Underlayer film material for self-assembling material

Abstract

An underlayer film, which is a backed product of a coating film of an underlayer film-forming composition, wherein the underlayer film-forming composition contains a polysiloxane that is a hydrolytic condensate of a hydrolyzable silane, the hydrolyzable silane contains a compound represented by formula (1) and may contain a compound represented by formula (2), the mole fraction of the compound represented by formula (1) in the hydrolyzable silane is 45 mol% or more, and the total mole fraction of the compound represented by formula (1) and the compound represented by formula (2) in the hydrolyzable silane is 65 mol% or more (including the case in which the mole fraction of the compound represented by formula (2) in the hydrolyzable silane is 0 mol%). (In formula (1), Ar represents an aromatic hydrocarbon group which may have a substituent. n represents an integer of 1-3. When n is 1, Ra represents a single bond or C1-C6 alkylene group. When n is 2 or 3, Ra represents an (n +1)-valent saturated C1-C6 hydrocarbon group. Each X independently represents a hydrolyzable group. When n is 2 or 3, a plurality of Ar's may be the same or different.) (In formula (2), Rb represents a non-aromatic C1-C6 hydrocarbon group. Each X independently represents a hydrolyzable group.)

Description

Underlayer materials for self-organizing materials

[0001] The present invention relates to a composition for forming an underlayer film and an underlayer film used in lithography using a resist film and a self-assembled film, and a method for manufacturing a semiconductor device using the same.

[0002]

[0003] In recent years, with the further miniaturization of large-scale integrated circuits (LSIs), there has been a demand for techniques for processing ever more delicate structures. In response to this demand, attempts have been made to form ever finer patterns by utilizing phase-separated structures formed by the self-assembly of block copolymers in which mutually incompatible polymers are bonded. For example, a pattern formation method has been proposed in which an underlayer film-forming composition is applied to a substrate to form an underlayer film made of the composition, a self-assembled film containing a block copolymer in which two or more polymers are bonded is formed on the surface of the underlayer film, the block copolymer in the self-assembled film is phase-separated, and at least one polymer phase of the polymers constituting the block copolymer is selectively removed.

[0003] Patent Document 1 discloses a composition for forming an underlayer film of a self-assembled film, which contains a polysiloxane and a solvent.

[0004] Patent Document 2 discloses a method for forming a microelectronic structure using directed self-assembly, the method including: providing a wafer stack, the stack including: a substrate having a surface; one or more optional intermediate layers on the substrate surface; and a hard mask layer adjacent to the intermediate layer if present, or on the substrate surface if no intermediate layer is present; and applying a self-assembling composition directly to the hard mask layer, the self-assembling composition self-assembling into a self-assembling layer directly adjacent to the hard mask layer, wherein the self-assembling layer includes a first self-assembled region and a second self-assembled region different from the first self-assembled region.

[0005] International Publication No. 2013 / 146600 Pamphlet Special Publication No. 2015-516686

[0006] When performing microfabrication using a self-assembled monolayer, a resist (photoresist, electron beam resist) that is used in conventional microfabrication may be used in combination. In this case, when the underlayer of the resist film also serves as the underlayer of the self-assembled monolayer, the underlayer is required to be able to form a vertical alignment in the self-assembled monolayer even when exposed to light exposure and development during resist pattern formation.

[0007] The present invention aims to provide an underlayer film that serves as both an underlayer film for a resist film and an underlayer film for a self-assembled film, and that can form a vertical alignment in the self-assembled film even when exposed to light exposure and development during resist pattern formation; an underlayer film-forming composition that can form the underlayer film; and a method for manufacturing a semiconductor element using the underlayer film-forming composition.

[0008] The present inventors have conducted extensive research to solve the above problems, and as a result have found that the above problems can be solved, and have completed the present invention having the following gist.

[0009] That is, the present invention encompasses the following: [1] An underlayer film that is a product obtained by baking a coating film of a composition for forming an underlayer film, which is used as an underlayer film for a resist film, either a photoresist film or an electron beam resist film, in lithography using a resist film and a self-assembled film, and then is further used as an underlayer film for the self-assembled film, the composition for forming an underlayer film contains a polysiloxane that is a hydrolysis condensate of a hydrolyzable silane, the hydrolyzable silane includes a compound represented by the following formula (1) and optionally includes a compound represented by the following formula (2), the molar ratio of the compound represented by formula (1) in the hydrolyzable silane is 45 mol % or more, and the total molar ratio of the compound represented by formula (1) and the compound represented by formula (2) in the hydrolyzable silane is 65 mol % or more (note that this includes the case where the molar ratio of the compound represented by formula (2) in the hydrolyzable silane is 0 mol %). In formula (1), Ar represents an aromatic hydrocarbon group which may have a substituent. n represents an integer of 1 to 3. When n is 1, R ａ represents a single bond or an alkylene group having 1 to 6 carbon atoms. When n is 2 or 3, Rａ represents a saturated hydrocarbon group having 1 to 6 carbon atoms and a valence of (n+1). Each X independently represents a hydrolyzable group. When n is 2 or 3, the multiple Ar's may be the same or different. (In formula (2), R ｂ represents a non-aromatic hydrocarbon group having 1 to 6 carbon atoms. Each X independently represents a hydrolyzable group. [2] In the formula (1), n ​​is 1, and R ａrepresents an alkylene group having 1 to 6 carbon atoms. [3] The underlayer film according to [2], wherein the molar ratio of the compound represented by formula (1) in the hydrolyzable silane is 65 mol % or more. [4] The underlayer film according to any one of [1] to [3], wherein the combined molar ratio of the compound represented by formula (1) and the compound represented by formula (2) in the hydrolyzable silane is 80 mol % or more (including the case where the molar ratio of the compound represented by formula (2) in the hydrolyzable silane is 0 mol %). [5] The underlayer film according to any one of [1] to [4], wherein the resist film is formed from a positive development resist. [6] The underlayer film according to any one of [1] to [5], wherein the self-assembled film is a film containing a block copolymer. [7] The underlayer film according to any one of [1] to [6], wherein the film thickness is 30 nm or less. [8] In lithography using a resist film, either a photoresist film or an electron beam resist film, and a self-assembled film, a composition for forming an underlayer film is used as an underlayer film for the resist film, and then is used as an underlayer film for the self-assembled film, the composition containing a polysiloxane that is a hydrolysis condensate of a hydrolyzable silane, the hydrolyzable silane containing a compound represented by the following formula (1) and optionally containing a compound represented by the following formula (2), the molar ratio of the compound represented by formula (1) in the hydrolyzable silane being 45 mol% or more, and the combined molar ratio of the compound represented by formula (1) and the compound represented by formula (2) in the hydrolyzable silane being 65 mol% or more (including the case where the molar ratio of the compound represented by formula (2) in the hydrolyzable silane is 0 mol%). In formula (1), Ar represents an aromatic hydrocarbon group which may have a substituent. n represents an integer of 1 to 3. When n is 1, R ａ represents a single bond or an alkylene group having 1 to 6 carbon atoms. When n is 2 or 3, R ａrepresents a saturated hydrocarbon group having 1 to 6 carbon atoms and a valence of (n+1). Each X independently represents a hydrolyzable group. When n is 2 or 3, the multiple Ar's may be the same or different. (In formula (2), R ｂ represents a non-aromatic hydrocarbon group having 1 to 6 carbon atoms. Each X independently represents a hydrolyzable group. [9] In the above (1), n ​​is 1, and R ａrepresents an alkylene group having 1 to 6 carbon atoms.

[10] The composition for forming an underlayer film according to [9], wherein the molar ratio of the compound represented by formula (1) in the hydrolyzable silane is 65 mol % or more.

[11] The composition for forming an underlayer film according to any one of [8] to

[10] , wherein the total molar ratio of the compound represented by formula (1) and the compound represented by formula (2) in the hydrolyzable silane is 80 mol % or more (including the case where the molar ratio of the compound represented by formula (2) in the hydrolyzable silane is 0 mol %).

[12] The composition for forming an underlayer film according to any one of [8] to

[11] , wherein the resist film is formed from a positive development resist.

[13] The composition for forming an underlayer film according to any one of [8] to

[12] , wherein the self-assembled film is a film containing a block copolymer.

[14] The composition for forming an underlayer film according to any one of [8] to

[13] , wherein the film thickness of the underlayer film is 30 nm or less.

[15] A method for manufacturing a semiconductor device, comprising: forming an underlayer film on a semiconductor substrate using the composition for forming an underlayer film according to any one of [8] to

[14] ; forming a resist film, which is either a photoresist film or an electron beam resist film, on the underlayer film; irradiating the resist film with light or an electron beam and then developing the resist film to obtain a resist pattern; and, after the step of obtaining the resist pattern, forming a self-assembled film on at least a portion of the underlayer film.

[16] The method for manufacturing a semiconductor device according to

[15] , wherein the step of forming the self-assembled film is a step of forming a self-assembled film between the resist patterns and on at least a portion of the underlayer film.

[17] The method for manufacturing a semiconductor device according to

[15] , comprising, between the step of obtaining the resist pattern and the step of forming the self-assembled film, a step of forming a brush layer between the resist patterns and on at least a portion of the underlayer film, in this order.

[18] The method for manufacturing a semiconductor element according to

[17] , further comprising, between the step of obtaining the resist pattern and the step of forming the brush layer, a step of performing surface modification by a dry process on the underlayer film exposed between the resist patterns.

[19] The method for manufacturing a semiconductor element according to

[15] , comprising, between the step of obtaining the resist pattern and the step of forming the self-assembled film, a step of surface-modifying the underlayer film exposed between the resist patterns by a dry process, and a step of removing the resist pattern, in this order.

[0010] According to the present invention, it is possible to provide an underlayer film that serves as both an underlayer film for a resist film and an underlayer film for a self-assembled film, and that can form a vertical alignment in the self-assembled film even when exposed to light exposure and development during resist pattern formation; an underlayer film-forming composition capable of forming the underlayer film; and a method for manufacturing a semiconductor element using the underlayer film-forming composition.

[0011] FIG. 1A is a cross-sectional view (part 1) illustrating an example of a method for manufacturing a semiconductor element of the present invention. FIG. 1B is a cross-sectional view (part 2) illustrating an example of a method for manufacturing a semiconductor element of the present invention. FIG. 1C is a cross-sectional view (part 3) illustrating an example of a method for manufacturing a semiconductor element of the present invention. FIG. 1D is a cross-sectional view (part 4) illustrating an example of a method for manufacturing a semiconductor element of the present invention. FIG. 1E is a cross-sectional view (part 5) illustrating an example of a method for manufacturing a semiconductor element of the present invention. FIG. 1F is a cross-sectional view (part 6) illustrating an example of a method for manufacturing a semiconductor element of the present invention. FIG. 2A is a cross-sectional view (part 1) illustrating another example of a method for manufacturing a semiconductor element of the present invention. FIG. 2B is a cross-sectional view (part 2) illustrating another example of a method for manufacturing a semiconductor element of the present invention. FIG. 2C is a cross-sectional view (part 3) illustrating another example of a method for manufacturing a semiconductor element of the present invention. FIG. 2D is a cross-sectional view (part 4) illustrating another example of a method for manufacturing a semiconductor element of the present invention. FIG. 2E is a cross-sectional view (part 5) illustrating another example of a method for manufacturing a semiconductor element of the present invention. FIG. 2F is a cross-sectional view (No. 6) illustrating another example of the method for manufacturing a semiconductor element of the present invention. FIG. 2G is a cross-sectional view (No. 7) illustrating another example of the method for manufacturing a semiconductor element of the present invention. FIG. 2H is a cross-sectional view (No. 8) illustrating another example of the method for manufacturing a semiconductor element of the present invention. FIG. 3A is a cross-sectional view (No. 1) illustrating another example of the method for manufacturing a semiconductor element of the present invention. FIG. 3B is a cross-sectional view (No. 2) illustrating another example of the method for manufacturing a semiconductor element of the present invention. FIG. 3C is a cross-sectional view (No. 3) illustrating another example of the method for manufacturing a semiconductor element of the present invention. FIG. 3D is a cross-sectional view (No. 4) illustrating another example of the method for manufacturing a semiconductor element of the present invention. FIG. 3E is a cross-sectional view (No. 5) illustrating another example of the method for manufacturing a semiconductor element of the present invention. FIG. 3F is a cross-sectional view (No. 6) illustrating another example of the method for manufacturing a semiconductor element of the present invention. FIG. 3G is a cross-sectional view (No. 7) illustrating another example of the method for manufacturing a semiconductor element of the present invention. FIG. 3H is a cross-sectional view (No. 8) illustrating another example of the method for manufacturing a semiconductor element of the present invention.FIG. 3I is a cross-sectional view illustrating another example of the method for manufacturing a semiconductor element of the present invention (No. 9). FIG. 4A is a cross-sectional view illustrating another example of the method for manufacturing a semiconductor element of the present invention (No. 1). FIG. 4B is a cross-sectional view illustrating another example of the method for manufacturing a semiconductor element of the present invention (No. 2). FIG. 4C is a cross-sectional view illustrating another example of the method for manufacturing a semiconductor element of the present invention (No. 3). FIG. 4D is a cross-sectional view illustrating another example of the method for manufacturing a semiconductor element of the present invention (No. 4). FIG. 4E is a cross-sectional view illustrating another example of the method for manufacturing a semiconductor element of the present invention (No. 5). FIG. 4F is a cross-sectional view illustrating another example of the method for manufacturing a semiconductor element of the present invention (No. 6). FIG. 4G is a cross-sectional view illustrating another example of the method for manufacturing a semiconductor element of the present invention (No. 7). FIG. 4H is a cross-sectional view illustrating another example of the method for manufacturing a semiconductor element of the present invention (No. 8). FIG. 5 is an electron microscope (SEM) photograph of the microphase-separated structure of a self-assembled film prepared using self-assembled film-forming composition 1 in Comparative Example 1. FIG. 6 is an SEM photograph of the microphase-separated structure of the self-assembled film produced using self-assembled film-forming composition 1 in Example 2-5.

[0012] The underlayer film of the present invention is a fired product of a coating film of a composition for forming an underlayer film. Therefore, the underlayer film of the present invention will be described after explaining the composition for forming an underlayer film.

[0013] (Composition for forming an underlayer film) The composition for forming an underlayer film of the present invention is a composition for forming an underlayer film for forming an underlayer film. The underlayer film is used as an underlayer film for a resist film in lithography using a resist film, either a photoresist film or an electron beam resist film, and a self-assembled film, and then is used as an underlayer film for the self-assembled film. The composition for forming an underlayer film of the present invention contains a polysiloxane. The polysiloxane is a hydrolysis condensate of a hydrolyzable silane. The hydrolyzable silane includes a compound represented by the following formula (1) and may also include a compound represented by the following formula (2). The molar proportion of the compound represented by formula (1) in the hydrolyzable silane is 45 mol% or more. The combined molar proportion of the compound represented by formula (1) and the compound represented by formula (2) in the hydrolyzable silane is 65 mol% or more (including the case where the molar proportion of the compound represented by formula (2) in the hydrolyzable silane is 0 mol%). In formula (1), Ar represents an aromatic hydrocarbon group which may have a substituent. n represents an integer of 1 to 3. When n is 1, R ａ represents a single bond or an alkylene group having 1 to 6 carbon atoms. When n is 2 or 3, R ａ represents a saturated hydrocarbon group having 1 to 6 carbon atoms and a valence of (n+1). Each X independently represents a hydrolyzable group. When n is 2 or 3, the multiple Ar's may be the same or different. (In formula (2), R ｂ represents a non-aromatic hydrocarbon group having 1 to 6 carbon atoms. Each X independently represents a hydrolyzable group.

[0014] Even in an underlayer film capable of forming a vertical alignment in a self-assembled film, exposure to light or development of the underlayer film may result in a decrease in the alignment of the self-assembled film. By including a certain amount of the compound represented by formula (1) as a constituent component in the polysiloxane contained in the composition for forming an underlayer film, it is possible to obtain an underlayer film capable of forming a vertical alignment in a self-assembled film even when exposed to light or development during resist pattern formation. Furthermore, the polysiloxane may also include a certain amount of the compound represented by formula (2) as a constituent component, in total with the compound represented by formula (1). The reason why an underlayer film capable of forming a vertical alignment in a self-assembled film even when exposed to light or development during resist pattern formation can be obtained is that (Ar) in the compound represented by formula (1) ｎ -R ａ group and R in the compound represented by formula (2) ｂ The present inventors believe that this is because the group is resistant to alteration even when exposed to light or development.

[0015] <Polysiloxane> The polysiloxane is a hydrolysis condensate of a hydrolyzable silane. The hydrolyzable silane contains a compound represented by the following formula (1) and may contain a compound represented by the following formula (2). The molar ratio of the compound represented by formula (1) in the hydrolyzable silane is 45 mol% or more. The total molar ratio of the compound represented by formula (1) and the compound represented by formula (2) in the hydrolyzable silane is 65 mol% or more (including the case where the molar ratio of the compound represented by formula (2) in the hydrolyzable silane is 0 mol%). In formula (1), Ar represents an aromatic hydrocarbon group which may have a substituent. n represents an integer of 1 to 3. When n is 1, R ａ represents a single bond or an alkylene group having 1 to 6 carbon atoms. When n is 2 or 3, R ａ represents a saturated hydrocarbon group having 1 to 6 carbon atoms and a valence of (n+1). Each X independently represents a hydrolyzable group. When n is 2 or 3, the multiple Ar's may be the same or different. (In formula (2), R ｂ represents a non-aromatic hydrocarbon group having 1 to 6 carbon atoms. Each X independently represents a hydrolyzable group.

[0016] <<Ar in Formula (1)>> The aromatic hydrocarbon ring in the aromatic hydrocarbon group of Ar in Formula (1) may be a monocyclic ring, a fused ring, or a polycyclic ring formed by two or more monocyclic rings bonded together by a single bond. Examples of aromatic hydrocarbon rings include a benzene ring, a naphthalene ring, a biphenyl ring, an anthracene ring, and a phenanthrene ring. Examples of aromatic hydrocarbon groups of Ar in Formula (1) include a monovalent group formed by removing one hydrogen atom from a benzene ring, a naphthalene ring, a biphenyl ring, an anthracene ring, or a phenanthrene ring. Examples of substituents on Ar in Formula (1) include a halogen atom, a hydroxy group, a carboxy group, a cyano group, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, and an alkoxyalkyl group having a total of 2 to 6 carbon atoms. Among these, alkyl groups having 1 to 6 carbon atoms and alkenyl groups having 2 to 6 carbon atoms are preferred from the viewpoint of optimally achieving the effects of the present invention. When Ar has two or more substituents, the two or more substituents may be the same or different. In addition, from the viewpoint of suitably obtaining the effects of the present invention, Ar is preferably unsubstituted. That is, Ar preferably represents an aromatic hydrocarbon group.

[0017] <<R in formula (1) ａ >> When n is 1, R in formula (1) ａ is a single bond or an alkylene group having 1 to 6 carbon atoms. When n is 2 or 3, R ａis an (n+1)-valent saturated hydrocarbon group having 1 to 6 carbon atoms. The alkylene group having 1 to 6 carbon atoms may be linear or branched. The alkylene group may have 1 to 4 carbon atoms. Examples of alkylene groups having 1 to 6 carbon atoms include methylene, ethylene, trimethylene, tetramethylene, pentamethylene, and hexamethylene. The (n+1)-valent saturated hydrocarbon group having 1 to 6 carbon atoms is a trivalent saturated hydrocarbon group when n is 2, and a tetravalent saturated hydrocarbon group when n is 3. The carbon chain constituting the saturated hydrocarbon group may be linear or branched. n is preferably 1. R in formula (1) ａ As the alkylene group, an alkylene group having 1 to 6 carbon atoms is preferred, and an alkylene group having 1 to 4 carbon atoms is more preferred, since the alignment of the self-assembled film is excellent even after the underlayer film is exposed to light or development.

[0018] <<X in Formula (1) and Formula (2)>> X in Formula (1) and Formula (2) is a hydrolyzable group. Examples of the hydrolyzable group include an alkoxy group, an aralkyloxy group, an acyloxy group, and a halogen atom.

[0019] Examples of the alkoxy group include linear, branched, and cyclic alkoxy groups having at least one alkyl moiety and having 1 to 20 carbon atoms. Examples of the linear or branched alkoxy group include methoxy, ethoxy, n-propoxy, i-propoxy, n-butoxy, i-butoxy, s-butoxy, t-butoxy, n-pentyloxy, 1-methyl-n-butoxy, 2-methyl-n-butoxy, 3-methyl-n-butoxy, 1,1-dimethyl-n-propoxy, 1,2-dimethyl-n-propoxy, 2,2-dimethyl-n-propoxy, 1-ethyl-n-propoxy, n-hexyloxy, 1-methyl-n-pentyloxy, 2-methyl-n-pentyl ... 1,1-dimethyl-n-propoxy, 1,1-dimethyl-n-propoxy, 1,1-dimethyl-n-propoxy, 1,1-dimethyl-n-pentyloxy, 2-methyl-n-pentyloxy, 3-methyl-n-butoxy, 1,1-dimethyl-n-propoxy, 1,1-dimethyl-n-propoxy, 1,1-dimethyl-n-propoxy, 1,1-dimethyl-n-propoxy, 1,1-dimethyl-n-propoxy, 1,1-dimethyl-n-pentyloxy, 1,1-dimethyl-n-pentyloxy, 1,1-dimethyl-n-pentyloxy, 1 Examples include a methyl-n-pentyloxy group, a 4-methyl-n-pentyloxy group, a 1,1-dimethyl-n-butoxy group, a 1,2-dimethyl-n-butoxy group, a 1,3-dimethyl-n-butoxy group, a 2,2-dimethyl-n-butoxy group, a 2,3-dimethyl-n-butoxy group, a 3,3-dimethyl-n-butoxy group, a 1-ethyl-n-butoxy group, a 2-ethyl-n-butoxy group, a 1,1,2-trimethyl-n-propoxy group, a 1,2,2-trimethyl-n-propoxy group, a 1-ethyl-1-methyl-n-propoxy group, and a 1-ethyl-2-methyl-n-propoxy group.

[0020] The aralkyloxy group is a monovalent group derived by removing a hydrogen atom from the hydroxy group of an aralkyl alcohol. The number of carbon atoms in the aralkyloxy group is not particularly limited, but can be, for example, 40 or less, preferably 30 or less, and more preferably 20 or less.

