Composition for resist underlayer film formation, resist underlayer film, method for forming resist pattern, and method for manufacturing semiconductor device

Abstract

A composition for resist underlayer film formation, comprising a resin (G) having a plurality of complex unit structures and a solvent, the complex unit structures having: a unit structure (A) containing a naphthalene ring having 1 or 2 phenolic hydroxyl groups, and a unit structure (B) having 1 or more carbon atoms, the resin (G) being a resin obtained by a reaction of generating a covalent bond between a carbon atom of the aromatic ring constituting the unit structure (A) and a carbon atom in the unit structure (B), a first complex unit structure containing a unit structure (B-I) having a naphthalene ring as the unit structure (B), and a second complex unit structure containing a unit structure (B-II) having an aliphatic hydrocarbon group as the unit structure (B).

Description

Technical Field

[0001] This invention relates to a composition for forming a resist underlayer film, a resist underlayer film, a method for forming a resist pattern, and a method for manufacturing a semiconductor device. Background Technology

[0002] In recent years, semiconductor manufacturing processes have advanced rapidly, accompanied by a strong demand for higher quality and improved properties of the resist underlayer film (see, for example, Patent Documents 1-6). In particular, for resist underlayer films known as high-carbon materials, there is a strong demand for imparting reflection suppression functionality (having excellent optical constants to suppress reflection).

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: U.S. Patent Application Publication No. 2016 / 311975

[0006] Patent Document 2: International Publication No. 2018 / 198960

[0007] Patent Document 3: Japanese Patent Application Publication No. 2021-81686

[0008] Patent Document 4: Japanese Patent Application Publication No. 2020-105513

[0009] Patent Document 5: International Publication No. 2013 / 146670

[0010] Patent Document 6: Japanese Patent Application Publication No. 2016-151024 Summary of the Invention

[0011] The problem that the invention aims to solve

[0012] The properties required for the resist underlayer include, for example, improved coating properties and planarization properties on substrates with uneven surfaces. These properties still have room for improvement as a material.

[0013] The present invention was made in view of the above circumstances, and its object is to provide a composition for forming a resist underlayer film having excellent optical constants for suppressing reflection, further improving the coating and planarization properties of substrates with high and low differences, as well as a resist underlayer film using the resist underlayer film forming composition, a method for forming a resist pattern, and a method for manufacturing a semiconductor device.

[0014] Methods for solving problems

[0015] In order to solve the above-mentioned problems, the inventors conducted in-depth research and found that the above-mentioned problems could be solved, thus completing the present invention with the following main points.

[0016] That is, the present invention includes the following solutions.

[0017] [1] A composition for forming a resist underlayer film, comprising a resin (G) having a plurality of composite unit structures and a solvent, The above-mentioned composite unit structure has the following characteristics: Unit structures containing a naphthalene ring with one or two phenolic hydroxyl groups (A), and Unit structures with one or more carbon atoms (B), The resin (G) described above is obtained by reacting carbon atoms of the naphthalene ring constituting the above-described unit structure (A) with carbon atoms in the above-described unit structure (B) to form covalent bonds. The first composite unit structure includes a unit structure (BI) having a naphthalene ring as the aforementioned unit structure (B). The second complex unit structure includes a unit structure (B-II) with an aliphatic hydrocarbon group as the aforementioned unit structure (B).

[0018] [2] According to the composition for forming the resist underlayer film described in [1], the structure of the first composite unit is represented by the following formula (1). The above-mentioned second composite unit structure is represented by at least one of the following equations (2) and (3).

[0019]

[0020] (In equation (1), n1 represents 1 or 2.)

[0021] (In equation (2), n2 represents 1 or 2, R) 2 R represents an alkyl group with 1 to 10 carbon atoms, an alkenyl group with 2 to 10 carbon atoms, an alkynyl group with 2 to 10 carbon atoms, or an alkoxy group with 1 to 10 carbon atoms, where m represents an integer from 1 to 5. When m is 2 or more, R... 2 They can be different, or they can be the same.

[0022] (In equation (3), n3 represents 1 or 2, R) 3 (This refers to an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, or an alkynyl group having 2 to 10 carbon atoms.)

[0023] [3] According to the composition for forming a lower layer of resist film as described in [1] or [2], the molar ratio of the above-mentioned unit structure (BI) to the above-mentioned unit structure (B-II) in the above-mentioned resin (G) is 20:80 to 80:20.

[0024] [4] The composition for forming a resist underlayer film according to any one of [1] to [3], wherein the resin (G) is a resin synthesized from the following reactants, which include: hydroxynaphthalene having one or two phenolic hydroxyl groups, naphthaldehyde, and an aldehyde compound containing an aliphatic hydrocarbon group. The aforementioned aliphatic hydrocarbon group is selected from one or more of the following: alkyl with 1 to 10 carbon atoms, alkenyl with 2 to 10 carbon atoms, and alkynyl with 2 to 10 carbon atoms.

[0025] [5] The composition for forming a resist underlayer film according to any one of [1] to [4], wherein the solvent comprises a solvent with a boiling point of 160°C or higher.

[0026] [6] The composition for forming a resist underlayer film according to any one of [1] to [5] further comprises at least one selected from acids and their salts, and acid-generating agents.

[0027] [7] The composition for forming a resist underlayer film according to any one of [1] to [6] further comprises a crosslinking agent.

[0028] [8] In the composition for forming a resist underlayer film according to [7], the crosslinking agent is selected from at least one of amino plastic crosslinking agents and phenolic plastic crosslinking agents.

[0029] [9] The composition for forming a resist underlayer film according to any one of [1] to [8] further comprises a surfactant.

[0030]

[10] A photoresist underlayer film on a semiconductor substrate, which is a cured product of the photoresist underlayer film forming composition described in any one of [1] to [9].

[0031]

[11] A method for forming a resist pattern for manufacturing a semiconductor, comprising a step of coating a resist underlayer film forming composition as described in any one of [1] to [9] onto a semiconductor substrate and firing it to form a resist underlayer film.

