Underlayer membrane material for self-assembled materials

Abstract

The underlayer film is a fired product of a coating film of a composition for forming an underlayer film, the underlayer film being used as the underlayer film of the resist film in lithography using a self-assembly film and either a photoresist film or an electron beam resist film, and the underlayer film being formed by firing the coating film of the composition for forming the underlayer film. The present invention is characterized in that the composition for forming an underlayer film is used as an underlayer film of the self-assembled film, and the composition for forming an underlayer film contains a polymer having a unit structure (A) having a polycyclic aromatic structure and a unit structure (B) having a reactive group, and a crosslinking agent having a functional group capable of reacting with the reactive group.

Description

Technical Field

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

[0002] In recent years, with the further miniaturization of large-scale integrated circuits (LSI), a technology for processing more delicate structures is required. For such a requirement, a phase separation structure formed by self-assembly of block copolymers formed by combining mutually incompatible polymers has been started to form an attempt to form a more delicate pattern. For example, the following pattern forming method is proposed: a lower film forming composition is applied on a substrate to form a lower film formed by the composition, a self-assembled film of a block copolymer formed by combining two or more polymers is formed on the lower film surface, the block copolymer in the self-assembled film is phase-separated, and the phase of at least one polymer in the polymer constituting the block copolymer is selectively removed.

[0003] Patent Document 1 discloses a primer containing a resin component in which 20 mol % to 80 mol % of the structural units of the entire components are structural units derived from a monomer containing an aromatic ring.

[0004] Patent document 2 discloses a composition for forming a lower layer film of a self-assembled film, which comprises a polymer having a unit structure of an aromatic vinyl compound such as styrene, vinylnaphthalene, acenaphthene, vinylcarbazole, etc. that can be substituted by 20 mol % or more relative to the total unit structure of the polymer, and a unit structure of a polycyclic aromatic vinyl compound that can be substituted by 1 mol % or more relative to the total unit structure of the aromatic vinyl compound.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: International Publication No. 2012 / 036121 Pamphlet

[0008] Patent Document 2: International Publication No. 2014 / 097993 Pamphlet Summary of the invention

[0009] Problems to be solved by the invention

[0010] When using the self-assembled film for microfabrication, sometimes the resist (photoresist, electron beam resist) used for the previous microfabrication is used in combination. In this case, when the lower film of the resist film also serves as the lower film of the self-assembled film, the lower film is required not to make the roughness of the resist pattern large and the self-assembled film can form a vertical arrangement.

[0011] The present invention aims to provide an underlayer film that serves as both an anti-etching film and an underlayer film of a self-assembled film, which can improve the roughness of the anti-etching pattern and form a vertically arranged underlayer film in the self-assembled film, a composition for forming an underlayer film that can form the underlayer film, and a method for manufacturing a semiconductor element using the composition for forming an underlayer film.

[0012] Means for solving problems

[0013] The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have found that the above-mentioned problems can be solved, and have completed the present invention having the following gist.

[0014] That is, the present invention includes the following aspects.

[0015] [1] An underlayer film which is a fired product of a coating film of a composition for forming an underlayer film,

[0016] The underlayer film is used as an underlayer film of the resist film in photolithography using any resist film of a photoresist film and an electron beam resist film and a self-assembled film, and then is further used as an underlayer film of the self-assembled film.

[0017] The above-mentioned lower layer film-forming composition contains a polymer and a crosslinking agent.

[0018] The polymer has a unit structure (A) having a polycyclic aromatic structure and a unit structure (B) having a reactive group.

[0019] The cross-linking agent has a functional group capable of reacting with the reactive group.

[0020] [2] The underlayer film according to [1], wherein the unit structure (A) is a unit structure represented by the following formula (A-1).

[0021]

[0022] (In formula (A-1), R 1 represents a hydrogen atom or a methyl group. 1 represents a single bond, an ester group or an amide group. 1 represents a single bond or an alkylene group having 1 to 6 carbon atoms. Ar represents an optionally substituted alkyl group selected from naphthalene, anthracene, phenanthrene, pyrene, benzo[9,10]phenanthrene, Tetracene, biphenylene, fluorene or carbazole with a monovalent group of hydrogen atoms removed.

[0023] [3] In the resist underlayer film according to [1] or [2], the unit structure (B) is at least one of a unit structure represented by the following formula (B-1) and a unit structure represented by the following formula (B-2).

[0024]

[0025] (In formula (B-1), R 11 represents a hydrogen atom or a methyl group. 11 represents an ester group or an amide group. 12 It represents a monovalent group having 1 to 12 carbon atoms and having the above-mentioned reactive group.

[0026] In formula (B-2), R 13 represents a monovalent group having 1 to 12 carbon atoms and having the above-mentioned reactive group. )

[0027] [4] According to any one of [1] to [3], the above-mentioned polymer also has a unit structure (C), and the unit structure (C) is at least any one of a unit structure (C-1) having a monocyclic aromatic structure and a unit structure (C-2) derived from a maleimide structure.

[0028] [5] The lower layer film according to [4], wherein the unit structure (C-1) is a unit structure represented by the following formula (C-1-1):

[0029] The unit structure (C-2) is a unit structure represented by the following formula (C-2-1).

[0030]

[0031] (In formula (C-1-1), R 21 represents a hydrogen atom or a methyl group. 21 represents a single bond, an ester group or an amide group. 21 represents a single bond or an alkylene group having 1 to 6 carbon atoms. 22 represents a halogen atom, an alkyl group having 1 to 6 carbon atoms which may be substituted with a halogen atom, or an alkoxy group having 1 to 6 carbon atoms which may be substituted with a halogen atom. n represents an integer of 0 to 5. 22 When there are 2 or more, 2 or more R 22 Can be the same or different.

[0032] In formula (C-2-1), R 23 represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms which may be substituted by a halogen atom, or an aryl group having 6 to 10 carbon atoms which may be substituted by a halogen atom.

[0033] [6] The underlayer film according to any one of [1] to [5], wherein the molar ratio of the unit structure (A) relative to all unit structures of the polymer is 40 mol% or more.

[0034] [7] The underlayer film according to any one of [1] to [6], wherein the molar ratio of the unit structure (B) relative to all unit structures of the polymer is 5 mol% to 40 mol%.

[0035] [8] The lower layer film according to [1], wherein the polymer further has a unit structure (C), wherein the unit structure (C) is at least one of a unit structure (C-1) having a monocyclic aromatic structure and a unit structure (C-2) derived from a maleimide structure,

[0036] The above-mentioned unit structure (A) is a unit structure represented by the following formula (A-1),

[0037] The unit structure (B) is at least one of a unit structure represented by the following formula (B-1) and a unit structure represented by the following formula (B-2),

[0038] The above-mentioned unit structure (C-1) is a unit structure represented by the following formula (C-1-1),

[0039] The above-mentioned unit structure (C-2) is a unit structure represented by the following formula (C-2-1),

[0040] The molar ratio of the unit structure (A) to all unit structures of the polymer is 40 mol% or more, and the molar ratio of the unit structure (B) to all unit structures of the polymer is 5 mol% to 40 mol%.

[0041]

[0042] (In formula (A-1), R 1 represents a hydrogen atom or a methyl group. 1 represents a single bond, an ester group or an amide group. 1 represents a single bond or an alkylene group having 1 to 6 carbon atoms. Ar represents an optionally substituted alkyl group selected from naphthalene, anthracene, phenanthrene, pyrene, benzo[9,10]phenanthrene, Tetracene, biphenylene, fluorene or carbazole with a monovalent group of hydrogen atoms removed.

[0043]

[0044] (In formula (B-1), R 11 represents a hydrogen atom or a methyl group. 11 represents an ester group or an amide group. 12 It represents a monovalent group having 1 to 6 carbon atoms and having the above-mentioned reactive group.

[0045] In formula (B-2), R 13 represents a monovalent group having 1 to 6 carbon atoms and having the above-mentioned reactive group. )

[0046]

[0047] (In formula (C-1-1), R 21 represents a hydrogen atom or a methyl group. 21 represents a single bond, an ester group or an amide group. 21 represents a single bond or an alkylene group having 1 to 6 carbon atoms. 22 represents a halogen atom, an alkyl group having 1 to 6 carbon atoms which may be substituted with a halogen atom, or an alkoxy group having 1 to 6 carbon atoms which may be substituted with a halogen atom. n represents an integer of 0 to 5. 22 When there are 2 or more, 2 or more R 22 Can be the same or different.

[0048] In formula (C-2-1), R 23 represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms which may be substituted by a halogen atom, or an aryl group having 6 to 10 carbon atoms which may be substituted by a halogen atom.

[0049] [9] The underlayer film according to any one of [1] to [8], wherein the content of the crosslinking agent in the underlayer film-forming composition is 20% by mass to 50% by mass of the polymer.

[0050]

[10] The underlayer film according to any one of [1] to [9], wherein the self-assembled film is a film comprising a block copolymer.

[0051]

[11] The underlayer film according to any one of [1] to

[10] , wherein the film thickness is less than 10 nm.

[0052]

[12] A composition for forming an underlayer film, the composition being used for forming an underlayer film, wherein the underlayer film is used as an underlayer film of the resist film in photolithography using any one of a photoresist film and an electron beam resist film and a self-assembled film, and then is further used as an underlayer film of the self-assembled film,

[0053] The lower layer film-forming composition contains a polymer and a cross-linking agent.

[0054] The polymer has a unit structure (A) having a polycyclic aromatic structure and a unit structure (B) having a reactive group.

[0055] The cross-linking agent has a functional group capable of reacting with the reactive group.

[0056]

[13] The composition for forming an underlayer film according to

[12] , wherein the unit structure (A) is a unit structure represented by the following formula (A-1).

[0057]

[0058] (In formula (A-1), R 1 represents a hydrogen atom or a methyl group. 1 represents a single bond, an ester group or an amide group. 1 represents a single bond or an alkylene group having 1 to 6 carbon atoms. Ar represents an optionally substituted alkyl group selected from naphthalene, anthracene, phenanthrene, pyrene, benzo[9,10]phenanthrene, Tetracene, biphenylene, fluorene or carbazole with a monovalent group of hydrogen atoms removed.

[0059]

[14] The composition for forming an underlayer film according to

[12] or

[13] , wherein the unit structure (B) is at least one of a unit structure represented by the following formula (B-1) and a unit structure represented by the following formula (B-2).

[0060]

[0061] (In formula (B-1), R 11 represents a hydrogen atom or a methyl group. 11 represents an ester group or an amide group. 12 It represents a monovalent group having 1 to 12 carbon atoms and having the above-mentioned reactive group.

[0062] In formula (B-2), R 13 represents a monovalent group having 1 to 12 carbon atoms and having the above-mentioned reactive group. )

[0063]

[15] According to the composition for forming a lower layer film as described in any one of

[12] to

[14] , the above-mentioned polymer also has a unit structure (C), and the unit structure (C) is at least any one of a unit structure (C-1) having a monocyclic aromatic structure and a unit structure (C-2) derived from a maleimide structure.

[0064]

[16] The composition for forming an underlayer film according to

[15] , wherein the unit structure (C-1) is a unit structure represented by the following formula (C-1-1):

[0065] The unit structure (C-2) is a unit structure represented by the following formula (C-2-1).

[0066]

[0067] (In formula (C-1-1), R 21 represents a hydrogen atom or a methyl group. 21 represents a single bond, an ester group or an amide group. 21 represents a single bond or an alkylene group having 1 to 6 carbon atoms. 22represents a halogen atom, an alkyl group having 1 to 6 carbon atoms which may be substituted with a halogen atom, or an alkoxy group having 1 to 6 carbon atoms which may be substituted with a halogen atom. n represents an integer of 0 to 5. 22 When there are 2 or more, 2 or more R 22 Can be the same or different.

[0068] In formula (C-2-1), R 23 represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms which may be substituted by a halogen atom, or an aryl group having 6 to 10 carbon atoms which may be substituted by a halogen atom.

[0069]

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

[12] to

[16] , wherein the molar ratio of the unit structure (A) relative to all unit structures of the polymer is 40 mol% or more.

[0070]

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

[12] to

[17] , wherein the molar ratio of the unit structure (B) relative to all unit structures of the polymer is 5 mol% to 40 mol%.

[0071]

[19] The composition for forming an underlayer film according to

[12] , wherein the polymer further has a unit structure (C), and the unit structure (C) is at least one of a unit structure (C-1) having a monocyclic aromatic structure and a unit structure (C-2) derived from a maleimide structure,

[0072] The above-mentioned unit structure (A) is a unit structure represented by the following formula (A-1),

[0073] The unit structure (B) is at least one of a unit structure represented by the following formula (B-1) and a unit structure represented by the following formula (B-2),

[0074] The above-mentioned unit structure (C-1) is a unit structure represented by the following formula (C-1-1),

[0075] The above-mentioned unit structure (C-2) is a unit structure represented by the following formula (C-2-1),

[0076] The molar ratio of the unit structure (A) to all unit structures of the polymer is 40 mol% or more, and the molar ratio of the unit structure (B) to all unit structures of the polymer is 5 mol% to 40 mol%.

[0077]

[0078] (In formula (A-1), R 1 represents a hydrogen atom or a methyl group. 1 represents a single bond, an ester group or an amide group.1 represents a single bond or an alkylene group having 1 to 6 carbon atoms. Ar represents an optionally substituted alkyl group selected from naphthalene, anthracene, phenanthrene, pyrene, benzo[9,10]phenanthrene, Tetracene, biphenylene, fluorene or carbazole with a monovalent group of hydrogen atoms removed.

[0079]

[0080] (In formula (B-1), R 11 represents a hydrogen atom or a methyl group. 11 represents an ester group or an amide group. 12 It represents a monovalent group having 1 to 6 carbon atoms and having the above-mentioned reactive group.

[0081] In formula (B-2), R 13 represents a monovalent group having 1 to 6 carbon atoms and having the above-mentioned reactive group. )

[0082]

[0083] (In formula (C-1-1), R 21 represents a hydrogen atom or a methyl group. 21 represents a single bond, an ester group or an amide group. 21 represents a single bond or an alkylene group having 1 to 6 carbon atoms. 22 represents a halogen atom, an alkyl group having 1 to 6 carbon atoms which may be substituted with a halogen atom, or an alkoxy group having 1 to 6 carbon atoms which may be substituted with a halogen atom. n represents an integer of 0 to 5. 22 When there are 2 or more, 2 or more R 22 Can be the same or different.

[0084] In formula (C-2-1), R 23 represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms which may be substituted by a halogen atom, or an aryl group having 6 to 10 carbon atoms which may be substituted by a halogen atom.

[0085]

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

[11] to

[19] , wherein the content of the crosslinking agent is 20% by mass to 50% by mass of the polymer.

[0086]

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

[12] to

[20] , wherein the self-assembled film is a film comprising a block copolymer.

[0087]

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

[12] to

[21] , wherein the underlayer film has a thickness of less than 10 nm.

[0088]

[23] A method for manufacturing a semiconductor device, comprising the following steps:

[0089] A step of forming an underlayer film on a semiconductor substrate using the underlayer film-forming composition described in any one of

[12] to

[22] ;

[0090] A step of forming a resist film of either a photoresist film or an electron beam resist film on the lower film;

[0091] A step of irradiating the resist film with light or electron beam, and then developing the resist film to obtain a resist pattern;

[0092] a step of etching the lower layer film using the resist pattern as a mask to form a patterned lower layer film; and

[0093] A step of forming a self-assembled film on the patterned underlayer film.

[0094]

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

[23] further includes a step of forming a brush layer in the gap of the pattern of the patterned lower film between the step of forming the patterned lower film and the step of forming the self-assembled film.

[0095]

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

[23] or

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

[0096]

[26] The method for manufacturing a semiconductor element according to any one of

[23] to

[25] , further comprising a step of removing the resist pattern after the step of forming the patterned lower layer film.

[0097] Effects of the Invention

[0098] According to the present invention, a lower layer film serving as both an anti-etching film and an underlayer film of a self-assembled film can be provided, the roughness of the anti-etching pattern can be improved, and a vertically arranged lower layer film can be formed in the self-assembled film, a lower layer film-forming composition capable of forming the lower layer film, and a method for manufacturing a semiconductor element using the lower layer film-forming composition can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0099] Figure 1A It is a schematic cross-sectional view (part 1) for explaining an example of the method for manufacturing a semiconductor element of the present invention.

[0100] Figure 1B This is a schematic cross-sectional view (part 2) for explaining an example of the method for manufacturing a semiconductor element of the present invention.

[0101] Figure 1CIt is a schematic cross-sectional view (part 3) for explaining an example of the method for manufacturing a semiconductor element of the present invention.

[0102] Figure 1D It is a schematic cross-sectional view (part 4) for explaining an example of the method for manufacturing a semiconductor element of the present invention.

[0103] Figure 1E It is a schematic cross-sectional view (part 5) for explaining an example of the method for manufacturing a semiconductor element of the present invention.

[0104] Figure 1F It is a schematic cross-sectional view (part 6) for explaining an example of the method for manufacturing a semiconductor element of the present invention.

[0105] Figure 1G It is a schematic cross-sectional view (part 7) for explaining an example of the method for manufacturing a semiconductor element of the present invention.

[0106] Figure 1H It is a schematic cross-sectional view (part 8) for explaining an example of the method for manufacturing a semiconductor element of the present invention.

