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 is 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 thin film is irradiated with active light such as ultraviolet light through a mask pattern on which a semiconductor device pattern is drawn, developed, and the substrate is etched using the obtained photoresist pattern as a protective film, thereby forming fine projections and recesses on the substrate surface corresponding to the pattern. However, in recent years, as the integration density of semiconductor devices has increased, the active light used has tended to be shortened from KrF excimer laser (248 nm) to ArF excimer laser (193 nm). As a result, the effect of reflection of the active light from the semiconductor substrate has become a major problem.

[0003] In addition, a film known as a hard mask containing metal elements such as silicon and 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 are significantly different, the speed at which they are removed by dry etching is largely dependent 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 a significant decrease in the thickness of the photoresist. Thus, in recent years, in the manufacture of semiconductor devices, a resist underlayer film has been placed between a semiconductor substrate and a photoresist to achieve various effects, including an anti-reflection effect. Although compositions for the resist underlayer film have been studied, the development of new materials for the resist underlayer film is desired due to the diversity 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] A highly polar polysiloxane solution 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, a filter containing a polar group may be used. The solution may be filtered through a filter. When a filter contains a polar group, the polar group may react with the polysiloxane component, causing problems such as an increase in the molecular weight of the polysiloxane or gelation. In addition, although volatile catalysts such as hydrochloric acid are removed in the solvent replacement process, which includes heat treatment of the polysiloxane solution, high molecular weight acids may be removed by the filter during filtration, which may cause the polysiloxane to become unstable when passing through the filter.

[0008] In view of the above circumstances, the present invention has an object to provide a resist underlayer film-forming composition for lithography that can be used in the manufacture of a semiconductor device, more specifically, to provide a resist underlayer film-forming composition for lithography for forming 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 that contains a polysiloxane that is stable even after undergoing a process of filtering out foreign matter through a filter. [Means for solving the problem]

[0009] As a result of extensive investigations aimed at solving the above problems, the inventors discovered that a polysiloxane solution containing a specific amount of nitric acid is stably filtered when passing 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 the steps of: (a) a hydrolysis condensate (c) of a hydrolyzable silane (a); nitrate ions; and a solvent. 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 R 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.) 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). As a third aspect, the present invention relates to the resist underlayer film forming composition according to the first aspect or the second aspect, in which nitrate ions are contained in the resist underlayer film forming composition in an amount of 1 ppm to 1000 ppm. . As a fourth viewpoint, 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 alkyl group (a) to the alkyl group (b) 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 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 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 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. As 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 formed by a combination of the hydrolyzable silane of formula (1) of the first aspect and the hydrolyzable silane of formula (3) of 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 hydrolyzable silane (a) and / or a hydrolyzate (b) thereof, nitrate ions, and a solvent, through a filter including a polar group-containing filter. The present invention relates to a ninth aspect, 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. As 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 on 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 by using the patterned resist layer and resist underlayer film. As a twelfth aspect, a step of forming an organic underlayer film on a semiconductor substrate, A seventh aspect relates to a method for manufacturing a semiconductor device, the method including the steps of: applying and baking the resist underlayer film-forming composition according to any one of the seventh aspects 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 with the resist pattern; etching an organic underlayer film with the patterned resist underlayer film; and processing a semiconductor substrate with the patterned organic underlayer film. The present specification also includes the following aspects of the invention [1] to [8]. [1] The compound contains a hydrolysis condensate (c) of a hydrolyzable silane (a) as a silane, nitrate ions, and a solvent, and 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 R 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.) 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.], on a semiconductor substrate, and baking the composition to form a resist underlayer film, a resist composition is applied on the underlayer film to form a resist layer, a resist layer is exposed to light, the resist is developed after exposure to obtain a resist pattern, a resist underlayer film is etched by the resist pattern, and a semiconductor substrate is processed by the patterned resist layer and resist underlayer film. [2] forming an organic underlayer film on a semiconductor substrate; and forming a hydrolysis condensate (c) of a hydrolyzable silane (a) on the organic underlayer film, the hydrolysis condensate (c) containing nitrate ions and a solvent, the hydrolyzable silane (a) being 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 R 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.) 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.], and baking to form a resist underlayer film, a step of applying a resist composition on the resist underlayer film to form a resist layer, a step of exposing the resist layer, a step of developing the resist after exposure to obtain a resist pattern, a step of etching the resist underlayer film with the resist pattern, a step of etching the organic underlayer film with the patterned resist underlayer film, and a step of processing a semiconductor substrate with the patterned organic underlayer film. [3] The method for producing a semiconductor device according to [1] or [2], further comprising a hydrolyzable silane (a) and / or a hydrolyzate thereof (b); [4] The method for manufacturing a semiconductor device according to any one of claims [1] to [3], wherein the resist underlayer film forming composition contains nitrate ions in the range of 1 ppm to 1000 ppm. [5] 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 5The method for manufacturing a semiconductor device according to any one of [1] to [4], wherein the molar ratio of the compound (a) to the compound (b) is 1% to 100%. [6] 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 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 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 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. [7] The method for producing a semiconductor device according to [6], comprising, as a polymer, a hydrolyzed condensate of hydrolyzable silanes consisting of a combination of a hydrolyzable silane of formula (1) of claim 1 or claim 2 and a hydrolyzable silane of formula (3) of claim 6. [8] The method for manufacturing a semiconductor device according to any one of [1] to [7], further comprising an additive comprising water, an acid, a photoacid generator, a surfactant, a metal oxide, or a combination thereof. Effect 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 the 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 is dry-etched using the resist film on which the resist pattern is formed to transfer the pattern, and the substrate is processed by the patterned resist underlayer film, or the organic underlayer film is etched to transfer the pattern, and the substrate is processed by the organic underlayer film.