[0021] An acyloxy group is a monovalent group derived by removing a hydrogen atom from the carboxyl group (—COOH) of a carboxylic acid compound, and typical examples include, but are not limited to, alkylcarbonyloxy groups, arylcarbonyloxy groups, and aralkylcarbonyloxy groups, which are derived by removing a hydrogen atom from the carboxyl group of an alkylcarboxylic acid, arylcarboxylic acid, or aralkylcarboxylic acid. Specific examples of the acyloxy group include acyloxy groups having 2 to 20 carbon atoms.

[0022] Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0023] <<R in formula (2) ｂ >> R in formula (2) ｂrepresents a non-aromatic hydrocarbon group having 1 to 6 carbon atoms. Examples of the non-aromatic hydrocarbon group include saturated aliphatic hydrocarbon groups and unsaturated aliphatic hydrocarbon groups. The saturated aliphatic hydrocarbon group is an alkyl group having 1 to 6 carbon atoms. The alkyl group having 1 to 6 carbon atoms may be linear, branched, or cyclic, 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, n-hexyl group, 1-methyl-n-pentyl group, 2-methyl-n-pentyl group, 3-methyl-n-pentyl group, 4-methyl-n-pentyl group, 1,1-dimethyl-n-butyl group, 1,2-dimethyl-n-butyl group, 1,3-dimethyl-n-butyl group, 2,2-dimethyl-n-butyl group, 2,3-dimethyl-n-butyl group, 3,3-dimethyl-n-butyl group, 1-ethyl-n-butyl group, 2-ethyl-n-butyl group, 1,1,2-trimethyl-n-propyl group, 1,2,Examples of the aliphatic unsaturated hydrocarbon group include an alkenyl group having 2 to 6 carbon atoms and an alkynyl group having 2 to 6 carbon atoms. Specific examples of the alkenyl group having 2 to 6 carbon atoms include ethenyl (vinyl), 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, and 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-cyclo pentenyl 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 ethyl-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 1-methyl-2-propenyl group, 1-ethyl-2-methyl-1-propenyl group, 1-ethyl-2-methyl-2-propenyl group, 1-i-propyl-1-propenyl group, 1-i-propyl-2-propenyl group, 1-methyl-2-cyclopentenyl group, 1-methyl-3-cyclopentenyl group, 2-methyl-1-cyclopentenyl group, 2-methyl-2-cyclopentenyl group, 2-methyl-3-cyclopentenyl group, 2-methyl-4-cyclopentenyl group, 2-methyl-5-cyclopentenyl group, 2-methyl-6-cyclopentenyl group, 2-methyl-7-cyclopentenyl group, 2-methyl-8-cyclopentenyl group, 2-methyl-9-cyclopentenyl group, 2-methyl-10-cyclopentenyl group, 2-methyl-11-cyclopentenyl group, 2-methyl-12-cyclopentenyl group, 2-methyl-13-cyclopentenyl group, 2-methyl-14-cyclopentenyl group, 2-methyl-15-cyclopentenyl group, 2-methyl-16-cyclopentenyl group, 2-methyl-17-cyclopentenyl group, 2-methyl-18-cyclopentenyl group, 2-methyl-19-cyclopentenyl group, 2-methyl-20-cyclopentenyl group, 2-methyl-21-cyclopentenyl group, 2-methyl-22-cyclopentenyl group, 2-methyl-23-cyclopentenyl group, 2-methyl-24-cyclopentenyl group, 2-methyl-25-cyclopentenyl group, 2-methyl-26-cyclopentenyl group, 2-methyl-27-cyclopentenyl group, 2-methyl-28-cyclopentenyl group, 2-methyl-29-cyclopentenyl group, 2-methyl-21-cyclopentenyl group, 2 Examples of the alkynyl group having 2 to 6 carbon atoms include ethynyl, 1-propynyl, 2-propynyl, butynyl, pentynyl, and hexynyl groups.

[0024] Examples of the compound represented by formula (1) include compounds represented by the following formula (1-1): (In formula (1-1), R ａ represents a single bond or an alkylene group having 1 to 6 carbon atoms. ｃrepresents a substituent. Each X independently represents a hydrolyzable group. n represents an integer of 0 to 5. When n is 2 or more, two or more R ｃ may be the same or different.)

[0025] n represents an integer of 0 to 5, with 0 being preferred.

[0026] Examples of the compound represented by formula (1) include the following compounds: (In the formula, each X independently represents a hydrolyzable group.)

[0027] Examples of the compound represented by formula (2) include the following compounds: (In the formula, each X independently represents a hydrolyzable group.)

[0028] The molar ratio of the compound represented by formula (1) in the hydrolyzable silane may be 45 mol% or more, or 65 mol% or more. The molar ratio of the compound represented by formula (1) in the hydrolyzable silane may be 100 mol% or less, or may be 100 mol%. R in formula (1) ａ When represents an alkylene group having 1 to 6 carbon atoms, the molar ratio of the compound represented by formula (1) in the hydrolyzable silane is preferably 65 mol % or more, from the viewpoint of more suitably achieving the effects of the present invention.

[0029] The total molar proportion of the compound represented by formula (1) and the compound represented by formula (2) in the hydrolyzable silane is 65 mol% or more, and from the viewpoint of more suitably achieving the effects of the present invention, it is preferably 80 mol% or more, and more preferably 90 mol% or more (including the case where the molar proportion of the compound represented by formula (2) in the hydrolyzable silane is 0 mol%). The total molar proportion of the compound represented by formula (1) and the compound represented by formula (2) in the hydrolyzable silane may be 100 mol% or less, or may be 100 mol%. The molar proportion of the compound represented by formula (1) in the hydrolyzable silane may be 100 mol%. The molar proportion of the compound represented by formula (2) in the hydrolyzable silane may be 0 mol%. When the hydrolyzable silane contains the compound represented by formula (2), the molar proportion of the compound represented by formula (1) in the hydrolyzable silane is less than 100 mol%. When the hydrolyzable silane does not contain the compound represented by formula (2), the molar proportion of the compound represented by formula (1) in the hydrolyzable silane may be 100 mol % or less.

[0030] The polysiloxane may include a modified polysiloxane in which some of the silanol groups have been modified, such as a polysiloxane modified product in which some of the silanol groups have been alcohol-modified or acetal-protected. The polysiloxane may also include, for example, a hydrolysis condensation product of a hydrolyzable silane, and may include a modified polysiloxane in which at least some of the silanol groups of the hydrolysis condensation product have been alcohol-modified or acetal-protected. The hydrolyzable silane in the hydrolysis condensation product may include one or more hydrolyzable silanes. The polysiloxane may have a structure having a cage-type, ladder-type, linear-type, or branched-type main chain. Furthermore, commercially available polysiloxanes may be used as the polysiloxane.

[0031] In the present invention, the "hydrolyzed condensate" of a hydrolyzable silane, i.e., the product of hydrolysis and condensation, includes not only polyorganosiloxane polymers that are condensates in which condensation has been completely completed, but also polyorganosiloxane polymers that are partial hydrolyzed condensates in which condensation has not been completely completed. Like the condensates in which condensation has been completely completed, such partial hydrolyzed condensates are polymers obtained by the hydrolysis and condensation of a hydrolyzable silane, but the hydrolysis has only partially stopped and the condensation has not been completed, and therefore Si—OH groups remain. In addition to the hydrolyzed condensate, the composition for forming an underlayer film may also contain uncondensed hydrolyzates (complete hydrolyzates, partial hydrolyzates) and monomers (hydrolyzable silanes). In this specification, "hydrolyzable silanes" may also be simply referred to as "silane compounds." In this specification, "polysiloxanes" may also be referred to as "hydrolyzed condensates."

[0032] The polysiloxane may be a hydrolysis condensate of a hydrolyzable silane containing a silane compound other than the above-mentioned examples, as long as the effect of the present invention is not impaired.

[0033] As described above, the polysiloxane can be a modified polysiloxane in which at least a portion of the silanol groups are modified. For example, a polysiloxane modified product in which a portion of the silanol groups is modified with alcohol or a polysiloxane modified product in which the silanol groups are protected with acetal can be used. Examples of the modified polysiloxane include a reaction product obtained by reacting at least a portion of the silanol groups in the hydrolysis condensation product of the hydrolyzable silane with hydroxy groups of an alcohol, a dehydration reaction product of the condensation product with an alcohol, and a modified product in which at least a portion of the silanol groups in the condensation product are protected with acetal groups.

[0034] The alcohol may be a monohydric alcohol, such as methanol, ethanol, 2-propanol, 1-butanol, 2-butanol, isobutyl alcohol, tert-butyl alcohol, 1-pentanol, 2-pentanol, 3-pentanol, 1-heptanol, 2-heptanol, tert-amyl alcohol, neopentyl alcohol, 2-methyl-1-propanol, 2-methyl-1-butanol, 3-methyl-1-butanol, 3-methyl-3-pentanol, cyclopentanol, or 1-hexanol. Examples of suitable alcohols include 2-methyl-1-pentanol, 2-hexanol, 3-hexanol, 2,3-dimethyl-2-butanol, 3,3-dimethyl-1-butanol, 3,3-dimethyl-2-butanol, 2-diethyl-1-butanol, 2-methyl-1-pentanol, 2-methyl-2-pentanol, 2-methyl-3-pentanol, 3-methyl-1-pentanol, 3-methyl-2-pentanol, 3-methyl-3-pentanol, 4-methyl-1-pentanol, 4-methyl-2-pentanol, 4-methyl-3-pentanol, and cyclohexanol. Further, for example, alkoxy group-containing alcohols such as 3-methoxybutanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol monomethyl ether (1-methoxy-2-propanol), propylene glycol monoethyl ether (1-ethoxy-2-propanol), and propylene glycol monobutyl ether (1-butoxy-2-propanol) can be used.

[0035] The reaction between the silanol groups of the condensate and the hydroxyl groups of the alcohol can be carried out by contacting the polysiloxane with the alcohol and reacting for 0.1 to 48 hours, for example, 24 hours, at a temperature of 40 to 160° C., for example, 60° C., to obtain a modified polysiloxane in which the silanol groups are capped. In this case, the alcohol capping agent can be used as a solvent in the composition containing the polysiloxane.

[0036] Furthermore, a dehydration reaction product of a polysiloxane composed of a hydrolysis condensate of a hydrolyzable silane and an alcohol can be produced by reacting the polysiloxane with an alcohol in the presence of an acid catalyst, capping the silanol groups with the alcohol, and removing the water produced by dehydration from the reaction system. The acid can be an organic acid having an acid dissociation constant (pka) of -1 to 5, preferably 4 to 5. Examples of the acid include trifluoroacetic acid, maleic acid, benzoic acid, isobutyric acid, and acetic acid, among others. Furthermore, the acid can have a boiling point of 70 to 160°C, such as trifluoroacetic acid, isobutyric acid, acetic acid, and nitric acid. Thus, the acid preferably has an acid dissociation constant (pka) of 4 to 5 or a boiling point of 70 to 160°C. In other words, either a weak acidity or a strong acidity but a low boiling point can be used. As the acid, any of the properties such as the acid dissociation constant and boiling point can be used.

[0037] Acetal protection of the silanol groups in the condensate can be achieved using a vinyl ether, for example, a vinyl ether represented by the following formula (5). By this reaction, a partial structure represented by the following formula (6) can be introduced into the polysiloxane.

[0038] In formula (5), R １ａ , R ２ａ , and R ３ａ each represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, R ４ａ represents an alkyl group having 1 to 10 carbon atoms, and R ２ａ and R ４ａ may be bonded to each other to form a ring. Examples of the alkyl group include those mentioned above. In formula (6), R １ ', R ２ ', and R ３ Each of R ′ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms; ４ ' represents an alkyl group having 1 to 10 carbon atoms, and R ２ ' and R ４In formula (6), * indicates a bond to an adjacent atom. The adjacent atom may be, for example, an oxygen atom of a siloxane bond, an oxygen atom of a silanol group, or R in formula (1). １ Examples of the alkyl group include the carbon atoms derived from the following.

[0039] Examples of the vinyl ether represented by formula (5) include aliphatic vinyl ether compounds such as methyl vinyl ether, ethyl vinyl ether, isopropyl vinyl ether, normal butyl vinyl ether, 2-ethylhexyl vinyl ether, tert-butyl vinyl ether, and cyclohexyl vinyl ether, and cyclic vinyl ether compounds such as 2,3-dihydrofuran, 4-methyl-2,3-dihydrofuran, and 3,4-dihydro-2H-pyran. In particular, ethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, ethylhexyl vinyl ether, cyclohexyl vinyl ether, 3,4-dihydro-2H-pyran, and 2,3-dihydrofuran are preferably used.

[0040] Acetal protection of silanol groups can be carried out using polysiloxane, vinyl ether, and an aprotic solvent such as propylene glycol monomethyl ether acetate, ethyl acetate, dimethylformamide, tetrahydrofuran, or 1,4-dioxane, and using a catalyst such as pyridium paratoluenesulfonate, trifluoromethanesulfonic acid, paratoluenesulfonic acid, methanesulfonic acid, hydrochloric acid, or sulfuric acid.

[0041] The capping of the silanol groups with an alcohol or the acetal protection may be carried out simultaneously with the hydrolysis and condensation of the hydrolyzable silane described below.

[0042] In a preferred embodiment of the present invention, the polysiloxane comprises at least one of a hydrolyzed silane hydrolyzed condensate and a modified product thereof, which contains a hydrolyzable silane represented by formula (1), and optionally a hydrolyzable silane represented by formula (2), and other hydrolyzable silanes. In a preferred embodiment, the polysiloxane comprises a dehydration reaction product of the hydrolyzed condensate and an alcohol.

[0043] The weight-average molecular weight of polysiloxane, which is a hydrolysis condensation product (which may include modified products) of hydrolyzable silane, can be, for example, 500 to 1,000,000. From the viewpoint of suppressing precipitation of the hydrolysis condensation product in the composition, the weight-average molecular weight is preferably 500,000 or less, more preferably 250,000 or less, and even more preferably 100,000 or less. From the viewpoint of achieving both storage stability and coatability, the weight-average molecular weight is preferably 500 or more, more preferably 600 or more. The weight-average molecular weight is the molecular weight obtained by GPC analysis in terms of polystyrene. The GPC analysis can be performed using, for example, a GPC apparatus (trade name HLC-8220GPC, manufactured by Tosoh Corporation), a GPC column (trade name Shodex (registered trademark) KF803L, KF802, KF801, manufactured by Showa Denko K.K.), a column temperature of 40°C, tetrahydrofuran as an eluent (elution solvent), a flow rate (flow rate) of 1.0 mL / min, and polystyrene (Shodex (registered trademark) manufactured by Showa Denko K.K.) as a standard sample.

[0044] The hydrolysis condensate of hydrolyzable silane can be obtained by hydrolyzing and condensing the aforementioned silane compound (hydrolyzable silane). The aforementioned silane compound (hydrolyzable silane) contains an alkoxy group, aralkyloxy group, acyloxy group, or halogen atom directly bonded to a silicon atom, i.e., an alkoxysilyl group, aralkyloxysilyl group, acyloxysilyl group, or halogenated silyl group (hereinafter referred to as a hydrolyzable group). To hydrolyze these hydrolyzable groups, typically 0.1 to 100 moles, for example, 0.5 to 100 moles, and preferably 1 to 10 moles, of water are used per mole of hydrolyzable group. During the hydrolysis and condensation, a hydrolysis catalyst may be used, or the hydrolysis and condensation may be carried out without the use of a hydrolysis catalyst, for example, to promote the reaction. When a hydrolysis catalyst is used, typically 0.0001 to 10 moles, preferably 0.001 to 1 mole, of the hydrolysis catalyst can be used per mole of hydrolyzable group. The reaction temperature during hydrolysis and condensation is usually in the range of room temperature or higher and the reflux temperature at normal pressure of the organic solvent that can be used for hydrolysis, and can be, for example, 20 to 110°C, or, for example, 20 to 80°C. The hydrolysis may be complete, i.e., all hydrolyzable groups are converted to silanol groups, or partial, i.e., unreacted hydrolyzable groups may remain. Examples of hydrolysis catalysts that can be used during hydrolysis and condensation include metal chelate compounds, organic acids, inorganic acids, organic bases, and inorganic bases.

[0045] Examples of metal chelate compounds as hydrolysis catalysts include triethoxy mono(acetylacetonate)titanium, tri-n-propoxy mono(acetylacetonate)titanium, tri-i-propoxy mono(acetylacetonate)titanium, tri-n-butoxy mono(acetylacetonate)titanium, tri-sec-butoxy mono(acetylacetonate)titanium, tri-t-butoxy mono(acetylacetonate)titanium, diethoxy bis(acetylacetonate)titanium, di-n-propoxy bis(acetylacetonate)titanium, di -i-propoxy bis(acetylacetonate)titanium, di-n-butoxy bis(acetylacetonate)titanium, di-sec-butoxy bis(acetylacetonate)titanium, di-t-butoxy bis(acetylacetonate)titanium, monoethoxy tris(acetylacetonate)titanium, mono-n-propoxy tris(acetylacetonate)titanium, mono-i-propoxy tris(acetylacetonate)titanium, mono-n-butoxy tris(acetylacetonate)titanium, mono-sec-butoxy tris(acetylacetonate) titanium acetate), mono-t-butoxy tris(acetylacetonate) titanium, tetrakis(acetylacetonate) titanium, triethoxy mono(ethylacetoacetate) titanium, tri-n-propoxy mono(ethylacetoacetate) titanium, tri-i-propoxy mono(ethylacetoacetate) titanium, tri-n-butoxy mono(ethylacetoacetate) titanium, tri-sec-butoxy mono(ethylacetoacetate) titanium, tri-t-butoxy mono(ethylacetoacetate) titanium, diethoxy bis(ethoxy di-n-propoxy bis(ethylacetoacetate) titanium, di-i-propoxy bis(ethylacetoacetate) titanium, di-n-butoxy bis(ethylacetoacetate) titanium, di-sec-butoxy bis(ethylacetoacetate) titanium, di-t-butoxy bis(ethylacetoacetate) titanium, monoethoxy tris(ethylacetoacetate) titanium, mono-n-propoxy tris(ethylacetoacetate) titanium, mono-i-propoxy tris(ethylacetoacetate) titanium,Titanium chelate compounds such as mono-n-butoxy tris(ethylacetoacetate)titanium, mono-sec-butoxy tris(ethylacetoacetate)titanium, mono-t-butoxy tris(ethylacetoacetate)titanium, tetrakis(ethylacetoacetate)titanium, mono(acetylacetonate)tris(ethylacetoacetate)titanium, bis(acetylacetonate)bis(ethylacetoacetate)titanium, and tris(acetylacetonate)mono(ethylacetoacetate)titanium; triethoxy mono(acetylacetonate) tri-n-propoxy mono(acetylacetonate) zirconium, tri-i-propoxy mono(acetylacetonate) zirconium, tri-n-butoxy mono(acetylacetonate) zirconium, tri-sec-butoxy mono(acetylacetonate) zirconium, tri-t-butoxy mono(acetylacetonate) zirconium, diethoxy bis(acetylacetonate) zirconium, di-n-propoxy bis(acetylacetonate) zirconium, di-i-propoxy bis(acetylacetonate) zirconium cetylacetonate) zirconium, di-n-butoxy bis(acetylacetonate) zirconium, di-sec-butoxy bis(acetylacetonate) zirconium, di-t-butoxy bis(acetylacetonate) zirconium, monoethoxy tris(acetylacetonate) zirconium, mono-n-propoxy tris(acetylacetonate) zirconium, mono-i-propoxy tris(acetylacetonate) zirconium, mono-n-butoxy tris(acetylacetonate) zirconium, mono-sec- Butoxy tris(acetylacetonate)zirconium, mono-t-butoxy tris(acetylacetonate)zirconium, tetrakis(acetylacetonate)zirconium, triethoxy mono(ethylacetoacetate)zirconium, tri-n-propoxy mono(ethylacetoacetate)zirconium, tri-i-propoxy mono(ethylacetoacetate)zirconium, tri-n-butoxy mono(ethylacetoacetate)zirconium, tri-sec-butoxy mono(ethylacetoacetate)zirconium,Tri-t-butoxy mono(ethylacetoacetate)zirconium, diethoxy bis(ethylacetoacetate)zirconium, di-n-propoxy bis(ethylacetoacetate)zirconium, di-i-propoxy bis(ethylacetoacetate)zirconium, di-n-butoxy bis(ethylacetoacetate)zirconium, di-sec-butoxy bis(ethylacetoacetate)zirconium, di-t-butoxy bis(ethylacetoacetate)zirconium, monoethoxy tris(ethylacetoacetate)zirconium, mono-n-propoxy tris(ethylacetoacetate)zirconium, mono-i-propoxy tris(ethylacetoacetate)zirconium, mono-n-butoxy Examples of the chelate compounds include, but are not limited to, zirconium chelate compounds such as tris(ethylacetoacetate)zirconium, mono-sec-butoxy tris(ethylacetoacetate)zirconium, mono-t-butoxy tris(ethylacetoacetate)zirconium, tetrakis(ethylacetoacetate)zirconium, mono(acetylacetonato)tris(ethylacetoacetate)zirconium, bis(acetylacetonato)bis(ethylacetoacetate)zirconium, and tris(acetylacetonato)mono(ethylacetoacetate)zirconium; and aluminum chelate compounds such as tris(acetylacetonato)aluminum and tris(ethylacetoacetate)aluminum.

[0046] Examples of organic acids that can be used as hydrolysis catalysts include, but are not limited to, acetic acid, propionic acid, butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, oxalic acid, maleic acid, methylmalonic acid, adipic acid, sebacic acid, gallic acid, butyric acid, mellitic acid, arachidonic acid, 2-ethylhexanoic acid, oleic acid, stearic acid, linoleic acid, linolenic acid, salicylic acid, benzoic acid, p-aminobenzoic acid, p-toluenesulfonic acid, benzenesulfonic acid, monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, trifluoroacetic acid, formic acid, malonic acid, sulfonic acid, phthalic acid, fumaric acid, citric acid, and tartaric acid.

[0047] Examples of inorganic acids that can be used as hydrolysis catalysts include, but are not limited to, hydrochloric acid, nitric acid, sulfuric acid, hydrofluoric acid, and phosphoric acid.