[0107] Fig. 1I It is a schematic cross-sectional view (part 9) for explaining an example of the method for manufacturing a semiconductor element of the present invention.

[0108] Figure 2A This is an electron microscope (SEM) photograph of the microphase separation structure of the self-assembled film produced using the self-assembled film-forming composition 1 in Example 1.

[0109] Figure 2B This is a SEM photograph of the microphase separation structure of the self-assembled film produced using the self-assembled film-forming composition 2 in Example 1.

[0110] Figure 3A This is a SEM photograph of the microphase separation structure of the self-assembled film produced in Example 2 using the self-assembled film-forming composition 1.

[0111] Figure 3B This is a SEM photograph of the microphase separation structure of the self-assembled film produced using the self-assembled film-forming composition 2 in Example 2.

[0112] Figure 4A This is a SEM photograph of the microphase separation structure of the self-assembled film produced using the self-assembled film-forming composition 1 in Comparative Example 1.

[0113] Figure 4B This is a SEM photograph of the microphase separation structure of the self-assembled film produced using the self-assembled film-forming composition 2 in Comparative Example 1. DETAILED DESCRIPTION

[0114] The underlayer film of the present invention is a fired product of a coating film of the underlayer film-forming composition. Therefore, after explaining the underlayer film-forming composition, the underlayer film of the present invention will be explained.

[0115] (Underlayer Film Forming Composition)

[0116] The underlayer film-forming composition of the present invention is a underlayer film-forming composition for forming an underlayer film.

[0117] The underlayer film is used as an underlayer film of a resist film in photolithography using any of a photoresist film and an electron beam resist film and a self-assembled film, and then is further used as an underlayer film of a self-assembled film.

[0118] The underlayer film-forming composition of the present invention contains a polymer and a cross-linking agent.

[0119] The polymer has a unit structure (A) having a polycyclic aromatic structure and a unit structure (B) having a reactive group.

[0120] The cross-linking agent has a functional group capable of reacting with a reactive group.

[0121] The composition for forming an underlayer film contains a polymer and a cross-linking agent, wherein the polymer has: a unit structure (A) having a polycyclic aromatic structure and a unit structure (B) having a reactive group, and the cross-linking agent has a functional group capable of reacting with the reactive group, thereby forming an underlayer film that serves as both an anti-etching film and an underlayer film of a self-assembled film, which can improve the roughness of the anti-etching pattern and form a vertically arranged underlayer film in the self-assembled film.

[0122] <Polymer>

[0123] The polymer has a unit structure (A) having a polycyclic aromatic structure and a unit structure (B) having a reactive group. Hereinafter, this polymer may be referred to as a "specific polymer".

[0124] <<Unit structure (A)>>

[0125] The unit structure (A) is a unit structure having a polycyclic aromatic structure.

[0126] The polycyclic aromatic structure referred to herein is a structure composed of two or more aromatic rings showing aromaticity, and includes a condensed polycyclic aromatic structure having a condensed ring and an aromatic ring aggregate structure in which a plurality of aromatic rings are directly bonded via a single bond.

[0127] The polycyclic aromatic structure may be a structure composed only of hydrocarbons or a structure having a heteroatom (for example, an oxygen atom, a nitrogen atom, or a sulfur atom).

[0128] The condensed polycyclic aromatic structure is not particularly limited, and examples thereof include a naphthalene structure, anthracene structure, phenanthrene structure, pyrene structure, benzo[9,10]phenanthrene structure, Structure, tetracene structure, biphenylene structure and fluorene structure, etc.

[0129] The aromatic ring aggregate structure is not particularly limited, and examples thereof include a carbazole structure, a biphenyl structure, a terphenyl structure, a quaterphenyl structure, a binaphthyl structure, a phenylnaphthalene structure, a phenylfluorene structure, and a diphenylfluorene structure.

[0130] The polycyclic aromatic structure may be substituted with a substituent. The substituent may be substituted without particular limitation, and examples thereof include halogen atoms, hydroxyl groups, alkyl groups, alkoxy groups, thiol groups, cyano groups, carboxyl groups, amino groups, amide groups, alkoxycarbonyl groups, and alkylthio groups.

[0131] Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0132] Examples of the alkyl group include an alkyl group having 1 to 6 carbon atoms. Examples of the alkyl group having 1 to 6 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, a 1-methyl-n-butyl group, a 2-methyl-n-butyl group, a 3-methyl-n-butyl group, a 1,1-dimethyl-n-propyl group, a 1,2-dimethyl-n-propyl group, a 2,2-dimethyl-n-propyl group, a 1-ethyl-n-propyl group, an n-hexyl group, a 1-methyl-n-pentyl group, a 2-methyl-n-pentyl group, a 3-methyl-n-pentyl group, 4-methyl-n-pentyl, 1,1-dimethyl-n-butyl, 1,2-dimethyl-n-butyl, 1,3-dimethyl-n-butyl, 2,2-dimethyl-n-butyl, 2,3-dimethyl-n-butyl, 3,3-dimethyl-n-butyl, 1-ethyl-n-butyl, 2-ethyl-n-butyl, 1,1,2-trimethyl-n-propyl, 1,2,2-trimethyl-n-propyl, 1-ethyl-1-methyl-n-propyl and 1-ethyl-2-methyl-n-propyl, etc. In addition, a cyclic alkyl group may be used as the alkyl group. For example, as the cyclic alkyl group having 1 to 10 carbon atoms, there may be mentioned a cyclopropyl group, a cyclobutyl group, a 1-methyl-cyclopropyl group, a 2-methyl-cyclopropyl group, a cyclopentyl group, a 1-methyl-cyclobutyl group, a 2-methyl-cyclobutyl group, a 3-methyl-cyclobutyl group, a 1,2-dimethyl-cyclopropyl group, a 2,3-dimethyl-cyclopropyl group, a 1-ethyl-cyclopropyl group, a 2-ethyl-cyclopropyl group, a cyclohexyl group, a 1-methyl-cyclopentyl group, a 2-methyl-cyclopentyl group, a 3-methyl-cyclopentyl group, a 1-ethyl-cyclobutyl group, a 2-ethyl-cyclobutyl group, a 3-ethyl-cyclobutyl group, a 1,2-dimethyl-cyclopropyl group, a 2,3-dimethyl-cyclopropyl group, a 1-ethyl-cyclopropyl group, a 2-ethyl-cyclopropyl group, a cyclohexyl group, a 1-methyl-cyclopentyl group, a 2-methyl-cyclopentyl group, a 3-methyl-cyclopentyl group, a 1-ethyl-cyclobutyl group, a 2-ethyl-cyclobutyl group, a -cyclobutyl, 1,3-dimethyl-cyclobutyl, 2,2-dimethyl-cyclobutyl, 2,3-dimethyl-cyclobutyl, 2,4-dimethyl-cyclobutyl, 3,3-dimethyl-cyclobutyl, 1-n-propyl-cyclopropyl, 2-n-propyl-cyclopropyl, 1-isopropyl-cyclopropyl, 2-isopropyl-cyclopropyl, 1,2,2-trimethyl-cyclopropyl, 1,2,3-trimethyl-cyclopropyl, 2,2,3-trimethyl-cyclopropyl, 1-ethyl-2-methyl-cyclopropyl, 2-ethyl-1-methyl-cyclopropyl, 2-ethyl-2-methyl-cyclopropyl and 2-ethyl-3-methyl-cyclopropyl, etc.

[0133] Examples of the alkoxy group include alkoxy groups having 1 to 6 carbon atoms. Examples of the alkoxy group having 1 to 6 carbon atoms include methoxy, ethoxy, isopropoxy, and the like.

[0134] Examples of the amide group include amide groups having 1 to 12 carbon atoms, such as formamide, acetamide, propionamide, isobutylamide, benzamide, naphthamide, and acrylamide.

[0135] Examples of the alkoxycarbonyl group include alkoxycarbonyl groups having 2 to 12 carbon atoms. Examples of the alkoxycarbonyl group having 2 to 12 carbon atoms include methoxycarbonyl, ethoxycarbonyl, benzyloxycarbonyl, and the like.

[0136] Examples of the alkylthio group include alkylthio groups having 1 to 6 carbon atoms. Examples of the alkylthio group having 1 to 6 carbon atoms include methylthio, ethylthio, butylthio, hexylthio and the like.

[0137] From the viewpoint of suitably obtaining the effects of the present invention, the polycyclic aromatic structure is preferably a naphthalene structure, anthracene structure, phenanthrene structure, pyrene structure, benzo[9,10]phenanthrene structure, The structure is preferably a naphthacene structure, a biphenylene structure, a fluorene structure or a carbazole structure, more preferably a naphthalene structure, an anthracene structure, a phenanthrene structure, a pyrene structure or a carbazole structure, and further preferably a naphthalene structure or a carbazole structure.

[0138] The polycyclic aromatic structure may be one or two or more, and is preferably one or two.

[0139] The unit structure (A) is not particularly limited, but a unit structure represented by the following formula (A-1) is preferred from the viewpoint of preferably obtaining the effects of the present invention.

[0140]

[0141] (In formula (A-1), R 1 represents a hydrogen atom or a methyl group. 1 represents a single bond, an ester group or an amide group. 1 represents a single bond or an alkylene group having 1 to 6 carbon atoms. Ar represents an optionally substituted alkyl group selected from naphthalene, anthracene, phenanthrene, pyrene, benzo[9,10]phenanthrene, Tetracene, biphenylene, fluorene or carbazole with a monovalent group of hydrogen atoms removed.

[0142] Examples of the substituent which Ar may have include a halogen atom, a hydroxyl group, an alkyl group, an alkoxy group, a thiol group, a cyano group, a carboxyl group, an amino group, an amide group, an alkoxycarbonyl group, and an alkylthio group.

[0143] The unit structure represented by the formula (A-1) is not particularly limited, but a unit structure represented by the following formula (A-1-1) is preferred from the viewpoint of preferably obtaining the effects of the present invention.

[0144]

[0145] (In formula (A-1-1), R 1 represents a hydrogen atom or a methyl group. 2represents a halogen atom, a hydroxyl group, an alkyl group, an alkoxy group, a thiol group, a cyano group, a carboxyl group, an amino group, an amide group, an alkoxycarbonyl group or an alkylthio group. n is an integer from 0 to 7. 2 When there are 2 or more, 2 or more R 2 Can be the same or different.)

[0146] As the unit structure represented by formula (A-1), the following unit structures can be mentioned, for example.

[0147]

[0148] The unit structure (A) in the specific polymer may be one or two or more types, but is preferably one or two types.

[0149] <<Unit structure (B)>>

[0150] The unit structure (B) is a unit structure having a reactive group.

[0151] The unit structure (B) is a structure different from the unit structure (A). For example, the unit structure (B) does not have a polycyclic aromatic structure.

[0152] The reactive group possessed by the unit structure (B) is not particularly limited, and examples thereof include a hydroxyl group, an epoxy group, an acyl group, an acetyl group, a formyl group, a benzoyl group, a carboxyl group, a carbonyl group, an amino group, an imino group, a cyano group, an azo group, an azido group, a thiol group, a sulfone group, and an allyl group.

[0153] The unit structure (B) is not particularly limited, but is preferably at least one of a unit structure represented by the following formula (B-1) and a unit structure represented by the following formula (B-2) from the viewpoint of preferably obtaining the effects of the present invention.

[0154]

[0155] (In formula (B-1), R 11 represents a hydrogen atom or a methyl group. 11 represents an ester group or an amide group. 12 It represents a monovalent group having 1 to 12 carbon atoms and having a reactive group.

[0156] In formula (B-2), R 13 It represents a monovalent group having 1 to 12 carbon atoms and having a reactive group.

[0157] As R 12 and R 13 The monovalent group having 1 to 12 carbon atoms and having a reactive group in ] includes, for example, a hydroxyalkyl group having 1 to 12 carbon atoms.

[0158] Examples of the hydroxyalkyl group having 1 to 12 carbon atoms include hydroxyalkyl groups having 1 to 6 carbon atoms.

[0159] Examples of the hydroxyalkyl group having 1 to 12 carbon atoms include hydroxymethyl, 1-hydroxyethyl, 2-hydroxyethyl, 1-hydroxypropyl, 2-hydroxypropyl, 3-hydroxypropyl, 1-hydroxybutyl, 2-hydroxybutyl, 3-hydroxybutyl, 4-hydroxybutyl, hydroxycyclohexyl, dihydroxycyclohexyl and 3-hydroxy-1-adamantyl.

[0160] The number of hydroxyl groups possessed by the hydroxyalkyl group having 1 to 12 carbon atoms may be 1 or 2 or more.

[0161] Examples of the unit structure represented by the formula (B-1) include a unit structure represented by the following formula (B-1-1).

[0162]

[0163] (In formula (B-1-1), R 11 and R 12 Each of them is the same as R in formula (B-1) 11 and R 12 Same meaning.)

[0164] Examples of the unit structure represented by formula (B-1) include the following unit structures.

[0165]

[0166] Examples of the unit structure represented by formula (B-2) include the following unit structures.

[0167]

[0168] Examples of the unit structure containing an epoxy group as a reactive group include unit structures derived from compounds represented by general formulae (I) to (XVII) described in JP-A-2012-62365.

[0169] The unit structure (B) in the specific polymer may be one or two or more types, and is preferably one or two types.

[0170] <<Unit Structure (C)>>

[0171] The specific polymer may have a unit structure other than the unit structure (A) and the unit structure (B). As such a unit structure, from the viewpoint of suitably obtaining the effect of the present invention, a unit structure (C) is preferred, wherein the unit structure (C) is at least one of a unit structure (C-1) having a monocyclic aromatic structure and a unit structure (C-2) derived from a maleimide structure.

[0172] It should be noted that the unit structure (C) is a unit structure different from the unit structure (A) and the unit structure (B).

[0173] For example, the unit structure (C) does not have the polycyclic aromatic structure and the reactive group that the unit structure (B) has.

[0174] The monocyclic aromatic ring contained in the unit structure (C-1) may be an aromatic hydrocarbon ring or an aromatic heterocyclic ring, but is preferably an aromatic hydrocarbon ring. Examples of such an aromatic hydrocarbon ring include a benzene ring.

[0175] The unit structure (C) is not particularly limited, but is preferably at least one of a unit structure represented by the following formula (C-1-1) and a unit structure represented by the following formula (C-2-1) from the viewpoint of preferably obtaining the effects of the present invention.

[0176]

[0177] (In formula (C-1-1), R 21 represents a hydrogen atom or a methyl group. 21 represents a single bond, an ester group or an amide group. 21 represents a single bond or an alkylene group having 1 to 6 carbon atoms. 22 represents a halogen atom, an alkyl group having 1 to 6 carbon atoms which may be substituted with a halogen atom, or an alkoxy group having 1 to 6 carbon atoms which may be substituted with a halogen atom. n represents an integer of 0 to 5. 22 When there are 2 or more, 2 or more R 22 Can be the same or different.

[0178] In formula (C-2-1), R 23 represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms which may be substituted by a halogen atom, or an aryl group having 6 to 10 carbon atoms which may be substituted by a halogen atom.

[0179] Examples of the unit structure represented by the formula (C-1-1) include a unit structure represented by the following formula (C-1-1-1) and a unit structure represented by the following formula (C-1-1-2).

[0180]

[0181] (In formula (C-1-1-1) and formula (C-1-1-2), R 21 Each independently represents a hydrogen atom or a methyl group. 21 represents a single bond or an alkylene group having 1 to 6 carbon atoms. 22Each independently represents a halogen atom, an alkyl group having 1 to 6 carbon atoms which may be substituted with a halogen atom, or an alkoxy group having 1 to 6 carbon atoms which may be substituted with a halogen atom. n represents an integer of 0 to 5. 22 When there are 2 or more, 2 or more R 22 Can be the same or different.)

[0182] In formula (C-1-1-2), n is preferably an integer of 1 to 5.

[0183] As the unit structure represented by formula (C-1-1), the following unit structures can be mentioned, for example.

[0184]

[0185] As the unit structure represented by formula (C-2-1), the following unit structures can be mentioned, for example.

[0186]

[0187] The unit structure (C) in the specific polymer may be one or two or more types, and is preferably one or two types.

[0188] The molar ratio of the unit structure (A) to all unit structures of the specific polymer is not particularly limited, but is preferably 40 mol % or more, more preferably 45 mol % or more, and particularly preferably 50 mol % or more from the viewpoint of suitably obtaining the effects of the present invention.

[0189] The molar ratio of the unit structure (A) to all unit structures of the specific polymer is preferably 95 mol% or less, more preferably 90 mol% or less, particularly preferably 80 mol% or less.

[0190] The molar ratio of the unit structure (B) to all unit structures of the specific polymer is not particularly limited, but is preferably 5 mol% or more, more preferably 10 mol% or more, and particularly preferably 15 mol% or more from the viewpoint of suitably obtaining the effects of the present invention.

[0191] The molar ratio of the unit structure (B) to all unit structures of the specific polymer is preferably 40 mol% or less, more preferably 35 mol% or less, particularly preferably 30 mol% or less.

[0192] When a specific polymer has a unit structure (C), the molar ratio of the unit structure (C) relative to all unit structures of the specific polymer is not particularly limited, but is preferably 5 mol% or more, more preferably 10 mol% or more, and particularly preferably 15 mol% or more from the viewpoint of suitably obtaining the effect of the present invention.