[0012] In forming a fine pattern on a resist film, the resist film tends to be thin in order to prevent the pattern from collapsing. In dry etching for transferring the pattern of the resist film to the film existing in the lower layer by thinning the resist, the etching rate of the lower layer must be higher than that of the upper layer. In the present invention, the resist underlayer film of the present invention (containing an inorganic silicon compound) is coated on the substrate with or without an organic underlayer film, and a resist film (organic resist film) is coated on the resist underlayer film. The dry etching rate of the organic component film and the inorganic component film is significantly different depending on the etching gas selected, and the dry etching rate of the organic component film is high with an oxygen-based gas, and the dry etching rate of the inorganic component film is high with a halogen-containing gas.

[0013] For example, a resist pattern is formed on a resist film, the resist underlayer film of the present invention existing below 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 organic underlayer film below it 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 towards thinner resists has been remarkable in cutting-edge semiconductor devices, and even in the Tri-Layer process, improved lithography properties are required for silicon-containing resist underlayer films. In the present invention, the phenolic hydroxyl group and hydroxyalkyl group improve adhesion with the upper resist layer, resulting in the development of good resist patterns and improved solvent resistance and developer resistance. When the upper resist layer is developed with an alkaline developer, it is effective in reducing scum during hole formation. In addition, when the upper resist layer is developed with an organic solvent, In this case, it is effective in preventing 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 proceeds simultaneously to form a gel structure. To avoid this, the phenol group is protected before hydrolysis and condensation are carried out. 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 solution to pass through a polar group-containing filter such as a nylon filter and remaining stable even after ionic foreign matter has been removed. Polysiloxane is obtained by condensing the hydrolyzate of a hydrolyzable silane, and the hydrolysis catalyst used is a non-volatile acid, and nitric acid that can pass through a nylon filter is used. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] The present invention is 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. 2R 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; 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 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 a hydrolyzate thereof (b).

[0021] Of the total silanes, the silanes of formula (1) can be used in the range of up to 50 mol%, 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) and another hydrolyzable silane (e.g., a hydrolyzable silane of formula (3)), a hydrolyzate thereof, or a hydrolyzed condensate thereof, and a solvent, and may contain, as optional components, an acid, water, an alcohol, a curing catalyst, an acid generator, another organic polymer, a light-absorbing compound, a metal oxide, a surfactant, and the like.

[0023] The solid content in the resist underlayer film forming composition of the present invention is, for example, 0.1% by mass to 50% by mass, or 0.1% by mass to 30% by mass, or 0.1% by mass to 25% by mass. The term "formula" refers to 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% by mass to 100% by mass, 60% by mass to 99% by mass, or 70% by mass 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-propyl group, an n-hexyl group, a 1-methyl-n-pentyl group, a 2 ... Examples of such groups include a 3-methyl-n-pentyl group, a 3-methyl-n-pentyl group, a 4-methyl-n-pentyl group, a 1,1-dimethyl-n-butyl group, a 1,2-dimethyl-n-butyl group, a 1,3-dimethyl-n-butyl group, a 2,2-dimethyl-n-butyl group, a 2,3-dimethyl-n-butyl group, a 3,3-dimethyl-n-butyl group, a 1-ethyl-n-butyl group, a 2-ethyl-n-butyl group, a 1,1,2-trimethyl-n-propyl group, a 1,2,2-trimethyl-n-propyl group, a 1-ethyl-1-methyl-n-propyl group, and a 1-ethyl-2-methyl-n-propyl group.

[0026] Cyclic alkyl groups can also be used. 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-ethyl ... 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 group, 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 of such groups 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-propylethenyl group, 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, 1-cyclopentenyl group, 2-cyclopentenyl group, 3-cyclopentenyl group, 1-hexenyl group, 2-hexenyl group, 3-hexenyl group, 4-hexenyl group, 5-hexenyl group, 1-methyl-1-pentenyl group, 1-methyl-2-pentenyl group, 1-methyl-3-pentenyl group, 1-methyl-4-pentenyl group, 1-n-butylethenyl group, 2-methyl-1-pentenyl group, 2-methyl-2 -pentenyl group, 2-methyl-3-pentenyl group, 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, 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, Examples of the cyclopentenyl group include a clopentenyl group, a 2-methyl-4-cyclopentenyl group, a 2-methyl-5-cyclopentenyl group, a 2-methylene-cyclopentyl group, a 3-methyl-1-cyclopentenyl group, a 3-methyl-2-cyclopentenyl group, a 3-methyl-3-cyclopentenyl group, a 3-methyl-4-cyclopentenyl group, a 3-methyl-5-cyclopentenyl group, a 3-methylene-cyclopentyl group, a 1-cyclohexenyl group, a 2-cyclohexenyl group, and a 3-cyclohexenyl group.