[0048] Examples of organic bases as hydrolysis catalysts include, but are not limited to, pyridine, pyrrole, piperazine, pyrrolidine, piperidine, picoline, trimethylamine, triethylamine, monoethanolamine, diethanolamine, dimethylmonoethanolamine, monomethyldiethanolamine, triethanolamine, diazabicyclooctane, diazabicyclononane, diazabicycloundecene, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, trimethylphenylammonium hydroxide, benzyltrimethylammonium hydroxide, and benzyltriethylammonium hydroxide.

[0049] Examples of inorganic bases as hydrolysis catalysts include, but are not limited to, ammonia, sodium hydroxide, potassium hydroxide, barium hydroxide, calcium hydroxide, and the like.

[0050] Of these catalysts, metal chelate compounds, organic acids and inorganic acids are preferred, and these may be used alone or in combination of two or more.

[0051] Among these, in the present invention, nitric acid can be preferably used as the hydrolysis catalyst. The use of nitric acid can improve the storage stability of the reaction solution after hydrolysis and condensation, and in particular, can suppress changes in the molecular weight of the hydrolysis condensate. It has been found that the stability of the hydrolysis condensate in a liquid depends on the pH of the solution. As a result of extensive investigation, it has been found that the pH of the solution falls within a stable range when an appropriate amount of nitric acid is used. Furthermore, as described above, nitric acid can also be used when obtaining a modified product of the hydrolysis condensate, for example, when capping silanol groups with an alcohol, and is therefore preferred from the viewpoint of being able to contribute to both the hydrolysis and condensation of hydrolyzable silanes and the alcohol capping of the hydrolysis condensate.

[0052] When carrying out the hydrolysis and condensation, an organic solvent may be used as the solvent, and specific examples thereof 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; benzene, toluene, xylene, ethylbenzene, trimethylbenzene, methylethylbenzene, n-propylbenzene, i-propylbenzene, diethylbenzene, i-propylbenzene, and the like. Aromatic hydrocarbon solvents such as butylbenzene, triethylbenzene, di-i-propylbenzene, and n-amylnaphthalene; methanol, ethanol, n-propanol, i-propanol, n-butanol, i-butanol, sec-butanol, t-butanol, n-pentanol, i-pentanol, 2-methylbutanol, sec-pentanol, t-pentanol, 3-methoxybutanol, n-hexanol, 2-methylpentanol, sec-hexanol, and 2-ethylbutanol , n-heptanol, sec-heptanol, 3-heptanol, n-octanol, 2-ethylhexanol, sec-octanol, n-nonyl alcohol, 2,6-dimethyl-4-heptanol, n-decanol, sec-undecyl alcohol, trimethylnonyl alcohol, sec-tetradecyl alcohol, sec-heptadecyl alcohol, phenol, cyclohexanol, methylcyclohexanol, 3,3,5-trimethylcyclohexanol, benzyl alcohol, Monoalcohol-based solvents such as phenylmethylcarbinol, diacetone alcohol, and cresol; and polyhydric alcohol-based solvents such as ethylene glycol, propylene glycol, 1,3-butylene glycol, 2,4-pentanediol, 2-methyl-2,4-pentanediol, 2,5-hexanediol, 2,4-heptanediol, 2-ethyl-1,3-hexanediol, 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, ethylene glycol monoethyl ether, 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, and ethylene glycol dibutyl ether-based solvents such as 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 (1-methoxy-2-propanol), propylene glycol monoethyl ether (1-ethoxy-2-propanol), propylene glycol monopropyl ether, propylene glycol monobutyl ether, propylene glycol monomethyl ether acetate (1-methoxy-2-propanol monoacetate), 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, diethylene glycol mono-n-butyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether acetate, dipropylene glycol acetate Examples of solvents include, but are not limited to, ester-based solvents such as methyl ether, dipropylene glycol monoethyl ether acetate, glycol diacetate, methoxytriglyceride, ethylene glycol diacetate, triethylene glycol methyl ether acetate, ethyl propionate, n-butyl propionate, i-amyl propionate, diethyl oxalate, di-n-butyl oxalate, methyl lactate, ethyl lactate, n-butyl lactate, n-amyl lactate, diethyl malonate, dimethyl phthalate, and diethyl phthalate; nitrogen-containing solvents such as N-methylformamide, N,N-dimethylformamide, N,N-diethylformamide, acetamide, N-methylacetamide, N,N-dimethylacetamide, N-methylpropionamide, and N-methyl-2-pyrrolidone; 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. ;

[0053] After completion of the hydrolysis and condensation reactions, the reaction solution can be used as is or after dilution or concentration, neutralized, and treated with an ion exchange resin to remove the hydrolysis catalyst, such as an acid or a base, used in the hydrolysis and condensation. Before or after such treatment, by-product alcohol and water, the hydrolysis catalyst, etc., can be removed from the reaction solution by vacuum distillation or the like.

[0054] The hydrolysis condensate thus obtained is in the form of a polysiloxane varnish dissolved in an organic solvent, which can be used as is to prepare a composition for forming an underlayer film. That is, the reaction solution can be used as is (or diluted) to prepare a composition for forming an underlayer film. At this time, the hydrolysis catalyst used in the hydrolysis and condensation, as well as by-products, may remain in the reaction solution as long as they do not impair the effects of the present invention. For example, the hydrolysis catalyst or the nitric acid used in the alcohol capping of silanol groups may remain in the polymer varnish solution at approximately 100 ppm to 5,000 ppm. The resulting polysiloxane varnish may be subjected to solvent substitution or diluted with an appropriate solvent. If the resulting polysiloxane varnish has sufficient storage stability, the organic solvent can be distilled off to achieve a film-forming component concentration of 100%. The film-forming component refers to the components of the composition excluding the solvent. The organic solvent used for solvent substitution or dilution of the polysiloxane varnish may be the same as or different from the organic solvent used in the hydrolysis and condensation reaction of the hydrolyzable silane. The dilution solvent is not particularly limited, and one or more kinds may be arbitrarily selected and used.

[0055] <<Solvent>> The solvent contained in the underlayer film-forming composition can be any solvent that can dissolve and mix the polysiloxane and, if necessary, other components contained in the underlayer film-forming composition.

[0056] Examples of the solvent include organic solvents, water, etc. Examples of the organic solvent include alcohols, carboxylic acids having a hydroxy group, linear or cyclic alkyl ketones, cyclic lactones, alkylene glycol alkyl ethers, and alkylene glycol monoalkyl ether carboxylic acid esters (monocarboxylic acid esters of alkylene glycol monoalkyl ethers, and alkoxycarboxylic acid esters of alkylene glycol monoalkyl ethers).

[0057] Examples of the alcohol include monoalcohol solvents and polyhydric alcohol solvents. Examples of the monoalcohol solvent include 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, n-heptanol, sec-heptanol, 3-heptanol, and n-octanol. Examples of the polyhydric alcohol solvent include ethanol, 2-ethylhexanol, sec-octanol, n-nonyl alcohol, 2,6-dimethyl-4-heptanol, 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, cresol, etc. Examples of the polyhydric alcohol solvent include ethylene glycol, propylene glycol, 1,3-butylene glycol, 2,4-pentanediol, 2-methyl-2,4-pentanediol, 2,5-hexanediol, 2,4-heptanediol, 2-ethyl-1,3-hexanediol, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol, glycerin, etc.

[0058] Examples of carboxylic acids having a hydroxy group include ethyl lactate, propyl lactate, isopropyl lactate, butyl lactate, isobutyl lactate, ethyl hydroxyacetate, ethyl 2-hydroxy-2-methylpropionate, ethyl 2-hydroxypropionate, and methyl 2-hydroxy-3-methylbutyrate.

[0059] Examples of linear or cyclic alkyl ketones include methyl ethyl ketone, cyclopentanone, and cyclohexanone.

[0060] An example of the cyclic lactone is γ-butyrolactone.

[0061] Examples of alkylene glycol alkyl ethers include alkylene glycol monoalkyl ethers and alkylene glycol dialkyl ethers. Examples of alkylene glycol monoalkyl ethers include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether (1-methoxy-2-propanol), propylene glycol monoethyl ether (1-ethoxy-2-propanol), methyl isobutyl carbinol, and propylene glycol monobutyl ether. Examples of alkylene glycol dialkyl ethers include 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, and propylene glycol dibutyl ether.

[0062] Examples of alkylene glycol monoalkyl ether carboxylic acid esters include monocarboxylic acid esters of alkylene glycol monoalkyl ethers and alkoxycarboxylic acid esters of alkylene glycol monoalkyl ethers. Examples of monocarboxylic acid esters of alkylene glycol monoalkyl ethers include alkylene glycol monoalkyl ether acetates. Examples of alkylene glycol monoalkyl ether acetates include methyl cellosolve acetate, ethyl cellosolve acetate, propylene glycol monomethyl ether acetate (1-methoxy-2-propanol monoacetate), propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether acetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, and ethylene glycol monobutyl ether acetate. Examples of the alkoxycarboxylic acid ester of alkylene glycol monoalkyl ether include 2-methoxyethyl methyl carbonate, 2-ethoxyethyl methyl carbonate, 2-ethoxyethyl ethyl carbonate, and 2-propoxyethyl methyl carbonate.

[0063] Specific examples of other solvents include toluene, xylene, ethyl ethoxyacetate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl 3-ethoxypropionate, methyl pyruvate, ethyl pyruvate, 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, and ethyl hydroxyacetate. Examples of suitable solvents include methyl 3-methoxy-2-methylpropionate, ethyl methoxyacetate, ethyl ethoxyacetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-methoxybutyl acetate, 3-methoxypropyl acetate, 3-methyl-3-methoxybutyl acetate, 3-methyl-3-methoxybutylpropionate, 3-methyl-3-methoxybutyl butyrate, methyl acetoacetate, methyl propyl ketone, methyl butyl ketone, 2-heptanone, 3-heptanone, 4-heptanone, N,N-dimethylformamide, N-methylacetamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, and 4-methyl-2-pentanol. These solvents can be used alone or in combination of two or more.

[0064] The underlayer film-forming composition may contain water as a solvent. When water is contained as a solvent, the content of water can be, for example, 30% by mass or less, preferably 20% by mass or less, and more preferably 15% by mass or less, based on the total mass of the solvents contained in the underlayer film-forming composition.

[0065] <<Curing Catalyst>> The underlayer film-forming composition may be a composition that does not contain a curing catalyst, but preferably contains a curing catalyst.

[0066] Examples of the curing catalyst that can be used include ammonium salts, phosphines, phosphonium salts, sulfonium salts, iodonium salts, and oxonium salts. The salts listed below as examples of the curing catalyst may be added in the form of a salt, or may form a salt in the composition (a compound that is added as a separate compound and forms a salt in the system).

[0067] The ammonium salt includes those represented by formula (D-1): (In the formula, m ａ represents an integer from 2 to 11, and n ａ represents an integer of 2 or 3, R ２１ represents an alkyl group, an aryl group, or an aralkyl group; Y － represents an anion;

[0068] Formula (D-2): (In the formula, R ２２ , R ２３ , R ２４ and R ２５ each independently represents an alkyl group, an aryl group, or an aralkyl group; Y － represents an anion, and R ２２ , R ２３ , R ２４ , and R ２５ are each bonded to a nitrogen atom.)

[0069] Formula (D-3): (In the formula, R ２６ and R ２７ each independently represents an alkyl group, an aryl group, or an aralkyl group; Y － represents an anion;

[0070] Formula (D-4): (In the formula, R ２８ represents an alkyl group, an aryl group, or an aralkyl group; Y － represents an anion;

[0071] Formula (D-5): (In the formula, R２９ and R ３０ each independently represents an alkyl group, an aryl group, or an aralkyl group; Y － represents an anion;

[0072] Formula (D-6): (In the formula, m ａ represents an integer from 2 to 11, and n ａ represents an integer of 2 or 3, and Y － represents an anion.

[0073] Furthermore, the phosphonium salt includes a compound of the formula (D-7): (In the formula, R ３１ , R ３２ , R ３３ , and R ３４ each independently represents an alkyl group, an aryl group, or an aralkyl group; Y － represents an anion, and R ３１ , R ３２ , R ３３ , and R ３４ are bonded to a phosphorus atom.

[0074] Furthermore, the sulfonium salt includes a compound represented by formula (D-8): (In the formula, R ３５ , R ３６ , and R ３７ each independently represents an alkyl group, an aryl group, or an aralkyl group; Y － represents an anion, and R ３５ , R ３６ , and R ３７ are each bonded to a sulfur atom.

[0075] The compound of formula (D-1) is a quaternary ammonium salt derived from an amine, m ａ represents an integer from 2 to 11, and n ａ represents an integer of 2 or 3. R of this quaternary ammonium salt ２１represents, for example, an alkyl group having 1 to 18 carbon atoms, preferably 2 to 10 carbon atoms, an aryl group having 6 to 18 carbon atoms, or an aralkyl group having 7 to 18 carbon atoms, and examples thereof include linear alkyl groups such as ethyl, propyl, and butyl groups, as well as benzyl, cyclohexyl, cyclohexylmethyl, and dicyclopentadienyl groups. － ) is a chloride ion (Cl － ), bromine ion (Br － ), iodine ion (I － ) and carboxylate ions (-COO － ), sulfonato (-SO ３ － ), alcoholate (-O － ) and the like.

[0076] The compound of 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, for example, an alkyl group having 1 to 18 carbon atoms such as an ethyl group, a propyl group, a butyl group, a cyclohexyl group, or a cyclohexylmethyl group, an aryl group having 6 to 18 carbon atoms such as a phenyl group, or an aralkyl group having 7 to 18 carbon atoms such as a benzyl group. － ) is a chloride ion (Cl － ), bromine ion (Br － ), iodine ion (I － ) and carboxylate ions (-COO － ), sulfonato (-SO ３ － ), 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.

[0077] The compound of formula (D-3) is a quaternary ammonium salt derived from a 1-substituted imidazole, and R ２６ and R ２７ The number of carbon atoms in R is, for example, 1 to 18. ２６ and R ２７ The total number of carbon atoms in R is preferably 7 or more. ２６ can be exemplified by alkyl groups such as methyl, ethyl, and propyl, aryl groups such as phenyl, and aralkyl groups such as benzyl, and R ２７ Examples of the anion (Y) include aralkyl groups such as benzyl, and alkyl groups such as octyl and octadecyl. － ) is a chloride ion (Cl － ), bromine ion (Br － ), iodine ion (I － ) and carboxylate ions (-COO － ), sulfonato (-SO ３ － ), alcoholate (-O － Although this compound is commercially available, it can also be produced by reacting an imidazole compound such as 1-methylimidazole or 1-benzylimidazole with an aralkyl halide, alkyl halide, or aryl halide such as benzyl bromide, methyl bromide, or benzene bromide.

[0078] The compound of formula (D-4) is a quaternary ammonium salt derived from pyridine, and R ２８is, for example, an alkyl group having 1 to 18 carbon atoms, preferably 4 to 18 carbon atoms, an aryl group having 6 to 18 carbon atoms, or an aralkyl group having 7 to 18 carbon atoms, and examples thereof include a butyl group, an octyl group, a benzyl group, and a lauryl group. － ) is a chloride ion (Cl － ), bromine ion (Br － ), iodine ion (I － ) and carboxylate ions (-COO － ), sulfonato (-SO ３ － ), alcoholate (-O － ) and other acid groups. This compound is commercially available, but can also be produced by reacting pyridine with an alkyl halide or aryl halide, such as lauryl chloride, benzyl chloride, benzyl bromide, methyl bromide, or octyl bromide. Examples of this compound include N-laurylpyridinium chloride and N-benzylpyridinium bromide.

[0079] The compound of formula (D-5) is a quaternary ammonium salt derived from a substituted pyridine, such as picoline, and R ２９ is, for example, an alkyl group having 1 to 18 carbon atoms, preferably 4 to 18 carbon atoms, an aryl group having 6 to 18 carbon atoms, or an aralkyl group having 7 to 18 carbon atoms, and examples of R include a methyl group, an octyl group, a lauryl group, and a benzyl group. ３０ is, for example, an alkyl group having 1 to 18 carbon atoms, an aryl group having 6 to 18 carbon atoms, or an aralkyl group having 7 to 18 carbon atoms. For example, when the compound represented by formula (D-5) is a quaternary ammonium derived from picoline, R ３０ is a methyl group. － ) is a chloride ion (Cl － ), bromine ion (Br － ), iodine ion (I － ) and carboxylate ions (-COO － ), sulfonato (-SO ３ － ), alcoholate (-O －) and other acid groups. This compound is commercially available, but can also be produced by reacting a substituted pyridine such as picoline with an alkyl halide or aryl halide such as methyl bromide, octyl bromide, lauryl chloride, benzyl chloride, or benzyl bromide. Examples of this compound include N-benzylpicolinium chloride, N-benzylpicolinium bromide, and N-laurylpicolinium chloride.

[0080] The compound of formula (D-6) is a tertiary ammonium salt derived from an amine, m ａ represents an integer from 2 to 11, and n ａ represents 2 or 3. Also, an anion (Y － ) is a chloride ion (Cl － ), bromine ion (Br － ), iodine ion (I － ) and carboxylate ions (-COO － ), sulfonato (-SO ３ － ), alcoholate (-O － The compound can be produced by reacting an amine with a weak acid such as a carboxylic acid or phenol. Examples of the carboxylic acid include formic acid and acetic acid. When formic acid is used, an anion (Y － ) is (HCOO － ) and when acetic acid is used, the anion (Y － ) is (CH ３ COO － ) When phenol is used, the anion (Y － ) is (C ６ H ５ O － )

[0081] The compound of 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 ３４is, for example, an alkyl group having 1 to 18 carbon atoms such as an ethyl group, a propyl group, a butyl group, or a cyclohexylmethyl group, an aryl group having 6 to 18 carbon atoms such as a phenyl group, or an aralkyl group having 7 to 18 carbon atoms such as a benzyl group, and preferably R ３１ ~R ３４ Three of the four substituents are unsubstituted phenyl groups or substituted phenyl groups, for example, phenyl groups and tolyl groups, and the remaining one is an alkyl group having 1 to 18 carbon atoms, an aryl group having 6 to 18 carbon atoms, or an aralkyl group having 7 to 18 carbon atoms. － ) is a chloride ion (Cl － ), bromine ion (Br － ), iodine ion (I － ) and carboxylate ions (-COO － ), sulfonato (-SO ３ － ), 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 (all of which the halogen atom is a chlorine atom or a bromine atom). In particular, triphenylmonoalkylphosphonium halides such as triphenylmethylphosphonium halide and triphenylethylphosphonium halide, triphenylmonoarylphosphonium halides such as triphenylbenzylphosphonium halide, tritolylmonoarylphosphonium halides such as tritolylmonophenylphosphonium halide, and tritolylmonoalkylphosphonium halides (the halogen atom is a chlorine atom or a bromine atom) are preferred.

[0082] 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.

[0083] The compound of 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 ３７is, for example, an alkyl group having 1 to 18 carbon atoms such as an ethyl group, a propyl group, a butyl group, or a cyclohexylmethyl group, an aryl group having 6 to 18 carbon atoms such as a phenyl group, or an aralkyl group having 7 to 18 carbon atoms such as a benzyl group, and preferably R ３５ ~R ３７ Two of the three substituents are unsubstituted phenyl groups or substituted phenyl groups, for example, phenyl groups and tolyl groups, and the remaining one is an alkyl group having 1 to 18 carbon atoms, an aryl group having 6 to 18 carbon atoms, or an aralkyl group having 7 to 18 carbon atoms. － ) is a chloride ion (Cl － ), bromine ion (Br － ), iodine ion (I － ) and carboxylate ions (-COO － ), sulfonato (-SO ３ － ), alcoholate (-O － Examples of suitable acid groups include trialkylsulfonium halides such as tri-n-butylsulfonium halides and tri-n-propylsulfonium halides, dialkylbenzylsulfonium halides such as diethylbenzylsulfonium halides, diphenylmonoalkylsulfonium halides such as diphenylmethylsulfonium halides and diphenylethylsulfonium halides, triphenylsulfonium halides (all of which the halogen atom is a chlorine atom or a bromine atom), trialkylsulfonium carboxylates such as tri-n-butylsulfonium carboxylate and tri-n-propylsulfonium carboxylate, dialkylbenzylsulfonium carboxylates such as diethylbenzylsulfonium carboxylate, diphenylmonoalkylsulfonium carboxylates such as diphenylmethylsulfonium carboxylate and diphenylethylsulfonium carboxylate, and triphenylsulfonium carboxylate. Furthermore, triphenylsulfonium halides and triphenylsulfonium carboxylates are preferably used.

[0084] Furthermore, a nitrogen-containing silane compound can be added as a curing catalyst, such as an imidazole ring-containing silane compound, such as N-(3-triethoxysilylpropyl)-4,5-dihydroimidazole.

[0085] The content of the curing catalyst in the underlayer film-forming composition is preferably 0.01 to 30 parts by mass, more preferably 0.01 to 25 parts by mass, and even more preferably 0.01 to 20 parts by mass, per 100 parts by mass of the polysiloxane.

[0086] <<Acid>> The underlayer film-forming composition preferably contains an acid. The acid may be added during the preparation of the underlayer film-forming composition, but when the underlayer film-forming composition contains a polysiloxane, an acid may be used as a hydrolysis catalyst or during alcohol capping of silanol groups in the production of the polysiloxane described above, and the acid remaining in the polysiloxane varnish may be treated as the acid.

[0087] Examples of the acid include organic acids and inorganic acids. Examples of the organic acid include acetic acid, propionic acid, butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, oxalic acid, maleic acid, methylmalonic acid, adipic acid, sebacic acid, gallic acid, butyric acid, mellitic acid, arachidonic acid, 2-ethylhexanoic acid, oleic acid, stearic acid, linoleic acid, linolenic acid, salicylic acid, benzoic acid, p-aminobenzoic acid, p-toluenesulfonic acid, benzenesulfonic acid, monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, trifluoroacetic acid, formic acid, malonic acid, sulfonic acid, phthalic acid, fumaric acid, citric acid, and tartar. Examples of the inorganic acid include hydrochloric acid, nitric acid, sulfuric acid, hydrofluoric acid, and phosphoric acid.

[0088] The amount of acid (residual acid amount) can be, for example, 0.0001% by mass to 1% by mass, or 0.001% by mass to 0.1% by mass, or 0.005% by mass to 0.05% by mass, based on the total mass of the underlayer film-forming composition.