[0193] The molar ratio of the unit structure (C) to all unit structures of the specific polymer is preferably 40 mol% or less, more preferably 35 mol% or less, particularly preferably 30 mol% or less.

[0194] The molar ratio of the unit structure (A) to the unit structure (B) in the specific polymer (unit structure (A) / unit structure (B)) is not particularly limited, but is preferably 1 to 9, more preferably 1.5 to 5.

[0195] The distribution of the unit structure in the specific polymer is not particularly limited. The specific polymer may be a block copolymer or a random copolymer.

[0196] The molecular weight of the specific polymer is not particularly limited, but the weight average molecular weight measured by gel permeation chromatography (hereinafter, sometimes abbreviated to GPC) is preferably 1,500 to 100,000, and more preferably 2,000 to 50,000.

[0197] <<Method for producing specific polymer>>

[0198] There are no particular restrictions on the method for producing a specific polymer. For example, the specific polymer of this embodiment can be obtained by reacting the carbon-carbon double bonds possessed by a monomer providing a unit structure (A), the carbon-carbon double bonds possessed by a monomer providing a unit structure (B), and the carbon-carbon double bonds possessed by a monomer providing an optional unit structure (C).

[0199] As a polymerization method for a specific polymer, a known polymerization method such as radical polymerization, anionic polymerization, cationic polymerization, etc. can be used. Various known techniques such as solution polymerization, suspension polymerization, emulsion polymerization, bulk polymerization, etc. can be used.

[0200] The polymerization initiator used in the polymerization is not particularly limited, and examples thereof include 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 4,4'-azobis(4-cyanovaleric acid), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(4-methoxy-2,4-dimethyl valeronitrile), 2,2'-azobis(isobutyronitrile), 1,1'-azobis(cyclohexane-1-carbonitrile), 1-[(1-cyano-1-methylethyl)azo]formamide, 2,2'-azobis[2-(2-imidazolin-2-yl)propane] dihydrochloride, 2,2'-azobis[2-(2-imidazolin-2-yl)propane] and 2,2'-azobis(2-methylpropionamidine) dihydrochloride, etc.

[0201] The solvent used in the polymerization is not particularly limited, and for example, diisocyanate may be used. alkyl, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, methyl cellosolve acetate, ethyl cellosolve acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol propyl ether acetate, toluene, xylene, methyl ethyl ketone, cyclopentanone, cyclohexanone, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxylate, ethyl hydroxylate, methyl 2-hydroxy-3-methylbutyrate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl 3-ethoxypropionate, methyl pyruvate, ethyl pyruvate, ethyl acetate, butyl acetate, ethyl lactate, butyl lactate, etc. These may be used alone or in combination.

[0202] The reaction temperature is not particularly limited, and may be, for example, 20°C to 150°C.

[0203] The reaction time is not particularly limited, and examples thereof include 1 hour to 72 hours.

[0204] The obtained solution containing the polymer can be directly used for the preparation of the composition for forming the underlayer film. Alternatively, the polymer can be recovered and used by precipitating it in a poor solvent such as methanol, ethanol, isopropanol, water, or a mixed solvent thereof.

[0205] The content of the specific polymer in the underlayer film-forming composition is not particularly limited, but is preferably 0.1 to 50% by mass, more preferably 0.1 to 10% by mass, based on the entire underlayer film-forming composition from the viewpoint of solubility.

[0206] The content of the specific polymer in the underlayer film-forming composition is preferably 50 to 95% by mass, more preferably 55 to 90% by mass, and particularly preferably 60 to 85% by mass, based on the film constituent components.

[0207] The film-constituting components refer to the components contained in the composition except the solvent.

[0208] <Cross-linking agent>

[0209] The underlayer film-forming composition contains a cross-linking agent.

[0210] The crosslinking agent has a functional group that can react with the reactive group contained in the unit structure (B).

[0211] The number of the functional groups in the cross-linking agent is not particularly limited, and may be one or two or more.

[0212] The functional group capable of reacting with the reactive group possessed by the unit structure (B) is not particularly limited, and examples thereof include a hydroxyl group, an epoxy group, an acyl group, an acetyl group, a formyl group, a benzoyl group, a carboxyl group, a carbonyl group, an amino group, an imino group, a cyano group, an azo group, an azido group, a thiol group, a sulfone group, an allyl group, and a structure represented by the following formula (D).

[0213]

[0214] (In formula (D), R 101 represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxyalkyl group having 2 to 6 carbon atoms. * represents a bond. )

[0215] The bonding bond is, for example, bonded to a nitrogen atom or a carbon atom constituting an aromatic hydrocarbon ring.

[0216] When the reactive group of the unit structure (B) is a hydroxyl group or a thiol group, examples of the functional group that can react with the reactive group of the unit structure (B) include a structure represented by formula (D).

[0217] When the reactive group of the unit structure (B) is an epoxy group, examples of the functional group that can react with the reactive group of the unit structure (B) include a carboxyl group, an amino group, and a thiol group.

[0218] Examples of the cross-linking agent include compounds having two or more structures represented by the above formula (D).

[0219] As R 101 , preferably a hydrogen atom, a methyl group, an ethyl group or a group represented by the following structure.

[0220]

[0221] (In the structure, R 102 represents a hydrogen atom, a methyl group, or an ethyl group. * represents a bond. )

[0222] As the crosslinking agent, melamine compounds, guanamine compounds, glycoluril compounds, urea compounds, and compounds having a phenolic hydroxyl group are preferred, and these may be used alone or in combination of two or more.

[0223] The melamine compound is not particularly limited as long as it has a group that can react with a reactive group (for example, a hydroxyl group) possessed by the unit structure (B).

[0224] Examples of the melamine compound include hexamethylolmelamine, hexamethoxymethylmelamine, a compound in which 1 to 6 methylol groups of hexamethylolmelamine are methoxymethylated, or a mixture thereof, hexamethoxyethylmelamine, hexaacyloxymethylmelamine, a compound in which 1 to 6 methylol groups of hexamethylolmelamine are acyloxymethylated, or a mixture thereof.

[0225] The guanamine compound is not particularly limited as long as it has a group that can react with a reactive group (for example, a hydroxyl group) possessed by the unit structure (B).

[0226] Examples of the guanamine compound include tetramethylolguanamine, tetramethoxymethylguanamine, a compound in which 1 to 4 hydroxymethyl groups of tetramethylolguanamine are methoxymethylated, or a mixture thereof, tetramethoxyethylguanamine, tetraacyloxyguanamine, a compound in which 1 to 4 hydroxymethyl groups of tetramethylolguanamine are acyloxymethylated, or a mixture thereof.

[0227] The glycoluril compound is not particularly limited as long as it has a group that can react with a reactive group (for example, a hydroxyl group) possessed by the unit structure (B).

[0228] Examples of the glycoluril compound include tetrakishydroxymethyl glycoluril, tetramethoxy glycoluril, tetramethoxymethyl glycoluril, compounds in which 1 to 4 hydroxymethyl groups of tetrakishydroxymethyl glycoluril are methoxymethylated or mixtures thereof, compounds in which 1 to 4 hydroxymethyl groups of tetrakishydroxymethyl glycoluril are acyloxymethylated or mixtures thereof, and the like.

[0229] In addition, the glycoluril compound may be, for example, a glycoluril derivative represented by the following formula (1E).

[0230]

[0231] (In formula (1E), the four R 1 Each independently represents a methyl group or an ethyl group, R 2 and R 3 Each independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a phenyl group.)

[0232] Examples of the glycoluril derivative represented by the above formula (1E) include compounds represented by the following formulas (1E-1) to (1E-6).

[0233]

[0234] The glycoluril derivative represented by the formula (1E) can be obtained, for example, by reacting a glycoluril derivative represented by the following formula (2E) with at least one compound represented by the following formula (3d).

[0235]

[0236] (In formula (2E), R 2 and R 3 Each independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a phenyl group, and R 4 Each independently represents an alkyl group having 1 to 4 carbon atoms. )

[0237]

[0238] (In formula (3d), R 1 represents a methyl or ethyl group. )

[0239] Examples of the glycoluril derivative represented by the above formula (2E) include compounds represented by the following formulas (2E-1) to (2E-4).

[0240] Further examples of the compound represented by the above formula (3d) include compounds represented by the following formulas (3d-1) and (3d-2).

[0241]

[0242]

[0243] The urea compound is not particularly limited as long as it has a group that can react with a reactive group (for example, a hydroxyl group) possessed by the unit structure (B).

[0244] Examples of the urea compound include tetramethylol urea, tetramethoxymethyl urea, a compound in which 1 to 4 methylol groups of tetramethylol urea are methoxymethylated, or a mixture thereof, and tetramethoxyethyl urea.

[0245] Examples of the compound having a phenolic hydroxyl group include compounds represented by the following formula (111) or formula (112).

[0246]

[0247] (In equations (111) and (112), Q 2 It represents a single bond or an m2-valent organic group.

[0248] R 8 , R 9 , R 11 and R 12 Each represents a hydrogen atom or a methyl group.

[0249] R 7 and R 10 Each represents an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 40 carbon atoms.

[0250] n 9 Indicates 1≤n 9 An integer ≤3, n 10 It means 2≤n 10 An integer ≤5, n 11 Indicates 0≤n 11 An integer ≤3, n 12 Indicates 0≤n 12 An integer ≤3, and n 9 、n 10 、n 11 、n 12 It means 3≤(n 9 +n 10 +n 11 +n 12 )≤6.

[0251] n 13 Indicates 1≤n 13 An integer ≤3, n 14 Indicates 1≤n 14 An integer ≤ 4, n 15 Indicates 0≤n 15 An integer ≤3, n 16 Indicates 0≤n 16 An integer ≤3, and n 13 、n 14 、n 15 、n 16 It means 2≤(n 13 +n 14 +n 15 +n 16 )≤5.

[0252] m2 represents an integer from 2 to 10. )

[0253] As Q 2 The m2-valent organic group in includes, for example, an m2-valent organic group having 1 to 4 carbon atoms.

[0254] Examples of the compound represented by formula (111) or formula (112) include the following compounds.

[0255]

[0256]

[0257] The above compounds can be obtained as products of Asahi Organic Materials Industries, Ltd. and Honshu Chemical Industries, Ltd. As the product, for example, TMOM-BP, a trade name of Asahi Organic Materials Industries, Ltd., can be mentioned.

[0258] Among them, glycoluril compounds are preferred, and specifically, tetrakishydroxymethyl glycoluril, tetramethoxy glycoluril, tetramethoxymethyl glycoluril, a compound in which 1 to 4 hydroxymethyl groups of tetrakishydroxymethyl glycoluril are methoxymethylated or a mixture thereof, a compound in which 1 to 4 hydroxymethyl groups of tetrakishydroxymethyl glycoluril are acyloxymethylated or a mixture thereof are preferred, and tetramethoxymethyl glycoluril is preferred.

[0259] The molecular weight of the cross-linking agent is not particularly limited, but is preferably 500 or less.

[0260] The content of the crosslinking agent in the underlayer film-forming composition is not particularly limited, but is preferably 5 to 60% by mass, more preferably 10 to 55% by mass, and particularly preferably 20 to 50% by mass, based on the specific polymer.

[0261] <Curing catalyst>

[0262] As the curing catalyst contained as an optional component in the underlayer film-forming composition, either a thermal acid generator or a photoacid generator may be used, but a thermal acid generator is preferably used.

[0263] Examples of the thermal acid generator include p-toluenesulfonic acid, trifluoromethanesulfonic acid, pyridine - p-Toluenesulfonate (pyridine -p-Toluenesulfonic acid), pyridine Phenolsulfonic acid, pyridine -p-Hydroxybenzenesulfonic acid (pyridinium phenolsulfonate Salt), pyridine - Sulfonic acid compounds and carboxylic acid compounds such as trifluoromethanesulfonic acid, salicylic acid, camphorsulfonic acid, 5-sulfosalicylic acid, 4-chlorobenzenesulfonic acid, 4-hydroxybenzenesulfonic acid, benzenedisulfonic acid, 1-naphthalenesulfonic acid, citric acid, benzoic acid, hydroxybenzoic acid, N-methylmorpholine-p-toluenesulfonic acid, N-methylmorpholine-p-hydroxybenzenesulfonic acid, and N-methylmorpholine-5-sulfosalicylic acid.

[0264] Examples of the photoacid generator include: Salt compounds, sulfonimide compounds and disulfonyldiazomethane compounds, etc.

[0265] As Salt compounds, for example, diphenyl iodide Hexafluorophosphate, diphenyl iodide Trifluoromethanesulfonate, diphenyl iodide Nonafluorobutane sulfonate, diphenyl iodide Perfluorooctane sulfonate, diphenyl iodide Camphorsulfonate, bis(4-tert-butylphenyl)iodide Camphorsulfonate and bis(4-tert-butylphenyl)iodide Trifluoromethanesulfonate and other iodine Sulfonium salt compounds, and sulfonium salt compounds such as triphenylsulfonium hexafluoroantimonate, triphenylsulfonium nonafluoro-n-butanesulfonate, triphenylsulfonium camphorsulfonate and triphenylsulfonium trifluoromethanesulfonate.

[0266] Examples of the sulfonyl imide compound include N-(trifluoromethanesulfonyloxy)succinimide, N-(nonafluoro-n-butanesulfonyloxy)succinimide, N-(camphorsulfonyloxy)succinimide, and N-(trifluoromethanesulfonyloxy)naphthalimide.

[0267] Examples of the disulfonyldiazomethane compound include bis(trifluoromethylsulfonyl)diazomethane, bis(cyclohexylsulfonyl)diazomethane, bis(phenylsulfonyl)diazomethane, bis(p-toluenesulfonyl)diazomethane, bis(2,4-dimethylbenzenesulfonyl)diazomethane, and methylsulfonyl-p-toluenesulfonyldiazomethane.

[0268] The curing catalyst may be used alone or in combination of two or more.

[0269] When a curing catalyst is used, the content ratio of the curing catalyst is, for example, 0.1 mass % to 50 mass %, preferably 1 mass % to 30 mass % based on the cross-linking agent.

[0270] <Other ingredients>

[0271] A surfactant may be further added to the underlayer film-forming composition in order to prevent pinholes, streaks, etc. from being generated and to further improve the coating properties on uneven surfaces.

[0272] Examples of the surfactant include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, and polyoxyethylene oleyl ether, polyoxyethylene alkyl aryl ethers such as polyoxyethylene octylphenol ether and polyoxyethylene nonylphenol ether, polyoxyethylene / polyoxypropylene block copolymers, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, sorbitan trioleate, and sorbitan tristearate, and sorbitan fatty acid esters such as polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, and polyoxyethylene sorbitan tristearate. Nonionic surfactants such as polyoxyethylene sorbitan fatty acid esters such as sorbitan tristearate, Eftop EF301, EF303, EF352 (trade names of Tokem Projects), Megaphac F171, F173, R-30 (trade names of DIC Corporation), Fluoro FC430, FC Fluorine-based surfactants such as 431 (manufactured by Sumitomo Slide Group, trade name), Asahigard AG710, Surflon S-382, SC101, SC102, SC103, SC104, SC105, and SC106 (manufactured by AGC Corporation, trade name), and organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.).

[0273] The amount of these surfactants blended is not particularly limited, but is usually 2.0% by mass or less, preferably 1.0% by mass or less, based on the underlayer film-forming composition.

[0274] These surfactants may be added alone or in combination of two or more.

[0275] <Solvent>

[0276] The underlayer film-forming composition may contain a solvent.

[0277] As the solvent, an organic solvent generally used for chemical solutions in semiconductor photolithography processes is preferred. Specifically, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, methyl cellosolve acetate, ethyl cellosolve acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monomethyl ether acetate, propylene glycol propyl ether acetate, toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, cycloheptanone, 4-methyl-2-pentanol, methyl 2-hydroxyisobutyrate, 2-hydroxyisobutyric acid ethyl ester, ethoxyethyl ester, 2-hydroxyethyl acetate, 3-methoxypropionic acid methyl ester, 3-methoxypropionic acid ethyl ester, 3-ethoxypropionic acid ethyl ester, 3-ethoxypropionic acid methyl ester, pyruvic acid methyl ester, pyruvic acid ethyl ester, ethyl acetate, butyl acetate, ethyl lactate, butyl lactate, 2-heptanone, methoxycyclopentane, anisole, γ-butyrolactone, N-methylpyrrolidone, N,N-dimethylformamide and N,N-dimethylacetamide. These solvents can be used alone or in combination of two or more.

[0278] Among these solvents, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, ethyl lactate, butyl lactate and cyclohexanone are preferred, and propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate are particularly preferred.

[0279] The content of the solvent in the underlayer film-forming composition is not particularly limited, but is preferably 80% by mass to 99.99% by mass, more preferably 90% by mass to 99.95% by mass, and particularly preferably 95% by mass to 99.9% by mass.

[0280] (Lower membrane)

[0281] The underlayer film of the present invention is a fired product of a coating film of the above-mentioned underlayer film-forming composition.

[0282] The underlayer film of the present invention is used as an underlayer film of the self-assembled film after being used as an underlayer film of the resist film in lithography using any resist film of a photoresist film and an electron beam resist film and a self-assembled film.

[0283] The underlayer film of the present invention can be produced by, for example, applying the underlayer film-forming composition on a semiconductor substrate and firing the coating.

