one is an alkyl group having 1 to 18 carbon atoms, an aryl group, or a silane compound bonded to a silicon atom by a Si-C bond. - ) is a chloride ion (Cl - ), bromide ion (Br - ), iodide ion (I - ) and carboxylate ions (-COO - ), sulfonato (-SO3 - ), alcoholate (-O- ) and other acid groups. This compound is commercially available, and examples thereof include tetraalkylphosphonium halides such as tetra-n-butylphosphonium halide and tetra-n-propylphosphonium halide, trialkylbenzylphosphonium halides such as triethylbenzylphosphonium halide, triphenylmonoalkylphosphonium halides such as triphenylmethylphosphonium halide and triphenylethylphosphonium halide, triphenylbenzylphosphonium halides, tetraphenylphosphonium halides, tritolylmonoarylphosphonium halides, and tritolylmonoalkylphosphonium halides (the halogen atom is a chlorine atom or a bromine atom). In particular, triphenylmonoalkylphosphonium halides such as triphenylmethylphosphonium halide and triphenylethylphosphonium halide, triphenylmonoarylphosphonium halides such as triphenylbenzylphosphonium halide, tritolylmonoarylphosphonium halides such as tritolylmonophenylphosphonium halide, and tritolylmonoalkylphosphonium halides (the halogen atom is a chlorine atom) such as tritolylmonoalkylphosphonium halides such as tritolylmonomethylphosphonium halide. or a bromine atom) is preferred.

[0073] Examples of phosphines include primary phosphines such as methylphosphine, ethylphosphine, propylphosphine, isopropylphosphine, isobutylphosphine, and phenylphosphine; secondary phosphines such as dimethylphosphine, diethylphosphine, diisopropylphosphine, diisoamylphosphine, and diphenylphosphine; and tertiary phosphines such as trimethylphosphine, triethylphosphine, triphenylphosphine, methyldiphenylphosphine, and dimethylphenylphosphine.

[0074] The compound represented by the above formula (D-8) is R 35 R 36 R 37 S + Y -It is a tertiary sulfonium salt having the structure: R 35 , R 36 , and R 37 is an alkyl group or aryl group having 1 to 18 carbon atoms, or a silane compound bonded to a silicon atom by a Si-C bond, preferably R 35 ~R 37 Two of the three substituents are phenyl groups or substituted phenyl groups, such as phenyl groups and tolyl groups, and the remaining one is an alkyl group or aryl group having 1 to 18 carbon atoms. - ) is a chloride ion (Cl - ), bromide ion (Br - ), iodide ion (I - ) and carboxylate ions (-COO - ), sulfonato (-SO3 - ), alcoholate (-O - Examples of acid groups include trialkylsulfonium halides such as tri-n-butylsulfonium halides and tri-n-propylsulfonium halides, trialkylbenzylsulfonium halides such as diethylbenzylsulfonium halides, diphenylmonoalkylsulfonium halides such as diphenylmethylsulfonium halides and diphenylethylsulfonium halides, triphenylsulfonium halides (the halogen atom is a chlorine atom or a bromine atom), trialkylsulfonium carboxylates such as tri-n-butylsulfonium carboxylate and tri-n-propylsulfonium carboxylate, trialkylbenzylsulfonium carboxylates such as diethylbenzylsulfonium carboxylate, diphenylmonoalkylsulfonium carboxylates such as diphenylmethylsulfonium carboxylate and diphenylethylsulfonium carboxylate, and triphenylsulfonium carboxylate. Furthermore, triphenylsulfonium halides and triphenylsulfonium carboxylates are preferably used.

[0075] In the present invention, a nitrogen-containing silane compound can be added as a curing catalyst, such as an imidazole ring-containing silane compound such as N-(3-triethoxysilylpropyl)-4,5-dihydroimidazole.

[0076] The curing catalyst is used in an amount of 0.01 to 10 parts by mass, or 0.01 to 5 parts by mass, or 0.01 to 3 parts by mass, per 100 parts by mass of the hydrolysis condensate of the hydrolyzable silane (polyorganosiloxane) (c).

[0077] A hydrolyzable silane is hydrolyzed and condensed in a solvent using a catalyst, and the by-product alcohol and water can be simultaneously removed from the obtained hydrolysis condensation product (polymer) by vacuum distillation, etc. In the resist underlayer film-forming composition for lithography of the present invention, an organic acid, water, an alcohol, or a combination thereof can be added to the resist underlayer film-forming composition containing the hydrolysis condensation product for stabilization.

[0078] Examples of the organic acid include oxalic acid, malonic acid, methylmalonic acid, succinic acid, maleic acid, malic acid, tartaric acid, phthalic acid, citric acid, glutaric acid, lactic acid, salicylic acid, etc. Among these, oxalic acid, maleic acid, etc. are preferred. The organic acid to be added is in an amount of 100 parts by mass of the hydrolysis condensate of the hydrolyzable silane (polyorganosiloxane) (c) The amount of water added may be 0.1 to 5.0 parts by mass. Pure water, ultrapure water, ion-exchanged water, or the like may be used, and the amount added may be 1 to 20 parts by mass per 100 parts by mass of the resist underlayer film-forming composition.

[0079] The alcohol to be added is preferably one that is easily evaporated by heating after application, and examples include methanol, ethanol, propanol, isopropanol, butanol, etc. The amount of alcohol to be added may be 1 to 20 parts by mass per 100 parts by mass of the resist underlayer film-forming composition.

[0080] In addition to the above components, the underlayer film-forming composition for lithography of the present invention may contain an organic polymer compound, a photoacid generator, a surfactant, and the like, as needed.

[0081] By using an organic polymer compound, it is possible to adjust the dry etching rate (amount of film thickness reduction per unit time), attenuation coefficient, refractive index, etc. of the resist underlayer film formed from the underlayer film-forming composition for lithography of the present invention.

[0082] The organic polymer compound is not particularly limited, and various organic polymers can be used. Condensation polymerization polymers and addition polymerization polymers can be used. Addition polymerization polymers and condensation polymerization polymers such as polyester, polystyrene, polyimide, acrylic polymer, methacrylic polymer, polyvinyl ether, phenol novolac, naphthol novolac, polyether, polyamide, and polycarbonate can be used. Organic polymers having an aromatic ring structure such as a benzene ring, naphthalene ring, anthracene ring, triazine ring, quinoline ring, or quinoxaline ring that functions as a light-absorbing moiety are preferably used.