[0029] The aryl group includes an aryl group 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 straight-chain, 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, a 3-methyl-n-butoxy group, a 1,1-dimethyl-n-propoxy group, a 1,2-dimethyl-n-propoxy group, a 2,2-dimethyl-n-propoxy group, a 1-ethyl-n-propoxy, n-hexyloxy, 1-methyl-n-pentyloxy, 2-methyl-n-pentyloxy, 3-methyl-n-pentyloxy, 4-methyl-n-pentyloxy, 1,1-dimethyl-n-butoxy, 1,2-dimethyl-n-butoxy, 1,3-dimethyl-n-butoxy, 2,2-dimethyl-n-butoxy, 2,3-dimethyl-n-butoxy, 3,3-dimethyl-n-butoxy, 1-ethyl-n-butoxy, 2-ethyl-n-butoxy, 1,1,2-trimethyl Examples of cyclic alkoxy groups include cyclopropoxy, cyclobutoxy, 1-methyl-cyclopropoxy, 2-methyl-cyclopropoxy, cyclopentyloxy, 1-methyl-cyclobutoxy, 2-methyl-cyclobutoxy, 3-methyl-cyclobutoxy, 1,2-dimethyl-cyclopropoxy, 2,3-dimethyl-cyclopropoxy, and the like. cyclohexyloxy, 1-ethylcyclopropoxy, 2-ethylcyclopropoxy, cyclohexyloxy, 1-methylcyclopentyloxy, 2-methylcyclopentyloxy, 3-methylcyclopentyloxy, 1-ethylcyclobutoxy, 2-ethylcyclobutoxy, 3-ethylcyclobutoxy, 1,2-dimethylcyclobutoxy, 1,3-dimethylcyclobutoxy, 2,2-dimethylcyclobutoxy, 2,3-dimethylcyclobutoxy, 2,4-dimethylcyclobutoxy, 3,Examples of the cyclopropoxy group include 3-dimethyl-cyclobutoxy group, 1-n-propyl-cyclopropoxy group, 2-n-propyl-cyclopropoxy group, 1-i-propyl-cyclopropoxy group, 2-i-propyl-cyclopropoxy group, 1,2,2-trimethyl-cyclopropoxy group, 1,2,3-trimethyl-cyclopropoxy group, 2,2,3-trimethyl-cyclopropoxy group, 1-ethyl-2-methyl-cyclopropoxy group, 2-ethyl-1-methyl-cyclopropoxy group, 2-ethyl-2-methyl-cyclopropoxy group, and 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, n-hexyloxy group, 1-methyl-n-pentylcarbonyloxy group, 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 atom includes fluorine, chlorine, bromine, iodine and the like.

[0038] Hydrolyzable silanes of formula (1) can be exemplified below. [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 is at least one hydrolyzable silane selected from the group consisting of the formulas (3) and (4). Cut.

[0041] In formula (3), R 7is 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 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 is 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, an alkoxy group, an acyloxy group, and a halogen group can be the same as those mentioned 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 methyltriphenyloxysilane. Tyltriphenethyloxysilane, 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-glycidoxypropylvinyldiethoxy Silane, 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 methylene bistrimethoxysilane, methylene bistrichlorosilane, methylene bistriacetoxysilane, ethylene bistriethoxysilane, ethylene bistrichlorosilane, ethylene bistriacetoxysilane, propylene bistriethoxysilane, butylene bistrimethoxysilane, phenylene bistrimethoxysilane, phenylene bistriethoxysilane, phenylene bismethyldiethoxysilane, phenylene bismethyldimethoxysilane, naphthylene bistrimethoxysilane, bistrimethoxydisilane, bistriethoxydisilane, bisethyldiethoxydisilane, and bismethyldimethoxydisilane.

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

[0047] Specific examples of the hydrolysis condensation product (polysiloxane) (c) used in the present invention are shown 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, reflux is performed, during which the protective group of phenol is eliminated at a rate of about 1% to 100%, and the phenol is converted to phenol. The hydrolysis condensation product (c) is a product in which the functional group of formula (2) in the hydrolyzable silane of formula (1) is (hydrogen atom) / (hydrogen atom + R 5 The molar ratio of the aryl 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 content is in the range of m. When the phenol protecting group is eliminated, the hydrolysis condensation product (polysiloxane) changes to the following structure. [ka] [ka]

[0050] The hydrolysis condensate (polyorganosiloxane) (c) of the above 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 (product name HLC-8220GPC, manufactured by Tosoh Corporation), a GPC column (product 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 velocity) 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 hydrolyzable group 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, hydrolyzates and monomers may remain in the hydrolysis condensate.

[0056] A catalyst can be used for hydrolysis and condensation. Nitric acid is used as a 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 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; 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, 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; polyhydric alcohol 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 monopropylene; ether solvents such as 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, 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, methoxytriglycol acetate, ethyl propionate, n-butyl propionate, i-amyl propionate, diethyl oxalate, di-n-butyl oxalate, methyl lactate, ethyl lactate, lactate Examples of suitable solvents include ester-based solvents such as n-butyl acetate, 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] Bisphenol S or a bisphenol S derivative may 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 given below. [ka]

[0061] The resist underlayer film forming composition of the present invention may contain a curing catalyst. The curing catalyst acts as a curing catalyst when the coating film containing the polyorganosiloxane (c) formed from the hydrolysis condensation product 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 the formula (D-1): [ka] (wherein 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.) 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 - represents 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) is an example of a tertiary ammonium salt.