[0032]

[12] A method for manufacturing a semiconductor device, comprising the following steps: The process of forming a photoresist underlayer film on a semiconductor substrate using any one of the compositions for forming photoresist underlayer film [1] to [9]; The process of forming a resist film on the aforementioned lower resist film; The process of forming a resist pattern by irradiating the resist film with light or an electron beam and developing it; The process of etching the resist underlayer film through the aforementioned resist pattern to form a patterned resist underlayer film; and The process of processing a semiconductor substrate using the patterned resist underlayer film described above.

[0033]

[13] A method for manufacturing a semiconductor device, comprising the following steps: The process of forming a photoresist underlayer film on a semiconductor substrate using any one of the compositions for forming photoresist underlayer film [1] to [9]; The process of forming a hard mask on the lower layer of the above-mentioned resist film; The next step is to form a resist film on the aforementioned hard mask; The process of forming a resist pattern by irradiating the resist film with light or an electron beam and developing it; The process of etching the hard mask using the aforementioned resist pattern to form a patterned hard mask; The process of etching the patterned photoresist underlayer film using the patterned hard mask to form the patterned photoresist underlayer film; and The process of processing a semiconductor substrate using the patterned resist underlayer film described above.

[0034]

[14] A method for manufacturing a semiconductor device, comprising the following steps: The process of forming a photoresist underlayer film on a semiconductor substrate using any one of the compositions for forming photoresist underlayer film [1] to [9]; The process of forming a hard mask on the lower layer of the above-mentioned resist film; The next step is to form a resist film on the aforementioned hard mask; The process of forming a resist pattern by irradiating the resist film with light or an electron beam and developing it; The process of etching the hard mask using the aforementioned resist pattern to form a patterned hard mask; The process of etching the patterned photoresist underlayer film through the patterned hard mask to form the patterned photoresist underlayer film. The process of removing the aforementioned hard mask; and The process of processing a semiconductor substrate using the patterned resist underlayer film described above.

[0035]

[15] A method for manufacturing a semiconductor device, comprising the following steps: The process of forming a photoresist underlayer film on a semiconductor substrate using any one of the compositions for forming photoresist underlayer film [1] to [9]; The process of forming a hard mask on the lower layer of the above-mentioned resist film; The next step is to form a resist film on the aforementioned hard mask; The process of forming a resist pattern by irradiating the resist film with light or an electron beam and developing it; The process of etching the hard mask using the aforementioned resist pattern to form a patterned hard mask; The process of etching the patterned photoresist underlayer film through the patterned hard mask to form the patterned photoresist underlayer film. The process of removing the aforementioned hard mask; The process of forming a vapor-deposited film on the resist underlayer after the hard mask is removed; The process of etching the above-mentioned vapor-deposited film; The process of removing the patterned resist underlayer film, leaving the patterned vapor-deposited film; and The process of processing a semiconductor substrate using the patterned vapor deposition film described above.

[0036]

[16] In the method of manufacturing a semiconductor device according to any one of

[13] to

[15] , the hard mask is formed by coating a composition containing inorganic materials or by vapor deposition of inorganic materials.

[0037]

[17] In the method for manufacturing a semiconductor device according to any one of

[12] to

[16] , the resist film is patterned by nanoimprinting or self-assembled film.

[0038]

[18] The hard mask described above is removed by etching or by an alkaline solution according to the semiconductor device manufacturing method described in

[14] or

[15] .

[0039] The effects of the invention

[0040] According to the present invention, a composition for forming a resist underlayer film with excellent optical constants for suppressing reflection, further improving the coating and planarization properties of substrates with high and low differences, as well as a resist underlayer film using the composition for forming a resist underlayer film, a method for forming a resist pattern, and a method for manufacturing a semiconductor device can be provided. Detailed Implementation

[0041] [Composition for forming the lower layer of resist]

[0042] The composition for forming a resist underlayer film of the present invention comprises a resin (G) having a plurality of composite unit structures and a solvent.

[0043] The above-mentioned composite unit structure has: a unit structure (A) containing a naphthalene ring with one or two phenolic hydroxyl groups, and a unit structure (B) having one or more carbon atoms.

[0044] Resin (G) is a resin obtained by reacting carbon atoms of the naphthalene ring constituting unit structure (A) with carbon atoms in unit structure (B) to form covalent bonds.

[0045] The first composite unit structure includes a unit structure (BI) with a naphthalene ring as a unit structure (B).

[0046] The second complex unit structure includes a unit structure (B-II) with an aliphatic hydrocarbon group as unit structure (B).

[0047] In this specification, resin (G) is sometimes referred to as "phenolic varnish resin".

[0048] The resin (G) contains the aforementioned unit structures (A) and (B), thereby providing a composition for forming a resist underlayer film that has excellent optical constants for suppressing reflection and further improves the coatability and planarization of substrates with high and low differences.

[0049] The first composite unit structure is one of the multiple composite unit structures possessed by the resin (G).

[0050] The second composite unit structure is one of the multiple composite unit structures possessed by the resin (G).

[0051] Resin (G) refers to a single resin having multiple composite unit structures, and does not refer to a mixture of two or more resins with different composite unit structures.

[0052] Unit structure (BI) and unit structure (B-II) are subordinate concepts of unit structure (B), and do not refer to a part of the structure of unit structure (B).

[0053] [I. Definition of the term]

[0054] In this specification, the definitions of key terms related to the phenolic varnish resin, which is one aspect of the invention of this application, are explained below. Unless otherwise specifically stated, the following definitions apply to phenolic varnish resin.