[0083] As the organic polymer compound, a polymer compound having a weight average molecular weight (Mw) of, for example, 1,000 to 1,000,000, or 3,000 to 300,000, or 5,000 to 200,000, or 10,000 to 100,000 can be used.

[0084] When an organic polymer compound is used, the proportion thereof is 1 to 200 parts by mass, or 5 to 100 parts by mass, or 10 to 50 parts by mass, or 20 to 30 parts by mass, per 100 parts by mass of the hydrolysis condensate of the hydrolyzable silane (polyorganosiloxane) (c).

[0085] The resist underlayer film forming composition of the present invention may contain an acid generator. Examples of the acid generator include a thermal acid generator and a photoacid generator. Photoacid generators generate acid when the resist is exposed to light. This allows the acidity of the underlayer film to be adjusted. This is one way to match the acidity of the underlayer film to that of the upper layer resist. Adjusting the acidity of the underlayer film also allows for adjustment of the pattern shape of the upper layer resist.

[0086] Examples of the photoacid generator contained in the resist underlayer film-forming composition of the present invention include onium salt compounds, sulfonimide compounds, and disulfonyldiazomethane compounds.

[0087] Examples of onium salt compounds 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.

[0088] Examples of the sulfonimide compound include N-(trifluoromethanesulfonyloxy)succinimide, N-(nonafluoronormalbutanesulfonyloxy)succinimide, N-(camphorsulfonyloxy)succinimide, and N-(trifluoromethanesulfonyloxy)naphthalimide.

[0089] Examples of disulfonyldiazomethane compounds include bis(trifluoromethylsulfonyl)diazomethane, bis(cyclohexylsulfonyl)diazomethane, bis(phenylsulfonyl)diazomethane, bis(p-toluenesulfonyl)diazomethane, bis(2,4-dimethylbenzenesulfonyl)diazomethane, and methylsulfonyl-p-toluenesulfonyldiazomethane.

[0090] The photoacid generators may be used singly or in combination of two or more. When a photoacid generator is used, the proportion thereof is 0.01 to 5 parts by mass, or 0.1 to 3 parts by mass, or 0.5 to 1 part by mass, per 100 parts by mass of the hydrolysis condensate of the hydrolyzable silane (polyorganosiloxane) (c).

[0091] As described in the above paragraph

[0022] , the resist underlayer film forming composition of the present invention may contain, as optional components, an acid, water, an alcohol, a curing catalyst, an acid generator, other organic polymers, a light-absorbing compound, a metal oxide, a surfactant, and the like. The amount of the metal oxide added can be 0.001 to 100 parts by mass per 100 parts by mass of the hydrolysis condensate of the hydrolyzable silane (polyorganosiloxane) (c).

[0092] Examples of the metal oxide or partial metal oxide to be added include hydrolyzed condensates containing TiOx (titanium oxide, x = 1 to 2), hydrolyzed condensates containing WOx (tungsten oxide, x = 1 to 3), hydrolyzed condensates containing HfOx (hafnium oxide, x = 1 to 2), hydrolyzed condensates containing ZrOx (zirconium oxide, x = 1 to 2), hydrolyzed condensates containing AlOx (aluminum oxide, x = 1 to 1.5), metatungstic acid, ammonium metatungstate, silicotungstic acid, ammonium silicotungstate, molybdic acid, ammonium molybdate, phosphomolybdic acid, and ammonium phosphomolybdate. The amount of metal oxide to be added can be 0.001 to 100 parts by mass per 100 parts by mass of the composition to be applied to the resist pattern. The metal oxide or partial metal oxide can be obtained as a hydrolyzed condensate of a metal alkoxide, and the partial metal oxide may contain an alkoxide group.

[0093] The surfactant is effective in suppressing the occurrence of pinholes, striations, and the like when the resist underlayer film-forming composition for lithography of the present invention is applied to a substrate.

[0094] Examples of surfactants contained in the resist underlayer film forming composition of the present invention 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 octyl phenol ether and polyoxyethylene nonyl phenol ether; polyoxyethylene-polyoxypropylene block copolymers; sorbitan monolaurate; nonionic surfactants such as sorbitan fatty acid esters such as sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, sorbitan trioleate, and sorbitan tristearate; and polyoxyethylene sorbitan fatty acid esters such as polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, and polyoxyethylene sorbitan tristearate; Examples of suitable surfactants include fluorine-based surfactants such as EF301, EF303, and EF352 (manufactured by Tochem Products Co., Ltd.), trade names Megafac F171, F173, R-08, R-30, R-30N, and R-40LM (manufactured by DIC Corporation), Fluorad FC430 and FC431 (manufactured by Sumitomo 3M Limited), and trade names Asahiguard AG710, Surflon S-382, SC101, SC102, SC103, SC104, SC105, and SC106 (manufactured by Asahi Glass Co., Ltd.), and organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.). These surfactants may be used alone or in combination of two or more. When a surfactant is used, the proportion thereof is 0.0001 to 5 parts by mass, or 0.001 to 1 part by mass, or 0.01 to 1 part by mass, per 100 parts by mass of the hydrolysis condensate of the hydrolyzable silane (polyorganosiloxane) (c).

[0095] Furthermore, a rheology modifier, an adhesion promoter, etc. may be added to the resist underlayer film-forming composition of the present invention. The rheology modifier is effective in improving the fluidity of the underlayer film-forming composition. The adhesion promoter is effective in improving the adhesion between the semiconductor substrate or resist and the underlayer film.