[0089] <<Amine, Hydroxide>> The composition for forming an underlayer film may contain at least one selected from an amine and a hydroxide.

[0090] Examples of amines include ammonia; primary amines such as monomethanolamine, monoethanolamine, monopropanolamine, methylamine, ethylamine, propylamine, and butylamine; secondary amines such as dimethylamine, ethylmethylamine, and diethylamine; tertiary amines such as trimethylamine, triethylamine, tripropylamine, dimethylethylamine, methyldiisopropylamine, diisopropylethylamine, diethylethanolamine, and triethanolamine; amines such as ethylenediamine and tetramethylethylenediamine; and cyclic amines such as pyridine and morpholine.

[0091] Examples of hydroxides include inorganic alkali hydroxides and organic alkali hydroxides. Examples of inorganic alkali hydroxides include sodium hydroxide and potassium hydroxide. Examples of organic alkali hydroxides include tetraalkylammonium hydroxide, triarylsulfonium hydroxide, diaryliodonium hydroxide, etc. Examples of tetraalkylammonium hydroxides include tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrabutylammonium hydroxide, etc. Examples of triarylsulfonium hydroxides include triphenylsulfonium hydroxide and tris(t-butylphenyl)sulfonium hydroxide, etc. Examples of diaryliodonium hydroxides include diphenyliodonium hydroxide and bis(t-butylphenyl)iodonium hydroxide, etc.

[0092] The contents of the amine and hydroxide in the underlayer film-forming composition are not particularly limited, but can be preferably 0.05 to 20 parts by mass, more preferably 0.1 to 15 parts by mass, and even more preferably 0.5 to 10 parts by mass, relative to 100 parts by mass of the polysiloxane.

[0093] <<Other Additives>> Various additives can be blended into the underlayer film-forming composition depending on the intended use of the composition. Examples of additives include crosslinking agents, crosslinking catalysts, stabilizers (organic acids, water, alcohols, etc.), organic polymers, acid generators, surfactants (nonionic surfactants, anionic surfactants, cationic surfactants, silicon-based surfactants, fluorine-based surfactants, UV-curable surfactants, etc.), pH adjusters, metal oxides, rheology adjusters, adhesion aids, and other known additives that are blended into materials (compositions) that form various films that can be used in the manufacture of semiconductor devices, such as resist underlayer films, anti-reflective films, and pattern reversal films. Examples of various additives are listed below, but the present invention is not limited to these.

[0094] -Stabilizer- When the underlayer film-forming composition contains polysiloxane, a stabilizer may be added for purposes such as stabilizing the hydrolysis condensate of the hydrolyzable silane mixture. Specific examples of stabilizers include organic acids, water, alcohols, and combinations thereof. Examples of organic acids 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. Among these, oxalic acid and maleic acid are preferred. When an organic acid is added, the amount added is 0.1 to 5.0% by mass relative to the mass of the hydrolysis condensate of the hydrolyzable silane mixture. These organic acids can also function as pH adjusters. Examples of water that can be used include pure water, ultrapure water, and ion-exchanged water. When used, the amount added can be 0.1 to 20 parts by mass per 100 parts by mass of the underlayer film-forming composition. The alcohol is preferably one that is easily evaporated by heating after application, and examples thereof include methanol, ethanol, propanol, i-propanol, butanol, etc. When an alcohol is added, the amount added can be 0.1 to 20 parts by mass per 100 parts by mass of the composition for forming the underlayer film.

[0095] -Organic Polymer- When the underlayer film-forming composition contains polysiloxane, adding an organic polymer to the underlayer film-forming composition can adjust the dry etching rate (amount of film thickness reduction per unit time), attenuation coefficient, refractive index, and other properties of the underlayer film formed from the underlayer film-forming composition. The organic polymer is not particularly limited and can be appropriately selected from various organic polymers (condensation polymerization polymers and addition polymerization polymers) depending on the purpose of addition. Specific examples include 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. In the present invention, organic polymers containing aromatic rings or heteroaromatic rings such as benzene rings, naphthalene rings, anthracene rings, triazine rings, quinoline rings, and quinoxaline rings that function as light-absorbing moieties can also be used when such functionality is required. Specific examples of such organic polymers include, but are not limited to, addition polymerization polymers containing, as structural units, addition-polymerizable monomers such as benzyl acrylate, benzyl methacrylate, phenyl acrylate, naphthyl acrylate, anthryl methacrylate, anthrylmethyl methacrylate, styrene, hydroxystyrene, benzyl vinyl ether, and N-phenylmaleimide, and condensation polymerization polymers such as phenol novolac and naphthol novolac.

[0096] When an addition polymerization polymer is used as the organic polymer, the polymer may be either a homopolymer or a copolymer. An addition polymerizable monomer is used to produce the addition polymerization polymer, and specific examples of such addition polymerizable monomers include, but are not limited to, acrylic acid, methacrylic acid, acrylic acid ester compounds, methacrylic acid ester compounds, acrylamide compounds, methacrylamide compounds, vinyl compounds, styrene compounds, maleimide compounds, maleic anhydride, and acrylonitrile.

[0097] Specific examples of acrylic acid ester compounds include methyl acrylate, ethyl acrylate, normal hexyl acrylate, i-propyl acrylate, cyclohexyl acrylate, benzyl acrylate, phenyl acrylate, anthrylmethyl acrylate, 2-hydroxyethyl acrylate, 3-chloro-2-hydroxypropyl acrylate, 2-hydroxypropyl acrylate, 2,2,2-trifluoroethyl acrylate, 2,2,2-trichloroethyl acrylate, 2-bromoethyl acrylate, 4-hydroxybutyl acrylate, 2-methoxyethyl acrylate, tetrahydrofurfuryl acrylate, 2-methyl-2-adamantyl acrylate, 5-acryloyloxy-6-hydroxynorbornene-2-carboxylic-6-lactone, 3-acryloxypropyltriethoxysilane, glycidyl acrylate, and the like, but are not limited to these.

[0098] Specific examples of methacrylic acid ester compounds include methyl methacrylate, ethyl methacrylate, normal hexyl methacrylate, i-propyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, phenyl methacrylate, anthrylmethyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2,2,2-trifluoroethyl methacrylate, 2,2,2-trichloroethyl methacrylate, 2-bromoethyl methacrylate, 4-hydroxybutyl methacrylate, 2-methoxyethyl methacrylate, tetrahydrofurfuryl methacrylate, 2-methyl-2-adamantyl methacrylate, 5-methacryloyloxy-6-hydroxynorbornene-2-carboxylic-6-lactone, 3-methacryloxypropyltriethoxysilane, glycidyl methacrylate, 2-phenylethyl methacrylate, hydroxyphenyl methacrylate, bromophenyl methacrylate, and the like, but are not limited to these.

[0099] Specific examples of the acrylamide compound include, but are not limited to, acrylamide, N-methylacrylamide, N-ethylacrylamide, N-benzylacrylamide, N-phenylacrylamide, N,N-dimethylacrylamide, and N-anthrylacrylamide.

[0100] Specific examples of methacrylamide compounds include methacrylamide, N-methylmethacrylamide, N-ethylmethacrylamide, N-benzylmethacrylamide, N-phenylmethacrylamide, N,N-dimethylmethacrylamide, and N-anthrylmethacrylamide, but are not limited to these.

[0101] Specific examples of vinyl compounds include, but are not limited to, vinyl alcohol, 2-hydroxyethyl vinyl ether, methyl vinyl ether, ethyl vinyl ether, benzyl vinyl ether, vinyl acetate, vinyltrimethoxysilane, 2-chloroethyl vinyl ether, 2-methoxyethyl vinyl ether, vinylnaphthalene, and vinylanthracene.

[0102] Specific examples of styrene compounds include, but are not limited to, styrene, hydroxystyrene, chlorostyrene, bromostyrene, methoxystyrene, cyanostyrene, and acetylstyrene.

[0103] Examples of maleimide compounds include, but are not limited to, maleimide, N-methylmaleimide, N-phenylmaleimide, N-cyclohexylmaleimide, N-benzylmaleimide, and N-hydroxyethylmaleimide.

[0104] When a condensation polymerization polymer is used as the polymer, examples of such a polymer include a condensation polymerization polymer of a glycol compound and a dicarboxylic acid compound. Examples of glycol compounds include diethylene glycol, hexamethylene glycol, butylene glycol, etc. Examples of dicarboxylic acid compounds include succinic acid, adipic acid, terephthalic acid, maleic anhydride, etc. Examples of polyesters, polyamides, and polyimides such as polypyromellitimide, poly(p-phenylene terephthalamide), polybutylene terephthalate, and polyethylene terephthalate, but are not limited to these. When the organic polymer contains a hydroxy group, this hydroxy group may undergo a crosslinking reaction with a hydrolysis condensate or the like.

[0105] The weight-average molecular weight of the organic polymer can usually be 1,000 to 1,000,000. When an organic polymer is incorporated, from the viewpoint of suppressing precipitation in the composition while fully obtaining the functional effect of the polymer, the weight-average molecular weight can be, for example, 3,000 to 300,000, or 5,000 to 300,000, or 10,000 to 200,000. Such organic polymers may be used alone or in combination of two or more.

[0106] When the composition for forming an underlayer film contains an organic polymer in combination with a polysiloxane, the content of the organic polymer cannot be generally specified because it is determined appropriately in consideration of the function of the organic polymer, etc., but can usually be in the range of 1 to 200% by mass relative to the mass of the polysiloxane. From the viewpoint of suppressing precipitation in the composition, etc., the content can be, for example, 100% by mass or less, preferably 50% by mass or less, and more preferably 30% by mass or less, and from the viewpoint of fully obtaining the effect, etc., the content can be, for example, 5% by mass or more, preferably 10% by mass or more, and more preferably 30% by mass or more.

[0107] -Acid Generator- Examples of the acid generator include thermal acid generators and photoacid generators, and photoacid generators are preferably used. Examples of the photoacid generator include onium salt compounds such as sulfonium salts, phosphonium salts, ammonium salts, iodonium salts, and oxonium salts, sulfonimide compounds, and disulfonyldiazomethane compounds, but are not limited to these. Note that the photoacid generator may also function as a curing catalyst depending on its type, for example, carboxylates such as nitrates and maleates of the onium salt compounds described below, or hydrochlorides. Examples of the thermal acid generator include, but are not limited to, tetramethylammonium nitrate.

[0108] Specific examples of the onium salt compound include iodonium salt compounds such as diphenyliodonium hexafluorophosphate, diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoro-normal butanesulfonate, diphenyliodonium perfluoro-normal octanesulfonate, diphenyliodonium camphorsulfonate, bis(4-t-butylphenyl)iodonium camphorsulfonate, and bis(4-t-butylphenyl)iodonium trifluoromethanesulfonate; and sulfonium salt compounds such as triphenylsulfonium hexafluoroantimonate, triphenylsulfonium nonafluoro-normal butanesulfonate, triphenylsulfonium camphorsulfonate, triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium nitrate, triphenylsulfonium trifluoroacetate, triphenylsulfonium maleate, and triphenylsulfonium chloride. However, the present invention is not limited to these.

[0109] Specific examples of the sulfonimide compound include N-(trifluoromethanesulfonyloxy)succinimide, N-(nonafluoronormalbutanesulfonyloxy)succinimide, N-(camphorsulfonyloxy)succinimide, and N-(trifluoromethanesulfonyloxy)naphthalimide, but are not limited to these.

[0110] Specific examples of the disulfonyldiazomethane compound include, but are not limited to, bis(trifluoromethylsulfonyl)diazomethane, bis(cyclohexylsulfonyl)diazomethane, bis(phenylsulfonyl)diazomethane, bis(p-toluenesulfonyl)diazomethane, bis(2,4-dimethylbenzenesulfonyl)diazomethane, methylsulfonyl-p-toluenesulfonyldiazomethane, and the like.

[0111] When the composition for forming an underlayer film contains an acid generator, its content cannot be generally defined because it is determined appropriately taking into account the type of acid generator, etc., but is usually in the range of 0.01 to 5% by mass relative to the mass of the polysiloxane, and from the viewpoint of suppressing precipitation of the acid generator in the composition, etc., it is preferably 3% by mass or less, more preferably 1% by mass or less, and from the viewpoint of fully obtaining its effects, it is preferably 0.1% by mass or more, more preferably 0.5% by mass or more. The acid generators can be used alone or in combination of two or more, and a photoacid generator and a thermal acid generator may be used in combination.

[0112] -Surfactant- A surfactant is effective in suppressing the occurrence of pinholes, striations, and the like when the underlayer film-forming composition is applied to a substrate. Examples of surfactants include nonionic surfactants, anionic surfactants, cationic surfactants, silicone surfactants, fluorine-based surfactants, and UV-curable surfactants. More specific examples include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, and polyoxyethylene oleyl ether; polyoxyethylene alkylaryl ethers such as polyoxyethylene octylphenol ether and polyoxyethylene nonylphenol ether; polyoxyethylene-polyoxypropylene block copolymers; sorbitan fatty acid esters such as sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, sorbitan trioleate, and sorbitan tristearate; polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, and polyoxyethylene sorbitan tristearate; Nonionic surfactants such as polyoxyethylene sorbitan fatty acid esters such as oleate and polyoxyethylene sorbitan tristearate, trade names of EFTOP (registered trademark) EF301, EF303, EF352 (manufactured by Mitsubishi Materials Electronic Chemicals Co., Ltd. (formerly Tochem Products Co., Ltd.)), trade names of MEGAFAC (registered trademark) F171, F173, R-08, R-30, R-30N, R-40LM (manufactured by DIC Corporation), Fluorad F Examples of suitable surfactants include, but are not limited to, fluorine-based surfactants such as C430 and FC431 (manufactured by 3M Japan Ltd.), Asahiguard (registered trademark) AG710 (manufactured by AGC Corporation), and Surflon (registered trademark) S-382, SC101, SC102, SC103, SC104, SC105, and SC106 (manufactured by AGC Seimi Chemical Co., Ltd.), and organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.). These surfactants can be used singly or in combination of two or more.

[0113] When the underlayer film-forming composition contains a surfactant, the content thereof can be typically 0.0001 to 5 mass %, preferably 0.001 to 4 mass %, and more preferably 0.01 to 3 mass %, relative to the mass of the polysiloxane.

[0114] Rheology Modifiers Rheology modifiers are added primarily to improve the fluidity of the underlayer film-forming composition, particularly in the baking step, to improve the film thickness uniformity of the formed film and the ability of the composition to fill holes. Specific examples include phthalic acid derivatives such as dimethyl phthalate, diethyl phthalate, di-i-butyl phthalate, dihexyl phthalate, and butyl i-decyl phthalate; adipic acid derivatives such as di-n-butyl adipate, di-i-butyl adipate, di-i-octyl adipate, and octyldecyl adipate; maleic acid derivatives such as di-n-butyl maleate, diethyl maleate, and dinonyl maleate; oleic acid derivatives such as methyl oleate, butyl oleate, and tetrahydrofurfuryl oleate; and stearic acid derivatives such as n-butyl stearate and glyceryl stearate. When these rheology modifiers are used, the amount added is typically less than 30% by mass of all the film-forming components of the underlayer film-forming composition.

[0115] -Adhesion aid- The adhesion aid is added mainly for the purpose of improving the adhesion between the substrate or resist and the underlayer film formed from the underlayer film-forming composition, and particularly for the purpose of suppressing or preventing peeling of the resist during development. Specific examples include chlorosilanes such as trimethylchlorosilane, dimethylvinylchlorosilane, methyldiphenylchlorosilane, and chloromethyldimethylchlorosilane; alkoxysilanes such as trimethylmethoxysilane, dimethyldiethoxysilane, methyldimethoxysilane, and dimethylvinylethoxysilane; silazanes such as hexamethyldisilazane, N,N'-bis(trimethylsilyl)urea, dimethyltrimethylsilylamine, and trimethylsilylimidazole; γ-chloropropyltrimethoxysilane; Examples of suitable adhesion promoters include other silanes such as γ-aminopropyltriethoxysilane and γ-glycidoxypropyltrimethoxysilane, heterocyclic compounds such as benzotriazole, benzimidazole, indazole, imidazole, 2-mercaptobenzimidazole, 2-mercaptobenzothiazole, 2-mercaptobenzoxazole, urazole, thiouracil, mercaptoimidazole, and mercaptopyrimidine, and urea or thiourea compounds such as 1,1-dimethylurea and 1,3-dimethylurea. When these adhesion promoters are used, the amount added is usually less than 5% by mass, and preferably less than 2% by mass, of the film-forming components of the underlayer film-forming composition.

[0116] pH Adjuster: Examples of pH adjusters include acids having one or more carboxylic acid groups, such as the organic acids listed above as stabilizers. When a pH adjuster is used, the amount added can be 0.01 to 20 parts by mass, 0.01 to 10 parts by mass, or 0.01 to 5 parts by mass relative to 100 parts by mass of the polysiloxane.

[0117] Metal Oxide Examples of metal oxides that can be added to the underlayer film-forming composition include, but are not limited to, oxides of one or a combination of two or more of metals such as tin (Sn), titanium (Ti), aluminum (Al), zirconium (Zr), zinc (Zn), niobium (Nb), tantalum (Ta), and tungsten (W), and semimetals such as boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), and tellurium (Te).

[0118] The concentration of the film-forming component in the underlayer film-forming composition can be, for example, 0.01 to 50 mass%, 0.01 to 30 mass%, 0.01 to 25 mass%, or 0.01 to 20.0 mass%, relative to the total mass of the composition. The content of polysiloxane in the film-forming component is usually 20 mass% to 100 mass%, but from the viewpoint of reproducibly achieving the effects of the present invention, the lower limit is preferably 50 mass%, more preferably 60 mass%, even more preferably 70 mass%, and even more preferably 80 mass%, and the upper limit is preferably 99 mass%, with the remainder being the above-mentioned additives. The underlayer film-forming composition also preferably has a pH of 1 to 5, more preferably 2 to 4.

[0119] The underlayer film-forming composition can be produced by mixing a polysiloxane, a solvent, and, if desired, other components. In this case, a solution containing the polysiloxane may be prepared in advance, and this solution may be mixed with the solvent and other components. In preparing the underlayer film-forming composition, heating may be performed as appropriate within a range that does not cause decomposition or deterioration of the components.

[0120] During the production of the underlayer film-forming composition or after all components have been mixed, the composition may be filtered using a submicrometer-order filter or the like. The material of the filter used here is not limited, and examples that can be used include polyethylene filters, nylon filters, fluororesin filters, and polyimide filters.

[0121] In the present invention, the resist film may be formed from a positive development resist or a negative development resist. In the case of a positive development resist, the exposed portion is developed. Therefore, if the underlayer film is an underlayer film in which the alignment of the self-assembled film decreases when exposed to exposure and development during resist pattern formation, when the resist film is formed from a positive development resist, the underlayer film exposed after development is also exposed, and therefore the alignment of the self-assembled film on the underlayer film decreases. On the other hand, the underlayer film formed from the underlayer film-forming composition of the present invention is an underlayer film that can form a vertical alignment in the self-assembled film even when exposed to exposure and development during resist pattern formation. Therefore, even if the resist film is formed from a positive development resist and the underlayer film exposed after development is also exposed, the alignment of the self-assembled film formed on the underlayer film is less likely to decrease, and a vertical alignment can be formed in the self-assembled film.

[0122] The underlayer film of the present invention is a fired product of a coating film of the composition for forming an underlayer film described above. In lithography using a resist film, either a photoresist film or an electron beam resist film, and a self-assembled film, the underlayer film of the present invention is used as an underlayer film of a resist film, and then used as an underlayer film of the self-assembled film.

[0123] The underlayer film of the present invention can be produced, for example, by applying a composition for forming an underlayer film onto a semiconductor substrate and baking it.

[0124] Examples of semiconductor substrates onto which the underlayer film-forming composition of the present invention can be applied include silicon wafers, germanium wafers, and wafers of compound semiconductors such as gallium arsenide, indium phosphide, gallium nitride, indium nitride, and aluminum nitride.

[0125] When a semiconductor substrate having an inorganic film formed on its surface is used, the inorganic film can be formed by, for example, ALD (atomic layer deposition), CVD (chemical vapor deposition), reactive sputtering, ion plating, vacuum deposition, or spin coating (spin-on glass: SOG). Examples of the inorganic film include a polysilicon film, a silicon oxide film, a silicon nitride film, a BPSG (Boro-Phospho Silicate Glass) film, a titanium nitride film, a titanium nitride oxide film, a tungsten film, a gallium nitride film, and a gallium arsenide film.

[0126] The semiconductor substrate may have a silicon- and organic group-containing film. The silicon- and organic group-containing film is a film formed from a hydrolysis condensation product of a hydrolyzable silane (also called an organosilicon compound) having an organic group. The silicon- and organic group-containing film contains, for example, a hydrolysis condensation product of a hydrolyzable silane containing a compound represented by the following formula (A): (In formula (A), R ａ represents an alkyl group, an aryl group, a halogenated alkyl group, a halogenated aryl group, an alkoxyaryl group, an alkenyl group, an organic group having an epoxy group, an organic group having an acryloyl group, an organic group having a methacryloyl group, an organic group having a mercapto group, or an organic group having a cyano group; R ｂ represents an alkoxy group, an acyloxy group, or a halogen atom, and x represents an integer of 0 to 3.

[0127] The silicon- and organic group-containing film can be formed, for example, from a silicon-containing resist underlayer film-forming composition. Examples of such a silicon-containing resist underlayer film-forming composition include the silicon-containing resist underlayer film-forming composition described below. Patent Publication No. 2020-076999, WO2019 / 181873 pamphlet, WO2019 / 082934 pamphlet, WO2019 / 009413 pamphlet, WO2018 / 181989 pamphlet, WO2018 / 079599 pamphlet, WO2016 / 080217 pamphlet, WO2016 / 009965 pamphlet, WO2016 / 009939 pamphlet, WO2015 / 194555 pamphlet, WO2014 / 098076 pamphlet, WO2014 / 069329 pamphlet, WO2014 / 046055 pamphlet, WO2013 / 191203 pamphlet, WO2013 / 115032 pamphlet, WO2013 / 022099 pamphlet, WO2012 / 102261 pamphlet, WO2012 / 053600 pamphlet, WO2012 / 039337 pamphlet, WO2011 / 105368 pamphlet, WO2011 / 102470 pamphlet, WO2011 / 033965 pamphlet, WO2010 / 140551 pamphlet, WO2010 / 071155 pamphlet, WO2010 / 021290 pamphlet, WO2009 / 104552 pamphlet, WO2009 / 088039 pamphlet, WO2009 / 069712 pamphlet

[0128] The composition for forming an underlayer film of the present invention is applied to such a semiconductor substrate by a suitable application method such as a spinner or coater. The underlayer film is then formed by baking using a heating means such as a hot plate. The baking conditions are appropriately selected from a baking temperature of 100°C to 400°C and a baking time of 0.3 to 60 minutes. A baking temperature of 120°C to 350°C and a baking time of 0.5 to 30 minutes are preferred, and a baking temperature of 150°C to 300°C and a baking time of 0.8 to 10 minutes are more preferred.