[0055] (I-1) "Phenolic varnish resin (Novolak resin)"

[0056] The term "phenolic varnish resin" not only refers to phenol-formaldehyde resin (so-called phenolic varnish type phenolic resin) and aniline-formaldehyde resin (so-called phenolic varnish type aniline resin) in a narrow sense, but also broadly includes the following resins in a broad sense: generally, in the presence of an acid catalyst or under equivalent reaction conditions, an organic compound having functional groups capable of covalently bonding with an aromatic ring [e.g., aldehyde group; ketone group; acetal group; ketal group; hydroxyl or alkoxy group bonded to a secondary or tertiary carbon atom; hydroxyl, alkoxy, or halogen group bonded to the α-carbon atom (benzyl carbon atom, etc.) of an alkyl aryl group; carbon-carbon unsaturated bonds of divinylbenzene, dicyclopentadiene, etc.] and a compound having an aromatic ring (preferably having heteroatoms such as oxygen, nitrogen, and sulfur atoms as atoms constituting or bonded to the aromatic ring) through covalent bonding (substitution reaction, addition reaction, condensation reaction, or addition-condensation reaction, etc.).

[0057] Therefore, the phenolic varnish resin mentioned in this application is formed by linking multiple compounds having aromatic rings together by an organic compound containing carbon atoms (sometimes referred to as "linking carbon atoms") derived from the above-mentioned functional groups to form covalent bonds with the aromatic rings in a compound having aromatic rings via the linking carbon atoms.

[0058] In this specification, the terms "unit structure (A)" and "unit structure (B)" are used as the unit structures constituting the "phenolic varnish resin". Unit structure (A) is a unit structure derived from a naphthalene ring having one or two phenolic hydroxyl groups. Unit structure (B) is a unit structure derived from a compound having an aldehyde group capable of covalently bonding with the naphthalene ring of unit structure (A).

[0059] <Resin (G)>

[0060] Resin (G) has a composite unit structure. Resin (G) can be a polymer.

[0061] The composite unit structure contains a unit structure with an aromatic ring (A) and a unit structure with more than one carbon atom (B).

[0062] The composite unit structure of resin (G) can be represented, for example, by the following formula (AB).

[0063]

[0064] (In equation (AB), A represents the unit structure (A), and B represents the unit structure (B).)

[0065] <<Unit Structure (A)>>

[0066] Unit structure (A) contains a naphthalene ring with one or two phenolic hydroxyl groups.

[0067] The naphthalene ring in unit structure (A) may have substituents. However, the naphthalene ring in unit structure (A) does not have more than three phenolic hydroxyl groups.

[0068] Examples of substituents include, for example, halogen groups (halogen atoms), alkyl groups, alkenyl groups, alkynyl groups, aryl groups, aryloxy groups, amino groups, hydroxyl groups, hydroxyalkyl groups, carboxyl groups, formyl groups, cyano groups, nitro groups, ester groups, amide groups, groups containing sulfonyl groups, thiols, groups containing thioethers, and groups containing ether bonds.

[0069] Examples of alkyl groups include straight-chain, branched, or cyclic alkyl groups having 1 to 20 carbon atoms.

[0070] Examples of alkenyl groups include straight-chain, branched, or cyclic alkenyl groups with 2 to 10 carbon atoms.

[0071] Examples of alkynyl groups include straight-chain, branched, or cyclic alkynyl groups with 2 to 10 carbon atoms.

[0072] Examples of alkoxy groups include those represented by -OR. Here, R represents a saturated or unsaturated straight-chain, branched, or cyclic hydrocarbon group that can be interrupted more than once by an oxygen atom in the middle of the hydrocarbon chain (-R). a Examples of carbon atoms that can be represented by an alkoxy group include 1 to 20.

[0073] Examples of aryl groups include those with 6 to 30 carbon atoms.

[0074] Examples of aryloxy groups include those with 6 to 30 carbon atoms.

[0075] Examples of amino groups include those represented by -NH2, -NHR, or -NR2. Here, R represents the aforementioned hydrocarbon group -R. a In -NR2, the two Rs can be the same or different.

[0076] Examples of hydroxyalkyl groups include straight-chain, branched, or cyclic hydroxyalkyl groups with 1 to 20 carbon atoms.

[0077] Examples of ester groups include those represented by -CO2R or -OCOR. Here, R represents the aforementioned hydrocarbon group -R. a .

[0078] Examples of amide groups include those represented by -NHCOR, -CONHR, -NRCOR, or -CONR2. Here, R represents the aforementioned hydrocarbon group -R. a When there are two Rs, the two Rs can be the same or different.

[0079] Examples of groups containing sulfonyl groups include the group represented by -SO2R. Here, R represents the aforementioned hydrocarbon group -R. a Or hydroxyl group -OH.

[0080] Examples of groups containing thioethers include the group represented by -SR. Here, R represents the aforementioned hydrocarbon group -R. a .

[0081] As a group containing an ether bond, R can be cited as an example. 11 -OR 11 The residues of the ether compound containing the ether bond are shown. Here, R 11 Each group independently represents an alkyl group (1-6 carbon atoms), such as methyl, ethyl, alkyl, phenyl, naphthyl, anthranyl, pyrene, etc. Groups containing ether bonds can be, for example, organic groups containing ether bonds, such as methoxy, ethoxy, or phenoxy.

[0082] Examples of naphthalene rings with one or two phenolic hydroxyl groups in unit structure (A) include the following structural formulas.

[0083]

[0084] <<Unit Structure (B)>>

[0085] The unit structure (B) has more than one carbon atom.

[0086] Examples of unit structures (B) include, for instance, those derived from aldehyde compounds.

[0087] Unit structure (B) is one or more unit structures containing connecting carbon atoms bonded to the aromatic ring in unit structure (A) [refer to (I-1) above], for example, including the structures shown in formula (1) or (2) described later. Unit structure (B) can connect two unit structures (A) by covalent bonding with unit structure (A).

[0088] <<<Unit Structure (BI)>>>

[0089] The unit structure (BI) has a naphthalene ring.

[0090] The unit structure (BI) is preferably derived from naphthaldehyde. Naphthaldehyde can be 1-naphthaldehyde or 2-naphthaldehyde.