[0096] The solvent used in the resist underlayer film-forming composition of the present invention is not particularly limited as long as it can dissolve the above-mentioned solid components. Examples of such solvents include methyl cellosolve acetate, ethyl cellosolve acetate, propylene glycol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, methyl isobutyl carbinol, propylene glycol monobutyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether acetate, toluene, xylene, methyl ethyl ketone, cyclopentanone, cyclohexanone, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxyacetate, ethyl hydroxyacetate, methyl 2-hydroxy-3-methylbutanoate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl 3-ethoxypropionate, methyl pyruvate, ethyl pyruvate, ethylene glycol monomethyl ether, ethylene glycol monomethyl ether, Ethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether, diethylene glycol dibutyl ether, propylene glycol monomethyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether, propylene glycol dipropyl ether, propylene glycol dibutyl ether, ethyl lactate, propyl lactate, isopropyl lactate, butyl lactate, isobutyl lactate, methyl formate, ethyl formate, propyl formate, isopropyl formate, butyl formate, isobutyl formate, amyl formate, isoamyl formate, methyl acetate, ethyl acetate, amyl acetate, isoamyl acetate, hexyl acetate, methyl propionate, ethyl propionate,Propionate, isopropyl propionate, butyl propionate, isobutyl propionate, methyl butyrate, ethyl butyrate, propyl butyrate, isopropyl butyrate, butyl butyrate, isobutyl butyrate, Examples of the solvent include ethyl hydroxyacetate, ethyl 2-hydroxy-2-methylpropionate, methyl 3-methoxy-2-methylpropionate, methyl 2-hydroxy-3-methylbutyrate, ethyl methoxyacetate, ethyl ethoxyacetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-methoxybutyl acetate, 3-methoxypropyl acetate, 3-methyl-3-methoxybutyl acetate, 3-methyl-3-methoxybutylpropionate, 3-methyl-3-methoxybutyl butyrate, methyl acetoacetate, toluene, xylene, methyl ethyl ketone, methyl propyl ketone, methyl butyl ketone, 2-heptanone, 3-heptanone, 4-heptanone, cyclohexanone, N,N-dimethylformamide, N-methylacetamide, N,N-dimethylacetamide, N-methylpyrrolidone, 4-methyl-2-pentanol, and γ-butyrolactone. These solvents may be used alone or in combination of two or more.

[0097] Hereinafter, the use of the resist underlayer film-forming composition of the present invention will be described. The resist underlayer film-forming composition of the present invention is applied to a substrate used in the manufacture of a semiconductor device (e.g., a silicon wafer substrate, a silicon / silicon dioxide-coated substrate, a silicon nitride substrate, a glass substrate, an ITO substrate, a polyimide substrate, or a low-dielectric-constant material (low-k material)-coated substrate) by a suitable application method such as a spinner or coater, and then baked to form a resist underlayer film. Baking conditions are appropriately selected from a baking temperature of 80°C to 250°C and a baking time of 0.3 to 60 minutes. Preferably, the baking temperature is 150°C to 250°C and the baking time is 0.5 to 2 minutes. The thickness of the underlayer film formed here is, for example, 10 to 1000 nm, or 20 to 500 nm, or 50 to 300 nm, or 100 to 200 nm.

[0098] Then, a layer of, for example, a photoresist is formed on the resist underlayer film. The formation of the photoresist layer can be carried out by a well-known method, i.e., by applying a photoresist composition solution onto the underlayer film and baking it. The film thickness of the photoresist is, for example, 50 nm to 10,000 nm, or 100 nm to 2,000 nm, or 200 nm to 1,000 nm.

[0099] In the present invention, an organic underlayer film is formed on a substrate, and then the resist underlayer film of the present invention is formed thereon, and a photoresist is then coated on top of that. This narrows the pattern width of the photoresist, and even when a thin layer of photoresist is applied to prevent pattern collapse, the substrate can be processed by selecting an appropriate etching gas. For example, a fluorine-based gas that exhibits a sufficiently high etching rate for the photoresist can be used as the etching gas to process the resist underlayer film of the present invention. An oxygen-based gas that exhibits a sufficiently high etching rate for the resist underlayer film of the present invention can be used as the etching gas to process the organic underlayer film. Furthermore, a fluorine-based gas that exhibits a sufficiently high etching rate for the organic underlayer film can be used as the etching gas to process the substrate.

[0100] The photoresist formed on the resist underlayer film of the present invention is not particularly limited as long as it is sensitive to the light used for exposure. Both negative and positive photoresists can be used. Examples include a positive photoresist composed of a novolak resin and a 1,2-naphthoquinone diazide sulfonic acid ester; a chemically amplified photoresist composed of a binder having a group that decomposes in the presence of an acid to increase the alkaline dissolution rate and a photoacid generator; a chemically amplified photoresist composed of a low molecular weight compound that decomposes in the presence of an acid to increase the alkaline dissolution rate of the photoresist, an alkali-soluble binder, and a photoacid generator; and a chemically amplified photoresist composed of a binder having a group that decomposes in the presence of an acid to increase the alkaline dissolution rate, a low molecular weight compound that decomposes in the presence of an acid to increase the alkaline dissolution rate of the photoresist, and a photoacid generator. Examples include APEX-E (trade name) manufactured by Shipley, PAR710 (trade name) manufactured by Sumitomo Chemical Co., Ltd., and SEPR430 (trade name) manufactured by Shin-Etsu Chemical Co., Ltd. Other examples include fluorine-containing polymer photoresists such as those described in Proc. SPIE, Vol. 3999, 330-334 (2000), Proc. SPIE, Vol. 3999, 357-364 (2000), and Proc. SPIE, Vol. 3999, 365-374 (2000).

[0101] Next, exposure is carried out through a predetermined mask. For exposure, a KrF excimer laser (wavelength 248 nm), an ArF excimer laser (wavelength 193 nm), an F2 excimer laser (wavelength 157 nm), or the like can be used. After exposure, a post-exposure bake (PEB) can be carried out as needed. The post-exposure bake is carried out under conditions appropriately selected from a heating temperature of 70°C to 150°C and a heating time of 0.3 to 10 minutes.

[0102] In addition, in the present invention, a resist for electron beam lithography or a resist for EUV lithography can be used instead of a photoresist. Either a negative or positive type electron beam resist can be used. Examples of such resists include chemically amplified resists consisting of an acid generator and a binder having a group that decomposes in the presence of an acid to change the alkaline dissolution rate; chemically amplified resists consisting of an alkali-soluble binder, an acid generator, and a low-molecular-weight compound that decomposes in the presence of an acid to change the alkaline dissolution rate of the resist; chemically amplified resists consisting of an acid generator, a binder having a group that decomposes in the presence of an acid to change the alkaline dissolution rate, and a low-molecular-weight compound that decomposes in the presence of an acid to change the alkaline dissolution rate of the resist; non-chemically amplified resists consisting of a binder having a group that decomposes in the presence of an electron beam to change the alkaline dissolution rate; and non-chemically amplified resists consisting of a binder having a moiety that is cleaved by an electron beam to change the alkaline dissolution rate. When using these electron beam resists, resist patterns can be formed in the same way as when using a photoresist using an electron beam as the irradiation source.

[0103] Furthermore, a methacrylate resin-based resist can be used as the EUV resist.