[0284] Examples of the semiconductor substrate to which the underlayer film-forming composition of the present invention is applied include silicon wafers, germanium wafers, and compound semiconductor wafers such as gallium arsenide, indium phosphide, gallium nitride, indium nitride, and aluminum nitride.

[0285] When a semiconductor substrate having an inorganic film formed on the surface is used, the inorganic film is formed by, for example, ALD (atomic layer deposition) method, CVD (chemical vapor deposition) method, reactive sputtering method, ion plating method, vacuum evaporation method, spin coating method (spin-on glass: SOG). Examples of the inorganic film include polysilicon film, silicon oxide film, silicon nitride film, BPSG (Boro-Phospho Silicate Glass) film, titanium nitride film, titanium oxide nitride film, tungsten film, gallium nitride film, and gallium arsenide film.

[0286] The semiconductor substrate may also have a film containing silicon and an organic group. The so-called film containing silicon and an organic group is a film formed by a hydrolysis condensate of a hydrolyzable silane (also referred to as an organosilicon compound) having an organic group. The film containing silicon and an organic group includes, for example, a hydrolysis condensate of a hydrolyzable silane containing a compound represented by the following formula (A).

[0287] R a x Si(R b ) 4-x (A)

[0288] (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, and R b represents an alkoxy group, an acyloxy group or a halogen atom, and x represents an integer of 0 to 3. )

[0289] The film containing silicon and an organic group can be formed, for example, by a resist underlayer film-forming composition containing silicon. Examples of such a resist underlayer film-forming composition containing silicon include the following resist underlayer film-forming compositions containing silicon.

[0290] Japanese Patent Application Laid-Open 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 brochure, WO2013 / 022099 brochure, WO2012 / 102261 brochure, WO2012 / 053600 brochure, WO2012 / 039337 brochure, WO2011 / 105368 brochure, WO2011 / 102470 brochure, WO2011 / 033965 brochure, WO2010 / 140551 brochure, WO2010 / 071155 brochure, WO2010 / 021290 brochure, WO2009 / 104552 brochure, WO2009 / 088039 brochure, WO2009 / 069712 brochure

[0291] On such a semiconductor substrate, the resist lower film forming composition of the present invention is applied by a suitable coating method such as a spin coater or a coater. Then, a heating means such as a hot plate is used to bake to form a resist lower film. As baking conditions, it is appropriately selected from a baking temperature of 100°C to 400°C and a baking time of 0.3 minutes to 60 minutes. Preferably, the baking temperature is 120°C to 350°C and the baking time is 0.5 minutes to 30 minutes, and more preferably, the baking temperature is 150°C to 300°C and the baking time is 0.8 minutes to 10 minutes.

[0292] As the film thickness of the lower film, from the viewpoint of suitably obtaining the effect of the present invention, preferably less than 10nm, more preferably below 9nm, further preferably below 8nm, particularly preferably below 7nm. In addition, as the film thickness of the lower film, can be more than 1nm, can be more than 2nm, can be more than 3nm.

[0293] Generally, if the film thickness of the resist underlayer film is reduced, it is difficult to obtain a film with a flat surface. When the surface is uneven, the film thickness of the resist film formed on the underlayer film varies greatly, and as a result, it is believed that the roughness of the resist pattern increases.

[0294] The composition for forming the lower film of the present invention contains the above-mentioned specific polymer, thereby having a tendency to obtain an underlayer film having excellent adhesion to the substrate and film-forming properties. Therefore, it is presumed that even if the thickness of the underlayer film is less than 10 nm, a film with a flat surface can be formed, which can improve the roughness (LWR, CDU) of the resist pattern. The above-mentioned LWR (line width roughness) is mainly an evaluation when the above-mentioned resist pattern is a line and a space (wiring pattern), but the underlayer film of the present application also shows an effect in improving CDU (Critical Dimension Uniformity, CD uniformity, CD uniformity) (less deviation in pore size) when the resist pattern is a contact hole (hole pattern).

[0295] The above-mentioned CDU can be evaluated by, for example, a method according to the method described in Japanese Patent Application Laid-Open No. 2020-003678 (paragraph

[0386] Evaluation of in-plane uniformity (CDU) of pattern size).

[0296] In addition, when a brush layer is formed in the gap of the pattern of the patterned lower film, the brush layer becomes a thin layer (for example, about 1 nm). In order to minimize the difference in film thickness with the brush layer, it is preferred that the film thickness of the lower film be thin. In this regard, the film thickness of the lower film is preferably less than 10 nm.

[0297] Furthermore, by making the thickness of the underlayer film thin, the pattern of the patterned self-assembled film can be easily transferred to the underlayer film. In this regard, the thickness of the underlayer film is preferably less than 10 nm.

[0298] The method for measuring the film thickness of the resist underlayer film in this specification is as follows.

[0299] ·Measurement device name: Ellipsometry film thickness measurement device RE-3100 (SCREEN Corporation)

[0300] SWE (Single Wavelength Ellipsometer) Mode

[0301] Arithmetic average of 8 points (e.g., 8 points at 1 cm intervals along the X direction of the wafer)

[0302] (Method for manufacturing semiconductor element)

[0303] The method for manufacturing a semiconductor device of the present invention includes first to fifth steps.

[0304] Step 1: a step of forming an underlayer film on a semiconductor substrate using the underlayer film-forming composition of the present invention

[0305] · Second step: a step of forming a photoresist film or an electron beam resist film on the lower layer film

[0306] Step 3: Irradiating the resist film with light or electron beams, and then developing the resist film to obtain a resist pattern.

[0307] Step 4: A step of etching the lower layer film using the resist pattern as a mask to form a patterned lower layer film

[0308] Step 5: Step of forming a self-assembled film on the patterned lower film

[0309] The method for manufacturing a semiconductor device of the present invention may further include a sixth step.

[0310] · Step 6: Step of forming a brush layer in the gaps between the patterns of the patterned lower film

[0311] It should be noted that the sixth step is a step performed between the fourth step and the fifth step.

[0312] <1st step>

[0313] The first step is a step of forming a lower film on a semiconductor substrate using the lower film forming composition of the present invention. There is no particular limitation on the method for forming the lower film, and the above-mentioned method can be cited as an example. That is, the lower film can be manufactured, for example, by applying the lower film forming composition on a semiconductor substrate and firing it.

[0314] As the film thickness of the lower film, from the viewpoint of suitably obtaining the effect of the present invention, preferably less than 10nm, more preferably below 9nm, further preferably below 8nm, particularly preferably below 7nm. In addition, as the film thickness of the lower film, can be more than 1nm, can be more than 2nm, can be more than 3nm.

[0315] <Step 2, Step 3, and Step 4>

[0316] The second step is a step of forming a resist film of either a photoresist film or an electron beam resist film on the underlying film.

[0317] The third step is a step of irradiating the resist film with light or electron beams and then developing the resist film to obtain a resist pattern.

[0318] The fourth step is a step of etching the lower layer film using the resist pattern as a mask to form a patterned lower layer film.

[0319] As the film thickness of the formed resist film, there is no particular restriction, but it is preferably below 200nm, more preferably below 150nm, further preferably below 100nm, and particularly preferably below 80nm. In addition, as the film thickness of the resist film, it is preferably more than 10nm, more preferably more than 20nm, and further preferably more than 30nm.

[0320] The resist formed by coating and firing on the underlying 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 photoresists and positive photoresists can be used.

[0321] It should be noted that in this specification, a resist that responds to EB is sometimes referred to as a photoresist.

[0322] As the photoresist, there are positive photoresists composed of novolac resin and 1,2-naphthoquinonediazosulfonate, chemically amplified photoresists composed of a binder having a group whose alkali dissolution rate increases when decomposed by acid and a photoacid generator, chemically amplified photoresists composed of a low molecular weight compound whose alkali dissolution rate increases when decomposed by acid, an alkali-soluble binder, and a photoacid generator, chemically amplified photoresists composed of a binder having a group whose alkali dissolution rate increases when decomposed by acid, a low molecular weight compound whose alkali dissolution rate increases when decomposed by acid, and a photoacid generator, resists containing metal elements, and the like. For example, JSR (trade name V146G), Shipley Co., Ltd. trade name APEX-E, Sumitomo Chemical (trade name PAR710) and Shin-Etsu Chemical (trade name AR2772, SEPR430, etc. In addition, for example, Proc. SPIE, Vol. 3999, 330-334 (2000), Proc. SPIE, Vol. 3999, 357-364 (2000), Proc. SPIE, Vol. 3999, 365-374 (2000) can be mentioned.

[0323] In addition, 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, WO2019 / 172054, W O2019 / 021975, WO2018 / 230334, WO2018 / 194123, Japanese Special Opening 2018-180525, WO2018 / 190088, Japanese Special Opening 2018-070596, Japanese Special Opening 2018-028090, Japanese Special Opening 2016-153409, Japanese Special Opening 2016-130240, Japanese Special Opening 2016-108325, Japanese Special Opening 2016-047920, Japanese Special Opening 2016-035570, Japan Special opening 2016-035567, Japanese special opening 2016-035565, Japanese special opening 2019-101417, Japanese special opening 2019-117373, Japan Special Opening 2019-052294, Japanese Special Opening 2019-008280, Japanese Special Opening 2019-008279, Japanese Special Opening 2019-003176, Japanese Special Opening 2019-003175, Japanese Special Opening 2018-197853, Japanese Special Opening 2019-191298, Japanese Special Opening 2019-06 1217, Japanese Special Opening 2018-045152, Japanese Special Opening 2018-022039, Japanese Special Opening 2016-090441, Japanese Special Opening 2015-10878, Japanese Special Opening 2012-168279, Japanese Special Opening 2012-022261, Japanese Special Opening 2012-022258, Japanese Special Opening 201 1-043749, Japanese Patent Application Laid-Open No. 2010-181857, Japanese Patent Application Laid-Open No. 2010-128369, WO2018 / 031896, Japanese Patent Application Laid-Open No. 2019-113855, WO2017 / 156388, WO2017 / 066319, Japanese Patent Application Laid-Open No. 2018-41099, WO2016 / 065120, WO2015 / 026482, Japanese Patent Application Laid-Open No. 2016-29498, Japanese Patent Application Laid-Open No. 2011-253185, etc., so-called resist compositions, and metal-containing resist compositions, but are not limited to these.

[0324] As the resist composition, for example, the following compositions can be mentioned.

[0325] An active light-sensitive or radiation-sensitive resin composition comprises a resin A and a compound represented by the following general formula (21), wherein the resin A has a repeating unit having an acid-decomposable group whose polar group is protected by a protecting group that is detached by the action of an acid.

[0326]

[0327] In the general formula (21), m represents an integer of 1-6.

[0328] R 1 and R 2 Each independently represents a fluorine atom or a perfluoroalkyl group.

[0329] L 1 Represents -O-, -S-, -COO-, -SO 2 -or-SO 3 -.

[0330] L 2 represents an alkylene group which may have a substituent or a single bond.

[0331] W 1 It represents a cyclic organic group which may have a substituent.

[0332] M + Represents a cation.

[0333] A metal-containing film-forming composition for extreme ultraviolet or electron beam lithography contains a compound having a metal-oxygen covalent bond and a solvent, wherein the metal element constituting the compound belongs to the third to seventh periods of the third to fifteenth groups of the periodic table.

[0334] A radiation-sensitive resin composition comprising a polymer and an acid generator, wherein the polymer has a first structural unit represented by the following formula (31) and a second structural unit represented by the following formula (32) and containing an acid-dissociable group.

[0335]

[0336] (In formula (31), Ar is a group obtained by removing (n+1) hydrogen atoms from an aromatic hydrocarbon having 6 to 20 carbon atoms. R 1 is a hydroxyl group, a thiol 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, a plurality of R 1 Same or different. 2 is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. 3is a monovalent group having 1 to 20 carbon atoms and containing the above-mentioned acid dissociable group. Z is a single bond, an oxygen atom or a sulfur atom. 4 is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. )

[0337] A resist composition comprises a resin (A1) and an acid generator, wherein the resin (A1) comprises 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.

[0338]

[0339] [Wherein,

[0340] 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, and X 1 Represents a single bond, -CO-O-* or -CO-NR 4 -*, * represents the bond with -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 a hydroxyl group and a carboxyl group.]

[0341] As the resist film, for example, the following resist films can be mentioned.

[0342] A resist film comprises a base resin, wherein the base resin comprises a repeating unit represented by the following formula (a1) and / or a repeating unit represented by the following formula (a2), and a repeating unit which generates an acid bonded to a polymer main chain upon exposure.

[0343]

[0344] (In formula (a1) and formula (a2), R A Each is independently a hydrogen atom or a methyl group. 1 and R 2 Each R is independently a tertiary alkyl group having 4 to 6 carbon atoms. 3 Each independently represents a fluorine atom or a methyl group. m represents an integer from 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. )

[0345] As the resist material, for example, the following resist materials can be mentioned.

[0346] A resist material comprising a polymer having a repeating unit represented by the following formula (b1) or (b2).

[0347]

[0348] (In formula (b1) and formula (b2), R A X 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 a part of the methylene group constituting the alkylene group may be substituted with an ether group, an ester group or a group containing a lactone ring, and X 2 At least one hydrogen atom is replaced by a bromine atom. 3 It 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 a part of the methylene group constituting the alkylene group may be substituted with an ether group or an ester group. 1 ~Rf 4 Each independently represents a hydrogen atom, a fluorine atom or a trifluoromethyl group, but at least one of them is a fluorine atom or a trifluoromethyl group. 1 and Rf 2 Can combine to form a carbonyl group. 1 ~R 5 Each is 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, and a part or all of the hydrogen atoms of these groups may be substituted with a hydroxyl group, a carboxyl group, a halogen atom, an oxo group, a cyano group, an amide group, a nitro group, a sultone group, a sulfone group or a group containing a sulfonium salt, and a part 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 group. In addition, R 1 With R 2 can combine to form a ring with the sulfur atom to which they are bound.)

[0349] A resist material includes a base resin, wherein the base resin includes a polymer having a repeating unit represented by the following formula (a).

[0350]

[0351] (In formula (a), R A is a hydrogen atom or a methyl group. 1 is a hydrogen atom or an acid-labile group. 2 It 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 or 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 -O-, -O-CH 2 - or -NH-. m is an integer of 1 to 4. u is an integer of 0 to 3. Wherein, m+u is an integer of 1 to 4. )

[0352] A resist composition that generates acid upon exposure and changes its solubility in a developer by the action of the acid.

[0353] The invention comprises a base component (A) whose solubility in a developer changes due to the action of an acid and a fluorine additive component (F) which is decomposable by an alkaline developer.

[0354] The fluorine additive component (F) contains a fluororesin component (F1) having a structural unit (f1) containing an alkali-dissociable group and a structural unit (f2) containing a group represented by the following general formula (f2-r-1).

[0355]

[0356] [In formula (f2-r-1), Rf 21 Each is independently a hydrogen atom, an alkyl group, an alkoxy group, a hydroxyl group, a hydroxyalkyl group or a cyano group. n" is an integer from 0 to 2. * is a bonding bond.]

[0357] 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).

[0358]

[0359] [In formula (f1-1) and (f1-2), 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 having no acid dissociable site. A aryl is a divalent aromatic cyclic group which may have a substituent. 01 is a single bond or a divalent linking group. 2 Each independently is an organic group having a fluorine atom.]

[0360] As the coating material, the coating solution and the coating composition, for example, the following coating materials, the coating solution and the coating composition can be mentioned.

[0361] A coating comprises a metal oxy-hydroxy network having organic ligands via metal carbon bonds and / or metal carboxylate bonds.

[0362] Inorganic oxygen / hydroxy based compositions.

[0363] A coating solution comprising: an organic solvent; a first organic metal composition having a formula Rz SnO (2-(z / 2)-(x / 2)) (OH) x (Here, 0<z≤2 and 0<(z+x)≤4), formula R' n S X 4-n (where n=1 or 2), or a mixture thereof, wherein R and R' are independently hydrocarbon 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 represented by the formula MX' v (here, M is a metal selected from Groups 2 to 16 of the periodic table, v is a number from 2 to 6, and X' is a ligand having a hydrolyzable MX bond or a combination thereof).

[0364] A coating solution comprising an organic solvent and a formula RSnO (3 / 2-x / 2) (OH) x The coating solution of the first organometallic compound represented by (wherein 0<x<3) contains about 0.0025M to about 1.5M of tin in the above solution, and R is an alkyl or cycloalkyl group having 3 to 31 carbon atoms, and the above alkyl or cycloalkyl group is bonded to tin at a secondary or tertiary carbon atom.

[0365] An aqueous inorganic pattern-forming precursor solution comprises a mixture of water, metal suboxide cations, polyatomic inorganic anions and a radiation-sensitive ligand containing a peroxide group.

[0366] The irradiation of light or electron beam is performed, for example, through a mask (photomask) for forming a predetermined pattern. There is no particular limitation on the wavelength of light. The lower film of the present invention is suitable for EB (electron beam) or EUV (extreme ultraviolet: 13.5nm) irradiation, but is more preferably used for EUV (extreme ultraviolet) exposure.

[0367] There is no particular limitation on the irradiation energy of EB and the exposure amount of EUV.

[0368] After irradiation with light or electron beams and before development, baking (PEB: Post Exposure Bake) may be performed.

[0369] 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.

[0370] 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.

[0371] In the development, for example, an alkaline developer is used.