[0091] The naphthalene ring in the unit structure (BI) can have substituents.

[0092] Here, as a substituent, examples can be found of the substituents described in the above unit structure (A).

[0093] <<<Unit Structure (B-II)>>>

[0094] The unit structure (B-II) has aliphatic hydrocarbon groups.

[0095] The unit structure (B-II) is preferably derived from the unit structure of an aldehyde compound having an aliphatic hydrocarbon group (hereinafter also referred to as "aldehyde derivative").

[0096] As an aliphatic hydrocarbon group, there are no particular limitations; examples include alkyl, alkenyl, and alkynyl groups.

[0097] These aliphatic hydrocarbon groups can be linear, branched, or cyclic.

[0098] These aliphatic hydrocarbon groups can be just one type or two or more types.

[0099] Furthermore, these aliphatic hydrocarbon groups can combine with each other through oxygen atoms, nitrogen atoms, etc.

[0100] At least one hydrogen atom of the aliphatic hydrocarbon group in the unit structure (B-II) can be replaced by a substituent.

[0101] Here, as a substituent, examples can be found of the substituents described in the above unit structure (A).

[0102] Aldehyde derivatives that serve as the source of the unit structure (B-II) can be, for example, aldehydes represented by the following formula. These aldehydes can be aliphatic aldehydes or aromatic aldehydes.

[0103]

[0104] Resin (G) has the following characteristics: The first composite unit structure comprises a unit structure (BI) having a naphthalene ring as a unit structure (B), and... The second complex unit structure contains a unit structure (B-II) with an aliphatic hydrocarbon group as unit structure (B).

[0105] The first composite unit structure and the second composite unit structure can be combined regularly or randomly.

[0106] In addition, the resin (G) may have composite unit structures other than the first composite unit structure and the second composite unit structure.

[0107] The preferred composite unit structure is the composite unit structure shown in formula (1) below.

[0108]

[0109] (In equation (1), n1 represents 1 or 2.)

[0110] In equation (1), n1 is 1 or 2.

[0111] When n1 is 2, the two hydroxyl groups can bind to one of the rings in the naphthalene ring, or they can bind to different rings.

[0112] The second composite unit structure is preferably a composite unit structure shown in at least one of the following formulas (2) and (3).

[0113]

[0114] (In equation (2), n2 represents 1 or 2, R) 2 R represents an alkyl group with 1 to 10 carbon atoms, an alkenyl group with 2 to 10 carbon atoms, an alkynyl group with 2 to 10 carbon atoms, or an alkoxy group with 1 to 10 carbon atoms, where m represents an integer from 1 to 5. When m is 2 or more, R... 2 They can be different, or they can be the same.

[0115] (In equation (3), n3 represents 1 or 2, R) 3 (This refers to an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, or an alkynyl group having 2 to 10 carbon atoms.)

[0116] Examples of alkyl groups having 1 to 10 carbon atoms include methyl, ethyl, n-propyl, isopropyl, cyclopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, cyclobutyl, 1-methyl-cyclopropyl, 2-methyl-cyclopropyl, n-pentyl, 1-methyl-n-butyl, 2-methyl-n-butyl, 3-methyl-n-butyl, 1,1-dimethyl-n-propyl, 1,2-dimethyl-n-propyl, 2,2-dimethyl-n-propyl, 1-ethyl-n-propyl, cyclopentyl, 1-methyl-cyclobutyl, and 2-methyl-cyclobutyl. 3-Methyl-cyclobutyl, 1,2-dimethyl-cyclopropyl, 2,3-dimethyl-cyclopropyl, 1-ethyl-cyclopropyl, 2-ethyl-cyclopropyl, n-hexyl, 1-methyl-n-pentyl, 2-methyl-n-pentyl, 3-methyl-n-pentyl, 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, 1-ethyl-2-methyl-n-propyl, cyclohexyl, 1-methyl-cyclopentyl, 2-methyl-cyclopentyl, 3-methyl-cyclopentyl, 1-ethyl-cyclobutyl, 2-ethyl-cyclobutyl, 3-ethyl-cyclobutyl, 1,2-dimethyl-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, 2-ethyl-3-methyl-cyclopropyl, n-heptyl, n-octyl, n-nonyl, and n-decyl.