[0104] Next, development is carried out using a developer (for example, an alkaline developer), whereby, if a positive photoresist is used, the photoresist in the exposed areas is removed, forming a photoresist pattern.

[0105] Examples of developing solutions include aqueous alkaline solutions such as aqueous solutions of alkali metal hydroxides such as potassium hydroxide and sodium hydroxide, aqueous solutions of quaternary ammonium hydroxides such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, and choline, and aqueous solutions of amines such as ethanolamine, propylamine, and ethylenediamine. Furthermore, surfactants and the like can also be added to these developing solutions. Development conditions are appropriately selected from a temperature of 5°C to 50°C and a time of 10 to 600 seconds.

[0106] In the present invention, an organic solvent can be used as a developer. After exposure, development is carried out with the developer (solvent). As a result, when a positive photoresist is used, for example, the photoresist in the unexposed areas is removed, and a photoresist pattern is formed.

[0107] Examples of the developer include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, isoamyl acetate, ethyl methoxyacetate, ethyl ethoxyacetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monophenyl ether acetate, diethylene ...propyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monophenyl ether acetate, diethylene glycol monomethyl ether acetate, ethylene glycol monopropyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monophenyl ether acetate, diethylene glycol monomethyl ether acetate, ethylene glycol monopropyl ether acetate, ethylene glycol monopropyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monophenyl ether acetate, di Diethylene glycol monomethyl ether acetate, diethylene glycol monopropyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monophenyl ether acetate, diethylene glycol monobutyl ether acetate, 2-methoxybutyl acetate, 3-methoxybutyl acetate, 4-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-ethyl-3-methoxybutyl acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, 2-ethoxybutyl acetate, 4-ethoxybutyl acetate, 4-propoxybutyl acetate, 2-methoxypentyl acetate, 3-methoxypentyl acetate, 4-methoxypentyl acetate, 2-methyl Examples of the developer include methyl-3-methoxypentyl acetate, 3-methyl-3-methoxypentyl acetate, 3-methyl-4-methoxypentyl acetate, 4-methyl-4-methoxypentyl acetate, propylene glycol diacetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate, ethyl carbonate, propyl carbonate, butyl carbonate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, butyl pyruvate, methyl acetoacetate, ethyl acetoacetate, methyl propionate, ethyl propionate, propyl propionate, isopropyl propionate, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, and propyl 3-methoxypropionate. Furthermore, surfactants and the like can be added to these developers. The conditions for development are suitably selected from a temperature of 5° C. to 50° C. and a time of 10 seconds to 600 seconds.

[0108] Then, the resist underlayer film (intermediate layer) of the present invention is removed using the patterned photoresist (upper layer) as a protective film, and then the organic underlayer film (lower layer) is removed using the film consisting of the patterned photoresist and the resist underlayer film (intermediate layer) of the present invention as a protective film. Finally, the semiconductor substrate is processed using the patterned resist underlayer film (intermediate layer) of the present invention and the organic underlayer film (lower layer) as protective films.

[0109] First, the resist underlayer film (intermediate layer) of the present invention in the area where the photoresist was removed is removed by dry etching to expose the semiconductor substrate. Gases such as tetrafluoromethane (CF), perfluorocyclobutane (CF), perfluoropropane (CF), trifluoromethane, carbon monoxide, argon, oxygen, nitrogen, sulfur hexafluoride, difluoromethane, nitrogen trifluoride, chlorine trifluoride, chlorine, trichloroborane, and dichloroborane can be used for dry etching of the resist underlayer film of the present invention. It is preferable to use a halogen-based gas for dry etching of the resist underlayer film. Photoresists composed primarily of organic substances are difficult to remove with dry etching using halogen-based gases. In contrast, the resist underlayer film of the present invention, which contains a large amount of silicon atoms, is quickly removed with halogen-based gases. Therefore, the reduction in photoresist film thickness associated with dry etching of the resist underlayer film can be suppressed. As a result, it becomes possible to use thin photoresists. Dry etching of the resist underlayer film is preferably performed using a fluorine-based gas, and examples of the fluorine-based gas include tetrafluoromethane (CF), perfluorocyclobutane (C), perfluoropropane (C), trifluoromethane, and difluoromethane (CHF).

[0110] Thereafter, the organic underlayer film is removed using the patterned photoresist and the resist underlayer film of the present invention as protective films. The organic underlayer film (underlayer) is preferably removed by dry etching using an oxygen-based gas. This is because the resist underlayer film of the present invention, which contains a large amount of silicon atoms, is difficult to remove by dry etching using an oxygen-based gas.

[0111] Finally, the semiconductor substrate is processed. The semiconductor substrate is processed using a fluorine-based gas. Preferably, this is done by etching.

[0112] Examples of fluorine-based gases include tetrafluoromethane (CF4), perfluorocyclobutane (C4F8), perfluoropropane (C3F8), trifluoromethane, and difluoromethane (CH2F2).

[0113] Furthermore, an organic antireflective coating can be formed on the resist underlayer film of the present invention before forming a photoresist. The antireflective coating composition used therein is not particularly limited, and any one can be selected from those conventionally used in lithography processes. The antireflective coating can be formed by a conventional method, such as coating with a spinner or coater and baking.

[0114] Furthermore, the substrate to which the resist underlayer film-forming composition of the present invention is applied may have an organic or inorganic antireflective film formed on its surface by a CVD method or the like, and a resist underlayer film formed from the resist underlayer film-forming composition of the present invention may be formed on top of the organic or inorganic antireflective film.

[0115] The resist underlayer film formed from the resist underlayer film-forming composition of the present invention may also absorb light depending on the wavelength of the light used in the lithography process. In such cases, it can function as an antireflective film that has the effect of preventing light reflected from the substrate. Furthermore, the resist underlayer film formed from the resist underlayer film-forming composition of the present invention can also be used as a layer for preventing interaction between the substrate and the photoresist, a layer having the function of preventing adverse effects on the substrate of materials used in the photoresist or substances generated during exposure of the photoresist, a layer having the function of preventing diffusion of substances generated from the substrate during heating and baking into an overlying photoresist, and a barrier layer for reducing the poisoning effect of the photoresist layer due to the dielectric layer of the semiconductor substrate.

[0116] Furthermore, the resist underlayer film formed from the resist underlayer film-forming composition of the present invention can be applied to a substrate having via holes formed therein for use in a dual damascene process, and can be used as a filling material capable of filling the holes without gaps. It can also be used as a planarizing material for planarizing the surface of an uneven semiconductor substrate.