[0372] As an image development temperature, 5 degreeC - 50 degreeC is mentioned, for example.

[0373] The development time may be, for example, 10 seconds to 300 seconds.

[0374] As alkaline developer, for example, inorganic bases such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, ammonia water, primary amines such as ethylamine, n-propylamine, secondary amines such as diethylamine, di-n-butylamine, tertiary amines such as triethylamine, methyldiethylamine, alcohol amines such as dimethylethanolamine, triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, quaternary ammonium salts such as choline, pyrrole, piperidine and other cyclic amines and other alkali aqueous solutions can be used. Further, it is also possible to add an appropriate amount of alcohols such as isopropanol, nonionic surfactants and the like to the aqueous solution of the above-mentioned alkalis and use them. Among them, the preferred developer is an aqueous solution of a quaternary ammonium salt, and more preferably an aqueous solution of tetramethylammonium hydroxide and an aqueous solution of choline. Further, surfactants and the like can also be added to these developers. It is also possible to use an organic solvent such as butyl acetate instead of an alkaline developer for development, and a method for developing the part where the alkali dissolution rate of the photoresist is not improved.

[0375] The type of the resist pattern to be formed is not particularly limited, and may be a line pattern or a hole pattern.

[0376] When the resist pattern is a line pattern, the line width is not particularly limited, and examples thereof include 30 nm to 200 nm.

[0377] When the resist pattern is a hole pattern, examples of the diameter of the holes include 30 nm to 200 nm.

[0378] Next, the lower layer film is etched using the formed resist pattern as a mask. The etching may be dry etching or wet etching, but dry etching is preferred.

[0379] After the fourth step, a step of removing the resist pattern may be included.

[0380] The resist pattern is removed by, for example, etching, which may be dry etching or wet etching.

[0381] The resist pattern is usually removed before the fifth step.

[0382] <Step 5>

[0383] The fifth step is a step of forming a self-assembled film on the patterned underlayer film.

[0384] The self-assembled film can be formed, for example, by applying a self-assembled film-forming composition and drying it.

[0385] The self-assembled film is, for example, a film containing a block copolymer.

[0386] 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.

[0387] <<Self-assembled film-forming composition>>

[0388] The self-assembled film-forming composition contains, for example, a block copolymer.

[0389] The self-assembled film-forming composition generally contains a solvent.

[0390] The solid content of the self-assembled film-forming composition may be 0.1 to 10% by mass, 0.1 to 5% by mass, or 0.1 to 3% by mass. The solid content is the remaining proportion after removing the solvent from the film-forming composition.

[0391] The proportion of the block copolymer in the solid content may be 30 to 100% by mass, or 50 to 100% by mass, or 50 to 90% by mass, or 50 to 80% by mass.

[0392] The number of types of blocks present in the block copolymer may be 2 or 3 or more. Furthermore, the number of blocks present in the block copolymer may be 2 or 3 or more.

[0393] <<<Block copolymer>>>

[0394] As block polymers, there are combinations such as AB, ABAB, ABA, and ABC.

[0395] As one of the methods for synthesizing block copolymers, active free radical polymerization and active cationic polymerization can be cited, in which the polymerization process is only composed of an initiation reaction and a growth reaction and is not accompanied by a side reaction that inactivates the growth end. The growth end can continue to maintain a growth active reaction in the polymerization reaction. By not allowing chain transfer to occur, a polymer (PA) of uniform length is obtained. By adding different monomers (mb), the growth end of the polymer (PA) can be utilized to polymerize the monomer (mb) to form a block copolymer (AB).

[0396] For example, when the types of blocks are two types, PA and PB, the molar ratio of the polymer chain (PA) to the polymer chain (PB) may be 1:9 to 9:1, preferably 3:7 to 7:3.

[0397] The volume ratio of the block copolymer is, for example, 30:70 to 70:30.

[0398] The homopolymer PA or PB is a polymer of a polymerizable compound having at least one reactive group (vinyl group or vinyl-containing organic group) capable of free radical polymerization.

[0399] The weight average molecular weight Mw of the block copolymer is preferably 1,000 to 100,000 or 5,000 to 100,000. When it is 1,000 or more, coating properties on a base substrate are excellent, and when it is 100,000 or less, solubility in a solvent is excellent.

[0400] The polydispersity (Mw / Mn) of the block copolymer is preferably 1.00 to 1.50, more preferably 1.00 to 1.20.

[0401] As the block copolymer used in the present invention, a known one can be used.

[0402] As a specific example of the block copolymer, for example, when a silicon-containing polymer chain and a silicon-free polymer chain are combined, for example, the difference in dry etching rate can be increased, which is preferable.

[0403] Examples of silicon-containing polymer chains include silylated polystyrene derivatives, etc. Examples of silylated polystyrene derivatives include polysilanes (e.g., polydihexylsilane), polysiloxanes (e.g., polydimethylsiloxane), poly(trimethylsilylstyrene), poly(pentamethyldisilylstyrene), etc.

[0404] The silylated polystyrene derivative is particularly preferably poly(4-trimethylsilylstyrene) or poly(4-pentamethyldisilylstyrene) having a substituent at the 4-position.

[0405] Preferred examples of block copolymers are block copolymers in which a silicon-free polymer having styrene which may be substituted with an organic group as a structural unit or a silicon-free polymer having a structure derived from lactide as a structural unit is combined with a silicon-containing polymer having styrene substituted with a silicon-containing group as a structural unit.

[0406] Among them, a combination of a silylated polystyrene derivative and a polystyrene derivative, or a combination of a silylated polystyrene derivative and polylactide is preferred.

[0407] Among them, 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.

[0408] More preferred specific 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).

[0409] 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).

[0410] 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.

[0411] All disclosures recorded in WO2018 / 135456 pamphlet are incorporated into this specification.

[0412] The block copolymer may be a block copolymer in which a silicon-free polymer and a silicon-containing polymer having styrene substituted with a silicon-containing group as a structural unit are combined, and the silicon-free polymer includes a unit structure represented by the following formula (1-1c) or formula (1-2c).

[0413]

[0414] (In formula (1-1c) or formula (1-2c), R 1 and R 2 Each independently represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 10 carbon atoms, and R 3 ~R 5 Each independently represents a hydrogen atom, a hydroxyl 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 amide group or a carbonyl group.

[0415] The silicon-containing group may contain one silicon atom.

[0416] The silicon-containing polymer may include a unit structure represented by the following formula (2c).

[0417]

[0418] (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.)

[0419] Furthermore, as the block copolymer, a block copolymer described in JP-A-2019-507815 including the following [BCP11] to [BCP14] can be used. All disclosures described in JP-A-2019-507815 are incorporated herein by reference.

[0420] [BCP11] A block copolymer comprising 5-vinylbenzo[d][1,3]dioxole.

[0421] [BCP12] The block copolymer according to [BCP11], further comprising a silicon-containing block.

[0422] [BCP13] The block copolymer according to [BCP12], further comprising pentamethyldisilylstyrene.

[0423] [BCP14] The block copolymer according to [BCP13], wherein the block copolymer is poly(5-vinylbenzo[d][1,3]dioxole)-b-poly(pentamethyldisilylstyrene).

[0424] The synthesis of the poly(5-vinylbenzo[d][1,3]dioxole-block-4-pentamethyldisilylstyrene) described above is shown in Scheme 1 below.

[0425]

[0426] Me represents a methyl group.

[0427] 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 thereof include phenyl, naphthyl, or anthracenyl.

[0428] All disclosures recorded in WO2020 / 017494 pamphlet are incorporated herein by reference.

[0429] In addition, a block copolymer formed 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, pentamethyldisilylstyrene.

[0430] Useful block copolymers may be diblock, triblock, tetrablock or the like copolymers containing at least two blocks and having different blocks. Each of the blocks may be a homopolymer or a random or alternating copolymer.

[0431] Typical block copolymers include polystyrene-b-polyvinylpyridine, polystyrene-b-polybutadiene, polystyrene-b-polyisoprene, polystyrene-b-polymethyl methacrylate, polystyrene-b-polyalkenyl aromatic, polyisoprene-b-polyethylene oxide, polystyrene-b-poly(ethylene-propylene), polyethylene oxide-b-polycaprolactone, polybutadiene-b-polyethylene oxide, polystyrene-b-poly(tert-butyl (meth)acrylate), polymethyl methacrylate-b-poly(tert-butyl methacrylate), polyethylene oxide-b-polypropylene oxide, polystyrene-b-polytetrahydrofuran The invention relates to a block copolymer of the present invention and a combination of at least one of the block copolymers. The block copolymers are preferably selected from the group consisting of 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 block copolymers.

[0432] In addition, block copolymers formed of a combination of the organic polymers and / or metal-containing polymers described below are also exemplified.

[0433] Typical organic polymers include poly(9,9-bis(6'-N,N,N-trimethylammonium)-hexyl)-fluorenylphenylene) (PEP), poly(4-vinylpyridine) (4PVP), hydroxypropylmethylcellulose (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(ethyl) oxazoline), poly(alkyl acrylate), polyacrylamide, poly(N-alkyl acrylamide), poly(N,N-dialkyl acrylamide), 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), polyacrylate, polymethacrylate, oligosaccharides or polysaccharides, but are not limited to these.

[0434] Examples of metal-containing polymers include, but are not limited to, silicon-containing polymers such as polydimethylsiloxane (PDMS), cage silsesquioxane (POSS), or poly(trimethylsilylstyrene) (PTMSS) or polymers containing silicon and iron such as poly(ferrocenyldimethylsilane) (PFS).

[0435] Typical block copolymers (copolymers) include 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-poly DL-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), but are not limited to these. In one embodiment, the PS-PTMSS-PS block copolymer comprises a poly(trimethylsilylstyrene) polymer block consisting of two chains of PTMSS connected by a linker comprising four styrene units. Modified versions of the block copolymers, such as those disclosed in U.S. Patent Application Publication No. 2012 / 0046415, are also contemplated.

[0436] As other block copolymers, for example, a block copolymer in which a polymer having styrene or its derivatives as a structural unit is bonded to a polymer having (meth)acrylate as a structural unit, a block copolymer in which a polymer having styrene or its derivatives as a structural unit is bonded to a polymer having siloxane or its derivatives as a structural unit, and a block copolymer in which a polymer having oxyalkylene as a structural unit is bonded to a polymer having (meth)acrylate as a structural unit, etc. It should be noted that the so-called "(meth)acrylate" refers to one or both of an acrylate having a hydrogen atom bonded to the α-position and a methacrylate having a methyl group bonded to the α-position.

[0437] Examples of (meth)acrylates include those having a substituent such as an alkyl group or a hydroxyalkyl group bonded to a carbon atom of (meth)acrylic acid. Examples of the alkyl group used as a substituent include a linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms. Specifically, examples of (meth)acrylates 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-epoxycyclohexylmethyl (meth)acrylate, and trimethoxysilylpropyl (meth)acrylate.

[0438] Examples of the styrene derivatives include α-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 4-tert-butylstyrene, 4-n-octylstyrene, 2,4,6-trimethylstyrene, 4-methoxystyrene, 4-tert-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.

[0439] Examples of the siloxane derivatives include dimethylsiloxane, diethylsiloxane, diphenylsiloxane, and methylphenylsiloxane.

[0440] Examples of the alkylene oxide include ethylene oxide, propylene oxide, isopropylene oxide, and butylene oxide.

[0441] Examples of the block copolymer include polystyrene / poly(methyl methacrylate) block copolymers, styrene-polyethyl methacrylate block copolymers, styrene-(poly-tert-butyl methacrylate) block copolymers, styrene-polymethacrylic acid block copolymers, styrene-polymethyl acrylate block copolymers, styrene-polyethyl acrylate block copolymers, styrene-(poly-tert-butyl acrylate) block copolymers, and styrene-polyacrylic acid block copolymers.

[0442] The entire disclosure of WO2022 / 039187 pamphlet is incorporated herein by reference.

[0443] <<<Solvent>>>

[0444] Examples of the solvent used for the self-assembled film-forming composition include the following organic solvents.

[0445] Aliphatic hydrocarbon solvents such as n-pentane, isopentane, n-hexane, isohexane, n-heptane, isoheptane, 2,2,4-trimethylpentane, n-octane, isooctane, cyclohexane, methylcyclohexane, etc.

[0446] · Aromatic hydrocarbon solvents such as benzene, toluene, xylene, ethylbenzene, trimethylbenzene, methylethylbenzene, n-propylbenzene, isopropylbenzene, diethylbenzene, isobutylbenzene, triethylbenzene, di-isopropylbenzene, n-pentylnaphthalene, trimethylbenzene, etc.

[0447] Monohydric alcohol solvents such as methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol, n-pentanol, isopentanol, 2-methylbutanol, sec-pentanol, tert-pentanol, 3-methoxybutanol, n-hexanol, 2-methylpentanol, sec-hexanol, 2-ethylbutanol, sec-heptanol, heptanol-3, n-octanol, 2-ethylhexanol, sec-octanol, n-nonanol, 2,6-dimethylheptanol-4, n-decanol, sec-undecyl alcohol, trimethylnonanol, sec-tetradecyl alcohol, sec-heptadecanol, phenol, cyclohexanol, methylcyclohexanol, 3,3,5-trimethylcyclohexanol, benzyl alcohol, phenylmethylcarbinol, diacetone alcohol, cresol, etc.

[0448] Ethylene glycol, propylene glycol, 1,3-butanediol, 2,4-pentanediol, 2,4-methylpentanediol, 2,5-hexanediol, 2,4-heptanediol, 1,3-ethylhexanediol, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol, glycerol and other polyol solvents

[0449] Ketone solvents such as acetone, methyl ethyl ketone, methyl-n-propyl ketone, methyl-n-butyl ketone, diethyl ketone, methyl-isobutyl ketone, methyl-n-amyl ketone, ethyl-n-butyl ketone, methyl-n-hexyl ketone, diisobutyl ketone, trimethyl nonanone, cyclohexanone, methylcyclohexanone, 2,4-pentanedione, acetone acetone, diacetone alcohol, acetophenone, fenchone, etc.

[0450] Ethyl ether, isopropyl ether, n-butyl ether, n-hexyl ether, 2-ethylhexyl ether, ethylene oxide, 1,2-propylene oxide, dioxolane, 4-methyldioxolane, di Alkane, dimethyl Ether solvents such as alkane, 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-ethyl butyl ether, ethylene glycol dibutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol diethyl ether, diethylene glycol mono-n-butyl ether, diethylene glycol di-n-butyl ether, diethylene glycol mono-n-hexyl ether, ethoxytriethylene glycol, 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, 2-methyltetrahydrofuran

[0451] ·Diethyl carbonate, methyl acetate, ethyl acetate, γ-butyrolactone, γ-valerolactone, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl 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, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethyl acetate Ester solvents such as glycol monoethyl ether, diethylene glycol mono-n-butyl acetate, propylene glycol monomethyl acetate, propylene glycol monoethyl acetate, propylene glycol monopropyl acetate, propylene glycol monobutyl acetate, dipropylene glycol monomethyl acetate, dipropylene glycol monoethyl acetate, ethylene glycol diacetate, methoxytriglycol acetate, ethyl propionate, n-butyl propionate, isopentyl propionate, diethyl oxalate, di-n-butyl oxalate, methyl lactate, ethyl lactate, n-butyl lactate, n-pentyl lactate, diethyl malonate, dimethyl phthalate, diethyl phthalate, etc.

[0452] · Nitrogen-containing solvents such as N-methylformamide, N,N-dimethylformamide, N,N-diethylformamide, acetamide, N-methylacetamide, N,N-dimethylacetamide, N-methylpropionamide, and N-methylpyrrolidone

[0453] Sulfur-containing solvents such as methyl sulfide, ethyl sulfide, thiophene, tetrahydrothiophene, dimethyl sulfoxide, sulfolane, 1,3-propane sultone, etc.

[0454] 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 the storage stability of the solution of the composition.

[0455] In addition, the solvent contained in the self-assembled film-forming composition 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.

[0456] Preferred low boiling point solvents (A) having a boiling point of 160° C. or less include, for example, propylene glycol monomethyl ether acetate (boiling point: 146° C.), n-butyl acetate (boiling point: 126° C.), and methyl isobutyl ketone (boiling point: 116° C.).

[0457] Preferred high boiling point solvents (B) having a boiling point of 170° C. or higher include, for example, 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-dimethylpropaneamide (boiling point: 215° C.), and γ-butyrolactone (boiling point: 204° C.).

[0458] Two or more low-boiling-point solvents (A) and high-boiling-point solvents (B) may be selected and mixed for use.

[0459] As a preferred embodiment, the composition contains the high boiling point solvent (B) in an amount of 0.3 to 2.0 wt %, and most preferably 0.5 to 1.5 wt %, based on the total amount of solvent contained in the composition.

[0460] The entire disclosure of WO2018 / 135456 pamphlet is incorporated into this specification.

[0461] <<Phase separation of self-assembled films>>

[0462] Phase separation of a self-assembled film (e.g., a film of a block copolymer) can be achieved by treatment that causes rearrangement of the self-assembled film, such as ultrasonic treatment, solvent treatment, thermal annealing, etc. In many applications, it is desirable to achieve phase separation of a self-assembled film by simple heating or so-called thermal annealing.

[0463] Thermal annealing can be performed in the atmosphere or in an inert gas under normal pressure, reduced pressure, or increased pressure.