[0117] Examples of alkenyl groups having 2 to 10 carbon atoms include vinyl, 1-propenyl, 2-propenyl, 1-methyl-1-vinyl, 1-butenyl, 2-butenyl, 3-butenyl, 2-methyl-1-propenyl, 2-methyl-2-propenyl, 1-ethylvinyl, 1-methyl-1-propenyl, 1-methyl-2-propenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl, 1-n-propylvinyl, 1-methyl-1-butenyl, 1-methyl-2-butenyl, 1-methyl-3-butenyl, 2-ethyl-2-propenyl, 2-methyl-1-butenyl, 2-methyl-2-butenyl, 2-methyl-3- Butenyl, 3-methyl-1-butenyl, 3-methyl-2-butenyl, 3-methyl-3-butenyl, 1,1-dimethyl-2-propenyl, 1-isopropylvinyl, 1,2-dimethyl-1-propenyl, 1,2-dimethyl-2-propenyl, 1-cyclopentenyl, 2-cyclopentenyl, 3-cyclopentenyl, 1-hexenyl, 2-hexenyl, 3-hexenyl, 4-hexenyl, 5-hexenyl, 1-methyl-1-pentenyl, 1-methyl-2-pentenyl, 1-methyl-3-pentenyl, 1-methyl-4-pentenyl, 1-n-butylvinyl, 2-methyl-1-pentenyl, 2-methyl-2-pentenyl, 2-methyl-3-pentenyl 2-Methyl-4-pentenyl, 2-n-propyl-2-propenyl, 3-methyl-1-pentenyl, 3-methyl-2-pentenyl, 3-methyl-3-pentenyl, 3-methyl-4-pentenyl, 3-ethyl-3-butenyl, 4-methyl-1-pentenyl, 4-methyl-2-pentenyl, 4-methyl-3-pentenyl, 4-methyl-4-pentenyl, 1,1-dimethyl-2-butenyl, 1,1-dimethyl-3-butenyl, 1,2-dimethyl-1-butenyl, 1,2-dimethyl-2-butenyl, 1,2-dimethyl-3-butenyl, 1-methyl-2-ethyl-2-propenyl, 1-sec-butylvinyl, 1,3- Dimethyl-1-butenyl, 1,3-dimethyl-2-butenyl, 1,3-dimethyl-3-butenyl, 1-isobutylvinyl, 2,2-dimethyl-3-butenyl, 2,3-dimethyl-1-butenyl, 2,3-dimethyl-2-butenyl, 2,3-dimethyl-3-butenyl, 2-isopropyl-2-propenyl, 3,3-dimethyl-1-butenyl, 1-ethyl-1-butenyl, 1-ethyl-2-butenyl, 1-ethyl-3-butenyl, 1-n-propyl-1-propenyl, 1-n-propyl-2-propenyl, 2-ethyl-1-butenyl, 2-ethyl-2-butenyl, 2-ethyl-3-butenyl, 1,1,2-Trimethyl-2-propenyl, 1-tert-butylvinyl, 1-Methyl-1-ethyl-2-propenyl, 1-Ethyl-2-methyl-1-propenyl, 1-Ethyl-2-methyl-2-propenyl, 1-Isopropyl-1-propenyl, 1-Isopropyl-2-propenyl, 1-Methyl-2-cyclopentenyl, 1-Methyl-3-cyclopentenyl, 2-Methyl-1-cyclopentenyl, 2-Methyl-2-cyclopentene The list includes 2-methyl-3-cyclopentenyl, 2-methyl-4-cyclopentenyl, 2-methyl-5-cyclopentenyl, 2-methylene-cyclopentenyl, 3-methyl-1-cyclopentenyl, 3-methyl-2-cyclopentenyl, 3-methyl-3-cyclopentenyl, 3-methyl-4-cyclopentenyl, 3-methyl-5-cyclopentenyl, 3-methylene-cyclopentenyl, 1-cyclohexenyl, 2-cyclohexenyl, and 3-cyclohexenyl, among others.

[0118] Examples of alkyne groups with 2 to 10 carbon atoms include ethynyl, 1-propynyl, propynyl (2-propynyl), etc., which are groups in which the carbon-carbon double bond of the alkyne group mentioned above is replaced by a carbon-carbon triple bond.

[0119] Examples of alkoxy groups having 1 to 10 carbon atoms include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy, tert-butoxy, n-pentyloxy, 1-methyl-n-butoxy, 2-methyl-n-butoxy, 3-methyl-n-butoxy, 1,1-dimethyl-n-propoxy, 1,2-dimethyl-n-propoxy, 2,2-dimethyl-n-propoxy, 1-ethyl-n-propoxy, n-hexyloxy, 1-methyl-n-pentyloxy, 2-methyl-n-pentyloxy, 3-methyl -n-pentyloxy, 4-methyl-n-pentyloxy, 1,1-dimethyl-n-butoxy, 1,2-dimethyl-n-butoxy, 1,3-dimethyl-n-butoxy, 2,2-dimethyl-n-butoxy, 2,3-dimethyl-n-butoxy, 3,3-dimethyl-n-butoxy, 1-ethyl-n-butoxy, 2-ethyl-n-butoxy, 1,1,2-trimethyl-n-propoxy, 1,2,2-trimethyl-n-propoxy, 1-ethyl-1-methyl-n-propoxy, and 1-ethyl-2-methyl-n-propoxy, etc.

[0120] In equation (2), m is an integer from 1 to 5, preferably from 1 to 3, and can be 1.

[0121] When m is greater than 2, R 2 They can be different or the same.

[0122] Furthermore, at least one hydrogen atom of the aliphatic hydrocarbon group in the above-mentioned unit structure (B-II) can be replaced with a substituent, which is bonded to the naphthalene ring or benzene ring in the above-mentioned unit structure (A) and unit structure (B).

[0123] Examples of such substituents include the substituents (S) shown in formulas (S1) to (S7) below.

[0124]

[0125] (In equations (S1) to (S7), R sa It represents a monovalent non-aromatic hydrocarbon group with 1 to 10 carbon atoms.

[0126] R sb Each can independently represent a single bond or a divalent non-aromatic hydrocarbon group with 1 to 10 carbon atoms.

[0127] R sc Each group independently represents a divalent non-aromatic hydrocarbon group with 1 to 10 carbon atoms.

[0128] R sd alkynyl Each group independently represents an alkynyl group with 2 to 4 carbon atoms.

[0129] Ar sa Each group independently represents a monovalent aromatic hydrocarbon group with 6 to 20 carbon atoms.

[0130] Ar sb Each group independently represents a divalent aromatic hydrocarbon group with 6 to 20 carbon atoms.

[0131] X sa and X sb Each independently represents a hydrogen atom or a monovalent hydrocarbon group with 1 to 20 carbon atoms, or X sa and X sb Together with the carbon atom bonded to the hydroxyl group, it forms a carbonyl group.

[0132] n represents an integer from 0 to 5.

[0133] (This represents a bonding bond.)

[0134] <R sa >

[0135] As R sa Examples of monovalent non-aromatic hydrocarbon groups with 1 to 10 carbon atoms include alkyl groups with 1 to 10 carbon atoms and monovalent unsaturated hydrocarbon groups with 2 to 10 carbon atoms.

[0136] A monovalent unsaturated hydrocarbon group with 2 to 10 carbon atoms has one or more carbon-carbon multiple bonds. When this type of group has two or more carbon-carbon multiple bonds, these bonds can be entirely carbon-carbon double bonds, entirely carbon-carbon triple bonds, or a mixture of both. These multiple carbon-carbon multiple bonds can be conjugated or not.