[0117] Furthermore, in addition to functioning as a hard mask, the resist underlayer film forming composition can also be used for the following purpose as an underlayer film for an EUV resist. That is, the resist underlayer film forming composition can be used as an underlayer antireflective film for an EUV resist that can prevent reflection from the substrate or interface of undesirable exposure light during EUV exposure (wavelength 13.5 nm), such as the above-mentioned UV or DUV (ArF light, KrF light), without intermixing with the EUV resist. Reflection can be efficiently prevented as an underlayer for an EUV resist. When used as an EUV resist underlayer film, the process can be carried out in the same way as for an underlayer film for a photoresist. [Example]

[0118] The present invention will now be described in detail with reference to examples, but the present invention is not limited to these examples.

[0119] (Synthesis Example 1) 25.2 g of tetraethoxysilane (70 mol % of all hydrolyzable silanes), 7.71 g of methyltriethoxysilane (25 mol % of all hydrolyzable silanes), 2.48 g of ethoxyethoxyphenyltrimethoxysilane (5 mol % of all hydrolyzable silanes), and 53.1 g of acetone were placed in a 300 ml flask, and 11.5 g of 0.01 M aqueous nitric acid solution was added dropwise while stirring the mixture with a magnetic stirrer. After the addition, the oil temperature was adjusted to 85°C. The flask was transferred to a bath and refluxed for 240 minutes. Then, 70 g of propylene glycol monomethyl ether acetate was added, and acetone, methanol, ethanol, and water were distilled off under reduced pressure. The mixture was concentrated to obtain an aqueous solution of the hydrolysis condensate (polymer). Further propylene glycol monomethyl ether acetate was added to adjust the solvent ratio to 100% propylene glycol monomethyl ether acetate to 20 weight percent, calculated as the solid residue at 140°C. The resulting polymer corresponded to formula (3-1), and then became a mixture of polymers corresponding to formula (3-1) and formula (4-1). The weight-average molecular weight (Mw) measured by GPC was 3,000 in terms of polystyrene.

[0120] (Synthesis Example 2) 22.6 g of tetraethoxysilane (70 mol % of total hydrolyzable silanes), 13.3 g of ethoxyethoxyphenyltrimethoxysilane (30 mol % of total hydrolyzable silanes), and 53.8 g of acetone were placed in a 300 ml flask, and 10.3 g of 0.01 M aqueous nitric acid solution was added dropwise while the mixture was stirred with a magnetic stirrer. After the addition, the flask was transferred to an oil bath adjusted to 85°C and refluxed for 240 minutes. 70 g of propylene glycol monomethyl ether acetate was then added, and the acetone, methanol, ethanol, and water were distilled off under reduced pressure. The solution was concentrated to obtain an aqueous solution of hydrolyzed condensate (polymer). Further propylene glycol monomethyl ether acetate was added, and the solvent ratio of 100% propylene glycol monomethyl ether acetate was adjusted to 20 weight percent, calculated as a solid residue at 140°C. The resulting polymer corresponded to formula (3-2), and then became a mixture of polymers corresponding to formula (3-2) and formula (4-2). The weight average molecular weight (Mw) measured by GPC was 2700 in terms of polystyrene.

[0121] (Synthesis Example 3) 25.5 g of tetraethoxysilane (70 mol % of total hydrolyzable silanes), 7.80 g of methyltriethoxysilane (25 mol % of total hydrolyzable silanes), 2.00 g of methoxyphenyltrimethoxysilane (5 mol % of total hydrolyzable silanes), and 53.0 g of acetone were placed in a 300 mL flask. While stirring the mixture with a magnetic stirrer, 11.7 g of 0.1 M aqueous nitric acid solution was added dropwise. After the addition, the flask was transferred to an oil bath adjusted to 85 °C and refluxed for 240 minutes. Subsequently, 70 g of propylene glycol monomethyl ether acetate was added, and acetone, methanol, ethanol, and water were distilled off under reduced pressure. The solution was concentrated to obtain an aqueous solution of hydrolyzed condensate (polymer). Further propylene glycol monomethyl ether acetate was added to adjust the solvent ratio to 100% propylene glycol monomethyl ether acetate to 20 weight percent as calculated as solid residue at 140 °C. The resulting polymer corresponded to formula (3-3), and then became a mixture of polymers corresponding to formula (3-3) and formula (4-1). The weight average molecular weight (Mw) measured by GPC was 2800 in terms of polystyrene.

[0122] (Synthesis Example 4) 24.2 g of tetraethoxysilane (70 mol % of total hydrolyzable silanes), 11.37 g of methoxyphenyltrimethoxysilane (30 mol % of total hydrolyzable silanes), and 53.4 g of acetone were placed in a 300 ml flask. While stirring the mixture with a magnetic stirrer, 11.1 g of 0.01 M aqueous nitric acid solution was added dropwise. After the addition, the flask was transferred to an oil bath adjusted to 85 °C and refluxed for 240 minutes. 70 g of propylene glycol monomethyl ether acetate was then added, and the acetone, methanol, ethanol, and water were removed under reduced pressure. The solution was concentrated to obtain an aqueous solution of the hydrolyzed condensate (polymer). Further propylene glycol monomethyl ether acetate was added to adjust the solvent ratio to 100% propylene glycol monomethyl ether acetate to 20 weight percent solid residue at 140 °C. The resulting polymer corresponded to Formula (3-4), which then became a mixture of polymers corresponding to Formula (3-4) and Formula (4-2). Weight average molecular weight by GPC ( Mw) was 2200 in terms of polystyrene.

[0123] (Synthesis Example 5) 25.5 g of tetraethoxysilane (70 mol % of total hydrolyzable silanes), 7.78 g of methyltriethoxysilane (25 mol % of total hydrolyzable silanes), 2.11 g of methoxybenzyltrimethoxysilane (5 mol % of total hydrolyzable silanes), and 53.0 g of acetone were placed in a 300 mL flask. While stirring the mixture with a magnetic stirrer, 11.6 g of 0.01 M aqueous nitric acid solution was added dropwise. After the addition, the flask was transferred to an oil bath adjusted to 85 °C and refluxed for 240 minutes. Subsequently, 70 g of propylene glycol monomethyl ether acetate was added, and acetone, methanol, ethanol, and water were distilled off under reduced pressure. The solution was concentrated to obtain an aqueous solution of hydrolyzed condensate (polymer). Further propylene glycol monomethyl ether acetate was added to adjust the solvent ratio to 100% propylene glycol monomethyl ether acetate to 20 weight percent as calculated as solid residue at 140 °C. The resulting polymer corresponded to formula (3-5), which then became a mixture of polymers corresponding to formula (3-5) and formula (4-3). The weight average molecular weight (Mw) measured by GPC was 2400 in terms of polystyrene.