[0464] The conditions for the thermal annealing are not particularly limited, but are preferably 180° C. to 300° C., more preferably 210° C. to 280° C., and particularly preferably 230° C. to 270° C. in the atmosphere.

[0465] The treatment time is not particularly limited, but is usually 1 to 30 minutes, preferably 3 to 10 minutes.

[0466] By phase separation of the self-assembled film, a domain oriented substantially vertically to the substrate or the underlying film surface is formed. The morphology of the domain is, for example, lamellar, spherical, cylindrical, etc. The domain spacing is, for example, 50 nm or less.

[0467] <<Patterning of self-assembled films>>

[0468] By selectively removing a portion of the phase-separated self-assembled film, a pattern corresponding to the morphology of the domains is obtained.

[0469] Examples of a method for selectively removing a portion of the phase-separated self-assembled film include a method of subjecting the phase-separated self-assembled film to an oxygen plasma treatment and a method of subjecting the phase-separated self-assembled film to a hydrogen plasma treatment.

[0470] <Step 6>

[0471] The sixth step is a step of forming a brush layer in gaps between patterns of the patterned lower layer film.

[0472] It should be noted that the sixth step is a step performed between the fourth step and the fifth step.

[0473] The method for forming the brush layer is not particularly limited, and an example thereof includes a method of applying a brush layer-forming composition and then drying it.

[0474] <<Brush layer forming composition>>

[0475] The brush layer-forming composition contains, for example, a brush polymer and a solvent.

[0476] The composition for forming a brush layer is, for example, a composition containing polymer chains that can directly bond to the surface of a substrate. A film or layer in which polymer chains are arranged on a substrate in a brush-like manner is sometimes referred to as a brush layer.

[0477] The brush layer-forming composition is, for example, a composition for forming an underlayer film for forming an underlayer film of a layer including a block copolymer.

[0478] In addition, the film formed by the composition for forming a brush layer, for example, plays the role of a guide for controlling the generation position of the polymer phase formed by self-assembly. For example, the film formed by the composition for forming a brush layer is a physical guide (grapho-epitaxy) having a concave-convex structure for forming a microphase separation pattern in the concave portion. In addition, for example, the film formed by the composition for forming a brush layer is a chemical guide (chemical-epitaxy) formed in the lower layer of the self-assembly material and controlling the formation position of the microphase separation pattern based on the difference in its surface energy.

[0479] <<<Brush polymer>>>

[0480] The brush polymer is not particularly limited as long as it is a brush polymer used for forming the lower layer film.

[0481] As an example of a brush polymer, for example, a polymer contained in a neutral wet bottom surface described in JP-A-2011-515537 can be cited. As such a polymer, for example, a random copolymer described in claim 15 of JP-A-2011-515537 and a blend of a plurality of grafted homopolymers described in claim 16 can be cited. The contents of JP-A-2011-515537 are incorporated into this specification to the same extent as if all were expressly stated.

[0482] As another example of a brush polymer, for example, a random copolymer described in Japanese Patent Publication No. 2011-518652 can be cited. An example of a random copolymer described in Japanese Patent Publication No. 2011-518652 is a random PS-r-PMMA capable of photocrosslinking described in paragraph

[0028] . The contents of Japanese Patent Publication No. 2011-518652 are incorporated into this specification to the same extent as if all were expressly stated.

[0483] As another example of a brush polymer, for example, a resin in which 20 mol% to 80 mol% of the total structural units are structural units derived from a monomer containing an aromatic ring. Such a resin is, for example, a resin component contained in a primer described in International Publication No. 2012 / 036121. The contents of International Publication No. 2012 / 036121 are incorporated into this specification to the same extent as if all were expressly stated.

[0484] Another example of the brush polymer is the random copolymer described in claim 1 of Japanese Patent Application Laid-Open No. 2013-166934. The contents of Japanese Patent Application Laid-Open No. 2013-166934 are incorporated into the present specification to the same extent as if all were expressly stated.

[0485] As another example of a brush polymer, for example, a polymer having a unit structure of a polycyclic aromatic vinyl compound in an amount of 0.2 mol% or more relative to the total unit structure can be cited. Such a polymer can be cited, for example, a polymer contained in a composition for forming an underlayer film described in International Publication No. 2014 / 097993. The contents of International Publication No. 2014 / 097993 are incorporated into this specification to the same extent as if all were expressly stated.

[0486] As another example of the brush polymer, for example, a polymer contained in the brush backfill composition described in Japanese Unexamined Patent Application Publication No. 2015-130496 (for example, a poly(alkyl acrylate) having a functional group capable of reacting with a semiconductor substrate) can be cited. The contents of Japanese Unexamined Patent Application Publication No. 2015-130496 are incorporated into this specification to the same extent as if all were expressly stated.

[0487] As another example of the brush polymer, for example, an addition polymer described in claim 1 of Japanese Patent Application Laid-Open No. 2016-148024 can be cited. The contents of Japanese Patent Application Laid-Open No. 2016-148024 are incorporated into this specification to the same extent as if all were expressly stated.

[0488] As another example of the brush polymer, for example, a polymer contained in the pinning material described in claim 1 of JP-A-2016-528713 can be cited. As such a polymer, for example, a polymer described in claim 3 of JP-A-2016-528713 can be cited. The contents of JP-A-2016-528713 are incorporated into this specification to the same extent as if all were expressly stated.

[0489] As another example of a brush polymer, for example, an acid-sensitive copolymer containing an acid-decomposable group, an attachment group, and a functional group as described in claim 1 of Japanese Patent Application Laid-Open No. 2018-139007 can be cited. The contents of Japanese Patent Application Laid-Open No. 2018-139007 are incorporated into this specification to the same extent as if all were expressly stated.

[0490] As another example of the brush polymer, for example, the hydrophobic polymer brush precursor described in claim 1 of JP-A-2018-503241 can be cited. The contents of JP-A-2018-503241 are incorporated into this specification to the same extent as if all were expressly stated.

[0491] The brush polymer preferably has a functional group capable of bonding to a substrate.

[0492] Examples of the functional group capable of bonding to the substrate include a hydroxyl group, an amino group, and a sulfonic acid group.

[0493] The brush polymer may have a functional group capable of bonding to a substrate at the terminal of the polymer chain or at a position other than the terminal of the polymer chain.

[0494] There are no particular limitations on the method for introducing a functional group capable of bonding to a substrate into the terminal of a polymer chain. For example, in the case of an addition polymer, a method using a compound having a functional group capable of bonding to a substrate as a polymerization initiator or a chain transfer agent can be mentioned.

[0495] The brush polymer is preferably an addition polymer.

[0496] The addition-polymerization type polymer is obtained by, for example, polymerizing one or more radical polymerizable monomers.

[0497] The radical polymerizable monomer is not particularly limited, and examples thereof include (meth)acrylic compounds and aromatic group-containing vinyl compounds.

[0498] Examples of the (meth)acrylic acid-based compound include (meth)acrylic acid and (meth)acrylic acid esters. 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.

[0499] Examples of the vinyl compound containing an aromatic group include styrene, α-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 4-tert-butylstyrene, 4-n-octylstyrene, 2,4,6-trimethylstyrene, 4-methoxystyrene, 4-tert-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.

[0500] <<<<Polymer (P)>>>>

[0501] The brush polymer is preferably a polymer (P) comprising the following structural units (A) and (B) because it can induce a microphase separation structure of the block copolymer to be perpendicular to the substrate.

[0502] 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 a substrate

[0503] Structural unit (B): Structural unit derived from a vinyl compound containing an aromatic group

[0504] The molar ratio of the structural unit (A) to all the structural units in the polymer (P) is more than 0% and 5% or less.

[0505] When the molar ratio of the structural unit (A) relative to all the structural units in the polymer (P) is greater than 0% and less than 5%, a film can be formed in which the microphase separation structure of the block copolymer is induced to be perpendicular to the substrate. If the molar ratio of the structural unit (A) relative to all the structural units in the polymer (P) exceeds 5%, the arrangement of the microphase separation structure of the block copolymer is disordered, and the microphase separation structure of the block copolymer cannot be induced to be perpendicular to the substrate.

[0506] 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 polymerization of a compound having a polymerizable unsaturated group. Examples of the polymerizable unsaturated group include ethylenic unsaturated groups. Examples of the ethylenic unsaturated group include vinyl, allyl, propargyl, butenyl, ethynyl, phenylethynyl, maleimide, nadimide, (meth)acryloyl, and the like.

[0507] The polymer (P) is, for example, a random copolymer.

[0508] The polymer (P) may also contain structural units other than the structural units (A) and (B).

[0509] The structural unit (A) is a structural unit derived from a (meth)acrylic compound.

[0510] The (meth)acrylic compound has a (meth)acryloyl group.

[0511] The (meth)acrylic compound has a functional group capable of bonding to a substrate.

[0512] The term "(meth)acryloyl" refers to an acryloyl group and a methacryloyl group. 2 =CH-CO-, the so-called methacryloyl group refers to CH 2 =C(CH 3 )-CO-.

[0513] The functional group capable of bonding to the substrate is not particularly limited, and examples thereof include a hydroxyl group, an amino group, and a sulfonic acid group.

[0514] The number of the functional groups capable of bonding to the substrate in the structural unit (A) may be one or two or more, but is preferably one.

[0515] The number of the (meth)acryloyl group in the (meth)acrylic compound may be one or two or more, but is preferably one.

[0516] The structural unit (A) is a structural unit different from the structural unit (B). Therefore, the structural unit (B) does not have an aromatic ring.

[0517] The structural unit (A) in the polymer (P) may be one kind or two or more kinds.

[0518] As the structural unit (A), it is preferred that the structural unit (A-1) represented by the following formula (1) is contained.

[0519]

[0520] (In formula (1), X represents -O- or -NH-. Y represents a hydroxyl 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. )

[0521] As the amino group, a primary amino group or a secondary amino group is preferred.

[0522] A primary amino group is a monovalent functional group (-NH 2 ).

[0523] The secondary amino group refers to a monovalent functional group obtained by removing a hydrogen atom from a primary amine (—NHR (wherein R represents an organic group). R represents, for example, an alkyl group having 1 to 6 carbon atoms.

[0524] The alkylene group having 1 to 10 carbon atoms which may be substituted with a halogen atom may be linear, branched or cyclic.

[0525] Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.

[0526] The number of halogen atoms in the alkylene group having 1 to 10 carbon atoms substituted with a halogen atom may be 1 or 2 or more.

[0527] 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 (trimethylene group), a 1-methylethylene group (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.

[0528] The molar ratio of the structural unit (A) to all structural units in the polymer (P) is more than 0% and is 5% or less, preferably 0.1% or more and 5% or less, more preferably 0.3% or more and 4.5% or less, particularly preferably 0.5% or more and 4.0% or less.

[0529] As a (meth)acrylic-type compound, the compound represented by following formula (1-1) is mentioned, for example.

[0530]

[0531] (In formula (1-1), X represents -O- or -NH-. Y represents a hydroxyl 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. )

[0532] Examples of the (meth)acrylic compound include hydroxyl group-containing (meth)acrylates, amino group-containing (meth)acrylates, sulfonic acid group-containing (meth)acrylates, hydroxyl group-containing (meth)acrylamide, sulfonic acid group-containing (meth)acrylamide, and the like.

[0533] Examples of the hydroxyl group-containing (meth)acrylate 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.

[0534] As an amino group-containing (meth)acrylate, a primary amino group-containing (meth)acrylate, a secondary amino group-containing (meth)acrylate, etc. are mentioned, for example.

[0535] As a primary amino group-containing (meth)acrylate, aminomethyl (meth)acrylate, aminoethyl (meth)acrylate, etc. are mentioned, for example.

[0536] As a (meth)acrylate containing a secondary amino group, tert-butylaminoethyl (meth)acrylate, tert-butylaminopropyl (meth)acrylate, etc. are mentioned, for example.

[0537] Examples of the sulfonic acid group-containing (meth)acrylate include 2-sulfoethyl (meth)acrylate and 3-sulfopropyl (meth)acrylate.

[0538] Examples of the (meth)acrylamide containing a hydroxyl group include N-(hydroxymethyl) (meth)acrylamide, N(2-hydroxyethyl) (meth)acrylamide, and N-(4-hydroxybutyl) (meth)acrylamide.

[0539] The structural unit (B) is a structural unit derived from a vinyl compound containing an aromatic group.

[0540] The aromatic ring of the aromatic group-containing vinyl compound may be an aromatic hydrocarbon ring or an aromatic heterocyclic ring, but an aromatic hydrocarbon ring is preferred.

[0541] Examples of the aromatic hydrocarbon ring include a benzene ring, a naphthalene ring, and an anthracene ring.

[0542] The aromatic group-containing vinyl compound does not have a functional group capable of bonding to a substrate, for example.

[0543] The aromatic group-containing vinyl compound does not have, for example, a hydroxyl group, an amino group, or a sulfonic acid group.

[0544] The structural unit (B) does not have a functional group capable of bonding to a substrate, for example.

[0545] The structural unit (B) does not have, for example, a hydroxyl group, an amino group, or a sulfonic acid group.

[0546] The structural unit (B) in the polymer (P) may be one kind or two or more kinds.

[0547] As the structural unit (B), it is preferred that the structural unit (B-1) represented by the following formula (2) be contained.

[0548] As the structural unit (B), it is preferred that the structural unit (B-2) represented by the following formula (3) be contained.

[0549]

[0550] (In formula (2), n Ys each independently represent a halogen atom, an alkyl group, an alkoxy group, an alkoxycarbonyl group or an alkylthio group, and n represents an integer of 0 to 7.)

[0551]

[0552] (In formula (3), R3 ~R 5 Each independently represents a hydrogen atom or a tert-butyl group. 3 ~R 5 1 or 2 of them represent tert-butyl groups. )

[0553] Examples of the halogen atom in Y in the formula (2) include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.

[0554] The alkyl group in 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, further 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.

[0555] As the alkoxy group in Y in formula (2), an alkoxy group having 1 to 15 carbon atoms is preferred, an alkoxy group having 1 to 10 carbon atoms is more preferred, an alkoxy group having 1 to 6 carbon atoms is further preferred, and an alkoxy group having 1 to 3 carbon atoms is particularly preferred. The alkyl group in the alkoxy group may be linear, branched, or cyclic.

[0556] As the alkoxycarbonyl group in Y in formula (2), an alkoxycarbonyl group having 2 to 15 carbon atoms is preferred, an alkoxycarbonyl group having 2 to 10 carbon atoms is more preferred, an alkoxycarbonyl group having 2 to 6 carbon atoms is further preferred, and an alkoxycarbonyl group having 2 to 3 carbon atoms is particularly preferred. The alkyl group in the alkoxycarbonyl group may be linear, branched, or cyclic.

[0557] Examples of the alkylthio group in Y in the formula (2) include groups in which -O- of the above-mentioned alkoxy group is replaced by -S-.

[0558] 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%.

[0559] The molar ratio of the structural unit (A) to the structural unit (B) (structural unit (A):structural unit (B)) in the polymer (P) is not particularly limited, but is preferably 1:200 to 1:10, more preferably 1:150 to 1:20.

[0560] 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.

[0561] 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.

[0562] When the polymer (P) contains the structural unit (B-1) represented by the formula (2) and the structural unit (B-2) represented by the 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.

[0563] 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).

[0564]

[0565] (In formula (2-1), n ​​Ys each independently represent a halogen atom, an alkyl group, an alkoxy group, an alkoxycarbonyl group or an alkylthio group, and n represents an integer of 0 to 7.)

[0566]

[0567] (In formula (3-1), R 3 ~R 5 Each independently represents a hydrogen atom or a tert-butyl group. 3 ~R 5 1 or 2 of them represent tert-butyl groups. )

[0568] The weight average molecular weight of the brush polymer measured by gel permeation chromatography (GPC) is not particularly limited, but is, in terms of polystyrene, for example, 1,000 to 50,000, and preferably 2,000 to 20,000.

[0569] <<<<Method for producing brush polymer>>>>

[0570] There is no particular limitation on the method for producing the brush polymer.

[0571] For example, when the brush polymer is an addition polymer, it can be produced by polymerizing the monomers by conventional methods such as bulk polymerization, solution polymerization, suspension polymerization or emulsion polymerization. Solution polymerization is particularly preferred, in which case, for example, the desired monomers can be added to a solvent to which a polymerization initiator is added and polymerized.

[0572] For example, when the brush polymer is an addition-polymerization type random copolymer, it can be produced by copolymerizing various monomers at an appropriate molar ratio by a conventional method such as bulk polymerization, solution polymerization, suspension polymerization or emulsion polymerization.

[0573] Examples of such polymerization include radical polymerization.

[0574] The brush polymer may be produced by a polymerization method other than radical polymerization, for example, by an ionic (anionic or cationic) addition polymerization, or by a condensation polymerization or addition polymerization reaction.

[0575] 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 a vinyl compound containing an aromatic group.

[0576] [Polymerization initiator]

[0577] As the polymerization initiator, an organic peroxide or a disazo compound can be used.

[0578] Examples of the organic peroxide include diacyl peroxides, peroxydicarbonates, peroxyesters, and peroxysulfonates.

[0579] Examples of the diacyl peroxides include diacetyl peroxide, diisobutyl peroxide, didecanoyl peroxide, benzoyl peroxide, and succinic acid peroxide.