[0137] <R sb and R sc >

[0138] As R sb and R sc Examples of divalent non-aromatic hydrocarbon groups with 1 to 10 carbon atoms include alkylene groups with 1 to 10 carbon atoms and divalent unsaturated hydrocarbon groups with 2 to 10 carbon atoms.

[0139] A divalent unsaturated hydrocarbon group with 2 to 10 carbon atoms has one or more carbon-carbon multiple bonds. When a divalent unsaturated hydrocarbon group with 2 to 10 carbon atoms has two or more carbon-carbon multiple bonds, these multiple bonds can be all carbon-carbon double bonds, all carbon-carbon triple bonds, or a mixture of both. The two or more carbon-carbon multiple bonds can be conjugated or not conjugated.

[0140] As R sb and R sc Examples of such groups include the following.

[0141]

[0142] ( (This represents a bonding bond.)

[0143] <R sd alkynyl >

[0144] R sd alkynyl This refers to an alkynyl group having 2 to 4 carbon atoms. Examples of alkynyl groups having 2 to 4 carbon atoms include ethynyl, 1-propynyl, and propynyl (2-propynyl).

[0145] <Ar sa >

[0146] Ar sa The monovalent aromatic hydrocarbon group with 6 to 20 carbon atoms is a residue from an aromatic hydrocarbon with 6 to 20 carbon atoms by removing one hydrogen atom. Examples of aromatic hydrocarbons with 6 to 20 carbon atoms include benzene, naphthalene, anthracene, phenanthrene, 2,3-dihydro-1H-phenanthrene, pyrene, fluorene, biphenyl, etc.

[0147] <Arsb >

[0148] Ar sb The divalent aromatic hydrocarbon group with 6 to 20 carbon atoms is a residue from an aromatic hydrocarbon with 6 to 20 carbon atoms by removing two hydrogen atoms. Examples of aromatic hydrocarbons with 6 to 20 carbon atoms include benzene, naphthalene, anthracene, phenanthrene, pyrene, fluorene, and biphenyl.

[0149] <X sa and X sb >

[0150] As X sa and X sb Monovalent hydrocarbon groups with 1 to 20 carbon atoms can be exemplified by, for example, monovalent non-aromatic hydrocarbon groups with 1 to 10 carbon atoms and monovalent aromatic hydrocarbon groups with 6 to 20 carbon atoms.

[0151] Examples of monovalent non-aromatic hydrocarbon groups having 1 to 10 carbon atoms include alkyl groups having 1 to 10 carbon atoms.

[0152] A monovalent aromatic hydrocarbon group with 6 to 20 carbon atoms is a residue from an aromatic hydrocarbon with 6 to 20 carbon atoms by removing one hydrogen atom. Examples of aromatic hydrocarbons with 6 to 20 carbon atoms include benzene, naphthalene, anthracene, phenanthrene, 2,3-dihydro-1H-phenanthrene, pyrene, fluorene, biphenyl, etc.

[0153] Examples of substituents shown in formula (S1) include the following groups.

[0154]

[0155] ( (This represents a bonding bond.)

[0156] Examples of substituents shown in formula (S2) include the following groups.

[0157]

[0158] ( (This represents a bonding bond.)

[0159] Examples of substituents shown in formula (S3) include the following groups.

[0160]

[0161] ( (This represents a bonding bond.)

[0162] Examples of substituents shown in formula (S4) include the following groups.

[0163]

[0164] ( (This represents a bonding bond.)

[0165] Examples of substituents shown in formula (S5) include the following groups.

[0166]

[0167] ( (This represents a bonding bond.)

[0168] Examples of substituents shown in formula (S6) include the following groups.

[0169]

[0170] ( (This represents a bonding bond.)

[0171] Examples of substituents shown in formula (S7) include the following groups.

[0172]

[0173] ( (This represents a bonding bond.)

[0174] Other substituents include, for example, the following groups.

[0175]

[0176] ( (This represents a bonding bond.)

[0177] The composite unit structure in resin (G) may include unit structures other than unit structure (A) and unit structure (B).

[0178] Examples of such unit structures include, for instance, unit structures with heterocyclic rings.

[0179] The resin (G) is preferably a resin synthesized from reaction raw materials containing hydroxynaphthalene having one or two phenolic hydroxyl groups, naphthaldehyde, and an aldehyde compound containing an aliphatic hydrocarbon group.

[0180] As a hydroxynaphthalene having one or two phenolic hydroxyl groups, the structural formula illustrated in the above unit structure (A) can be cited.

[0181] Examples of naphthaldehyde include 1-naphthaldehyde or 2-naphthaldehyde.

[0182] Examples of aldehyde compounds containing aliphatic hydrocarbon groups include the aldehydes exemplified in the above unit structure (B-II).

[0183] Phenolic varnish resins having the structure shown in formula (AB) can be formulated using known methods. For example, they can be formulated by condensing the cyclic compound shown in HAH with the aldehyde compound shown in OHC-B. Here, A and B have the same meaning as described above.

[0184] One type of cyclic compound or aldehyde compound can be used, or two or more can be used in combination. In this condensation reaction, the aldehyde compound can be used in a ratio of 0.1 to 10 moles, preferably 0.1 to 2 moles, relative to 1 mole of the cyclic compound.

[0185] As catalysts used in condensation reactions, inorganic acids such as sulfuric acid, phosphoric acid, and perchloric acid, organic sulfonic acids such as p-toluenesulfonic acid, p-toluenesulfonic acid monohydrate, methanesulfonic acid, and trifluoromethanesulfonic acid, and carboxylic acids such as formic acid and oxalic acid can be used. The amount of catalyst used varies depending on the type of catalyst used, but is typically 0.001 to 10,000 parts by mass relative to 100 parts by mass of the cyclic compound (in the case of multiple compounds, their totality), preferably 0.01 to 1,000 parts by mass, and more preferably 0.05 to 100 parts by mass.