[0124] (Synthesis Example 6) 23.8 g of tetraethoxysilane (70 mol % of total hydrolyzable silanes), 11.9 g of methoxybenzyltrimethoxysilane (30 mol % of total hydrolyzable silanes), and 53.5 g of acetone were placed in a 300 ml flask. While stirring the mixture with a magnetic stirrer, 10.8 g of 1 M aqueous nitric acid solution was added dropwise. After the addition, the flask was transferred to an oil bath adjusted to 85 °C and refluxed for 240 minutes. 70 g of propylene glycol monomethyl ether acetate was then added, and the acetone, methanol, ethanol, and water were removed under reduced pressure. The solution was concentrated to obtain an aqueous solution of the hydrolyzed condensate (polymer). Further propylene glycol monomethyl ether acetate was added to adjust the solvent ratio to 100% propylene glycol monomethyl ether acetate to 20 weight percent solid residue at 140 °C. The resulting polymer corresponded to Formula (3-6), which then became a mixture of polymers corresponding to Formula (3-6) and Formula (4-4). The weight average molecular weight (Mw) measured by GPC was 3500 in terms of polystyrene.

[0125] (Synthesis Example 7) 24.9 g of tetraethoxysilane (70 mol % of total hydrolyzable silanes), 7.61 g of methyltriethoxysilane (25 mol % of total hydrolyzable silanes), 2.94 g of triethoxy((2-methoxy-4-(methoxymethyl)phenoxy)methyl)silane (5 mol % of total hydrolyzable silanes), and 53.2 g of acetone were placed in a 300 ml flask, and 11.4 g of 0.01 M aqueous nitric acid solution was added dropwise while stirring the mixture with a magnetic stirrer. After the addition, the flask was transferred to an oil bath adjusted to 85 °C and refluxed for 240 minutes. Then, 70 g of propylene glycol monomethyl ether acetate was added, and acetone, methanol, ethanol, and water were distilled off under reduced pressure. The mixture was concentrated to obtain an aqueous solution of hydrolyzed condensate (polymer). Further, propylene glycol monomethyl ether acetate was added to adjust the solvent ratio to 20 weight percent (based on the solid residue at 140 °C) as 100% propylene glycol monomethyl ether acetate. The resulting polymer corresponded to formula (3-7), followed by a mixture of polymers corresponding to formula (3-7), formula (4-5), and formula (4-7). The weight average molecular weight (Mw) measured by GPC was 2800 in terms of polystyrene.

[0126] (Synthesis Example 8) Tetraethoxysilane 21.1 g (70 mol % of all hydrolyzable silanes), triethoxy((2-methoxy-4-(methoxymethyl)phenoxy)methyl)silane 14.99 g 54.2 g of acetone (30 mol% of total hydrolyzable silanes) was placed in a 300 ml flask, and 9.67 g of 0.01 M aqueous nitric acid solution was added dropwise while stirring the mixture with a magnetic stirrer. After the addition, the flask was transferred to an oil bath adjusted to 85°C and refluxed for 240 minutes. 70 g of propylene glycol monomethyl ether acetate was then added, and acetone, methanol, ethanol, and water were removed under reduced pressure. The solution was concentrated to obtain an aqueous solution of the hydrolyzed condensate (polymer). Further propylene glycol monomethyl ether acetate was added, adjusting the solvent ratio to 100% propylene glycol monomethyl ether acetate to 20 weight percent solid residue at 140°C. The resulting polymer corresponded to formula (3-8), followed by a mixture of polymers corresponding to formulas (3-8), (4-6), and (4-8). The weight-average molecular weight (Mw) measured by GPC was 2500 in terms of polystyrene.

[0127] (Comparative Synthesis Example 1) 25.8 g of tetraethoxysilane, 9.5 g of triethoxymethylsilane, and 52.9 g of acetone were placed in a 300 mL flask. While stirring the mixture with a magnetic stirrer, 11.8 g of 0.01 M aqueous hydrochloric acid was added dropwise. After the addition, the flask was transferred to an oil bath adjusted to 85°C and refluxed for 240 minutes. Then, 70 g of propylene glycol monomethyl ether acetate was added, and the acetone, methanol, ethanol, and water were removed under reduced pressure. The mixture was concentrated to obtain an aqueous solution of hydrolyzed condensate (polymer). Further propylene glycol monomethyl ether acetate was added, adjusting the concentration to 20 weight percent based on the solid residue at 140°C. The resulting polymer corresponded to formula (5-1), and its weight-average molecular weight (Mw) measured by GPC was 1800 in terms of polystyrene. [ka]

[0128] (Comparative Synthesis Example 2) 25.8g of tetraethoxysilane, 9.5g of triethoxymethylsilane, and 52.9g of acetone were placed in a 300ml flask, and 11.8g of 11M aqueous nitric acid solution was added dropwise to the mixture while stirring with a magnetic stirrer. After the addition, the flask was placed in an oil bath adjusted to 85°C, and acetone was added to adjust the concentration. The mixture was refluxed for 240 minutes. After that, a white precipitate formed, and the target polymer was not obtained. The polymer solution contained 10,000 ppm of nitrate ions.