[0064] As the phosphonium salt, there may be mentioned a compound represented by 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, Y - represents 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, Y - represents 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, 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 the like 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 is 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; R 26 and R 27 It is preferable that the total number of carbon atoms in R is 7 or more. For example, 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 - This compound is commercially available, but 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 an aryl group having 1 to 18 carbon atoms, preferably 4 to 18 carbon atoms, and examples of the alkyl group 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 is also possible to use a compound prepared by mixing, for example, 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 an 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. For example, in the case of a quaternary ammonium derived from 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 can be obtained commercially, but can also be produced by reacting a substituted pyridine such as picoline with an alkyl halide such as methyl bromide, octyl bromide, lauryl chloride, benzyl chloride, benzyl bromide, or an aryl halide. 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 carboxylates (-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. Carboxylic acids include formic acid and acetic acid. When formic acid is used, the anion (Y - ) is (HCOO - ) and when acetic acid is used, the anion (Y - ) is (CH3COO - ) 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 R 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 31 ~R 34 Of the four substituents, three are phenyl groups or substituted phenyl groups, such as phenyl 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, triitolylmonoarylphosphonium halides such as triphenylmonophenylphosphonium halide, and triitolylmonoalkylphosphonium halides (the halogen atom is a chlorine atom) and other halogenated triphenylmonoalkylphosphonium halides such as triphenylmethylphosphonium halide and triphenylethylphosphonium halide, triphenylmonoarylphosphonium halides such as triphenylbenzylphosphonium halide, triitolylmonoarylphosphonium halides such as triitolylmonophenylphosphonium halide, and other halogenated triitolylmonoalkylphosphonium halides such as triitolylmonomethylphosphonium halide (the halogen atom is a chlorine atom). 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 R is an alkyl or aryl group having 1 to 18 carbon atoms, or a silane compound bonded to a silicon atom by a Si-C bond, preferably 35 ~R 37 Of the three substituents, two 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 - ), maleic acid anion, nitrate anion, and other acid groups can be mentioned. This compound is commercially available, and examples thereof include halogenated trialkylsulfonium such as halogenated tri-n-butylsulfonium and halogenated tri-n-propylsulfonium, halogenated trialkylbenzylsulfonium such as halogenated diethylbenzylsulfonium, halogenated diphenylmonoalkylsulfonium such as halogenated diphenylmethylsulfonium and halogenated diphenylethylsulfonium, halogenated triphenylsulfonium (halogen atom is chlorine atom or bromine atom), trialkylsulfonium carboxylate such as tri-n-butylsulfonium carboxylate and tri-n-propylsulfonium carboxylate, trialkylbenzylsulfonium carboxylate such as diethylbenzylsulfonium carboxylate, diphenylmonoalkylsulfonium carboxylate such as diphenylmethylsulfonium carboxylate and diphenylethylsulfonium carboxylate, and triphenylsulfonium carboxylate. In addition, halogenated triphenylsulfonium and triphenylsulfonium carboxylate can be preferably used.

[0075] In the present invention, a nitrogen-containing silane compound can be added as a curing catalyst. Examples of the nitrogen-containing silane compound include imidazole ring-containing silane compounds 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] 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, 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, and salicylic acid. Of these, oxalic acid and maleic acid 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 with respect to 100 parts by mass of the resist underlayer film-forming composition.

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

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

[0081] By using the 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, a naphthalene ring, an anthracene ring, a triazine ring, a quinoline ring, and a quinoxaline ring that functions as a light absorbing site 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 hydrolyzed condensate of the hydrolyzable silane (polyorganosiloxane) (c).

[0085] The resist underlayer film forming composition of the present invention may contain an acid generator. The acid generator includes 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 to be adjusted. This is one way to match the acidity of the underlayer to that of the upper resist. Adjusting the acidity of the underlayer also allows the pattern shape of the resist formed in the upper layer to be adjusted.

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

[0087] Examples of the 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-n-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 the disulfonyldiazomethane compound include bis(trifluoromethylsulfonyl)diazomethane, bis(cyclohexylsulfonyl)diazomethane, bis(phenylsulfonyl)diazomethane, bis(p-toluenesulfonyl)diazomethane, bis(2,4-dimethylbenzenesulfonyl)diazomethane, and methylsulfonyl-p-toluenesulfonyldiazomethane.

[0090] The photoacid generator may be used alone or in combination of two or more kinds. 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 hydrolyzed condensate of the hydrolyzable silane (polyorganosiloxane) (c).

[0091] As described in paragraph

[0022] above, the resist underlayer film forming composition of the present invention can 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 may 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 hydrolysis condensates containing TiOx (titanium oxide, x=1 to 2), hydrolysis condensates containing WOx (tungsten oxide, x=1 to 3), hydrolysis condensates containing HfOx (hafnium oxide, x=1 to 2), hydrolysis condensates containing ZrOx (zirconium oxide, x=1 to 2), hydrolysis 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 the metal oxide to be added can be 0.001 to 100 parts by mass relative to 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 hydrolysis 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 the surfactant 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 allyl ethers such as polyoxyethylene octyl phenol ether and polyoxyethylene nonyl phenol ether; polyoxyethylene-polyoxypropylene block copolymers; sorbitan monolaurate; and nonionic surfactants such as sorbitan fatty acid esters, such as sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, sorbitan trioleate, and sorbitan tristearate; 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 the surfactant include fluorosurfactants such as EF301, EF303, EF352 (manufactured by Tochem Products Co., Ltd.), trade names Megafac F171, F173, R-08, R-30, R-30N, R-40LM (manufactured by DIC Corporation), Fluorad FC430, FC431 (manufactured by Sumitomo 3M Co., Ltd.), trade names Asahiguard AG710, Surflon S-382, SC101, SC102, SC103, SC104, SC105, 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 hydrolyzed condensate of the hydrolyzable silane (polyorganosiloxane) (c).