[0186] Although condensation reactions can occur under solvent-free conditions, they are usually carried out using a solvent. There are no particular limitations on the solvent, as long as it can dissolve the reaction substrate and does not hinder the reaction. Examples include 1,2-dimethoxyethane, diethylene glycol dimethyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, tetrahydrofuran, tetrahydropyran, and dimethyl ether. Alkane, 1,2-dichloromethane, 1,2-dichloroethane, toluene, N-methylpyrrolidone, dimethylformamide, etc. The condensation reaction temperature is typically 40℃ to 200℃, preferably 100℃ to 180℃. The reaction time varies depending on the reaction temperature, typically ranging from 5 minutes to 50 hours, preferably 5 minutes to 24 hours.

[0187] The phenolic varnish resin involved in one aspect of the present invention typically has a weight-average molecular weight of 500 to 100,000, preferably 600 to 50,000, 700 to 10,000, or 800 to 8,000.

[0188] The content of resin (G) in the composition for forming the lower layer of the resist film is, for example, 25 to 100% by mass relative to the mass of the film-forming component, more preferably 50 to 100% by mass, and even more preferably 70 to 100% by mass.

[0189] Here, the term "film-forming component" refers to the component from which the solvent component has been removed from the composition used to form the underlying film of the resist.

[0190] The molar ratio ((A):(B)) of unit structure (A) to unit structure (B) in resin (G) is preferably 30:70 to 70:30, and more preferably 40:60 to 60:40.

[0191] Furthermore, the molar ratio of unit structure (A) to unit structure (B) in resin (G) can also be expressed by the molar ratio of compound (A) which is the raw material of unit structure (A) to compound (B) which is the raw material of unit structure (B).

[0192] The molar ratio ((A):(B)) of compound (A):(B) is preferably 30:70 to 70:30, more preferably 40:60 to 60:40. Here, compound (A) may be one or more compounds. Similarly, compound (B) may be one or more compounds.

[0193] In resin (G), the total content (molar ratio) of unit structure (BI) and unit structure (B-II) in unit structure (B) is preferably 80 mol% or more, more preferably 90 mol% or more, even more preferably 95 mol% or more, and can be 100 mol%.

[0194] Furthermore, the total molar ratio of unit structure (BI) and unit structure (B-II) in unit structure (B) can also be expressed as the total molar ratio of compound (BI) which is the raw material of unit structure (BI) in compound (B) and compound (B-II) which is the raw material of unit structure (B-II).

[0195] The total molar ratio of compound (BI) to compound (B-II) in compound (B) is preferably 80 mol% or more, more preferably 90 mol% or more, even more preferably 95 mol% or more, and can be 100 mol%.

[0196] The molar ratio ((BI):(B-II)) of unit structure (BI):(B-II) in resin (G) is preferably 20:80 to 80:20, and more preferably 30:70 to 70:30.

[0197] Furthermore, the molar ratio of unit structure (BI) to unit structure (B-II) in resin (G) can also be expressed by the molar ratio of compound (BI) that is the raw material of unit structure (BI) to compound (B-II) that is the raw material of unit structure (B-II).

[0198] The molar ratio of compound (BI) to compound (B-II) ((BI):(B-II)) is preferably 20:80 to 80:20, and more preferably 30:70 to 70:30.

[0199] The molar ratio of the first composite unit structure to the second composite unit structure in resin (G) can be represented by the molar ratio of unit structure (BI) to unit structure (B-II) in resin (G) ((BI):(B-II)).

[0200] That is, the molar ratio of the first composite unit structure to the second composite unit structure in the resin (G) is preferably 20:80 to 80:20, and more preferably 30:70 to 70:30.

[0201] <Solvent>

[0202] The composition for forming a resist underlayer film, as one aspect of the present invention, comprises a solvent.

[0203] There are no particular limitations on the solvent, as long as it can dissolve the specific phenolic varnish resin and any other ingredients added as needed.

[0204] Examples of solvents include, for instance, methyl cellosolve acetate, ethyl cellosolve acetate, propylene glycol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, methyl isobutyl methanol, propylene glycol monobutyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether acetate, toluene, xylene, methyl ethyl ketone, cyclopentanone, cyclohexanone, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxylate, ethyl hydroxyacetate, methyl 2-hydroxy-3-methylbutyrate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, 3- Ethyl ethoxypropionate, methyl 3-ethoxypropionate, methyl pyruvate, ethyl pyruvate, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether, diethylene glycol dibutyl ether, propylene glycol monomethyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether, propylene glycol dipropyl ether, propylene glycol dibutyl ether, ethyl lactate, propyl lactate, isopropyl lactate, butyl lactate Isobutyl lactate, methyl formate, ethyl formate, propyl formate, isopropyl formate, butyl formate, isobutyl formate, amyl formate, isoamyl formate, methyl acetate, ethyl acetate, amyl acetate, isoamyl acetate, hexyl acetate, methyl propionate, ethyl propionate, propyl propionate, isopropyl propionate, butyl propionate, isobutyl propionate, methyl butyrate, ethyl butyrate, propyl butyrate, isopropyl butyrate, butyl butyrate, isobutyl butyrate, ethyl hydroxyethyl acetate, methyl 2-hydroxy-2-methylpropionate, ethyl 2-hydroxy-2-methylpropionate, methyl 3-methoxy-2-methylpropionate, methyl 2-hydroxy-3-methylbutyrate, ethyl methoxyethyl acetate, ethyl... Ethyl oxyethyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-methoxybutylacetate, 3-methoxypropylacetate, 3-methyl-3-methoxybutylacetate, 3-methyl-3-methoxybutylpropionate, 3-methyl-3-methoxybutylbutyrate, methyl acetoacetate, toluene, xylene, methyl ethyl ketone, methyl propyl ketone, methyl butyl ketone, 2-heptanone, 3-heptanone, 4-heptanone, cyclohexanone, N,N-dimethylformamide, N-methylacetamide, N,N-dimethylacetamide, N-methylpyrrolidone, 4-methyl-2-pentanol, and γ-butyrolactone, etc. These solvents can be used alone or in combination of two or more.