[0129] [Post-filtration stability of synthesized polymers] The polysiloxane (polymer) obtained in the above synthesis example was filtered through a nylon filter with a pore size of 10 nm, and the change in molecular weight before and after filtration was evaluated using GPC spectrum changes. As a result, a molecular weight change of 10% or less was rated as good, and a change of 10% or more was rated as bad. The results are shown in Table 1. [Table 1]

[0130] [Preparation of Resist Underlayer Film-Forming Composition] The polysiloxane (polymer), acid, and solvent obtained in the above synthesis example are shown below. 2 The components were mixed in the ratios shown in Table 1 and filtered through a 0.1 μm polyethylene filter to prepare the compositions to be applied to the resist patterns. 2 The polymer addition ratio in the table indicates the amount of polymer itself added, not the amount of polymer solution added. In the table, ultrapure water was used. The amount of each additive is shown in parts by mass. MA refers to maleic acid, TPSNO3 refers to triphenylsulfonium nitrate, TPSTFA refers to triphenylsulfonium trifluoroacetate, TPSML refers to triphenylsulfonium maleate, TPSCl refers to triphenylsulfonium chloride, BTEAC refers to benzyltriethylammonium chloride, TMANO3 refers to tetramethylammonium nitrate, TPSCS refers to triphenylsulfonium camphorsulfonate, and TPSAdTf refers to triphenylsulfonium adamantanecarboxylate butyltrifluoromethanesulfonate. PGEE refers to propylene glycol monoethyl ether, PGMEA refers to propylene glycol monomethyl ether acetate, and PGME refers to propylene glycol monomethyl ether.

[0131] [Table 2]

[0132] [Table 3]

[0133] [Preparation of Organic Underlayer Film (A Layer) Forming Composition] Under nitrogen, a 100 mL four-neck flask was charged with carbazole (6.69 g, 0.040 mol, Tokyo Chemical Industry Co., Ltd.), 9-fluorenone (7.28 g, 0.040 mol, Tokyo Chemical Industry Co., Ltd.), and paratoluenesulfonic acid monohydrate (0.76 g, 0.0040 mol, Tokyo Chemical Industry Co., Ltd.), and 1,4-dioxane (6.69 g, Kanto Chemical Co., Ltd.) was added and stirred. The mixture was heated to 100 °C to dissolve and initiate polymerization. After 24 hours, the mixture was allowed to cool to 60 °C, and then diluted with chloroform (34 g, Kanto Chemical Co., Ltd.). The mixture was then reprecipitated in methanol (168 g, Kanto Chemical Co., Ltd.). The resulting precipitate was filtered and dried in a vacuum oven at 80 °C for 24 hours to yield 9.37 g of the target polymer (formula (3-1), hereafter abbreviated as PCzFL). [ka] PCzFL 1 The results of H-NMR measurement were as follows: 1 H-NMR(400MHz,DMSO-d6):δ7.03-7.55(br,12H),δ7.61-8.10(br,4H),δ11.18(br,1H) The weight average molecular weight (Mw) of PCzFL measured by GPC in terms of polystyrene was 2800, and the polydispersity index: Mw (weight average molecular weight) / Mn (number average molecular weight) was 1.77. . 20 g of the resulting resin was mixed with 3.0 g of tetramethoxymethylglycoluril (Mitsui Cytec Co., Ltd., product name Powder Link 1174) as a crosslinker, 0.30 g of pyridinium paratoluenesulfonate as a catalyst, and 0.06 g of Megafac R-30 (DIC Corporation, product name) as a surfactant, and dissolved in 88 g of propylene glycol monomethyl ether acetate to form a solution. The mixture was then filtered using a polyethylene microfilter with a pore size of 0.10 μm, and further filtered using a polyethylene microfilter with a pore size of 0.05 μm to prepare a solution of an organic underlayer film (layer A) forming composition for use in a multilayer lithography process.

[0134] [Solvent resistance test] The resist underlayer film-forming compositions prepared in Examples 1 to 8 and Comparative Examples 1 and 2 were applied to silicon wafers using a spinner. Each was heated on a hot plate at 215°C for 1 minute to form a resist underlayer film. A solvent consisting of propylene glycol monomethyl ether / propylene glycol monomethyl ether acetate = 7 / 3 (mass ratio) was then applied to the resist underlayer film, which was then spin-dried. The presence or absence of a change in film thickness before and after solvent application was evaluated. Films with a film thickness change of 1% or less were rated "good," and films with a film thickness change of 1% or more were rated "not cured." The results are shown in Table 4.

[0135] [Developer solubility test] The resist underlayer film-forming compositions prepared in Examples 1 to 8 and Comparative Examples 1 and 2 were applied to silicon wafers using a spinner. Each was heated on a hot plate at 215°C for 1 minute to form a resist underlayer film. An alkaline developer (a 2.38% aqueous solution of TMAH (TMAH stands for tetramethylammonium hydroxide)) was then applied to the resist underlayer film, which was then spin-dried, and the presence or absence of change in film thickness before and after solvent application was evaluated. Films with a film thickness change of 1% or less were rated "good," and films with a film thickness change of 1% or more were rated "not cured." The results are also shown in Table 4.

[0136] [Table 4]

[0137] [Resist pattern formation by EUV exposure: positive alkaline development] The organic underlayer film (A layer)-forming composition was applied to a silicon wafer and baked on a hot plate at 215°C for 60 seconds to obtain a 90 nm-thick organic underlayer film (A layer). The resist underlayer film-forming composition solutions prepared in Examples 1 to 8 and Comparative Example 2 were spin-coated thereon and heated at 215°C for 1 minute to form a resist underlayer film (B) layer (20 nm). An EUV resist solution (methacrylate resin-based resist) was spin-coated on the resist underlayer film (hard mask) and heated to form an EUV resist layer (C) layer. The EUV resist layer was then exposed using an ASML EUV exposure system (NXE3300B) under conditions of NA = 0.33, σ = 0.67 / 0.90, and cQuad. After exposure, the wafer was subjected to PEB, cooled to room temperature on a cooling plate, developed for 60 seconds using an alkaline developer (2.38% TMAH aqueous solution), and rinsed to form a resist pattern. The evaluation consisted of whether or not 20 nm holes could be formed at a pitch of 40 nm, and the pattern shape was evaluated by observing the cross section of the pattern. The results are shown in Table 5. In Table 5, "good" indicates a shape between footing and undercut, with no significant residue in the space, "collapsed" indicates an undesirable state in which the resist pattern has peeled off and collapsed, and "bridged" indicates an undesirable state in which the upper or lower parts of the resist pattern are in contact with each other.

[0138] [Table 5]

[0139] [Resist pattern formation by EUV exposure: negative solvent development] The organic underlayer film (A layer)-forming composition was applied to a silicon wafer and baked on a hot plate at 215°C for 60 seconds to obtain a 90 nm-thick organic underlayer film (A layer). The resist underlayer film-forming composition solutions prepared in Examples 1 to 8 and Comparative Example 2 were spin-coated thereon and heated at 215°C for 1 minute to form a resist underlayer film (B) layer (20 nm). An EUV resist solution (methacrylate resin-based resist) was spin-coated on the resist underlayer film (hard mask) and heated to form an EUV resist layer (C). The EUV resist layer was then exposed using an ASML EUV exposure system (NXE3300B) under conditions of NA = 0.33, σ = 0.67 / 0.90, and Dipole. After exposure, the wafer was subjected to PEB, cooled to room temperature on a cooling plate, developed for 60 seconds using an organic solvent developer (butyl acetate), and rinsed to form a resist pattern. The evaluation consisted of whether or not a 20 nm line and space could be formed, and the pattern shape was evaluated by observing the cross section of the pattern. The results are shown in Table 6.