[0095] In addition, a rheology control agent, an adhesion promoter, and the like can be added to the resist underlayer film forming composition of the present invention. The rheology control agent 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 can be any solvent capable of dissolving the above-mentioned solid components without any particular limitations. 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 mono 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,Propyl propionate, isopropyl propionate, butyl propionate, isobutyl propionate, methyl butyrate, ethyl butyrate, propyl butyrate, isopropyl butyrate, butyl butyrate, isobutyl butyrate, Examples of the hydroxyethyl acetate include 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-methoxybutyl propionate, 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. Here, the resist underlayer film forming composition of the present invention is applied onto a substrate (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, and a substrate coated with a low dielectric constant material (low-k material)) used in the manufacture of a semiconductor device by a suitable application method such as a spinner or a coater, and then baked to form a resist underlayer film. The baking conditions are appropriately selected from a baking temperature of 80°C to 250°C and a baking time of 0.3 minutes to 60 minutes. Preferably, the baking temperature is 150°C to 250°C and the baking time is 0.5 minutes to 2 minutes. Here, the thickness of the underlayer film formed is, for example, 10 nm to 1000 nm, or 20 nm to 500 nm, or 50 nm to 300 nm, or 100 nm to 200 nm.

[0098] Then, for example, a photoresist layer is formed on the resist underlayer film. The photoresist layer can be formed by a well-known method, that is, by applying a photoresist composition solution onto the underlayer film and baking it. The 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 then a photoresist is further coated thereon. This narrows the pattern width of the photoresist, and even if the photoresist is thinly coated to prevent pattern collapse, the substrate can be processed by selecting an appropriate etching gas. For example, the resist underlayer film of the present invention can be processed by using a fluorine-based gas that has a sufficiently high etching rate for the photoresist as an etching gas, and the organic underlayer film can be processed by using an oxygen-based gas that has a sufficiently high etching rate for the resist underlayer film of the present invention as an etching gas, and the substrate can be processed by using a fluorine-based gas that has a sufficiently high etching rate for the organic underlayer film as an etching gas.

[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. Either a negative photoresist or a positive photoresist can be used. A positive photoresist made of a novolac resin and a 1,2-naphthoquinone diazide sulfonic acid ester, a chemically amplified photoresist made of a binder having a group that decomposes in an acid to increase the alkaline dissolution rate and a photoacid generator, a chemically amplified photoresist made of a low molecular compound that decomposes in an acid to increase the alkaline dissolution rate of the photoresist, an alkali-soluble binder, and a photoacid generator, and a chemically amplified photoresist made of a binder having a group that decomposes in an acid to increase the alkaline dissolution rate, a low molecular compound that decomposes in an acid to increase the alkaline dissolution rate of the photoresist, and a photoacid generator. Examples of such photoresists 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. Further examples of such photoresists include fluorine-containing polymer photoresists as 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 performed 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, post exposure bake (PEB) can be performed as necessary. The post exposure bake is performed under appropriately selected conditions from a heating temperature of 70°C to 150°C and a heating time of 0.3 minutes 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 as a resist. Either a negative type or a positive type can be used as the electron beam resist. There are chemically amplified resists consisting of an acid generator and a binder having a group that decomposes with an acid to change the alkaline dissolution rate, a chemically amplified resist consisting of an alkali-soluble binder, an acid generator, and a low molecular weight compound that decomposes with an acid to change the alkaline dissolution rate of the resist, a chemically amplified resist consisting of an acid generator, a binder having a group that decomposes with an acid to change the alkaline dissolution rate, and a low molecular weight compound that decomposes with an acid to change the alkaline dissolution rate of the resist, a non-chemically amplified resist consisting of a binder having a group that decomposes with an electron beam to change the alkaline dissolution rate, and a non-chemically amplified resist consisting of a binder having a site that is cut by an electron beam to change the alkaline dissolution rate. When these electron beam resists are used, a resist pattern can be formed in the same manner as when a photoresist is used with an electron beam as the irradiation source.

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

[0104] Next, development is carried out with a developer (for example, an alkaline developer). As a result, when a positive photoresist is used, the photoresist in the exposed portion is removed, and a photoresist pattern is formed.

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

[0106] In the present invention, an organic solvent can be used as a developer. After exposure, development is performed with the developer (solvent). As a result, when a positive photoresist is used, the photoresist in the unexposed area 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, diethyl ethylene 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 development conditions are appropriately 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 (middle layer) of the present invention is removed using the pattern of the photoresist (upper layer) thus formed 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 (middle layer) of the present invention as a protective film. Finally, the semiconductor substrate is processed using the patterned resist underlayer film (middle 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 from the portion where the photoresist has been removed is removed by dry etching to expose the semiconductor substrate. For dry etching of the resist underlayer film of the present invention, gases such as tetrafluoromethane (CF4), perfluorocyclobutane (C4F8), perfluoropropane (C3F8), 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, it is preferable to use a halogen-based gas. In dry etching with a halogen-based gas, photoresists basically made of organic substances are difficult to remove. In contrast, the resist underlayer film of the present invention, which contains a large number of silicon atoms, is quickly removed by a halogen-based gas. Therefore, it is possible to suppress the decrease in the film thickness of the photoresist caused by dry etching of the resist underlayer film. As a result, it becomes possible to use the photoresist in a thin film. The dry etching of the resist underlayer film is preferably performed using a fluorine-based gas, and examples of the fluorine-based gas include tetrafluoromethane (CF4), perfluorocyclobutane (C4F8), perfluoropropane (C3F8), trifluoromethane, and difluoromethane (CH2F2).

[0110] Thereafter, the organic underlayer film is removed using the patterned photoresist and the film consisting of 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. This is preferably done by etching.