[0129] The film thickness of the underlayer film may be 30 nm or less, 25 nm or less, 20 nm or less, or 15 nm or less. The film thickness of the underlayer film may be 1 nm or more, 2 nm or more, or 3 nm or more. When a brush layer is formed in the gaps of the patterned underlayer film, the brush layer becomes a thin layer (for example, about 1 nm). In order to minimize the difference in film thickness from the brush layer, a thin underlayer film is preferable. In this respect, the film thickness of the underlayer film is preferably 15 nm or less. Furthermore, by reducing the film thickness of the underlayer film, the pattern of the patterned self-assembled film can be easily transferred to the underlayer film. In this respect, the film thickness of the underlayer film is preferably 15 nm or less. On the other hand, when the underlayer film is used as an etching mask, a thicker underlayer film is preferable. In this respect, the film thickness of the underlayer film is preferably 30 nm or less.

[0130] The method for measuring the thickness of the underlayer film in this specification is as follows: Measurement device name: Ellipso film thickness measurement device RE-3100 (SCREEN Corporation) SWE (single wavelength ellipsometer) mode Arithmetic mean of 8 points (for example, measuring 8 points at 1 cm intervals in the X direction of the wafer)

[0131] (Method for manufacturing a semiconductor element) The method for manufacturing a semiconductor element of the present invention includes steps 1 to 4. Step 1: A step of forming an underlayer film on a semiconductor substrate using the composition for forming an underlayer film of the present invention. Step 2: A step of forming a resist film, which is either a photoresist film or an electron beam resist film, on the underlayer film. Step 3: A step of irradiating the resist film with light or an electron beam, and then developing the resist film to obtain a resist pattern. Step 4: A step of forming a self-assembled film on at least a portion of the underlayer film after the step of obtaining the resist pattern.

[0132] In one example (first embodiment) of a method for manufacturing a semiconductor element, the step (fourth step) of forming a self-assembled film is a step of forming a self-assembled film between the resist patterns and on at least a part of the underlayer film. In other words, this example (first embodiment) of a method for manufacturing a semiconductor element includes the following step 4A as the fourth step. - Step 4A: A step of forming a self-assembled film between the resist patterns and on at least a part of the underlayer film.

[0133] An example (second embodiment) of a method for manufacturing a semiconductor element includes, between the step of obtaining a resist pattern (second step) and the step of forming a self-assembled film (fourth step), a step of forming a brush layer between the resist patterns and on at least a part of the underlayer film, and a step of removing the resist pattern, in this order. In other words, instead of the fourth step, this example (second embodiment) of a method for manufacturing a semiconductor element includes the following steps 4B to 6B, in this order: - step 4B: a step of forming a brush layer between the resist patterns and on at least a part of the underlayer film; - step 5B: a step of removing the resist pattern; and - step 6B: a step of forming a self-assembled film on the brush layer and the exposed underlayer film.

[0134] An example of a method for manufacturing a semiconductor element (third embodiment) includes a step of surface-modifying an underlayer film exposed between the resist patterns by a dry process between the step of obtaining a resist pattern (step 3) and the step of forming a brush layer (step 4B). In other words, this example of a method for manufacturing a semiconductor element (third embodiment) includes the following steps 4C to 7C, in this order, instead of step 4: step 4C: surface-modifying an underlayer film exposed between the resist patterns by a dry process; step 5C: forming a brush layer on the surface-modified underlayer film; step 6C: removing the resist pattern; and step 7C: forming a self-assembled film on the brush layer and the exposed underlayer film. In the third embodiment, by surface-modifying an underlayer film exposed between the resist patterns by a dry process, the adhesion between the brush layer and the underlayer film can be improved.

[0135] An example of a method for manufacturing a semiconductor element (fourth embodiment) includes, between the step of obtaining a resist pattern (third step) and the step of forming a self-assembled film (fourth step), a step of surface-modifying an underlayer film exposed between the resist patterns by a dry process, and a step of removing the resist pattern, in this order. In other words, instead of step 4, this example of a method for manufacturing a semiconductor element (fourth embodiment) includes the following steps 4D to 6D, in this order: - step 4D: a step of surface-modifying an underlayer film exposed between the resist patterns by a dry process; - step 5D: a step of removing the resist pattern; - step 6D: a step of forming a self-assembled film on the underlayer film. In the fourth embodiment, by surface-modifying a portion of the underlayer film to eliminate the vertical alignment formability of that portion of the underlayer film, that portion can be used in place of a brush layer. This eliminates the need for a brush layer.

[0136] <First Step> The first step is a step of forming an underlayer film on a semiconductor substrate using the composition for forming an underlayer film of the present invention. The method for forming the underlayer film is not particularly limited, and examples thereof include the methods described above. That is, the underlayer film can be produced, for example, by applying the composition for forming an underlayer film on a semiconductor substrate and baking it.

[0137] <Second Step and Third Step> The second step is a step of forming a resist film, either a photoresist film or an electron beam resist film, on the underlayer film. The third step is a step of irradiating the resist film with light or an electron beam, and then developing the resist film to obtain a resist pattern.

[0138] The thickness of the resist film to be formed is not particularly limited, but is preferably 200 nm or less, more preferably 150 nm or less, even more preferably 100 nm or less, and particularly preferably 80 nm or less. The thickness of the resist film is preferably 10 nm or more, more preferably 20 nm or more, and even more preferably 30 nm or more.

[0139] The resist formed by coating and baking on the underlayer film by a known method is not particularly limited as long as it responds to light or electron beam (EB) used for irradiation. Both negative and positive resists can be used. In this specification, resists that respond to EB are also sometimes referred to as photoresists. Examples of photoresists include positive photoresists composed of a novolak resin and a 1,2-naphthoquinone diazide sulfonic acid ester; chemically amplified photoresists composed of a binder having a group that decomposes in the presence of an acid to increase the alkaline dissolution rate and a photoacid generator; chemically amplified photoresists composed of a low molecular weight compound that decomposes in the presence of an acid to increase the alkaline dissolution rate of the photoresist, an alkali-soluble binder, and a photoacid generator; chemically amplified photoresists composed of a binder having a group that decomposes in the presence of an acid to increase the alkaline dissolution rate of the photoresist, a low molecular weight compound that decomposes in the presence of an acid to increase the alkaline dissolution rate of the photoresist, and a photoacid generator; and resists containing metal elements. Examples of such photoresists include V146G (trade name) manufactured by JSR Corporation, APEX-E (trade name) manufactured by Shipley Co., Ltd., PAR710 (trade name) manufactured by Sumitomo Chemical Co., Ltd., and AR2772 and SEPR430 (trade names) manufactured by Shin-Etsu Chemical Co., Ltd. Further examples include fluorine-containing polymer photoresists such as those described in Proc. SPIE, Vol. 3999, 330-334 (2000), Proc. SPIE, Vol. 3999, 357-364 (2000), and Proc. SPIE, Vol. 3999, 365-374 (2000).

[0140] Also, WO2019 / 188595, WO2019 / 187881, WO2019 / 187803, WO2019 / 167737, WO2019 / 167725, WO2019 / 187445, WO2019 / 167419, WO2019 / 123842, WO2019 / 054282, WO2019 / 058945, WO2019 / 058890, WO2019 / 039290, WO2019 / 044259, WO2019 / 044231, WO2019 / 026549, WO2018 / 193954, WO201 9 / 172054, WO2019 / 021975, WO2018 / 230334, WO2018 / 194123, JP 2018-180525, WO2018 / 190088, JP 2018-070596, JP 2018-028090, JP 2016-153409, JP 2016-130240, JP 2016-108325, JP 2016-047920, JP 2016-035570, JP 2016-035567, JP 2016-035565, JP 2019-101417, JP 2019-117373, JP 2019-052294, JP 2019-008280, JP 2019-008279, JP 2019-003176, JP 2019-003175, JP 2018-197853, JP 2019-191298, JP 2019-061217, JP 2018-045152, JP 2018-022039, JP 2016-090441, JP 2015-10878, JP 2012-168279, JP 2012-022261, JP 2012-022258, JP 2011-043749, JP 2010-18 1857, JP 2010-128369, WO2018 / 031896, JP 2019-113855, WO2017 / 156388, WO2017 / 066319, JP 2018-41099, WO2016 / 065120, WO2015 / 026482, JP 2016-29498, JP 2011-253185, etc. Resist compositions, radiation-sensitive resin compositions, high-resolution patterning compositions based on organometallic solutions, and metal-containing resist compositions can be used, but are not limited to these.

[0141] Examples of the resist composition include the following compositions.

[0142] An actinic ray-sensitive or radiation-sensitive resin composition comprising: Resin A having a repeating unit having an acid-decomposable group in which a polar group is protected with a protecting group that is cleaved by the action of an acid; and a compound represented by the following general formula (21):

[0143] In the general formula (21), m represents an integer of 1 to 6. １ and R ２ each independently represents a fluorine atom or a perfluoroalkyl group. １ is -O-, -S-, -COO-, -SO ２ - or -SO ３ - represents. ２ represents an alkylene group which may have a substituent or a single bond. １ represents a cyclic organic group which may have a substituent. ＋ represents a cation.

[0144] A metal-containing film-forming composition for extreme ultraviolet or electron beam lithography, comprising a compound having a metal-oxygen covalent bond and a solvent, wherein the metal element constituting the compound belongs to Periods 3 to 7 of Groups 3 to 15 of the periodic table.

[0145] A radiation-sensitive resin composition comprising: a polymer having a first structural unit represented by the following formula (31) and a second structural unit represented by the following formula (32) containing an acid-dissociable group; and an acid generator.

[0146] In formula (31), Ar is a group obtained by removing (n+1) hydrogen atoms from an arene having 6 to 20 carbon atoms. １ is a hydroxy group, a sulfanyl group, or a monovalent organic group having 1 to 20 carbon atoms. n is an integer of 0 to 11. When n is 2 or more, multiple R １ are the same or different. ２ is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. ３ is a monovalent group having 1 to 20 carbon atoms containing the above acid-dissociable group. Z is a single bond, an oxygen atom, or a sulfur atom. R ４ is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0147] A resist composition comprising: a resin (A1) containing a structural unit having a cyclic carbonate structure, a structural unit represented by the following formula, and a structural unit having an acid labile group; and an acid generator.

[0148] [In the formula, R ２ represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom; X １ represents a single bond, —CO—O—*, or —CO—NR ４ -*, * represents a bond to -Ar, R ４ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and Ar represents an aromatic hydrocarbon group having 6 to 20 carbon atoms which may have one or more groups selected from the group consisting of a hydroxy group and a carboxyl group.]

[0149] Examples of the resist film include the following.

[0150] A resist film comprising a base resin comprising a repeating unit represented by the following formula (a1) and / or a repeating unit represented by the following formula (a2), and a repeating unit that generates an acid bonded to a polymer main chain upon exposure: (In formula (a1) and formula (a2), R Ａ are each independently a hydrogen atom or a methyl group. １ and R ２ are each independently a tertiary alkyl group having 4 to 6 carbon atoms. ３ are each independently a fluorine atom or a methyl group, and m is an integer of 0 to 4. １ X is a single bond, a phenylene group, or a naphthylene group, or a linking group having 1 to 12 carbon atoms and containing at least one selected from an ester bond, a lactone ring, a phenylene group, and a naphthylene group. ２ is a single bond, an ester bond, or an amide bond.

[0151] Examples of resist materials include the following:

[0152] A resist material comprising a polymer having a repeating unit represented by the following formula (b1) or (b2):

[0153] (In formula (b1) and formula (b2), R Ａ is a hydrogen atom or a methyl group. １ is a single bond or an ester group. ２ is a linear, branched or cyclic alkylene group having 1 to 12 carbon atoms or an arylene group having 6 to 10 carbon atoms, and some of the methylene groups constituting the alkylene group may be substituted with an ether group, an ester group or a lactone ring-containing group; and X ２ At least one hydrogen atom contained in X is substituted with a bromine atom. ３ Rf is a single bond, an ether group, an ester group, or a linear, branched, or cyclic alkylene group having 1 to 12 carbon atoms, and some of the methylene groups constituting the alkylene group may be substituted with an ether group or an ester group. １ ~Rf ４ are each independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group, but at least one is a fluorine atom or a trifluoromethyl group. １ and Rf ２ may combine to form a carbonyl group. １ ~R ５ are each independently a linear, branched, or cyclic alkyl group having 1 to 12 carbon atoms, a linear, branched, or cyclic alkenyl group having 2 to 12 carbon atoms, an alkynyl group having 2 to 12 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, or an aryloxyalkyl group having 7 to 12 carbon atoms, in which some or all of the hydrogen atoms may be substituted with a hydroxy group, a carboxy group, a halogen atom, an oxo group, a cyano group, an amide group, a nitro group, a sultone group, a sulfone group, or a sulfonium salt-containing group, and in which some of the methylene groups constituting these groups may be substituted with an ether group, an ester group, a carbonyl group, a carbonate group, or a sulfonate ester group. １ and R ２ may be bonded to form a ring together with the sulfur atom to which they are attached.

[0154] A resist material comprising a base resin containing a polymer containing a repeating unit represented by the following formula (a):

[0155] (In formula (a), R Ａ is a hydrogen atom or a methyl group. １ is a hydrogen atom or an acid labile group. ２ is a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms, or a halogen atom other than bromine. １ X is a single bond, a phenylene group, or a linear, branched or cyclic alkylene group having 1 to 12 carbon atoms which may contain an ester group or a lactone ring. ２ is -O-, -O-CH ２ - or -NH-. m is an integer of 1 to 4. u is an integer of 0 to 3. However, m+u is an integer of 1 to 4.

[0156] A resist composition that generates an acid upon exposure, and whose solubility in a developer changes due to the action of the acid, comprising: a base component (A) whose solubility in a developer changes due to the action of the acid; and a fluorine additive component (F) that exhibits decomposition in an alkaline developer, wherein the fluorine additive component (F) comprises a fluororesin component (F1) that has a structural unit (f1) that includes a base dissociable group, and a structural unit (f2) that includes a group represented by the following general formula (f2-r-1):

[0157] [In formula (f2-r-1), Rf ２１ are each independently a hydrogen atom, an alkyl group, an alkoxy group, a hydroxyl group, a hydroxyalkyl group, or a cyano group; n" is an integer of 0 to 2; * is a bond.

[0158] The structural unit (f1) includes a structural unit represented by the following general formula (f1-1) or a structural unit represented by the following general formula (f1-2).

[0159] [In formulas (f1-1) and (f1-2), each R is independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. X is a divalent linking group that does not have an acid-dissociable site. A ａｒｙｌ represents a divalent aromatic cyclic group which may have a substituent. ０１ is a single bond or a divalent linking group. ２ are each independently an organic group having a fluorine atom.

[0160] Coatings, coating solutions, and coating compositions include, for example:

[0161] A coating comprising a metal oxo-hydroxo network having organic ligands with metal carbon and / or metal carboxylate bonds.

[0162] Inorganic oxo / hydroxo-based compositions.

[0163] a coating solution comprising an organic solvent; a first organometallic composition having the formula R ｚ SnO （２－（ｚ／２）－（ｘ／２）） (OH) ｘ (where 0<z≦2 and 0<(z+x)≦4), formula R′ ｎ SnX ４－ｎ wherein n=1 or 2, or mixtures thereof, where R and R′ are independently hydrocarbyl groups having 1 to 31 carbon atoms, and X is a ligand having a hydrolyzable bond to Sn, or a combination thereof; and a hydrolyzable metal compound having the formula MX′ ｖ wherein M is a metal selected from groups 2 to 16 of the periodic table of the elements, v is a number from 2 to 6, and X' is a ligand having a hydrolyzable M-X bond or a combination thereof.

[0164] an organic solvent and a solution of the formula RSnO （３／２－ｘ／２） (OH) ｘand a first organometallic compound of the formula: wherein 0<x<3, wherein the solution contains from about 0.0025M to about 1.5M tin, and R is an alkyl or cycloalkyl group having from 3 to 31 carbon atoms, the alkyl or cycloalkyl group being bonded to the tin at a secondary or tertiary carbon atom.

[0165] An aqueous inorganic patterning precursor solution comprising a mixture of water, metal suboxide cations, polyatomic inorganic anions, and radiation-sensitive ligands comprising peroxide groups.

[0166] Other examples of metal-containing resists include those described in JP 2011-253185 A, WO 2015 / 026482, WO 2016 / 065120, WO 2017 / 066319, WO 2017 / 156388, WO 2018 / 031896, JP 2020-122959 A, JP 2020-122960 A, WO 2019 / 099981, WO 2019 / 199467, WO 2019 / 195522, WO 2019 / 195522, WO 2020 / 210660, WO 2021 / 011367, and WO 2021 / 016229. The contents of these are incorporated herein in their entirety to the same extent as if set forth in full.

[0167] The method for forming a metal-containing resist film from a metal-containing resist is not particularly limited, and examples include a method in which a coating-type resist material (a composition for forming a metal-containing resist film) that is a metal-containing resist is coated and baked.

[0168] The metal-containing resist film may also be formed by vapor deposition. Examples of methods for forming a metal-containing resist film by vapor deposition include the method described in JP 2017-116923 A. The contents of JP 2017-116923 A are incorporated herein by reference to the same extent as if fully set forth herein. In JP 2017-116923 A, the metal-containing resist film of the present invention is referred to as a metal oxide-containing film.

[0169] The irradiation with light or electron beam is carried out, for example, through a mask (reticle) for forming a predetermined pattern. The wavelength of the light is not particularly limited, and i-line, KrF excimer laser, ArF excimer laser, EUV (extreme ultraviolet), or EB (electron beam) can be used. The irradiation energy of EB and the exposure dose of light are not particularly limited.

[0170] After irradiation with light or electron beams and before development, baking (PEB: Post Exposure Bake) may be performed. The baking temperature is not particularly limited, but is preferably 60° C. to 150° C., more preferably 70° C. to 120° C., and particularly preferably 75° C. to 110° C. The baking time is not particularly limited, but is preferably 1 second to 10 minutes, more preferably 10 seconds to 5 minutes, and particularly preferably 30 seconds to 3 minutes.

[0171] For example, an alkaline developer or an organic solvent is used for development. The development temperature is, for example, 5°C to 50°C. The development time is, for example, 10 seconds to 300 seconds. Examples of alkaline developers that can be used include aqueous solutions of alkalis such as inorganic alkalis (e.g., sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia); primary amines (e.g., ethylamine and n-propylamine); secondary amines (e.g., diethylamine and di-n-butylamine); tertiary amines (e.g., triethylamine and methyldiethylamine); alcohol amines (e.g., dimethylethanolamine and triethanolamine); quaternary ammonium salts (e.g., tetramethylammonium hydroxide, tetraethylammonium hydroxide, and choline); and cyclic amines (e.g., pyrrole and piperidine). Furthermore, the aqueous solutions of the alkalis may be used by adding an appropriate amount of alcohols (e.g., isopropyl alcohol) or a nonionic surfactant. Among these, preferred developers are aqueous solutions of quaternary ammonium salts, more preferably aqueous solutions of tetramethylammonium hydroxide and choline. Furthermore, surfactants and the like may also be added to these developers. Alternatively, development may be carried out with an organic solvent such as butyl acetate instead of an alkaline developer, and the portions of the photoresist where the alkaline dissolution rate is not improved may be developed.

[0172] An organic solvent can be used as a developer for the metal-containing resist, and development is carried out with the developer (solvent) after irradiation with light or electron beams. As a result, for example, when a negative metal-containing resist film is used, the metal-containing resist film in the unexposed areas is removed, and a pattern of the metal-containing resist film is formed. Examples of the developer (organic solvent) include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, isoamyl acetate, ethyl methoxyacetate, ethyl ethoxyacetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monophenyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monopropyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monophenyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, 2-methoxybutyl acetate, 3-methoxybutyl acetate, 4-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-ethyl-3-methyl ... -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-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,Examples of the developer include 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 also be added to these developers.

[0173] The type of resist pattern to be formed is not particularly limited, and may be a line pattern or a hole pattern. When the resist pattern is a line pattern, the line width is not particularly limited, and may be, for example, 30 nm to 200 nm. When the resist pattern is a hole pattern, the diameter of the hole may be, for example, 30 nm to 200 nm.

[0174] <Fourth Step> The fourth step is a step of forming a self-assembled film on at least a portion of the underlayer film after the step of obtaining a resist pattern. In one example (first embodiment) of a method for manufacturing a semiconductor device, the step of forming a self-assembled film includes a step of forming a self-assembled film between the resist patterns and on at least a portion of the underlayer film. The self-assembled film can be formed, for example, by applying a composition for forming a self-assembled film and drying it. The self-assembled film is, for example, a film containing a block copolymer.

[0175] The thickness of the self-assembled film is not particularly limited, but is preferably 10 nm to 100 nm, more preferably 30 nm to 80 nm, and particularly preferably 40 nm to 60 nm.

[0176] <<Self-Assembled Film-Forming Composition>> The self-assembled film-forming composition contains, for example, a block copolymer. The self-assembled film-forming composition usually contains a solvent.

[0177] The solids content of the self-assembled film-forming composition can be 0.1 to 10% by mass, or 0.1 to 5% by mass, or 0.1 to 3% by mass. The solids content is the percentage remaining after removing the solvent from the film-forming composition. The proportion of the block copolymer in the solids content can be 30 to 100% by mass, or 50 to 100% by mass, or 50 to 90% by mass, or 50 to 80% by mass. The number of types of blocks present in the block copolymer can be two or three or more. The number of blocks present in the block copolymer can be two or three or more.