[0580] Examples of the peroxydicarbonates include diisopropyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, and diallyl peroxydicarbonate.

[0581] Examples of the peroxyesters include tert-butyl peroxyisobutyrate, tert-butyl neodecanoate, and cumene peroxyneodecanoate.

[0582] Examples of the peroxysulfonate esters include acetylcyclohexylsulfonyl peroxide and the like.

[0583] Examples of the disazo compound include 2,2′-azobisisobutyronitrile, 4,4′-azobis(4-cyanovaleric acid), 2,2′-azobis(4-methoxy-2,4-dimethoxyvaleronitrile), and 2,2′-azobis(2-cyclopropylpropionitrile).

[0584] When the polymerization is to be completed 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.

[0585] The amount of the polymerization initiator used is, for example, 0.0001 to 0.2 equivalents, or preferably 0.0005 to 0.1 equivalents, based on the total amount of the monomers used.

[0586] [Solvent]

[0587] The solvent used for the polymerization is not particularly limited as long as it is a solvent that does not participate in the polymerization reaction and is compatible with the resulting brush polymer. Examples thereof include aromatic hydrocarbons, alicyclic hydrocarbons, aliphatic hydrocarbons, ketones, ethers, esters, amides, sulfoxides, alcohols, and polyol derivatives.

[0588] Examples of the aromatic hydrocarbons include benzene, toluene, and xylene.

[0589] Examples of the alicyclic hydrocarbons include cyclohexane and the like.

[0590] Examples of the aliphatic hydrocarbons include n-hexane and n-octane.

[0591] Examples of ketones include acetone, methyl ethyl ketone, and cyclohexanone.

[0592] Examples of the ethers include tetrahydrofuran, dihydrofuran, Alkane, etc.

[0593] Examples of the esters include ethyl acetate and butyl acetate.

[0594] Examples of the amides include N,N-dimethylformamide and N,N-dimethylacetamide.

[0595] Examples of the sulfoxides include dimethyl sulfoxide and the like.

[0596] Examples of the alcohols include methanol and ethanol.

[0597] Examples of the polyol derivatives include ethylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, and propylene glycol monomethyl ether acetate.

[0598] These can be used individually by 1 type or in combination of 2 or more types.

[0599] The polymerization temperature is not particularly limited as long as it is a temperature range in which the monomers are consumed and the polymerization is completed without causing side reactions such as transfer reaction and termination reaction, but it is preferably carried out at a temperature range of -100°C or higher and below the boiling point of the solvent.

[0600] The concentration of the monomer relative to the solvent is not particularly limited, but is usually 1 to 40% by weight, preferably 10 to 30% by weight.

[0601] The time for the polymerization reaction can be appropriately selected, but is usually in the range of 2 hours to 50 hours.

[0602] <<<Solvent>>>

[0603] The solvent contained in the brush layer-forming composition is not particularly limited as long as it is a solvent that dissolves the brush polymer.

[0604] 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.

[0605] These can be used individually by 1 type or in combination of 2 or more types.

[0606] 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.

[0607] <<<Other ingredients>>>

[0608] 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.

[0609] In the present invention, "no crosslinking agent is contained" may include a case where a crosslinking agent is contained slightly to such an extent that the crosslinking agent does not fully function. In the embodiment where 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.

[0610] Examples of the cross-linking agent include nitrogen-containing compounds having 2 to 4 nitrogen atoms substituted with hydroxymethyl groups or alkoxymethyl groups.

[0611] Examples of the crosslinking agent include hexamethoxymethylmelamine, tetramethoxymethyl glycoluril, tetramethoxymethyl benzoguanamine, 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.

[0612] The brush layer-forming composition may contain a surfactant. The surfactant is an additive for improving the coating properties on the substrate.

[0613] As the surfactant, a known surfactant such as a nonionic surfactant or a fluorine-based surfactant can be used.

[0614] As content of the surfactant in the brush layer-forming composition, for example, 0.1 mass % to 5 mass % is mentioned with respect to the brush polymer.

[0615] In the brush layer-forming composition, if the components other than the solvent are defined as a solid component, the solid component includes a brush polymer and additives added as necessary.

[0616] The concentration of the solid content in the brush layer-forming composition is not particularly limited, but is, for example, 0.1 mass % to 15 mass %, and preferably 0.1 mass % to 10 mass %.

[0617] An example of a method for manufacturing a semiconductor element of the present invention will be described using drawings.

[0618] Figure 1A to Figure 1I It is a schematic cross-sectional view for explaining an example of the method for manufacturing a semiconductor element of the present invention.

[0619] Using the underlayer film-forming composition of the present invention, an underlayer film 2 ( Figure 1A ).

[0620] Next, a resist film 3 is formed on the lower film 2 ( Figure 1B ).

[0621] Next, the resist film 3 is irradiated with light or electron beams, and then the resist film 3 is developed to obtain a resist pattern (a patterned resist film 3) ( Figure 1C ).

[0622] Next, the lower layer film 2 is etched using the resist pattern (the patterned resist film 3) as a mask, thereby forming a patterned lower layer film 2 ( Figure 1D )

[0623] Next, the resist pattern (the patterned resist film 3) is removed ( Figure 1E ).

[0624] Next, a brush layer-forming composition is applied onto the semiconductor substrate 1 and the patterned lower film 2 to form a brush layer 4 ( Figure 1F ).

[0625] Next, a portion of the brush layer 4 is removed, and the brush layer 4 is formed in the gaps of the pattern of the patterned lower film 2 ( Figure 1G ).

[0626] Next, a self-assembled film 5 is formed on the patterned lower film 2 and the brush layer 4. The self-assembled film 5 is, for example, a film of a block copolymer having an A block and a B block. By phase-separating the self-assembled film 5, a microphase-separated structure having a domain 5a of the A block and a domain 5b of the B block is obtained ( Figure 1H ).

[0627] By selectively removing a portion of the microphase-separated self-assembled film 5 (for example, the domain 5b of the B block), a pattern corresponding to the morphology of the microphase-separated domain is obtained ( Fig. 1I ).

[0628] Although not shown, further steps include a step of processing the semiconductor substrate using a pattern corresponding to the morphology of the microphase-separated domains as a mask, or using the lower film 2 and the brush layer 4 to which the pattern is transferred as a mask.

[0629] Example

[0630] Next, the present invention will be specifically described with reference to Examples, but the present invention is not limited to these.

[0631] The weight average molecular weights of the polymers shown in Synthesis Examples 1 to 7 and Comparative Synthesis Examples 1 to 3 in this specification are the results of measurements obtained by gel permeation chromatography (hereinafter referred to as GPC). A GPC apparatus manufactured by Tosoh Corporation was used for the measurements, and the measurement conditions and the like were as follows.

[0632] GPC column: TSKgel Super-MultiporeHZ-N (2 columns)

[0633] Column temperature: 40°C

[0634] Solvent: Tetrahydrofuran (THF)

[0635] Flow rate: 0.35ml / min

[0636] Standard sample: Polystyrene (manufactured by Tosoh Corporation)

[0637] <Synthesis example 1>

[0638] 5.68 g of 2-vinylnaphthalene (75% by molar ratio relative to the whole polymer 1), 1.60 g of 2-hydroxyethyl methacrylate (25% by molar ratio relative to the whole polymer 1) and 0.73 g of 2,2'-azobisisobutyronitrile were dissolved in 32.00 g of propylene glycol monomethyl ether acetate. After the reaction vessel was purged with nitrogen, the solution was heated and stirred at 140°C for about 4 hours. The reaction solution was added dropwise to isopropanol, and the precipitate was recovered by suction filtration, and then the polymer 1 was recovered by drying under reduced pressure at 60°C. The weight average molecular weight Mw measured by GPC in terms of polystyrene was 8500. The structure present in polymer 1 is shown in the following formula.

[0639]

[0640] <Synthesis example 2>

[0641] 4.75 g of 2-vinylnaphthalene (55% by molar ratio relative to the whole polymer 2), 2.96 g of benzyl methacrylate (30% by molar ratio relative to the whole polymer 2), 1.21 g of 2-hydroxypropyl methacrylate (15% by molar ratio relative to the whole polymer 2) and 1.07 g of 2,2'-azobisisobutyronitrile were dissolved in 40.00 g of propylene glycol monomethyl ether acetate. After the reaction vessel was purged with nitrogen, the solution was heated and stirred at 140°C for about 4 hours. The reaction solution was added dropwise to isopropanol, and the precipitate was recovered by suction filtration, and then the polymer 2 was recovered by drying under reduced pressure at 60°C. The weight average molecular weight Mw measured by GPC in terms of polystyrene was 5900. The structure present in polymer 2 is shown in the following formula.

[0642]

[0643] <Synthesis Example 3>

[0644] 2.94 g of 2-vinylnaphthalene (50% by molar ratio relative to the whole polymer 3), 1.24 g of hydroxyethyl methacrylate (25% by molar ratio relative to the whole polymer 3), 1.71 g of N-cyclohexylmaleimide (25% by molar ratio relative to the whole polymer 3) and 0.12 g of 2,2'-azobisisobutyronitrile were dissolved in 24.00 g of propylene glycol monomethyl ether acetate. After the reaction vessel was purged with nitrogen, the solution was heated and stirred at 140°C for about 4 hours. The reaction solution was added dropwise to isopropanol, and the precipitate was recovered by suction filtration, and then polymer 3 was recovered by drying under reduced pressure at 60°C. The weight average molecular weight Mw measured by GPC in terms of polystyrene was 16300. The structure present in polymer 3 is shown in the following formula.

[0645]

[0646] <Synthesis Example 4>

[0647] 2.86 g of 2-vinylnaphthalene (50% by molar ratio relative to the whole polymer 4), 1.68 g of N-cyclohexylmaleimide (25% by molar ratio relative to the whole polymer 4), 1.32 g of N-hydroxyethylmaleimide (25% by molar ratio relative to the whole polymer 4) and 0.12 g of 2,2'-azobisisobutyronitrile were dissolved in 24.00 g of propylene glycol monomethyl ether acetate. After the reaction vessel was purged with nitrogen, the solution was heated and stirred at 140°C for about 4 hours. The reaction solution was added dropwise to isopropanol, and the precipitate was recovered by suction filtration, and then polymer 4 was recovered by drying under reduced pressure at 60°C. The weight average molecular weight Mw measured by GPC in terms of polystyrene was 11900. The structure present in polymer 4 is shown in the following formula.

[0648]

[0649] <Synthesis Example 5>

[0650] 7.03 g of 2-vinylnaphthalene (71% by molar ratio relative to polymer 5), 0.87 g of 4-methoxystyrene (10% by molar ratio relative to the whole polymer 5), 1.77 g of 2-hydroxypropyl methacrylate (19% by molar ratio relative to the whole polymer 5) and 0.49 g of 2,2'-azobisisobutyronitrile were dissolved in 40.00 g of propylene glycol monomethyl ether acetate. After the reaction vessel was replaced with nitrogen, the solution was heated and stirred at 140°C for about 4 hours. The reaction solution was added dropwise to methanol, and the precipitate was recovered by suction filtration, and then polymer 5 was recovered by drying under reduced pressure at 60°C. The weight average molecular weight Mw measured by GPC in terms of polystyrene was 7200. The structure present in polymer 5 is shown in the following formula.

[0651]

[0652] <Synthesis example 6>

[0653] 7.22 g of 2-vinylnaphthalene (71% by molar ratio relative to the whole polymer 6), 0.50 g of 4-tert-butylstyrene (10% by molar ratio relative to the whole polymer 6), 1.80 g of 2-hydroxypropyl methacrylate (19% by molar ratio relative to the whole polymer 6) and 0.48 g of 2,2'-azobisisobutyronitrile were dissolved in 40.00 g of propylene glycol monomethyl ether acetate. After the reaction vessel was replaced with nitrogen, the solution was heated and stirred at 140°C for about 4 hours. The reaction solution was added dropwise to methanol, and the precipitate was recovered by suction filtration, and then polymer 6 was recovered by drying under reduced pressure at 60°C. The weight average molecular weight Mw measured by GPC in terms of polystyrene was 7300. The structure present in polymer 6 is shown in the following formula.

[0654]

[0655] <Synthesis Example 7>

[0656] 5.00 g of 2-vinylnaphthalene (55% by molar ratio relative to the whole polymer 7), 2.91 g of 2-phenylethyl methacrylate (26% by molar ratio relative to the whole polymer 7), 1.61 g of 2-hydroxypropyl methacrylate (19% by molar ratio relative to the whole polymer 7) and 0.48 g of 2,2'-azobisisobutyronitrile were dissolved in 40.00 g of propylene glycol monomethyl ether acetate. After the reaction vessel was purged with nitrogen, the solution was heated and stirred at 140°C for about 4 hours. The reaction solution was added dropwise to methanol, and the precipitate was recovered by suction filtration, and then polymer 7 was recovered by drying under reduced pressure at 60°C. The weight average molecular weight Mw measured by GPC in terms of polystyrene was 6600. The structure present in polymer 7 is shown in the following formula.

[0657]

[0658] <Comparative Synthesis Example 1>

[0659] 100.00 g of monoallyl diglycidyl isocyanuric acid (manufactured by Shikoku Chemicals Co., Ltd.), 66.4 g of 5,5-diethylbarbituric acid (manufactured by Tateyama Chemicals Co., Ltd.) and 4.1 g of benzyltriethylammonium chloride were added to 682.00 g of propylene glycol monomethyl ether in a reaction container and dissolved. After nitrogen substitution of the reaction container, the reaction was carried out at 130° C. for 24 hours to obtain a solution containing comparative polymer 1. GPC analysis was performed, and the comparative polymer 1 obtained had a weight average molecular weight of 6,800 in terms of standard polystyrene. The structure present in comparative polymer 1 is shown in the following formula.

[0660]

[0661] <Comparative Synthesis Example 2>

[0662] 7.25 g of styrene (80% by molar ratio relative to the whole comparative polymer 2), 2.51 g of 2-hydroxypropyl methacrylate (20% by molar ratio relative to the whole comparative polymer 2) and 0.24 g of 2,2'-azobisisobutyronitrile were dissolved in 40.00 g of propylene glycol monomethyl ether acetate. After the reaction container was purged with nitrogen, the solution was heated and stirred at 140°C for about 4 hours. The reaction solution was added dropwise to methanol, and the precipitate was recovered by suction filtration, and then the comparative polymer 2 was recovered by reduced pressure drying at 60°C. The weight average molecular weight Mw measured by GPC in terms of polystyrene was 13000. The structure present in the comparative polymer 2 is shown in the following formula.

[0663]

[0664] <Comparative Synthesis Example 3>

[0665] 5.62 g of styrene (60% by molar ratio relative to the whole comparative polymer 3), 1.80 g of methyl methacrylate (20% by molar ratio relative to the whole comparative polymer 3), 2.34 g of 2-hydroxyethyl methacrylate (20% by molar ratio relative to the whole comparative polymer 3) and 0.24 g of 2,2'-azobisisobutyronitrile were dissolved in 40.00 g of propylene glycol monomethyl ether acetate. After the reaction vessel was replaced with nitrogen, the solution was heated and stirred at 140°C for about 4 hours. The reaction solution was added dropwise to methanol, and the precipitate was recovered by suction filtration, and then the comparative polymer 3 was recovered by drying under reduced pressure at 60°C. The weight average molecular weight Mw measured by GPC in terms of polystyrene was 13300. The structure present in the comparative polymer 3 is shown in the following formula.

[0666]

[0667] (Preparation of Lower Layer Film-Forming Composition)

[0668] The components were mixed at the ratios shown in Table 1 and filtered using a polyethylene microfilter having a pore size of 0.05 μm to prepare underlayer film-forming compositions of Examples 1 to 7 and underlayer film-forming compositions of Comparative Examples 1 to 3, respectively.

[0669] The abbreviations in Table 1 are as follows.

[0670] PyPSA: Pyridine -4-Hydroxybenzenesulfonic acid

[0671] PyPTS: Pyridine -p-Toluenesulfonic acid

[0672] PGMEA: Propylene glycol monomethyl ether acetate

[0673] PGME: Propylene glycol monomethyl ether

[0674] PGME-PL: Imidazo[4,5-d]imidazole-2,5(1H,3H)-dione,tetrahydro-1,3,4,6-tetrakis[(2-methoxy-1-methylethoxy)methyl]-(structural formula below)

[0675]

[0676] TMOM-BP: 3,3',5,5'-tetrakis(methoxymethyl)-[1,1'-biphenyl]-4,4'-diol (trade name: TMOM-BP, manufactured by Honshu Chemical Industry Co., Ltd., structural formula shown below)

[0677]

[0678] PL-LI: 1,3,4,6-Tetrakis(methoxymethyl)glycoluril (structural formula below)

[0679]

[0680] [Table 1]

[0681]

[0682] (Resist Pattern Formation Evaluation)

[0683] <Formation of the lower layer>

[0684] The compositions for forming the lower layer film of Examples 1 to 7 and Comparative Examples 1 to 3 were applied to silicon wafers using a spin coater. The silicon wafers were baked on a hot plate at 205 to 250° C. for 60 seconds to obtain the lower layer films of Examples 1 to 7 and Comparative Examples 1 to 3. The film thicknesses are shown in Table 1. The film thicknesses were measured using an ellipsometric film thickness measuring device RE-3100 (SCREEN Corporation).