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

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

[0114] In addition, 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 thereon.

[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 a case, it can function as an anti-reflection film having 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 a function of preventing the adverse effect on the substrate of the materials used in the photoresist or the substances generated during exposure to the photoresist, a layer having a function of preventing the diffusion of substances generated from the substrate during heating and baking into the upper photoresist, and a barrier layer for reducing the poisoning effect of the photoresist layer due to the dielectric layer of the semiconductor substrate.

[0116] In addition, the resist underlayer film formed from the resist underlayer film forming composition of the present invention can be applied to a substrate having a via hole used in a dual damascene process, and can be used as a filling material capable of filling the hole without gaps. It can also be used as a planarizing material for planarizing the surface of a semiconductor substrate having irregularities.

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

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

[0119] (Synthesis Example 1) 25.2 g of tetraethoxysilane (70 mol % in total hydrolyzable silanes), 7.71 g of methyltriethoxysilane (25 mol % in total hydrolyzable silanes), 2.48 g of ethoxyethoxyphenyltrimethoxysilane (5 mol % in total 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 mixed solution with a magnetic stirrer. After the addition, the oil was adjusted to 85°C. The flask was transferred to a bath and refluxed for 240 minutes. After that, 70 g of propylene glycol monomethyl ether acetate was added, and acetone, methanol, ethanol, and water were distilled off under reduced pressure, and the mixture was concentrated to obtain an aqueous solution of hydrolysis condensate (polymer). Further, propylene glycol monomethyl ether acetate was added to adjust the solvent ratio of 100% propylene glycol monomethyl ether acetate to 20 weight percent in terms of solid residue at 140 ° C. The obtained 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) by GPC was 3000 in terms of polystyrene.

[0120] (Synthesis Example 2) 22.6g of tetraethoxysilane (70 mol% in total hydrolyzable silane), 13.3g of ethoxyethoxyphenyltrimethoxysilane (30 mol% in total hydrolyzable silane), and 53.8g of acetone were placed in a 300ml flask, and 10.3g of 0.01M aqueous nitric acid solution was added dropwise while stirring the mixed solution 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, 70g of propylene glycol monomethyl ether acetate was added, and acetone, methanol, ethanol, and water were distilled off under reduced pressure, and 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 in terms of solid residue at 140°C. The polymer obtained corresponds to formula (3-2), and then becomes a mixture of polymers corresponding to formula (3-2) and formula (4-2). The weight average molecular weight (Mw) by GPC was 2700 in terms of polystyrene.

[0121] (Synthesis Example 3) 25.5g of tetraethoxysilane (70 mol% in total hydrolyzable silanes), 7.80g of methyltriethoxysilane (25 mol% in total hydrolyzable silanes), 2.00g of methoxyphenyltrimethoxysilane (5 mol% in total hydrolyzable silanes), and 53.0g of acetone were placed in a 300ml flask, and 11.7g of 0.1M aqueous nitric acid solution was added dropwise while stirring the mixed solution 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, 70g of propylene glycol monomethyl ether acetate was added, and acetone, methanol, ethanol, and water were distilled off under reduced pressure, and 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 in terms of solid residue at 140°C. The polymer obtained corresponds to formula (3-3), and then becomes 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) 24.2g of tetraethoxysilane (70 mol% in total hydrolyzable silanes), 11.37g of methoxyphenyltrimethoxysilane (30 mol% in total hydrolyzable silanes), and 53.4g of acetone were placed in a 300ml flask, and 11.1g of 0.01M aqueous nitric acid solution was added dropwise while stirring the mixed solution 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, 70g of propylene glycol monomethyl ether acetate was added, and acetone, methanol, ethanol, and water were distilled off under reduced pressure, and 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 in terms of solid residue at 140°C. The obtained polymer corresponded to formula (3-4), and then became a mixture of polymers corresponding to formula (3-4) and formula (4-2). Weight average molecular weight by GPC ( The Mw was 2200 in terms of polystyrene.

[0123] (Synthesis Example 5) 25.5g of tetraethoxysilane (70 mol% in total hydrolyzable silanes), 7.78g of methyltriethoxysilane (25 mol% in total hydrolyzable silanes), 2.11g of methoxybenzyltrimethoxysilane (5 mol% in total hydrolyzable silanes), and 53.0g of acetone were placed in a 300ml flask, and 11.6g of 0.01M aqueous nitric acid solution was added dropwise while stirring the mixed solution 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, 70g of propylene glycol monomethyl ether acetate was added, and acetone, methanol, ethanol, and water were distilled off under reduced pressure, and 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 in terms of solid residue at 140°C. The polymer obtained corresponds to formula (3-5), and then becomes a mixture of polymers corresponding to formula (3-5) and formula (4-3). The weight average molecular weight (Mw) by GPC was 2400 in terms of polystyrene.

[0124] (Synthesis Example 6) 23.8g of tetraethoxysilane (70 mol% in total hydrolyzable silanes), 11.9g of methoxybenzyltrimethoxysilane (30 mol% in total hydrolyzable silanes), and 53.5g of acetone were placed in a 300ml flask, and 10.8g of 1M aqueous nitric acid solution was added dropwise while stirring the mixed solution 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, 70g of propylene glycol monomethyl ether acetate was added, and acetone, methanol, ethanol, and water were distilled off under reduced pressure, and 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 in terms of solid residue at 140°C. The obtained polymer corresponded to formula (3-6), and 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 3,500 in terms of polystyrene.