[0178] <<<Block Copolymers>>> Block polymers include combinations such as AB, ABAB, ABA, and ABC. Methods for synthesizing block copolymers include living radical polymerization and living cationic polymerization, in which the polymerization process consists only of an initiation reaction and a propagation reaction, and does not involve side reactions that deactivate the growing ends. The growing ends can maintain their propagation activity during the polymerization reaction. By preventing chain transfer, a polymer (PA) of uniform length can be obtained. By adding a different monomer (mb), the growing end of this polymer (PA) can be used to polymerize the monomer (mb) and form a block copolymer (AB).

[0179] For example, when there are two types of blocks, PA and PB, the molar ratio of the polymer chain (PA) to the polymer chain (PB) can be 1:9 to 9:1, preferably 3:7 to 7:3. The volume ratio of the block copolymer is, for example, 30:70 to 70:30. The homopolymer PA or PB is a polymer of a polymerizable compound having at least one radically polymerizable reactive group (vinyl group or vinyl group-containing organic group).

[0180] The weight average molecular weight Mw of the block copolymer is preferably 1,000 to 100,000, or 5,000 to 100,000. A molecular weight Mw of 1,000 or more provides excellent coatability onto the base substrate, while a molecular weight Mw of 100,000 or less provides excellent solubility in solvents. The polydispersity index (Mw / Mn) of the block copolymer is preferably 1.00 to 1.50, and more preferably 1.00 to 1.20.

[0181] Known block copolymers can be used in the present invention. Specific examples of block copolymers include a combination of a silicon-containing polymer chain and a silicon-free polymer chain, which is preferable because it can increase the difference in dry etching rate. Examples of silicon-containing polymer chains include silylated polystyrene derivatives. Examples of silylated polystyrene derivatives include polysilanes (e.g., polydihexylsilane), polysiloxanes (e.g., polydimethylsiloxane), poly(trimethylsilylstyrene), and poly(pentamethyldisilylstyrene). In particular, the silylated polystyrene derivatives are preferably poly(4-trimethylsilylstyrene) and poly(4-pentamethyldisilylstyrene), which have a substituent at the 4-position.

[0182] A preferred example of the block copolymer is a block copolymer obtained by combining a silicon-containing polymer having a structural unit of styrene, which may be substituted with an organic group, or a silicon-containing polymer having a structural unit derived from lactide, with a silicon-containing polymer having a structural unit of styrene substituted with a silicon-containing group. Among these, a combination of a silylated polystyrene derivative and a polystyrene derivative, or a combination of a silylated polystyrene derivative and polylactide is preferred. Among these, a combination of a silylated polystyrene derivative having a substituent at the 4-position and a polystyrene derivative having a substituent at the 4-position, or a combination of a silylated polystyrene derivative having a substituent at the 4-position and polylactide is preferred. More preferred examples of the block copolymer include a combination of poly(trimethylsilylstyrene) and polymethoxystyrene, a combination of polystyrene and poly(trimethylsilylstyrene), and a combination of poly(trimethylsilylstyrene) and poly(D,L-lactide). More preferred specific examples of the block copolymer include a combination of poly(4-trimethylsilylstyrene) and poly(4-methoxystyrene), a combination of polystyrene and poly(4-trimethylsilylstyrene), and a combination of poly(4-trimethylsilylstyrene) and poly(D,L-lactide). Most preferred specific examples of the block copolymer include a poly(4-methoxystyrene) / poly(4-trimethylsilylstyrene) block copolymer and a polystyrene / poly(4-trimethylsilylstyrene) block copolymer. The entire disclosure of WO2018 / 135456 is incorporated herein by reference.

[0183] The block copolymer may be a block copolymer obtained by bonding a non-silicon-containing polymer with a silicon-containing polymer having a structural unit of styrene substituted with a silicon-containing group, and the non-silicon-containing polymer may be a block copolymer containing a unit structure represented by the following formula (1-1c) or formula (1-2c): (In formula (1-1c) or formula (1-2c), R １ and R ２each independently represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 10 carbon atoms; R ３ ~R ５ each independently represents a hydrogen atom, a hydroxy group, a halogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a cyano group, an amino group, an amido group, or a carbonyl group.

[0184] The silicon-containing group may contain one silicon atom. The silicon-containing polymer may contain a unit structure represented by the following formula (2c): (In formula (2c), R ６ ~R ８ each independently represents an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 40 carbon atoms.

[0185] Furthermore, the block copolymer may be one described in JP-T-2019-507815 A, including the following [BCP11] to [BCP14]. The entire disclosure of JP-T-2019-507815 A is incorporated herein by reference. [BCP11]: A block copolymer containing 5-vinylbenzo[d][1,3]dioxole. [BCP12]: The block copolymer described in [BCP11], wherein the block copolymer further contains a silicon-containing block. [BCP13]: The block copolymer described in [BCP12], wherein the block copolymer further contains pentamethyldisilylstyrene. [BCP14]: The block copolymer described in [BCP13], wherein the block copolymer is poly(5-vinylbenzo[d][1,3]dioxole)-b-poly(pentamethyldisilylstyrene).

[0186] The synthesis of the above-described poly(5-vinylbenzo[d][1,3]dioxole-block-4-pentamethyldisilylstyrene) is shown in Scheme 1 below. Me represents a methyl group.

[0187] Preferably, the silicon-containing polymer or silicon-containing block is poly(4-trimethylsilylstyrene) derived from 4-trimethylsilylstyrene. Preferably, the silicon-containing polymer or silicon-containing block is poly(pentamethyldisilylstyrene) derived from pentamethyldisilylstyrene. The aryl group having 6 to 40 carbon atoms refers to a monovalent group of a monocyclic or polycyclic aromatic hydrocarbon having 6 to 40 carbon atoms, and specific examples include a phenyl group, a naphthyl group, and an anthryl group. The entire disclosure of WO2020 / 017494 is incorporated herein by reference.

[0188] Also, a block copolymer made of a combination of the following monomers may be used: styrene, methyl methacrylate, dimethylsiloxane, propylene oxide, ethylene oxide, vinylpyridine, vinylnaphthalene, D,L-lactide, methoxystyrene, methylenedioxystyrene, trimethylsilylstyrene, and pentamethyldisilylstyrene.

[0189] Useful block copolymers contain at least two blocks and may be diblock, triblock, tetrablock, etc. copolymers with distinct blocks, each of which may be a homopolymer or a random or alternating copolymer.

[0190] Typical block copolymers include polystyrene-b-polyvinylpyridine, polystyrene-b-polybutadiene, polystyrene-b-polyisoprene, polystyrene-b-polymethylmethacrylate, polystyrene-b-polyalkenyl aromatic, polyisoprene-b-polyethylene oxide, polystyrene-b-poly(ethylene-propylene), polyethylene oxide-b-polycaprolactone, polybutadiene-b-polyethylene oxide, polystyrene-b-poly(t-butyl (meth)acrylate), polymethylmethacrylate-b-poly(t-butyl methacrylate), polyethylene oxide-b-polypropylene oxide, polystyrene-b-polytetrafluoroethylene Examples of block copolymers include hydrofuran, polystyrene-b-polyisoprene-b-polyethylene oxide, poly(styrene-b-dimethylsiloxane), poly(methyl methacrylate-b-dimethylsiloxane), poly(methyl (meth)acrylate-r-styrene)-b-polymethyl methacrylate, poly(methyl (meth)acrylate-r-styrene)-b-polystyrene, poly(p-hydroxystyrene-r-styrene)-b-polymethyl methacrylate, poly(p-hydroxystyrene-r-styrene)-b-polyethylene oxide, polyisoprene-b-polystyrene-b-polyferrocenylsilane, or a combination comprising at least one of the foregoing block copolymers.

[0191] Further examples include block copolymers formed from a combination of the organic polymers and / or metal-containing polymers described below.

[0192] Typical organic polymers include poly(9,9-bis(6'-N,N,N-trimethylammonium)-hexyl)-fluorenephenylene) (PEP), poly(4-vinylpyridine) (4PVP), hydroxypropyl methylcellulose (HPMC), polyethylene glycol (PEG), poly(ethylene oxide)-poly(propylene oxide) diblock or multiblock copolymers, polyvinyl alcohol (PVA), poly(ethylene-vinyl alcohol) (PEVA), polyacrylic acid (PAA), polylactic acid (PLA), poly(ethyloxazoline), poly(alkyl acrylate), poly(acrylic acid), poly(ethylene-vinyl alcohol ... Examples of suitable polyvinyl alcohols include, but are not limited to, polyvinyl amides, poly(N-alkylacrylamides), poly(N,N-dialkylacrylamides), polypropylene glycol (PPG), polypropylene oxide (PPO), partially or fully hydrogenated poly(vinyl alcohol), dextran, polystyrene (PS), polyethylene (PE), polypropylene (PP), polyisoprene (PI), polychloroprene (CR), polyvinyl ether (PVE), polyvinyl acetate (PVA), polyvinyl chloride (PVC), polyurethane (PU), polyacrylates, polymethacrylates, oligosaccharides, or polysaccharides.

[0193] Metal-containing polymers include, but are not limited to, silicon-containing polymers such as polydimethylsiloxane (PDMS), polyhedral silsesquioxane (POSS), or poly(trimethylsilylstyrene) (PTMSS) or polymers containing silicon and iron such as poly(ferrocenyldimethylsilane) (PFS).

[0194] Exemplary block copolymers include, but are not limited to, diblock copolymers such as polystyrene-b-polydimethylsiloxane (PS-PDMS), poly(2-vinylpropylene)-b-polydimethylsiloxane (P2VP-PDMS), polystyrene-b-poly(ferrocenyldimethylsilane) (PS-PFS), or polystyrene-b-polyDL-lactic acid (PS-PLA) or triblock copolymers such as polystyrene-b-poly(ferrocenyldimethylsilane)-b-poly(2-vinylpyridine) (PS-PFS-P2VP), polyisoprene-b-polystyrene-b-poly(ferrocenyldimethylsilane) (PI-PS-PFS), or polystyrene-b-poly(ferrocenyldimethylsilane)-b-polystyrene (PS-PTMSS-PS). In one embodiment, the PS-PTMSS-PS block copolymer comprises a poly(trimethylsilylstyrene) polymer block composed of two chains of PTMSS connected by a linker containing four styrene units. Modified versions of block copolymers, such as those disclosed in U.S. Patent Application Publication No. 2012 / 0046415, are also contemplated.

[0195] Other block copolymers include, for example, a block copolymer in which a polymer having styrene or a derivative thereof as a constituent unit is bonded to a polymer having a (meth)acrylic acid ester as a constituent unit, a block copolymer in which a polymer having styrene or a derivative thereof as a constituent unit is bonded to a polymer having siloxane or a derivative thereof as a constituent unit, and a block copolymer in which a polymer having alkylene oxide as a constituent unit is bonded to a polymer having a (meth)acrylic acid ester as a constituent unit. Note that "(meth)acrylic acid ester" refers to either or both of an acrylic acid ester having a hydrogen atom bonded to the α-position and a methacrylic acid ester having a methyl group bonded to the α-position.

[0196] Examples of (meth)acrylic acid esters include those in which a substituent such as an alkyl group or a hydroxyalkyl group is bonded to a carbon atom of (meth)acrylic acid. Examples of the alkyl group used as the substituent include linear, branched, or cyclic alkyl groups having 1 to 10 carbon atoms. Specific examples of (meth)acrylic acid esters include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, cyclohexyl (meth)acrylate, octyl (meth)acrylate, nonyl (meth)acrylate, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, benzyl (meth)acrylate, anthracene (meth)acrylate, glycidyl (meth)acrylate, 3,4-epoxycyclohexylmethane (meth)acrylate, and propyltrimethoxysilane (meth)acrylate.

[0197] Examples of styrene derivatives include α-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 4-t-butylstyrene, 4-n-octylstyrene, 2,4,6-trimethylstyrene, 4-methoxystyrene, 4-t-butoxystyrene, 4-hydroxystyrene, 4-nitrostyrene, 3-nitrostyrene, 4-chlorostyrene, 4-fluorostyrene, 4-acetoxyvinylstyrene, vinylcyclohexane, 4-vinylbenzyl chloride, 1-vinylnaphthalene, 4-vinylbiphenyl, 1-vinyl-2-pyrrolidone, 9-vinylanthracene, and vinylpyridine.

[0198] Examples of siloxane derivatives include dimethylsiloxane, diethylsiloxane, diphenylsiloxane, methylphenylsiloxane, etc. Examples of alkylene oxides include ethylene oxide, propylene oxide, isopropylene oxide, butylene oxide, etc.

[0199] Examples of the block copolymer include polystyrene / poly(methyl methacrylate) block copolymer, styrene-polyethyl methacrylate block copolymer, styrene-(poly-t-butyl methacrylate) block copolymer, styrene-polymethacrylic acid block copolymer, styrene-polymethyl acrylate block copolymer, styrene-polyethyl acrylate block copolymer, styrene-(poly-t-butyl acrylate) block copolymer, styrene-polyacrylic acid block copolymer, etc. The entire disclosure of WO2022 / 039187 is incorporated herein by reference.

[0200] <<<Solvents>>> Examples of solvents that can be used in the self-assembled film-forming composition include the following organic solvents: 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, sec-heptanol, heptanol-3, n-octanol, 2-ethylhexanol, Monoalcohol solvents such as sec-octanol, n-nonyl alcohol, 2,6-dimethylheptanol-4, n-decanol, sec-undecyl alcohol, trimethylnonyl alcohol, sec-tetradecyl alcohol, sec-heptadecyl alcohol, phenol, cyclohexanol, methylcyclohexanol, 3,3,5-trimethylcyclohexanol, benzyl alcohol, phenylmethylcarbinol, diacetone alcohol, and cresol; Polyalcohol solvents such as ethylene glycol, propylene glycol, 1,3-butylene glycol, pentanediol-2,4, 2-methylpentanediol-2,4, hexanediol-2,5, heptanediol-2,4, 2-ethylhexanediol-1,3, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol, and glycerin.Ketone solvents such as acetone, methyl ethyl ketone, methyl n-propyl ketone, methyl n-butyl ketone, diethyl ketone, methyl i-butyl ketone, methyl n-pentyl ketone, ethyl n-butyl ketone, methyl n-hexyl ketone, di-i-butyl ketone, trimethylnonanone, cyclohexanone, methylcyclohexanone, 2,4-pentanedione, acetonylacetone, diacetone alcohol, acetophenone, and fenchone Ethyl ether, i-propyl ether, n-butyl ether, n-hexyl ether, 2-ethylhexyl ether, ethylene oxide, 1,2-propylene oxide, dioxolane, 4-methyldioxolane, dioxane, dimethyldioxane, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, 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 solvents such as ether, diethylene glycol mono-n-butyl ether, diethylene glycol di-n-butyl ether, diethylene glycol mono-n-hexyl ether, ethoxytriglycol, tetraethylene glycol di-n-butyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, 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, di Ester solvents such as ethylene 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, n-butyl lactate, n-amyl lactate, diethyl malonate, dimethyl phthalate, and diethyl phthalate. Nitrogen-containing solvents such as N-methylformamide, N,N-dimethylformamide, N,N-diethylformamide, acetamide, N-methylacetamide, N,N-dimethylacetamide, N-methylpropionamide, and N-methylpyrrolidone Sulfur-containing solvents such as dimethyl sulfide, diethyl sulfide, thiophene, tetrahydrothiophene, dimethyl sulfoxide, sulfolane, and 1,3-propane sultone

[0201] In particular, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, and propylene glycol monopropyl ether acetate are preferred in terms of storage stability of the solution of the composition.

[0202] Furthermore, the solvent contained in the composition for forming a self-assembled film may be a combination of a low-boiling point solvent (A) having a boiling point of 160°C or less and a high-boiling point solvent (B) having a boiling point of 170°C or more, as described in WO2018 / 135456.

[0203] Preferred examples of the low-boiling solvent (A) having a boiling point of 160°C or less include propylene glycol monomethyl ether acetate (boiling point: 146°C), n-butyl acetate (boiling point: 126°C), and methyl isobutyl ketone (boiling point: 116°C).

[0204] Preferred examples of the high-boiling solvent (B) having a boiling point of 170°C or higher include N-methylpyrrolidone (boiling point: 204°C), diethylene glycol monomethyl ether (boiling point: 193°C), N,N-dimethylisobutyramide (boiling point: 175°C), 3-methoxy-N,N-dimethylpropanamide (boiling point: 215°C), and γ-butyrolactone (boiling point: 204°C).

[0205] Two or more low-boiling point solvents (A) and two or more high-boiling point solvents (B) may be selected and mixed for use.

[0206] In a preferred embodiment, the composition contains 0.3 to 2.0 wt% of the high-boiling point solvent (B) relative to the total weight of the solvents contained in the composition. Most preferably, the composition contains 0.5 to 1.5 wt% of the high-boiling point solvent (B). The entire disclosure of WO2018 / 135456 is incorporated herein by reference.

[0207] <<Phase Separation of Self-Assembled Monolayers>> Phase separation of a self-assembled monolayer (e.g., a block copolymer film) can be achieved by a treatment that brings about rearrangement of the self-assembled monolayer, such as ultrasonic treatment, solvent treatment, or thermal annealing. In many applications, it is desirable to achieve phase separation of a self-assembled monolayer by simple heating or so-called thermal annealing. Thermal annealing can be performed in the atmosphere or in an inert gas under normal pressure, reduced pressure, or increased pressure. The conditions for thermal annealing are not particularly limited, but are preferably 180°C to 300°C in the atmosphere, more preferably 210°C to 280°C, and particularly preferably 230°C to 270°C. The treatment time is not particularly limited, but is usually 1 minute to 30 minutes, preferably 3 minutes to 10 minutes.

[0208] Phase separation of the self-assembled monolayer forms domains oriented substantially perpendicular to the surface of the substrate or underlying film. The domains may have, for example, a lamellar, spherical, or cylindrical shape. The domain spacing is, for example, 50 nm or less.

[0209] <<Patterning of Self-Assembled Monolayers>> A pattern corresponding to the morphology of the domains can be obtained by selectively removing portions of a phase-separated self-assembled monolayer. Examples of methods for selectively removing portions of a phase-separated self-assembled monolayer include a method of subjecting the phase-separated self-assembled monolayer to oxygen plasma treatment or hydrogen plasma treatment.

[0210] <Step of forming a brush layer> An example of a method for manufacturing a semiconductor element includes a step of forming a brush layer. An example of a method for manufacturing a semiconductor element (second embodiment) includes a step of forming a brush layer between the resist patterns and on at least a part of the underlayer film between the resist patterns and the self-assembled film forming step. An example of a method for manufacturing a semiconductor element (third embodiment) includes a step of forming a brush layer on the surface-modified underlayer film.

[0211] The method for forming the brush layer is not particularly limited, but may be, for example, a method in which a brush layer-forming composition is applied and dried.

[0212] <<Brush Layer-Forming Composition>> The brush layer-forming composition contains, for example, a brush polymer and a solvent. The brush layer-forming composition is, for example, a composition containing polymer chains capable of directly bonding to the substrate surface. A film or layer formed by polymer chains arranged in a brush-like pattern on a substrate is sometimes called a brush layer. The brush layer-forming composition is, for example, a composition for forming an underlayer film for forming an underlayer film of a layer containing a block copolymer. Furthermore, a film formed from the brush layer-forming composition serves, for example, as a guide that controls the position of the polymer phase formed by self-assembly. For example, a film formed from the brush layer-forming composition has a concave-convex structure and serves as the sidewall of a recess in a physical guide (grapho-epitaxy) for forming a microphase-separated pattern in the recess. Furthermore, for example, a film formed from the brush layer-forming composition is, for example, a chemical guide (chemical-epitaxy) that is formed under a self-assembling material and controls the position of the microphase-separated pattern based on the difference in surface energy.

[0213] <<<Brush Polymer>>> The brush polymer is not particularly limited as long as it is a brush polymer used in forming the underlayer film.

[0214] An example of a brush polymer is a polymer having a neutral wetting bottom surface, as described in JP-A-2011-515537. Examples of such a polymer include a random copolymer as described in claim 15 of JP-A-2011-515537 and a grafted blend of multiple homopolymers as described in claim 16. The contents of JP-A-2011-515537 are incorporated herein by reference to the same extent as if expressly set forth in its entirety.

[0215] Another example of the brush polymer is the random copolymer described in JP-T-2011-518652. One example of the random copolymer described in JP-T-2011-518652 is the photocrosslinkable random PS-r-PMMA described in paragraph

[0028] . The contents of JP-T-2011-518652 are incorporated herein by reference to the same extent as if set forth in their entirety.

[0216] Another example of a brush polymer is a resin in which 20 mol % to 80 mol % of the total structural units are derived from aromatic ring-containing monomers. Such a resin is, for example, the resin component contained in the primer described in WO 2012 / 036121. The contents of WO 2012 / 036121 are incorporated herein by reference in their entirety.

[0217] Another example of the brush polymer is the random copolymer described in claim 1 of JP 2013-166934 A. The contents of JP 2013-166934 A are incorporated herein by reference in their entirety to the same extent as if set forth explicitly herein.

[0218] Another example of the brush polymer is a polymer having 0.2 mol% or more of a polycyclic aromatic vinyl compound unit structure per total unit structure. Examples of such polymers include the polymers contained in the underlayer film-forming composition described in International Publication No. 2014 / 097993. The contents of International Publication No. 2014 / 097993 are incorporated herein by reference in their entirety.

[0219] Another example of a brush polymer is the polymer contained in the brush backfill composition described in JP 2015-130496 A (e.g., poly(alkyl acrylate) having functional groups capable of reacting with semiconductor substrates), the contents of which are incorporated herein by reference in their entirety to the same extent as if set forth herein.

[0220] Another example of the brush polymer is the addition polymer described in claim 1 of JP 2016-148024 A. The contents of JP 2016-148024 A are incorporated herein by reference in their entirety to the same extent as if set forth explicitly herein.

[0221] Another example of the brush polymer is the polymer contained in the pinning material described in claim 1 of JP-T-2016-528713. Such a polymer is, for example, the polymer described in claim 3 of JP-T-2016-528713. The contents of JP-T-2016-528713 are incorporated herein by reference in their entirety to the same extent as if set forth explicitly herein.

[0222] Another example of a brush polymer is an acid-sensitive copolymer comprising an acid-decomposable group, an attachment group, and a functional group, as described in claim 1 of JP 2018-139007 A. The contents of JP 2018-139007 A are incorporated herein by reference in their entirety to the same extent as if set forth herein.