[0685] <Test of forming resist pattern using electron beam lithography equipment>

[0686] A positive resist solution for EUV was spin-coated on the lower film of Examples 1 to 7 and Comparative Examples 1 to 3, and heated at 130°C for 60 seconds to form an EUV resist film with a film thickness of 35 nm. The resist film was exposed under specified conditions using an electron beam lithography device (ELS-G130). After exposure, baking (PEB) was performed at 90°C for 60 seconds, cooling on a cooling plate to room temperature, and paddle development was performed for 30 seconds using a 2.38% tetramethylammonium hydroxide aqueous solution (manufactured by Tokyo Ohka Industry Co., Ltd., trade name NMD-3) as a photoresist developer. A resist pattern with a line size of 16nm to 28nm was formed. A scanning electron microscope (manufactured by Hitachi High-Tech Nolods, CG4100) was used to measure the length of the resist pattern.

[0687] The photoresist pattern obtained by the above operation was observed from the top of the pattern, and the charge amount forming 22nm line / 44nm spacing (line and space (L / S=1 / 1) was set to the optimal irradiation energy, and the LWR at this time, which is a value representing the roughness of the pattern shape, was confirmed. LWR represents 3 times the value (3σ) (unit: nm) of the standard deviation (σ) obtained from the measurement results of 400 line positions along the length direction of the line measured by a scanning electron microscope (manufactured by Hitachi High-Tech Novel Devices, CG4100). The smaller the value of LWR, the more likely it is that a good pattern can be formed. The results are shown in Table 2.

[0688] (Evaluation of Self-Assembly of Block Copolymers)

[0689] <Preparation of Self-Assembly Film-Forming Composition 1>

[0690] 0.5 g of a polystyrene / poly(methyl methacrylate) copolymer (manufactured by POLYMER SOURCE INC., PS (Mw: 22,000, Mn: 21,000)-b-PMMA (Mw: 22,900, Mn: 21,000), polydispersity = 1.07) as block copolymer 1 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 a self-assembled film-forming composition 1 containing block copolymer 1 (BCP1).

[0691] <Preparation of Self-Assembly Film-Forming Composition 2>

[0692] In the preparation of the self-assembled film-forming composition 1, a 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 = 1.06) was used as a block copolymer 2 instead of the block copolymer 1. Otherwise, a self-assembled film-forming composition 2 containing the block copolymer 2 (BCP2) was prepared by the same method as that for preparing the self-assembled film-forming composition 1.

[0693] <Induction of microphase separation structure>

[0694] The compositions for forming the lower layer film of Examples 1 to 7 and Comparative Examples 1 to 3 were coated on a silicon wafer, respectively, and baked on a hot plate at 205 to 250°C for 60 seconds to obtain the lower layer films of Examples 1 to 7 and Comparative Examples 1 to 3. The film thickness is shown in Table 1. The self-assembled film-forming composition 1 or the self-assembled film-forming composition 2 was coated on the wafer by a spin coater, and heated on a hot plate at 100°C for 1 minute to form a self-assembled film with a film thickness of 40 nm. The wafer formed with the self-assembled film was placed on a N 2 The microphase separation structure of the self-assembled film was induced by heating at 260 °C for 15 min under a gas atmosphere.

[0695] <Observation of microphase separation structure>

[0696] The silicon wafer with the induced microphase separation structure was etched using an etching apparatus (Lam2300Versys Kiyo45) manufactured by Lam Lisachi Co., Ltd. 2 / N 2 The gas was used as an etching gas for etching for 3 seconds to preferentially etch the poly(methyl methacrylate) region, and then the shape was observed with an electron microscope (S-4800, manufactured by Hitachi High-Tech Novel Devices).

[0697] <Confirmation of block copolymer alignment>

[0698] The alignment of the block copolymers (BCP1, BCP2) prepared in Examples 1 to 7 and Comparative Examples 1 to 3 was confirmed. The results are shown in Table 2 and are Figure 2A , Figure 2B , Figure 3A , Figure 3B , Figure 4A and Figure 4B The results of electron microscope observation (magnification: 200K) show various examples of vertical alignment (vertically aligned layer structure) and poor alignment. It should be noted that the so-called "vertical alignment" in Table 2 means "vertically aligned layer or tube structure".

[0699] Figure 2A This is an electron microscope (SEM) photograph of the microphase separation structure of the self-assembled film produced using the self-assembled film-forming composition 1 in Example 1.

[0700] Figure 2B This is a SEM photograph of the microphase separation structure of the self-assembled film produced using the self-assembled film-forming composition 2 in Example 1.

[0701] Figure 3A This is a SEM photograph of the microphase separation structure of the self-assembled film produced in Example 2 using the self-assembled film-forming composition 1.

[0702] Figure 3B This is a SEM photograph of the microphase separation structure of the self-assembled film produced using the self-assembled film-forming composition 2 in Example 2.

[0703] Figure 4A This is a SEM photograph of the microphase separation structure of the self-assembled film produced using the self-assembled film-forming composition 1 in Comparative Example 1.

[0704] Figure 4B This is a SEM photograph of the microphase separation structure of the self-assembled film produced using the self-assembled film-forming composition 2 in Comparative Example 1.

[0705] [Table 2]

[0706]

[0707] Explanation of symbols

[0708] 1 Semiconductor substrate

[0709] 2 Lower membrane

[0710] 3. Resist film

[0711] 4 Brush Layer

[0712] 5 Self-assembled membranes

[0713] 5a Domain structure of the A block

[0714] 5b Domain structure of the B block.

Claims

1. An underlayer film, which is a fired product of a coating film of a composition for forming an underlayer film, The underlayer film is used as an underlayer film of the resist film in photolithography using any resist film of a photoresist film and an electron beam resist film and a self-assembled film, and then is further used as an underlayer film of the self-assembled film. The lower layer film-forming composition contains a polymer and a cross-linking agent. The polymer has: a unit structure (A) having a polycyclic aromatic structure and a unit structure (B) having a reactive group, The cross-linking agent has a functional group capable of reacting with the reactive group.

2. The lower layer film according to claim 1, wherein the unit structure (A) is a unit structure represented by the following formula (A-1): In formula (A-1), R 1 represents a hydrogen atom or a methyl group; X 1 represents a single bond, an ester group or an amide group; Y 1 represents a single bond or an alkylene group having 1 to 6 carbon atoms; Ar represents an alkylene group which may be substituted, naphthalene, anthracene, phenanthrene, pyrene, benzo[9,10]phenanthrene, In tetracene, biphenylene, fluorene or carbazole, a monovalent group of a hydrogen atom is removed.

3. The resist underlayer film according to claim 1, wherein the unit structure (B) is at least one of a unit structure represented by the following formula (B-1) and a unit structure represented by the following formula (B-2), In formula (B-1), R 11 represents a hydrogen atom or a methyl group; X 11 Represents an ester group or an amide group; R 12 represents a monovalent group having 1 to 12 carbon atoms and having the reactive group; In formula (B-2), R 13 It represents a monovalent group having 1 to 12 carbon atoms and having the above-mentioned reactive group.

4. The lower layer film according to claim 1, wherein the polymer further has a unit structure (C), and the unit structure (C) is at least any one of a unit structure (C-1) having a monocyclic aromatic structure and a unit structure (C-2) derived from a maleimide structure.

5. The lower layer film according to claim 4, wherein the unit structure (C-1) is a unit structure represented by the following formula (C-1-1): The unit structure (C-2) is a unit structure represented by the following formula (C-2-1), In formula (C-1-1), R 21 represents a hydrogen atom or a methyl group; X 21 represents a single bond, an ester group or an amide group; Y 21 represents a single bond or an alkylene group having 1 to 6 carbon atoms; R 22 represents a halogen atom, an alkyl group having 1 to 6 carbon atoms which may be substituted by a halogen atom, or an alkoxy group having 1 to 6 carbon atoms which may be substituted by a halogen atom; n represents an integer of 0 to 5; in R 22 When there are 2 or more, 2 or more R 22 It can be the same or different; In formula (C-2-1), R 23 It represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms which may be substituted by a halogen atom, or an aryl group having 6 to 10 carbon atoms which may be substituted by a halogen atom. 6 . The underlayer film according to claim 1 , wherein the molar ratio of the unit structure (A) to all unit structures of the polymer is 40 mol % or more. 7 . The underlayer film according to claim 1 , wherein the molar ratio of the unit structure (B) relative to all unit structures of the polymer is 5 mol % to 40 mol %.

8. The lower layer film according to claim 1, wherein the polymer further comprises a unit structure (C), wherein the unit structure (C) is at least one of a unit structure (C-1) having a monocyclic aromatic structure and a unit structure (C-2) derived from a maleimide structure, The unit structure (A) is a unit structure represented by the following formula (A-1), The unit structure (B) is at least one of a unit structure represented by the following formula (B-1) and a unit structure represented by the following formula (B-2), The unit structure (C-1) is a unit structure represented by the following formula (C-1-1), The unit structure (C-2) is a unit structure represented by the following formula (C-2-1), The molar ratio of the unit structure (A) to the total unit structures of the polymer is 40 mol% or more, The molar ratio of the unit structure (B) relative to the total unit structures of the polymer is 5 mol% to 40 mol%; In formula (A-1), R 1 represents a hydrogen atom or a methyl group; X 1 represents a single bond, an ester group or an amide group; Y 1 represents a single bond or an alkylene group having 1 to 6 carbon atoms; Ar represents an alkylene group which may be substituted, naphthalene, anthracene, phenanthrene, pyrene, benzo[9,10]phenanthrene, The monovalent group of hydrogen atom is removed from tetracene, biphenylene, fluorene or carbazole; In formula (B-1), R 11 represents a hydrogen atom or a methyl group; X 11 Represents an ester group or an amide group; R 12 represents a monovalent group having 1 to 6 carbon atoms and having the reactive group; In formula (B-2), R 13 represents a monovalent group having 1 to 6 carbon atoms and having the reactive group; In formula (C-1-1), R 21 represents a hydrogen atom or a methyl group; X 21 represents a single bond, an ester group or an amide group; Y 21 represents a single bond or an alkylene group having 1 to 6 carbon atoms; R 22 represents a halogen atom, an alkyl group having 1 to 6 carbon atoms which may be substituted by a halogen atom, or an alkoxy group having 1 to 6 carbon atoms which may be substituted by a halogen atom; n represents an integer of 0 to 5; in R 22 When there are 2 or more, 2 or more R 22 It can be the same or different; In formula (C-2-1), R 23 It represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms which may be substituted by a halogen atom, or an aryl group having 6 to 10 carbon atoms which may be substituted by a halogen atom. 9 . The underlayer film according to claim 1 , wherein a content of the crosslinking agent in the underlayer film-forming composition is 20% by mass to 50% by mass of the polymer. 10 . The underlayer film according to claim 1 , wherein the self-assembled film is a film comprising a block copolymer. The underlayer film according to claim 1 , which has a film thickness of less than 10 nm.

12. A composition for forming an underlayer film, the composition being used for forming an underlayer film, wherein the underlayer film is used as an underlayer film of any resist film of a photoresist film and an electron beam resist film in photolithography using a self-assembled film, and further used as an underlayer film of the self-assembled film. The lower layer film-forming composition contains a polymer and a cross-linking agent. The polymer has: a unit structure (A) having a polycyclic aromatic structure and a unit structure (B) having a reactive group, The cross-linking agent has a functional group capable of reacting with the reactive group.

13. The composition for forming an underlayer film according to claim 12, wherein the unit structure (A) is a unit structure represented by the following formula (A-1): In formula (A-1), R 1 represents a hydrogen atom or a methyl group; X 1 represents a single bond, an ester group or an amide group; Y 1 represents a single bond or an alkylene group having 1 to 6 carbon atoms; Ar represents an alkylene group which may be substituted, naphthalene, anthracene, phenanthrene, pyrene, benzo[9,10]phenanthrene, In tetracene, biphenylene, fluorene or carbazole, a monovalent group of a hydrogen atom is removed.

14. The composition for forming an underlayer film according to claim 12, wherein the unit structure (B) is at least any one of a unit structure represented by the following formula (B-1) and a unit structure represented by the following formula (B-2); In formula (B-1), R 11 represents a hydrogen atom or a methyl group; X 11 Represents an ester group or an amide group; R 12 represents a monovalent group having 1 to 12 carbon atoms and having the reactive group; In formula (B-2), R 13 It represents a monovalent group having 1 to 12 carbon atoms and having the above-mentioned reactive group.

15. The composition for forming an underlayer film according to claim 12, wherein the polymer further has a unit structure (C), and the unit structure (C) is at least any one of a unit structure (C-1) having a monocyclic aromatic structure and a unit structure (C-2) derived from a maleimide structure.

16. The composition for forming an underlayer film according to claim 15, wherein the unit structure (C-1) is a unit structure represented by the following formula (C-1-1): The unit structure (C-2) is a unit structure represented by the following formula (C-2-1); In formula (C-1-1), R 21 represents a hydrogen atom or a methyl group; X 21 represents a single bond, an ester group or an amide group; Y 21 represents a single bond or an alkylene group having 1 to 6 carbon atoms; R 22 represents a halogen atom, an alkyl group having 1 to 6 carbon atoms which may be substituted by a halogen atom, or an alkoxy group having 1 to 6 carbon atoms which may be substituted by a halogen atom; n represents an integer of 0 to 5; in R 22 When there are 2 or more, 2 or more R 22 It can be the same or different; In formula (C-2-1), R 23 It represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms which may be substituted by a halogen atom, or an aryl group having 6 to 10 carbon atoms which may be substituted by a halogen atom. 17 . The composition for forming an underlayer film according to claim 12 , wherein the molar ratio of the unit structure (A) relative to all unit structures of the polymer is 40 mol % or more. 18 . The composition for forming an underlayer film according to claim 12 , wherein the molar ratio of the unit structure (B) relative to all unit structures of the polymer is 5 mol % to 40 mol %.

19. The composition for forming an underlayer film according to claim 12, wherein the polymer further comprises a unit structure (C), wherein the unit structure (C) is at least one of a unit structure (C-1) having a monocyclic aromatic structure and a unit structure (C-2) derived from a maleimide structure, The unit structure (A) is a unit structure represented by the following formula (A-1), The unit structure (B) is at least one of a unit structure represented by the following formula (B-1) and a unit structure represented by the following formula (B-2), The unit structure (C-1) is a unit structure represented by the following formula (C-1-1), The unit structure (C-2) is a unit structure represented by the following formula (C-2-1), The molar ratio of the unit structure (A) to the total unit structures of the polymer is 40 mol% or more, The molar ratio of the unit structure (B) to the total unit structures of the polymer is 5 mol% to 40 mol%, In formula (A-1), R 1 represents a hydrogen atom or a methyl group; X 1 represents a single bond, an ester group or an amide group; Y 1 represents a single bond or an alkylene group having 1 to 6 carbon atoms; Ar represents an alkyl group selected from naphthalene, anthracene, phenanthrene, pyrene, benzo[9,10]phenanthrene, The monovalent group of hydrogen atom is removed from tetracene, biphenylene, fluorene or carbazole; In formula (B-1), R 11 represents a hydrogen atom or a methyl group; X 11 Represents an ester group or an amide group; R 12 represents a monovalent group having 1 to 6 carbon atoms and having the reactive group; In formula (B-2), R 13 represents a monovalent group having 1 to 6 carbon atoms and having the reactive group; In formula (C-1-1), R 21 represents a hydrogen atom or a methyl group; X 21 represents a single bond, an ester group or an amide group; Y 21 represents a single bond or an alkylene group having 1 to 6 carbon atoms; R 22 represents a halogen atom, an alkyl group having 1 to 6 carbon atoms which may be substituted by a halogen atom, or an alkoxy group having 1 to 6 carbon atoms which may be substituted by a halogen atom; n represents an integer of 0 to 5; in R 22 When there are 2 or more, 2 or more R 22 It can be the same or different; In formula (C-2-1), R 23 It represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms which may be substituted by a halogen atom, or an aryl group having 6 to 10 carbon atoms which may be substituted by a halogen atom. 20 . The composition for forming an underlayer film according to claim 12 , wherein a content of the crosslinking agent is 20% to 50% by mass of the polymer. 21 . The composition for forming an underlayer film according to claim 12 , wherein the self-assembled film is a film comprising a block copolymer. 22 . The composition for forming an underlayer film according to claim 12 , wherein the underlayer film has a thickness of less than 10 nm.

23. A method for manufacturing a semiconductor device, comprising the following steps: A step of forming an underlayer film on a semiconductor substrate using the underlayer film-forming composition according to any one of claims 12 to 22; A step of forming a resist film of either a photoresist film or an electron beam resist film on the underlying film; A step of irradiating the resist film with light or electron beam, and then developing the resist film to obtain a resist pattern; a step of etching the underlying film using the resist pattern as a mask to form a patterned underlying film; and The step of forming a self-assembled film on the patterned lower layer film. 24 . The method for manufacturing a semiconductor element according to claim 23 , further comprising a step of forming a brush layer in gaps of the pattern of the patterned lower layer film between the step of forming the patterned lower layer film and the step of forming the self-assembled film. 25 . The method for manufacturing a semiconductor device according to claim 23 , wherein the self-assembled film is a film containing a block copolymer. 26 . The method for manufacturing a semiconductor device according to claim 23 , further comprising a step of removing the resist pattern after the step of forming the patterned lower layer film.

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