[0140] In Table 6, "good" indicates a shape between footing and undercut, with no significant residue in the space, "collapsed" indicates an undesirable state in which the resist pattern has peeled off and collapsed, and "bridged" indicates an undesirable state in which the upper or lower parts of the resist pattern are in contact with each other.

[0141] [Table 6] [Industrial Applicability]

[0142] The present invention can provide a resist underlayer film-forming composition for lithography that can be used in the production of semiconductor devices and that is used to form a resist underlayer film that can be used as a hard mask.

Claims

1. The compound contains a hydrolysis condensate (c) of a hydrolyzable silane (a) as the silane, nitrate ions, and a solvent, and the hydrolyzable silane (a) is represented by the formula (1): 【Chemistry 1】 [In formula (1), R １ is expressed as equation (2): 【Chemistry 2】 (In formula (2), X represents an oxygen atom, a sulfur atom, or a nitrogen atom; R ４ represents a single bond or an alkylene group having 1 to 10 carbon atoms; R ５ represents an alkyl group having 1 to 10 carbon atoms; R ６ represents an alkyl group having 1 to 10 carbon atoms, n1 is 1≦n1≦5, 0≦n2≦(5−n1), n3 is 1, and * represents the bonding position to the silicon atom.) and is bonded to the silicon atom by a Si—C bond. ２ R is an organic group having an alkyl group, an aryl group, a halogenated alkyl group, a halogenated aryl group, an alkoxyaryl group, an alkenyl group, or an epoxy group, an acryloyl group, a methacryloyl group, a mercapto group, an amino group, or a cyano group, and is bonded to a silicon atom by a Si—C bond. ３ represents an alkoxy group, an acyloxy group, or a halogen group; a represents an integer of 1, b represents an integer of 0 to 2, and a+b represents an integer of 1 to 3; The resist underlayer film-forming composition for lithography, wherein the hydrolysis condensate (c) is represented by the following formula: 【Transformation 3】

2. A resist underlayer film forming composition as described in claim 1, further comprising a hydrolyzable silane (a) and / or its hydrolyzate (b).

3. A resist underlayer film forming composition according to claim 1 or claim 2, containing nitrate ions in the range of 1 ppm to 1000 ppm in the resist underlayer film forming composition.

4. A resist underlayer film forming composition described in any one of claims 1 to 3, wherein the hydrolyzed condensate (c) is a composition in which the functional group of formula (2) in the hydrolyzable silane of formula (1) is in a molar ratio of (hydrogen atom) / (hydrogen atom + R 5 group) of 1% to 100%.

5. The hydrolyzable silane (a) is a combination of the hydrolyzable silane of formula (1) and another hydrolyzable silane, wherein the other hydrolyzable silane is a compound of formula (3): 【Chemistry 4】 (in formula (3), R 7 represents an alkyl group, an aryl group, a halogenated alkyl group, a halogenated aryl group, an alkoxyaryl group, an alkenyl group, or an organic group having an epoxy group, an acryloyl group, a methacryloyl group, a mercapto group, or a cyano group, and is bonded to a silicon atom via a Si—C bond; R 8 represents an alkoxy group, an acyloxy group, or a halogen atom; and c represents an integer of 0 to 3), and formula (4): 【Transformation 5】 (In formula (4), R 9 is an alkyl group and is bonded to the silicon atom by a Si—C bond.) wherein R 10 represents an alkoxy group, an acyloxy group, or a halogen group; Y represents an alkylene group or an arylene group; d represents an integer of 0 or 1; and e represents an integer of 0 or 1. The resist underlayer film forming composition according to any one of claims 1 to 4, wherein the resist underlayer film forming composition is at least one hydrolyzable silane selected from the group consisting of

6. A resist underlayer film forming composition according to claim 5, comprising as a polymer a hydrolyzed condensate of hydrolyzable silanes consisting of a combination of a hydrolyzable silane of formula (1) of claim 1 and a hydrolyzable silane of formula (3) of claim 5.

7. A resist underlayer film forming composition described in any one of claims 1 to 6, further containing an additive consisting of water, acid, a photoacid generator, a surfactant, a metal oxide, or a combination thereof.

8. A method for producing a resist underlayer film-forming composition according to any one of claims 1 to 7, comprising a step (A) of filtering a polymer solution containing a hydrolyzed condensate (c) of a hydrolyzable silane, or a polymer solution containing the hydrolyzed condensate (c) of a hydrolyzable silane, a hydrolyzable silane (a) and / or its hydrolyzate (b), nitrate ions and a solvent through a filter containing a polar group-containing filter.

9. A method for producing a resist underlayer film forming composition according to claim 8, wherein the polar group-containing filter is a nylon filter.

10. A method for producing a resist underlayer film forming composition according to claim 8 or claim 9, further comprising a step (B) of filtering a solution obtained by adding the additive according to claim 7 to a polymer solution through a filter.

11. A method for manufacturing a semiconductor device, comprising the steps of applying a resist underlayer film forming composition according to any one of claims 1 to 7 onto a semiconductor substrate, baking the composition to form a resist underlayer film, applying a resist composition onto the underlayer film to form a resist layer, exposing the resist layer, developing the resist after exposure to obtain a resist pattern, etching the resist underlayer film using the resist pattern, and processing a semiconductor substrate using the patterned resist layer and resist underlayer film.

12. A method for manufacturing a semiconductor device, comprising the steps of: forming an organic underlayer film on a semiconductor substrate; applying a resist underlayer film forming composition described in any one of claims 1 to 7 thereon and baking to form a resist underlayer film; applying a resist composition on the resist underlayer film to form a resist layer; exposing the resist layer; developing the resist after exposure to obtain a resist pattern; etching the resist underlayer film with the resist pattern; etching the organic underlayer film with the patterned resist underlayer film; and processing a semiconductor substrate with the patterned organic underlayer film.

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