[0223] Another example of the brush polymer is the hydrophobic polymer brush precursor described in claim 1 of JP-T-2018-503241, the contents of which are incorporated herein by reference in their entirety to the same extent as if set forth herein.

[0224] The brush polymer preferably has a functional group capable of bonding to a substrate. Examples of functional groups capable of bonding to a substrate include a hydroxy group, an amino group, and a sulfonic acid group. The brush polymer may have the functional group capable of bonding to a substrate at the end of the polymer chain, or at a location other than the end of the polymer chain. There are no particular limitations on the method for introducing the functional group capable of bonding to a substrate into the end of the polymer chain. For example, in the case of an addition polymerization type polymer, a method may be used in which a compound having a functional group capable of bonding to a substrate is used as a polymerization initiator or chain transfer agent.

[0225] The brush polymer is preferably an addition polymerization type polymer obtained, for example, by polymerizing one or more radically polymerizable monomers.

[0226] The radical polymerizable monomer is not particularly limited, and examples thereof include (meth)acrylic compounds, aromatic group-containing vinyl compounds, etc. Examples of the (meth)acrylic compound include (meth)acrylic acid, (meth)acrylic acid esters, etc. Examples of the (meth)acrylic acid esters include methyl (meth)acrylate, ethyl (meth)acrylate, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, sec-butyl (meth)acrylate, and tert-butyl (meth)acrylate. Examples of aromatic group-containing vinyl compounds include styrene, α-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 4-t-butylstyrene, 4-n-octylstyrene, 2,4,6-trimethylstyrene, 4-methoxystyrene, 4-t-butoxystyrene, 4-hydroxystyrene, 4-nitrostyrene, 3-nitrostyrene, 4-chlorostyrene, 4-fluorostyrene, 4-acetoxyvinylstyrene, vinylcyclohexane, 4-vinylbenzyl chloride, 1-vinylnaphthalene, 4-vinylbiphenyl, 1-vinyl-2-pyrrolidone, 9-vinylanthracene, and vinylpyridine.

[0227] <<<<<Polymer (P)>>>> The brush polymer is preferably a polymer (P) containing the following structural units (A) and (B), in that a microphase-separated structure of the block copolymer can be induced perpendicular to the substrate. Structural unit (A): a structural unit derived from a (meth)acrylic compound having a (meth)acryloyl group and a functional group capable of bonding to the substrate. Structural unit (B): a structural unit derived from an aromatic group-containing vinyl compound.

[0228] The molar ratio of the structural unit (A) to all structural units in the polymer (P) is more than 0% and not more than 5%. When the molar ratio of the structural unit (A) to all structural units in the polymer (P) is more than 0% and not more than 5%, a film can be formed in which a microphase-separated structure of the block copolymer is induced perpendicular to the substrate. When the molar ratio of the structural unit (A) to all structural units in the polymer (P) exceeds 5%, the arrangement of the microphase-separated structure of the block copolymer becomes disordered, and it is not possible to induce a microphase-separated structure of the block copolymer perpendicular to the substrate.

[0229] The polymer (P) is not particularly limited as long as it contains the structural units (A) and (B), but is preferably an addition polymer obtained by polymerizing a compound having a polymerizable unsaturated group. Examples of the polymerizable unsaturated group include an ethylenically unsaturated group. Examples of the ethylenically unsaturated group include a vinyl group, an allyl group, a propargyl group, a butenyl group, an ethynyl group, a phenylethynyl group, a maleimide group, a nadimide group, and a (meth)acryloyl group.

[0230] The polymer (P) is, for example, a random copolymer.

[0231] The polymer (P) may contain structural units other than the structural units (A) and (B).

[0232] The structural unit (A) is a structural unit derived from a (meth)acrylic compound. The (meth)acrylic compound has a (meth)acryloyl group. The (meth)acrylic compound has a functional group capable of bonding to a substrate. The (meth)acryloyl group is a notation that indicates an acryloyl group and a methacryloyl group. The acryloyl group is a CH ２ =CH-CO-, and a methacryloyl group is a group represented by CH ２ =C(CH ３ )-CO-.

[0233] The functional group capable of bonding to a substrate is not particularly limited, and examples thereof include a hydroxy group, an amino group, and a sulfonic acid group. The number of functional groups capable of bonding to a substrate in the structural unit (A) may be one or two or more, but is preferably one. The number of (meth)acryloyl groups in the (meth)acrylic compound may be one or two or more, but is preferably one.

[0234] The structural unit (A) is a structural unit different from the structural unit (B), and therefore the structural unit (B) does not have an aromatic ring.

[0235] The structural unit (A) in the polymer (P) may be of one type or of two or more types.

[0236] The structural unit (A) preferably contains a structural unit (A-1) represented by the following formula (1). (In formula (1), X represents —O— or —NH—. Y represents a hydroxy group, an amino group, or a sulfonic acid group. R １ represents an alkylene group having 1 to 10 carbon atoms which may be substituted with a halogen atom. ２ represents a hydrogen atom or a methyl group.

[0237] The amino group is preferably a primary amino group or a secondary amino group. A primary amino group is a monovalent functional group (—NH ２ A secondary amino group refers to a monovalent functional group (-NHR (wherein R represents an organic group) formed by removing a hydrogen atom from a primary amine. R represents, for example, an alkyl group having 1 to 6 carbon atoms.

[0238] The alkylene group having 1 to 10 carbon atoms and optionally substituted with a halogen atom may be linear, branched, or cyclic. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. The number of halogen atoms in the alkylene group having 1 to 10 carbon atoms and optionally substituted with a halogen atom may be one or two or more.

[0239] The alkylene group having 1 to 10 carbon atoms may be a linear or branched alkylene group, and examples thereof include a methylene group, an ethylene group, a 1,3-propylene group (a trimethylene group), a 1-methylethylene group (a 1,2-propylene group), a 1,4-butylene group, a 1-ethylethylene group, a 1-methylpropylene group, a 2-methylpropylene group, a 1,5-pentylene group, a 1-methylbutylene group, a 2-methylbutylene group, a 1,1-dimethylpropylene group, a 1,2-dimethylpropylene group, a 1-ethylpropylene group, a 2-ethylpropylene group, a 1,6-hexylene group, a 1,4-cyclohexylene group, a 1,8-octylene group, a 2-ethyloctylene group, a 1,9-nonylene group, and a 1,10-decylene group.

[0240] The molar ratio of the structural unit (A) to all structural units in the polymer (P) is more than 0% and 5% or less, preferably 0.1% or more and 5% or less, more preferably 0.3% or more and 4.5% or less, and particularly preferably 0.5% or more and 4.0% or less.

[0241] Examples of the (meth)acrylic compound include compounds represented by the following formula (1-1). (In formula (1-1), X represents —O— or —NH—. Y represents a hydroxy group, an amino group, or a sulfonic acid group. R １ represents an alkylene group having 1 to 10 carbon atoms which may be substituted with a halogen atom. ２ represents a hydrogen atom or a methyl group.

[0242] Examples of the (meth)acrylic compound include hydroxy group-containing (meth)acrylates, amino group-containing (meth)acrylates, sulfonic acid group-containing (meth)acrylates, hydroxy group-containing (meth)acrylamides, and sulfonic acid group-containing (meth)acrylamides.

[0243] Examples of hydroxy group-containing (meth)acrylates include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, and 1,4-cyclohexanedimethanol mono(meth)acrylate.

[0244] Examples of amino group-containing (meth)acrylates include primary amino group-containing (meth)acrylates and secondary amino group-containing (meth)acrylates. Examples of primary amino group-containing (meth)acrylates include aminomethyl (meth)acrylate and aminoethyl (meth)acrylate. Examples of secondary amino group-containing (meth)acrylates include t-butylaminoethyl (meth)acrylate and t-butylaminopropyl (meth)acrylate.

[0245] Examples of sulfonic acid group-containing (meth)acrylates include 2-sulfoethyl (meth)acrylate and 3-sulfopropyl (meth)acrylate.

[0246] Examples of hydroxy group-containing (meth)acrylamides include N-(hydroxymethyl)(meth)acrylamide, N-(2-hydroxyethyl)(meth)acrylamide, and N-(4-hydroxybutyl)(meth)acrylamide.

[0247] The structural unit (B) is a structural unit derived from an aromatic group-containing vinyl compound. The aromatic ring contained in the aromatic group-containing vinyl compound may be an aromatic hydrocarbon ring or an aromatic heterocycle, but an aromatic hydrocarbon ring is preferred. Examples of the aromatic hydrocarbon ring include a benzene ring, a naphthalene ring, and an anthracene ring. The aromatic group-containing vinyl compound does not have, for example, a functional group capable of bonding to a substrate. The aromatic group-containing vinyl compound does not have, for example, a hydroxy group, an amino group, or a sulfonic acid group.

[0248] The structural unit (B) does not have, for example, a functional group capable of bonding to a substrate, such as a hydroxy group, an amino group, or a sulfonic acid group.

[0249] The structural unit (B) in the polymer (P) may be of one type or of two or more types.

[0250] The structural unit (B) preferably contains a structural unit (B-1) represented by the following formula (2): The structural unit (B) preferably contains a structural unit (B-2) represented by the following formula (3): (In formula (2), n Ys each independently represent a halogen atom, an alkyl group, an alkoxy group, an alkoxycarbonyl group, or a thioalkyl group, and n represents an integer of 0 to 7.) (In formula (3), R ３ ~R ５ each independently represents a hydrogen atom or a tert-butyl group. ３ ~R ５ One or two of represents a tert-butyl group.

[0251] Examples of the halogen atom for Y in formula (2) include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. The alkyl group for Y in formula (2) is preferably an alkyl group having 1 to 15 carbon atoms, more preferably an alkyl group having 1 to 10 carbon atoms, even more preferably an alkyl group having 1 to 6 carbon atoms, and particularly preferably an alkyl group having 1 to 3 carbon atoms. The alkyl group may be linear, branched, or cyclic. The alkoxy group for Y in formula (2) is preferably an alkoxy group having 1 to 15 carbon atoms, more preferably an alkoxy group having 1 to 10 carbon atoms, even more preferably an alkoxy group having 1 to 6 carbon atoms, and particularly preferably an alkoxy group having 1 to 3 carbon atoms. The alkyl group in the alkoxy group may be linear, branched, or cyclic. The alkoxycarbonyl group for Y in formula (2) is preferably an alkoxycarbonyl group having 2 to 15 carbon atoms, more preferably an alkoxycarbonyl group having 2 to 10 carbon atoms, even more preferably an alkoxycarbonyl group having 2 to 6 carbon atoms, and particularly preferably an alkoxycarbonyl group having 2 to 3 carbon atoms. The alkyl group in the alkoxycarbonyl group may be linear, branched, or cyclic. Examples of the thioalkyl group for Y in formula (2) include groups in which -O- of the above alkoxy group is replaced with -S-.

[0252] The molar ratio of the structural unit (B) to all structural units in the polymer (P) is not particularly limited, but is preferably 80% or more and less than 100%, more preferably 90% or more and less than 100%, and particularly preferably more than 95% and less than 100%.

[0253] The molar ratio of the structural unit (A) to the structural unit (B) in the polymer (P) (structural unit (A):structural unit (B)) is not particularly limited, but is preferably 1:200 to 1:10, and more preferably 1:150 to 1:20.

[0254] When the polymer (P) contains the structural unit (B-1) represented by formula (2), the molar ratio of the structural unit (A) to the structural unit (B-1) in the polymer (P) (structural unit (A):structural unit (B-1)) is not particularly limited, but is preferably 1:100 to 1:5, and more preferably 1:75 to 1:10.

[0255] When the polymer (P) contains the structural unit (B-2) represented by formula (3), the molar ratio of the structural unit (A) to the structural unit (B-2) in the polymer (P) (structural unit (A):structural unit (B-2)) is not particularly limited, but is preferably 1:100 to 1:5, and more preferably 1:75 to 1:10.

[0256] When the polymer (P) contains the structural unit (B-1) represented by formula (2) and the structural unit (B-2) represented by formula (3), the molar ratio of the structural unit (B-1) to the structural unit (B-2) in the polymer (P) (structural unit (B-1):structural unit (B-2)) is not particularly limited, but is preferably 1.0:0.1 to 0.1:1.0, more preferably 1.0:0.5 to 0.5:1.0, and particularly preferably 1.0:0.7 to 0.7:1.0.

[0257] Examples of the aromatic group-containing vinyl compound include a compound represented by the following formula (2-1) and a compound represented by the following formula (3-1). (In formula (2-1), n ​​Ys each independently represent a halogen atom, an alkyl group, an alkoxy group, an alkoxycarbonyl group, or a thioalkyl group, and n represents an integer of 0 to 7.) (In formula (3-1), R ３ ~R ５ each independently represents a hydrogen atom or a tert-butyl group. ３ ~R ５ One or two of represents a tert-butyl group.

[0258] The weight average molecular weight of the brush polymer measured by gel permeation chromatography (GPC) is not particularly limited, but is, for example, 1,000 to 50,000, and preferably 2,000 to 20,000, in terms of polystyrene.

[0259] <<<<<Method for Producing Brush Polymers>>>> The method for producing a brush polymer is not particularly limited. For example, when the brush polymer is an addition polymerization type polymer, it can be produced by polymerizing monomers by a conventional method, such as bulk polymerization, solution polymerization, suspension polymerization, or emulsion polymerization. Solution polymerization is particularly preferred, and in this case, for example, polymerization can be carried out by adding the desired monomer to a solvent to which a polymerization initiator has been added. For example, when the brush polymer is an addition polymerization type random copolymer, it can be produced by copolymerizing various monomers to an appropriate molar ratio by a conventional method, such as bulk polymerization, solution polymerization, suspension polymerization, or emulsion polymerization. Examples of such polymerization include radical polymerization. The brush polymer can also be produced by a polymerization method other than radical polymerization. For example, it can be produced by ionic (anionic or cationic) addition polymerization, polycondensation, or polyaddition reaction.

[0260] The polymer (P) can be produced, for example, by solution polymerization of a monomer mixture containing a (meth)acrylic compound having a (meth)acryloyl group and a functional group capable of bonding to a substrate, and an aromatic group-containing vinyl compound.

[0261] [Polymerization Initiator] As the polymerization initiator, an organic peroxide or a diazo compound can be used.

[0262] Examples of organic peroxides include diacyl peroxides, peroxydicarbonates, peroxyesters, and peroxysulfonates. Examples of diacyl peroxides include diacetyl peroxide, diisobutyl peroxide, didecanoyl peroxide, benzoyl peroxide, and succinic acid peroxide. Examples of peroxydicarbonates include diisopropyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, and diallyl peroxydicarbonate. Examples of peroxyesters include tert-butyl peroxyisobutyrate, tert-butyl neodecanoate, and cumene peroxyneodecanate. Examples of peroxysulfonates include acetylcyclohexylsulfonyl peroxide.

[0263] Examples of diazo compounds include 2,2'-azobisisobutyronitrile, 4,4'-azobis(4-cyanovaleric acid), 2,2'-azobis(4-methoxy-2,4-dimethoxyvaleronitrile), and 2,2'-azobis(2-cyclopropylpropionitrile).

[0264] When it is desired to complete the polymerization in a short time, it is preferable to use a polymerization initiator having a decomposition half-life of 10 hours or less at 80° C. As such a polymerization initiator, benzoyl peroxide and 2,2′-azobisisobutyronitrile are preferred, and 2,2′-azobisisobutyronitrile is more preferred.

[0265] The amount of the polymerization initiator used is, for example, 0.0001 to 0.2 equivalents, and preferably 0.0005 to 0.1 equivalents, based on the total amount of the monomers used.

[0266] [Solvent] The solvent used in the polymerization is not particularly limited as long as it is inert to the polymerization reaction and compatible with the resulting brush polymer. Examples of the solvent include aromatic hydrocarbons, alicyclic hydrocarbons, aliphatic hydrocarbons, ketones, ethers, esters, amides, sulfoxides, alcohols, and polyhydric alcohol derivatives. Examples of aromatic hydrocarbons include benzene, toluene, and xylene. Examples of alicyclic hydrocarbons include cyclohexane. Examples of aliphatic hydrocarbons include n-hexane and n-octane. Examples of ketones include acetone, methyl ethyl ketone, and cyclohexanone. Examples of ethers include tetrahydrofuran and dioxane. Examples of esters include ethyl acetate and butyl acetate. Examples of amides include N,N-dimethylformamide and N,N-dimethylacetamide. Examples of sulfoxides include dimethyl sulfoxide. Examples of alcohols include methanol and ethanol. Examples of polyhydric alcohol derivatives include ethylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate, etc. These may be used alone or in combination of two or more.

[0267] The polymerization temperature is not particularly limited as long as it is within a temperature range in which side reactions such as transfer reactions and termination reactions do not occur and the monomer is consumed to complete the polymerization, but it is preferably carried out within a temperature range of -100°C or higher and the boiling point of the solvent or lower. The concentration of the monomer relative to the solvent is not particularly limited, but is usually 1 to 40% by mass, preferably 10 to 30% by weight. The polymerization reaction time can be appropriately selected, but is usually within a range of 2 to 50 hours.

[0268] <<<Solvent>>> The solvent contained in the brush layer-forming composition is not particularly limited as long as it dissolves the brush polymer. Examples of the solvent include propylene glycol monomethyl ether (PGME), propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monopropyl ether, methyl ethyl ketone, ethyl lactate, cyclohexanone, N,N-2-trimethylpropionamide, γ-butyrolactone, N-methyl-2-pyrrolidone, methyl 2-hydroxyisobutyrate, and ethyl 3-ethoxypropionate. These can be used alone or in combination of two or more.

[0269] The content of the solvent in the brush layer-forming composition is not particularly limited, but is, for example, 90% by mass or more and 99.9% by mass or less.

[0270] <<<Other Components>>> The brush layer-forming composition preferably does not contain a crosslinking agent. For example, by reacting the brush polymer with the substrate, the film obtained from the brush layer-forming composition becomes a film that is insoluble in the solvent contained in the self-assembled film-forming composition containing the block copolymer. Therefore, the brush layer-forming composition does not need to contain a crosslinking agent. In the present invention, "not containing a crosslinking agent" may also include the inclusion of a small amount of crosslinking agent to the extent that it does not fully function as a crosslinking agent. In an embodiment in which the brush layer-forming composition does not contain a crosslinking agent, the content of the crosslinking agent in the brush layer-forming composition is preferably less than 0.1% by mass, more preferably 0.01% by mass or less, and particularly preferably 0.001% by mass or less, relative to the brush polymer.

[0271] Examples of the crosslinking agent include nitrogen-containing compounds having 2 to 4 nitrogen atoms substituted with methylol groups or alkoxymethyl groups.

[0272] Examples of crosslinking agents include hexamethoxymethylmelamine, tetramethoxymethylglycoluril, tetramethoxymethylbenzoguanamine, 1,3,4,6-tetrakis(methoxymethyl)glycoluril, 1,3,4,6-tetrakis(butoxymethyl)glycoluril, 1,3,4,6-tetrakis(hydroxymethyl)glycoluril, 1,3-bis(hydroxymethyl)urea, 1,1,3,3-tetrakis(butoxymethyl)urea, and 1,1,3,3-tetrakis(methoxymethyl)urea.

[0273] The brush layer-forming composition may contain a surfactant. The surfactant is an additive for improving the coatability to the substrate. Known surfactants such as nonionic surfactants and fluorine-based surfactants can be used as the surfactant. The content of the surfactant in the brush layer-forming composition is, for example, 0.1% by mass to 5% by mass relative to the brush polymer.

[0274] In the brush layer-forming composition, if the components excluding the solvent are defined as the solid content, the solid content includes the brush polymer and additives added as needed. The concentration of the solid content in the brush layer-forming composition is not particularly limited, but is, for example, 0.1% by mass to 15% by mass, and preferably 0.1% by mass to 10% by mass.

[0275] <Surface Modification Step> An example of a method for manufacturing a semiconductor element includes a surface modification step. The surface modification is preferably performed by a dry process. Examples of dry processes include plasma treatment, corona treatment, and UV treatment. In the plasma treatment, for example, O ２ , CO ２ , CO, etc. are used. The plasma treatment is sometimes called plasma etching. The conditions for the dry process are not particularly limited.

[0276] The surface-modified portion of the underlayer film may have improved adhesion to the brush layer formed thereon, or may lose its function as a film capable of forming vertical alignment (e.g., a neutral film).

[0277] <Step of Removing Resist Pattern> One example of a method for manufacturing a semiconductor device includes a step of removing the resist pattern. The resist pattern is removed by, for example, etching. The etching may be dry etching or wet etching.

[0278] An example of a method for manufacturing a semiconductor device of the present invention will be described with reference to the drawings. FIGS. 1A to 1F are schematic cross-sectional views illustrating an example of the method for manufacturing a semiconductor device of the present invention. An underlayer film 2 is formed on a semiconductor substrate 1 using an underlayer film-forming composition of the present invention ( FIG. 1A ). Next, a resist film 3 is formed on the underlayer film 2 ( FIG. 1B ). The resist film 3 is then irradiated with light or an electron beam, and subsequently developed to obtain a resist pattern (patterned resist film) 3a ( FIG. 1C ). Next, a self-assembled film 4 is formed between the resist patterns 3a and on at least a portion of the underlayer film 2 ( FIG. 1D ). The self-assembled film 4 is, for example, a film of a block copolymer having an A block and a B block. By phase-separating the self-assembled film 4, a microphase-separated structure having domains 4a of the A block and domains 4b of the B block is obtained ( FIG. 1D ). Next, by selectively removing a portion of the microphase-separated self-assembled film 4 (e.g., domains 4b of the B block), a pattern corresponding to the morphology of the microphase-separated domains is obtained ( FIG. 1E ). Next, the underlayer film 2 is etched using a pattern corresponding to the morphology of the microphase-separated domains as a mask to obtain a patterned underlayer film 2a (FIG. 1F). Although not shown, in a further step, the semiconductor substrate 1 may be processed using the patterned underlayer film 2a as a mask.