[0125] (Synthesis Example 7) 24.9g of tetraethoxysilane (70 mol% in total hydrolyzable silanes), 7.61g of methyltriethoxysilane (25 mol% in total hydrolyzable silanes), 2.94g of triethoxy((2-methoxy-4-(methoxymethyl)phenoxy)methyl)silane (5 mol% in total hydrolyzable silanes), and 53.2g of acetone were placed in a 300ml flask, and 11.4g of 0.01M aqueous nitric acid solution was added dropwise while stirring the mixed solution 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, 70g of propylene glycol monomethyl ether acetate was added, and acetone, methanol, ethanol, and water were distilled off under reduced pressure, and 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 of 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 (30 mol% in total hydrolyzable silane), 54.2 g of acetone 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 mixed solution 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, and the solution was concentrated to obtain an aqueous solution of hydrolysis condensate (polymer). Further, propylene glycol monomethyl ether acetate was added, and the solvent ratio of propylene glycol monomethyl ether acetate was adjusted to 20 weight percent in terms of solid residue at 140 ° C. as 100%. The obtained polymer corresponded to formula (3-8), and then became a mixture of polymers corresponding to formula (3-8), formula (4-6), and formula (4-8). The weight average molecular weight (Mw) by GPC was 2500 in terms of polystyrene.

[0127] (Comparative Synthesis Example 1) 25.8g of tetraethoxysilane, 9.5g of triethoxymethylsilane, and 52.9g of acetone were placed in a 300ml flask, and 11.8g of 0.01M aqueous hydrochloric acid solution was added dropwise to the mixed solution while stirring the mixed solution 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, 70g of propylene glycol monomethyl ether acetate was added, and acetone, methanol, ethanol, and water were distilled off under reduced pressure, and the solution was concentrated to obtain an aqueous solution of hydrolysis condensate (polymer). Further, propylene glycol monomethyl ether acetate was added and adjusted to 20 weight percent in terms of solid residue at 140°C. The obtained polymer corresponds to formula (5-1), and the weight average molecular weight (Mw) 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 mixed solution while stirring it with a magnetic stirrer. After the addition, the flask was transferred to an oil bath adjusted to 85°C, and then acetone was added to adjust the concentration and refluxed for 240 minutes. After that, a white precipitate was generated 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 the GPC spectrum change. As a result, those with a molecular weight change of 10% or less were rated as good, and those with a change of 10% or more were 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 ratio of polymer added in the table indicates the amount of polymer itself added, not the amount of polymer solution added. In the table, ultrapure water was used as water. 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, 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, carbazole (6.69g, 0.040mol, manufactured by Tokyo Chemical Industry Co., Ltd.), 9-fluorenone (7.28g, 0.040mol, manufactured by Tokyo Chemical Industry Co., Ltd.), and paratoluenesulfonic acid monohydrate (0.76g, 0.0040mol, manufactured by Tokyo Chemical Industry Co., Ltd.) were added to a 100ml four-neck flask, and 1,4-dioxane (6.69g, manufactured by Kanto Chemical Co., Ltd.) was charged and stirred, and the temperature was raised to 100°C to dissolve and initiate polymerization. After 24 hours, the mixture was allowed to cool to 60°C, and then chloroform (34g, manufactured by Kanto Chemical Co., Ltd.) was added to dilute the mixture, and the mixture was reprecipitated in methanol (168g, manufactured by Kanto Chemical Co., Ltd.). The resulting precipitate was filtered and dried in a vacuum dryer at 80°C for 24 hours to obtain 9.37g of the target polymer (formula (3-1), hereinafter abbreviated as PCzFL). [ka] PCzFL 1 The H-NMR measurement results 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: Mw (weight average molecular weight) / Mn (number average molecular weight) was 1.77. . 20 g of the obtained resin was mixed with 3.0 g of tetramethoxymethylglycoluril (manufactured by Mitsui Cytec Co., Ltd., product name Powder Link 1174) as a crosslinking agent, 0.30 g of pyridinium paratoluenesulfonate as a catalyst, and 0.06 g of Megafac R-30 (manufactured by DIC Co., Ltd., product name) as a surfactant, and dissolved in 88 g of propylene glycol monomethyl ether acetate to obtain 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 (A layer) forming composition used in a lithography process using a multilayer film.

[0134] [Solvent resistance test] The resist underlayer film forming compositions prepared in Examples 1 to 8 and Comparative Examples 1 and 2 were applied onto a silicon wafer using a spinner. The compositions were heated on a hot plate at 215°C for 1 minute to form resist underlayer films. Thereafter, a solvent of propylene glycol monomethyl ether / propylene glycol monomethyl ether acetate = 7 / 3 (mass ratio) was applied onto the resist underlayer film, which was then spin-dried, and 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 as "good," and films with a film thickness change of 1% or more were rated as "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 onto a silicon wafer using a spinner. Each was heated on a hot plate at 215° C. for 1 minute to form a resist underlayer film. Then, an alkaline developer (a 2.38% aqueous solution of TMAH (TMAH stands for tetramethylammonium hydroxide)) was applied onto the resist underlayer film, which was then spin-dried, and 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 as "good," and films with a film thickness change of 1% or more were rated as "not cured." The results are also shown in Table 4.

[0136] [Table 4]

[0137] [Formation of resist patterns by EUV exposure: positive alkaline development] The organic underlayer film (A layer) forming composition was applied onto a silicon wafer and baked on a hot plate at 215°C for 60 seconds to obtain an organic underlayer film (A layer) having a film thickness of 90 nm. The resist underlayer film forming composition solution prepared in Examples 1 to 8 and Comparative Example 2 was 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 onto the resist underlayer film (hard mask) and heated to form an EUV resist layer (C) layer, and exposed under conditions of NA = 0.33, σ = 0.67 / 0.90, cQuad using an ASML EUV exposure device (NXE3300B). After exposure, PEB was performed, the film was 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 of the pattern shape by observing the cross section of the pattern. The results are shown in Table 5. In Table 5, "good" refers to a shape between footing and undercut with no significant residue in the space, "collapsed" refers to an undesirable state in which the resist pattern has peeled off and collapsed, and "bridged" refers to an undesirable state in which the upper or lower parts of the resist pattern are in contact with each other.

[0138] [Table 5]

[0139] [Formation of resist pattern by EUV exposure: negative-tone solvent development] The organic underlayer film (A layer) forming composition was applied onto a silicon wafer and baked on a hot plate at 215°C for 60 seconds to obtain an organic underlayer film (A layer) having a film thickness of 90 nm. The resist underlayer film forming composition solution prepared in Examples 1 to 8 and Comparative Example 2 was 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 onto the resist underlayer film (hard mask) and heated to form an EUV resist layer (C) layer, and exposed under conditions of NA = 0.33, σ = 0.67 / 0.90, and Dipole using an ASML EUV exposure device (NXE3300B). After exposure, PEB was performed, the film was 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 20 nm lines and spaces 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" refers to a shape between footing and undercut with no significant residue in the space, "collapsed" refers to an undesirable state in which the resist pattern has peeled off and collapsed, and "bridged" refers to 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 resist underlayer film-forming composition for lithography can be used in the production of a semiconductor device, and can provide a resist underlayer film-forming composition for lithography for forming a resist underlayer film that can be used as a hard mask.

Claims

1. A resist underlayer film-forming composition for lithography, comprising a hydrolysis condensate (c) obtained by hydrolysis condensation of a hydrolyzable silane (a) using nitric acid as a hydrolysis catalyst, nitrate ions derived from the nitric acid, and a solvent, The nitrate ion is contained in the composition in a range of 1 ppm to 1000 ppm, The hydrolyzable silane (a) has the formula (1): 【Chemistry 1】 [In formula (1), R １ is expressed by the formula (2): 【Chemistry 2】 (In formula (2), X represents an oxygen atom, a sulfur atom, or a nitrogen atom; R ４ represents a single bond, 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 R represents an alkyl group having 1 to 10 carbon atoms, n1 represents 1≦n1≦5, 0≦n2≦(5-n1), n3 represents 0, and * represents the bonding position to the silicon atom.) and is bonded to the silicon atom by a Si-C bond. ２ 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 connected to a silicon atom by a Si-C bond. It is bonded. 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.], on a semiconductor substrate, and baking the composition to form a resist underlayer film, a step of applying a resist composition on the underlayer film to form a resist layer, a step of exposing the resist layer, a step of developing the resist after exposure to obtain a resist pattern, a step of etching the resist underlayer film with the resist pattern, and a step of processing a semiconductor substrate with the patterned resist layer and the resist underlayer film.

2. A process for forming an organic underlayer film on a semiconductor substrate, and forming on the organic underlayer film a composition for forming a resist underlayer film for lithography, the composition comprising: a hydrolysis condensate (c) obtained by hydrolyzing and condensing a hydrolyzable silane (a) using nitric acid as a hydrolysis catalyst; nitrate ions derived from the nitric acid; and a solvent, The nitrate ion is contained in the composition in a range of 1 ppm to 1000 ppm, The hydrolyzable silane (a) has the formula (1): 【Chemistry 3】 [In formula (1), R １ is expressed by the formula (2): 【Chemistry 4】 (In formula (2), X represents an oxygen atom, a sulfur atom, or a nitrogen atom; R ４ represents a single bond, 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 R represents an alkyl group having 1 to 10 carbon atoms, n1 represents 1≦n1≦5, 0≦n2≦(5-n1), n3 represents 0, 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.], and baking the composition to form a resist underlayer film, a step of applying a resist composition on the resist underlayer film to form a resist layer, a step of exposing the resist layer, a step of developing the resist after exposure to obtain a resist pattern, a step of etching the resist underlayer film with the resist pattern, a step of etching the organic underlayer film with the patterned resist underlayer film, and a step of processing a semiconductor substrate with the patterned organic underlayer film.

3. 3. The method for producing a semiconductor device according to claim 1, further comprising: (a) a hydrolyzable silane and / or (b) a hydrolyzate thereof.

4. The hydrolysis condensation product (c) is a product of the hydrolysis silane of the formula (1) in which the functional group of the formula (2) is (hydrogen atom) / (hydrogen atom + R ５ 4. The method for manufacturing a semiconductor device according to claim 1, wherein the molar ratio of the aryl group to the alkyl group is 1% to 100%.

5. 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): 【Chemistry 5】 (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 formula (4): 【Chemistry 6】 (In formula (4), R ９ is an alkyl group bonded to a silicon atom by a Si-C bond, 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.

6. 6. The method for producing a semiconductor device according to claim 5, comprising, as a polymer, a hydrolysis condensate of hydrolyzable silanes comprising a combination of the hydrolyzable silane of formula (1) of claim 1 or 2 and the hydrolyzable silane of formula (3) of claim 5.

7. 7. The method for manufacturing a semiconductor device according to claim 1, further comprising an additive selected from the group consisting of water, acid, a photoacid generator, a surfactant, a metal oxide, and a combination thereof.

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