[0279] Another example of the method for manufacturing a semiconductor device of the present invention will be described with reference to the drawings. FIGS. 2A to 2H are schematic cross-sectional views illustrating another example of the method for manufacturing a semiconductor device of the present invention. An underlayer film 2 is formed on a semiconductor substrate 1 using an underlayer film-forming composition of the present invention ( FIG. 2A ). Next, a resist film 3 is formed on the underlayer film 2 ( FIG. 2B ). The resist film 3 is then irradiated with light or an electron beam, and the resist film 3 is then developed to obtain a resist pattern (patterned resist film) 3a ( FIG. 2C ). Next, a brush layer 5 is formed between the resist patterns 3a and on at least a portion of the underlayer film 2 ( FIG. 2D ). The resist pattern 3a is then removed ( FIG. 2E ). Next, a self-assembled film 4 is formed on the brush layer 5 and the exposed underlayer film 2 ( FIG. 2F ). The self-assembled film 4 is, for example, a film of a block copolymer having an A block and a B block. By phase-separating the self-assembled film 4 on the underlayer film 2, a microphase-separated structure having domains 4a of the A block and domains 4b of the B block is obtained. On the other hand, the self-assembled film 4 on the brush layer 5 does not phase separate, and therefore non-phase-separated domains 4c are formed on the brush layer 5 (FIG. 2F). Next, a portion of the microphase-separated self-assembled film 4 (e.g., domains 4b of the B block) is selectively removed to obtain a pattern corresponding to the morphology of the microphase-separated domains (FIG. 2G). Next, the underlayer film 2 is etched using the pattern corresponding to the morphology of the microphase-separated domains as a mask to obtain a patterned underlayer film 2a (FIG. 2H). Although not shown, in a further step, the semiconductor substrate 1 may be processed using the patterned underlayer film 2a as a mask.

[0280] Another example of the method for manufacturing a semiconductor device of the present invention will be described with reference to the drawings. FIGS. 3A to 3I are schematic cross-sectional views illustrating another example of the method for manufacturing a semiconductor device of the present invention. An underlayer film 2 is formed on a semiconductor substrate 1 using an underlayer film-forming composition of the present invention ( FIG. 3A ). Next, a resist film 3 is formed on the underlayer film 2 ( FIG. 3B ). The resist film 3 is then irradiated with light or an electron beam, and then developed to obtain a resist pattern (patterned resist film) 3a ( FIG. 3C ). Next, the underlayer film 2 exposed between the resist patterns 3a is surface-modified by a dry process ( FIG. 3D ). Next, a brush layer 5 is formed on the surface-modified underlayer film 2 (surface-modified region 2x) ( FIG. 3E ). Next, the resist pattern 3a is removed ( FIG. 3F ). Next, a self-assembled film 4 is formed on the brush layer 5 and the exposed underlayer film 2 ( FIG. 3G ). The self-assembled film 4 is, for example, a film of a block copolymer having an A block and a B block. By phase-separating the self-assembled monolayer 4 on the underlayer film 2, a microphase-separated structure having A block domains 4a and B block domains 4b is obtained. On the other hand, the self-assembled monolayer 4 on the brush layer 5 does not phase-separate, so non-phase-separated domains 4c are formed on the brush layer 5 ( FIG. 3G ). Next, by selectively removing a portion of the microphase-separated self-assembled monolayer 4 (e.g., B block domains 4b), a pattern corresponding to the morphology of the microphase-separated domains is obtained ( FIG. 3H ). Next, the underlayer film 2 is etched using the pattern corresponding to the morphology of the microphase-separated domains as a mask, to obtain a patterned underlayer film 2a ( FIG. 3I ). Although not shown, in a further step, the semiconductor substrate 1 may be processed using the patterned underlayer film 2a as a mask.

[0281] Another example of the method for manufacturing a semiconductor device of the present invention will be described with reference to the drawings. FIGS. 4A to 4H are schematic cross-sectional views illustrating another example of the method for manufacturing a semiconductor device of the present invention. An underlayer film 2 is formed on a semiconductor substrate 1 using an underlayer film-forming composition of the present invention ( FIG. 4A ). Next, a resist film 3 is formed on the underlayer film 2 ( FIG. 4B ). Next, the resist film 3 is irradiated with light or an electron beam, and then developed to obtain a resist pattern (patterned resist film) 3a ( FIG. 4C ). Next, the underlayer film 2 exposed between the resist patterns 3a is surface-modified by a dry process ( FIG. 4D ). Next, the resist pattern 3a is removed ( FIG. 4E ). Next, a self-assembled film 4 is formed on the underlayer film 2 including the surface-modified region 2x ( FIG. 4F ). The self-assembled film 4 is, for example, a film of a block copolymer having an A block and a B block. By phase-separating the self-assembled monolayer 4 on the underlayer film 2 in the region other than the surface-modified region 2x, a microphase-separated structure having A-block domains 4a and B-block domains 4b is obtained. On the other hand, the self-assembled monolayer 4 on the surface-modified region 2x does not phase-separate, resulting in non-phase-separated domains 4c on the surface-modified region 2x ( FIG. 4F ). Next, by selectively removing a portion of the microphase-separated self-assembled monolayer 4 (e.g., B-block domains 4b), a pattern corresponding to the morphology of the microphase-separated domains is obtained ( FIG. 4G ). Next, the underlayer film 2 is etched using the pattern corresponding to the morphology of the microphase-separated domains as a mask, resulting in a patterned underlayer film 2a ( FIG. 4H ). Although not shown, in a further step, the semiconductor substrate 1 may be processed using the patterned underlayer film 2a as a mask.

[0282] The present invention will be explained in more detail below with reference to synthesis examples and examples, but the present invention is not limited to the following examples.

[0283] In the examples, the apparatus and conditions used for analyzing the physical properties of samples are as follows. (1) Molecular Weight Measurement The molecular weight of the polysiloxane used in the present invention is the molecular weight obtained by GPC analysis in terms of polystyrene. The GPC measurement conditions are a GPC apparatus (trade name HLC-8220GPC, manufactured by Tosoh Corporation), a GPC column (trade name Shodex (registered trademark) KF803L, KF802, KF801, manufactured by Showa Denko K.K.), a column temperature of 40°C, tetrahydrofuran as eluent (elution solvent), a flow rate (flow rate) of 1.0 mL / min, and polystyrene (manufactured by Showa Denko K.K.) as a standard sample.

[0284] Compounds 1 to 4 used in each synthesis are shown below. In the above formula, Me represents a methyl group and Et represents an ethyl group.

[0285] [1] Synthesis of Hydrolysis Condensate (Polysiloxane) <Synthesis Example 1> 22.9 g of compound 1, 8.8 g of compound 2, and 47.5 g of 1-ethoxy-2-propanol were placed in a 200 mL flask and stirred. The resulting solution was stirred with a magnetic stirrer, and 20.8 g of a 0.2 mol / L aqueous solution of nitric acid was added dropwise thereto. After the dropwise addition, the flask was transferred to an oil bath adjusted to 65°C, and the reaction was allowed to proceed for 20 hours. Thereafter, the reaction solution was cooled to room temperature, and 50 g of 1-ethoxy-2-propanol was added to the reaction solution. Water, nitric acid, and the reaction by-products methanol and ethanol were distilled off under reduced pressure to obtain a concentrated solution of hydrolysis condensate (polymer 1) in which 1-ethoxy-2-propanol was used as a solvent. The solids concentration of the resulting concentrated solution exceeded 20% by mass in terms of solid residue when heated at 150°C. The weight average molecular weight (Mw) of the obtained hydrolysis condensate (polymer 1: polysiloxane) measured by GPC was 1,000 in terms of polystyrene.

[0286] Synthesis Example 2 16.6 g of compound 1, 14.9 g of compound 2, and 47.3 g of 1-ethoxy-2-propanol were placed in a 200 mL flask and stirred. The resulting solution was stirred with a magnetic stirrer, and 21.1 g of a 0.2 mol / L aqueous solution of nitric acid was added dropwise thereto. After the dropwise addition, the flask was transferred to an oil bath adjusted to 65°C, and the reaction was allowed to proceed for 20 hours. Thereafter, the reaction solution was cooled to room temperature, and 50 g of 1-ethoxy-2-propanol was added to the reaction solution. Water, nitric acid, and the reaction by-products methanol and ethanol were distilled off under reduced pressure to obtain a concentrated solution of a hydrolysis condensate (polymer 2) using 1-ethoxy-2-propanol as a solvent. The solids concentration of the resulting concentrated solution exceeded 20% by mass in terms of solid residue when heated at 150°C. The weight average molecular weight (Mw) of the obtained hydrolysis condensate (polymer 2: polysiloxane) measured by GPC was 1,200 in terms of polystyrene.

[0287] Synthesis Example 3 8.2 g of compound 2, 24.2 g of compound 3, and 48.5 g of 1-ethoxy-2-propanol were placed in a 200 mL flask and stirred. The resulting solution was stirred with a magnetic stirrer, and 19.2 g of a 0.2 mol / L aqueous solution of nitric acid was added dropwise thereto. After the dropwise addition, the flask was transferred to an oil bath adjusted to 65°C, and the reaction was allowed to proceed for 20 hours. Thereafter, the reaction solution was cooled to room temperature, and 50 g of 1-ethoxy-2-propanol was added to the reaction solution. Water, nitric acid, and the reaction by-products methanol and ethanol were distilled off under reduced pressure to obtain a concentrated solution of a hydrolysis condensate (polymer 3) using 1-ethoxy-2-propanol as a solvent. The solids concentration of the resulting concentrated solution exceeded 20% by mass in terms of solid residue when heated at 150°C. The weight average molecular weight (Mw) of the obtained hydrolysis condensate (polymer 3: polysiloxane) measured by GPC was 1,200 in terms of polystyrene.

[0288] Synthesis Example 4 32.7 g of compound 3 and 49.1 g of 1-ethoxy-2-propanol were placed in a 200 mL flask and stirred. The resulting solution was stirred with a magnetic stirrer, and 18.2 g of a 0.2 mol / L aqueous solution of nitric acid was added dropwise thereto. After the dropwise addition, the flask was transferred to an oil bath adjusted to 65°C, and the reaction was allowed to proceed for 20 hours. The reaction solution was then cooled to room temperature, and 50 g of 1-ethoxy-2-propanol was added to the reaction solution. Water, nitric acid, and the reaction by-product methanol were distilled off under reduced pressure to obtain a concentrated solution of a hydrolysis condensation product (polymer 4) using 1-ethoxy-2-propanol as a solvent. The solids concentration of the resulting concentrated solution exceeded 20% by mass, calculated as the solid residue when heated at 150°C. The weight-average molecular weight (Mw) of the resulting hydrolysis condensation product (polymer 4: polysiloxane) measured by GPC was 1,000, calculated as polystyrene.

[0289] Comparative Synthesis Example 1 21.0 g of compound 2, 10.5 g of compound 4, and 47.3 g of 1-ethoxy-2-propanol were placed in a 200 mL flask and stirred. The resulting solution was stirred with a magnetic stirrer, and 21.2 g of a 0.2 mol / L aqueous solution of nitric acid was added dropwise thereto. After the dropwise addition, the flask was transferred to an oil bath adjusted to 65°C, and the reaction was allowed to proceed for 20 hours. Thereafter, the reaction solution was cooled to room temperature, and 50 g of 1-ethoxy-2-propanol was added to the reaction solution. Water, nitric acid, and the reaction by-product ethanol were distilled off under reduced pressure to obtain a concentrated solution of a hydrolysis condensate (polymer 5) using 1-ethoxy-2-propanol as a solvent. The solids concentration of the resulting concentrated solution exceeded 20% by mass in terms of solid residue when heated at 150°C. The weight average molecular weight (Mw) of the obtained hydrolysis condensate (Polymer 5: polysiloxane) measured by GPC was 1,300 in terms of polystyrene.

[0290] [2] Preparation Examples 1 to 4 and Comparative Preparation Example 1: Preparation of compositions (coating solutions) for forming silicon-containing underlayer films Hydrolyzed condensates (polymers) 1 to 4 obtained in the above Synthesis Examples and the hydrolyzed condensate (polymer) of the Comparative Synthesis Example were mixed with additives and solvents in the proportions shown in Table 1, and filtered through a 0.02 μm polyethylene filter to prepare compositions for forming silicon-containing underlayer films. The amounts of each additive in Table 1 are shown in parts by mass. In Table 1, the 0.5 parts by mass of each polymer listed in the composition column means that the hydrolyzed condensate is 0.5 parts by mass.

[0291] In Table 1, the abbreviations are as follows: PGEE: Propylene glycol monoethyl ether PGME: Propylene glycol monomethyl ether DIW: Ultrapure water Add. 1: The following structural formula (Add. 1) Add. 2: The following structural formula (Add. 2)

[0292]

[0293] <Preparation of Self-Assembled Film-Forming Composition 1> 0.5 g of a block copolymer, polystyrene / poly(methyl methacrylate) copolymer (manufactured by POLYMER SOURCE INC., PS (Mw: 39,800, Mn: 37,500)-b-PMMA (Mw: 19,100, Mn: 18,000), polydispersity index = 1.06), was dissolved in 24.5 g of propylene glycol monomethyl ether acetate to prepare a 2 mass % solution, which was then filtered using a polyethylene microfilter with a pore size of 0.02 μm, to prepare self-assembled film-forming composition 1 containing block copolymer 1.

[0294] <Evaluation of Self-Assembly of Block Copolymer 1> [Example A] The silicon-containing underlayer film-forming compositions obtained in Preparation Examples 1 to 4 and Comparative Preparation Example 1 were each applied to a silicon wafer and heated on a hot plate at 240°C for 1 minute to obtain a coating film having a thickness of 5 to 10 nm. The self-assembled film-forming composition 1 prepared above was applied thereon using a spin coater and heated on a hot plate in a nitrogen atmosphere at 260°C for 5 minutes to induce a microphase-separated structure of a self-assembled film having a thickness of 40 nm.

[0295] <Observation of Microphase Separation Structure> The silicon wafer in which the microphase separation structure was induced was etched using an etching apparatus (Lam 2300 Versys Kiyo45) manufactured by Lam Research, with O 2 as the etching gas. ２ / N ２ The poly(methyl methacrylate) region was preferentially etched by etching using gas for 3 seconds, and then the shape was observed using an electron microscope (CG-4100 length measurement scanning electron microscope, manufactured by Hitachi High-Tech Corporation). The observed results, i.e., the alignment direction and alignment of the block copolymer (BCP), are shown in Table 2. When the BCP exhibited the desired vertical alignment, it was rated as "good." When the BCP exhibited only vertical alignment throughout the entire observed image, it was rated as "very good." When an alignment other than vertical alignment was exhibited, it was rated as "poor." The results of observation at 200,000x magnification for Comparative Example 1 are shown in Figure 5.

[0296]

[0297] <Evaluation of Block Copolymer Self-Assembly 2> [Example B] The silicon-containing underlayer film-forming compositions obtained in Preparation Examples 1 to 4 were each applied to a silicon wafer and heated on a hot plate at 240°C for 1 minute to obtain a coating film with a thickness of 5 to 10 nm. The coating film was exposed to light using an ArF exposure system (Nikon) under specified conditions, with the left half of the silicon wafer on which the coating film had been formed. After exposure, the wafer was developed and rinsed with ultrapure water. Butyl acetate or NMD-3 (a tetramethylammonium hydroxide-based developer, Tokyo Ohka Kogyo Co., Ltd.) was used as the developer. Note that a neutral film remained after development. The self-assembled film-forming composition 1 prepared above was applied thereon using a spin coater and heated on a hot plate at 260°C for 5 minutes in a nitrogen atmosphere to induce a microphase-separated structure in a self-assembled film with a thickness of 40 nm. The reason for ArF exposure and development of the neutral film is that in semiconductor manufacturing processes using self-assembled films, exposure and development are sometimes performed when patterning the neutral film using photoresist, and this evaluation was performed under conditions similar to those of that process.

[0298] <Observation of Microphase Separation Structure> The silicon wafer in which the microphase separation structure was induced was etched using an etching apparatus (Lam 2300 Versys Kiyo45) manufactured by Lam Research, with O 2 as the etching gas. ２ / N ２ The poly(methyl methacrylate) region was preferentially etched by etching using gas for 3 seconds, and then the shape was observed using an electron microscope (a length-measuring scanning electron microscope CG-4100 manufactured by Hitachi High-Tech Corporation). The observed results, i.e., the alignment direction and alignment of the block copolymer (BCP), are shown in Table 3. A case in which the BCP exhibited the desired vertical alignment was rated "good," a case in which the BCP exhibited only vertical alignment in the entire observed image was rated "very good," and a case in which an alignment other than vertical alignment was exhibited was rated "poor." The results of observation of Example 2-5 at a magnification of 200,000 times are shown in FIG. 6.

[0299]

[0300] REFERENCE SIGNS LIST 1 Semiconductor substrate 2 Underlayer film 2a Patterned underlayer film 2x Surface modified region 3 Resist film 3a Resist pattern 4 Self-assembled film 4a A block domain 4b B block domain 4c Non-phase separated domain 5 Brush layer

Claims

1. An underlayer film that is a fired product of a coating film of a composition for forming an underlayer film, which is used as an underlayer film for lithography using a resist film, either a photoresist film or an electron beam resist film, and a self-assembled film, and then is further used as an underlayer film for the self-assembled film, wherein the composition for forming an underlayer film contains polysiloxane that is a hydrolysis condensate of hydrolyzable silane, and the hydrolyzable silane includes a compound represented by the following formula (1) and may include a compound represented by the following formula (2), the molar ratio of the compound represented by formula (1) in the hydrolyzable silane is 45 mol % or more, and the combined molar ratio of the compound represented by formula (1) and the compound represented by formula (2) in the hydrolyzable silane is 65 mol % or more (this includes the case where the molar ratio of the compound represented by formula (2) in the hydrolyzable silane is 0 mol %). In formula (1), Ar represents an aromatic hydrocarbon group which may have a substituent. n represents an integer of 1 to 3. When n is 1, R ａ represents a single bond or an alkylene group having 1 to 6 carbon atoms. When n is 2 or 3, R ａ represents a saturated hydrocarbon group having 1 to 6 carbon atoms and a valence of (n+1). Each X independently represents a hydrolyzable group. When n is 2 or 3, the multiple Ar's may be the same or different. (In formula (2), R ｂ represents a non-aromatic hydrocarbon group having 1 to 6 carbon atoms. Each X independently represents a hydrolyzable group.

2. In the formula (1), n ​​is 1, and R ａ The underlayer film of claim 1 , wherein represents an alkylene group having 1 to 6 carbon atoms.

3. The underlayer film according to claim 2, wherein the molar ratio of the compound represented by formula (1) in the hydrolyzable silane is 65 mol % or more.

4. The underlayer film according to claim 1, wherein the total molar ratio of the compound represented by formula (1) and the compound represented by formula (2) in the hydrolyzable silane is 80 mol % or more (including the case where the molar ratio of the compound represented by formula (2) in the hydrolyzable silane is 0 mol %).

5. The underlayer film of claim 1, wherein the resist film is formed from a positive development resist.

6. The underlayer film of claim 1, wherein the self-assembled film is a film comprising a block copolymer.

7. The underlayer film of claim 1, having a film thickness of 30 nm or less.

8. A composition for forming an underlayer film, which is used as an underlayer film for a resist film, either a photoresist film or an electron beam resist film, in lithography using a self-assembled film, and the composition is used as an underlayer film for the resist film and then used as an underlayer film for the self-assembled film, the composition containing polysiloxane which is a hydrolysis condensate of hydrolyzable silane, the hydrolyzable silane containing a compound represented by the following formula (1) and optionally containing a compound represented by the following formula (2), the molar ratio of the compound represented by formula (1) in the hydrolyzable silane being 45 mol% or more, and the combined molar ratio of the compound represented by formula (1) and the compound represented by formula (2) in the hydrolyzable silane being 65 mol% or more (this includes the case where the molar ratio of the compound represented by formula (2) in the hydrolyzable silane is 0 mol%). In formula (1), Ar represents an aromatic hydrocarbon group which may have a substituent. n represents an integer of 1 to 3. When n is 1, R ａ represents a single bond or an alkylene group having 1 to 6 carbon atoms. When n is 2 or 3, R ａ represents a saturated hydrocarbon group having 1 to 6 carbon atoms and a valence of (n+1). Each X independently represents a hydrolyzable group. When n is 2 or 3, the multiple Ar's may be the same or different. (In formula (2), R ｂ represents a non-aromatic hydrocarbon group having 1 to 6 carbon atoms. Each X independently represents a hydrolyzable group.

9. In the above (1), n ​​is 1, and R ａ The composition for forming an underlayer film according to claim 8, wherein represents an alkylene group having 1 to 6 carbon atoms.

10. The composition for forming an underlayer film according to claim 9, wherein the molar ratio of the compound represented by formula (1) in the hydrolyzable silane is 65 mol % or more.

11. The composition for forming an underlayer film according to claim 8, wherein the total molar ratio of the compound represented by formula (1) and the compound represented by formula (2) in the hydrolyzable silane is 80 mol % or more (including the case where the molar ratio of the compound represented by formula (2) in the hydrolyzable silane is 0 mol %).

12. The composition for forming an underlayer film according to claim 8, wherein the resist film is formed from a positive development resist.

13. The underlayer film-forming composition according to claim 8, wherein the self-assembled film is a film containing a block copolymer.

14. The composition for forming an underlayer film according to claim 8, wherein the underlayer film has a thickness of 30 nm or less.

15. A method for manufacturing a semiconductor device, comprising: a step of forming an underlayer film on a semiconductor substrate using a composition for forming an underlayer film according to any one of claims 8 to 14; a step of forming a resist film, which is either a photoresist film or an electron beam resist film, on the underlayer film; a step of irradiating the resist film with light or an electron beam, and then developing the resist film to obtain a resist pattern; and a step of forming a self-assembled film on at least a portion of the underlayer film after the step of obtaining the resist pattern.

16. The method for manufacturing a semiconductor device according to claim 15, wherein the step of forming a self-assembled film is a step of forming a self-assembled film between the resist patterns and on at least a portion of the underlayer film.

17. The method for manufacturing a semiconductor element according to claim 15, comprising, between the step of obtaining the resist pattern and the step of forming the self-assembled film, a step of forming a brush layer between the resist patterns and on at least a portion of the underlayer film, and a step of removing the resist pattern, in this order.

18. The method for manufacturing a semiconductor device according to claim 17, further comprising a step of performing surface modification by a dry process on the underlayer film exposed between the resist patterns, between the step of obtaining the resist pattern and the step of forming the brush layer.

19. A method for manufacturing a semiconductor device according to claim 15, comprising, between the step of obtaining the resist pattern and the step of forming the self-assembled film, a step of surface-modifying the underlayer film exposed between the resist patterns by a dry process, and a step of removing the resist pattern, in this order.

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