[0205] In addition, solvents with a boiling point above 160°C and solvents with a boiling point below 160°C can be combined.

[0206] As such a high-boiling-point solvent, the following compounds, for example, described in International Publication No. 2018 / 131562 (A1), may be preferred.

[0207]

[0208] [R in equation (i)] 1 R 2 and R 3 Each alkyl group represents a hydrogen atom or an alkyl group with 1 to 20 carbon atoms, which can be interrupted by an oxygen atom, a sulfur atom, or an amide bond. These groups can be the same or different and can combine to form a ring structure.

[0209] Alternatively, 1,6-diacetoxyhexane (boiling point 260°C), tripropylene glycol monomethyl ether (boiling point 242°C), and various high-boiling solvents described in other paragraph 0082 of Japanese Patent Application Publication No. 2021-84974 may be preferred.

[0210] Alternatively, the following materials may be preferred: dipropylene glycol monomethyl ether acetate (boiling point 213°C), diethylene glycol monoethyl ether acetate (boiling point 217°C), diethylene glycol monobutyl ether acetate (boiling point 247°C), dipropylene glycol dimethyl ether (boiling point 171°C), dipropylene glycol monomethyl ether (boiling point 187°C), dipropylene glycol monobutyl ether (boiling point 231°C), and tripropylene glycol monomethyl ether (boiling point 247°C), as described in Japanese Patent Application Publication No. 2019-20701. The following are examples of high-boiling solvents described in paragraphs 0023 to 0031 of this publication: γ-butyrolactone (boiling point 242°C), benzyl alcohol (boiling point 204°C), propylene carbonate (boiling point 205°C), tetraethylene glycol dimethyl ether (boiling point 275°C), 1,6-diacetoxyhexane (boiling point 260°C), dipropylene glycol (boiling point 230°C), 1,3-butanediol diacetate (boiling point 232°C).

[0211] As one aspect of the invention, the composition for forming a resist underlayer film may contain an acid and / or its salt and / or an acid-generating agent.

[0212] Examples of acids include p-toluenesulfonic acid, trifluoromethanesulfonic acid, salicylic acid, 5-sulfosalicylic acid, 4-phenolsulfonic acid, camphorsulfonic acid, 4-chlorobenzenesulfonic acid, benzenedisulfonic acid, 1-naphthalenesulfonic acid, citric acid, benzoic acid, hydroxybenzoic acid, and naphthoic acid.

[0213] Salts of the aforementioned acids can also be used as salts. There are no limitations on the salt composition; salts of ammonia derivatives such as trimethylamine salts and triethylamine salts, pyridine derivatives, and morpholine derivatives can be used appropriately.

[0214] Acids and / or their salts may be used alone, or two or more may be used in combination. The mixing amount relative to the total solid content is typically 0.0001 to 20% by mass, preferably 0.0005 to 10% by mass, and more preferably 0.01 to 5% by mass.

[0215] Examples of acid-producing agents include thermal acid-producing agents and photo-producing acid-producing agents.

[0216] Examples of heat-generating acid agents include 2,4,4,6-tetrabromocyclohexadienone, benzoin toluene sulfonate, 2-nitrobenzyl toluene sulfonate, K-PURE (registered trademark) CXC-1612, K-PURE CXC-1614, K-PURE TAG-2172, K-PURE TAG-2179, K-PURE TAG-2678, K-PURE TAG2689, K-PURE TAG2700 (manufactured by King Industries), and organic alkyl sulfonates such as SI-45, SI-60, SI-80, SI-100, SI-110, and SI-150 (manufactured by Sanshin Chemical Industry Co., Ltd.).

[0217] Photoacid-generating agents produce acid during the exposure of the photoresist. Therefore, the acidity of the underlying film can be adjusted. This is one method to match the acidity of the underlying film with that of the upper photoresist. Furthermore, by adjusting the acidity of the underlying film, the pattern shape of the photoresist formed on the upper layer can be adjusted.

[0218] Examples of photoacid-generating agents included in the resist lower layer film forming composition of the present invention include: Salt compounds, sulfonylimide compounds, and disulfonyldiazomethane compounds, etc.

[0219] As Salt compounds, for example, diphenyliodine Hexafluorophosphate, diphenyliodine Trifluoromethanesulfonate, diphenyliodine Nonafluoro-n-butane sulfonate, diphenyl iodide Perfluorooctane sulfonate, diphenyl iodide Camphor sulfonate, bis(4-tert-butylphenyl)iodine Camphor sulfonate and bis(4-tert-butylphenyl)iodine Iodine, such as trifluoromethanesulfonate Salt compounds, as well as sulfonium salt compounds such as triphenylsulfonium hexafluoroantimonate, triphenylsulfonium nonafluoro n-butane sulfonate, triphenylsulfonium camphor sulfonate, and triphenylsulfonium trifluoromethane sulfonate.

[0220] Examples of sulfonylimide compounds include, for example, N-(trifluoromethanesulfonyloxy)succinimide, N-(nonafluoron-butanesulfonyloxy)succinimide, N-(camphorsulfonyloxy)succinimide, and N-(trifluoromethanesulfonyloxy)naphthalenediformimide.

[0221] Examples of disulfonyldiazomethane compounds include, for example, bis(trifluoromethylsulfonyl)diazomethane, bis(cyclohexylsulfonyl)diazomethane, bis(phenylsulfonyl)diazomethane, bis(p-toluenesulfonyl)diazomethane, bis(2,4-dimethylbenzenesulfonyl)diazomethane, and methylsulfonyl-p-toluenesulfonyldiazomethane.

[0222] Acid-producing agents can be used alone, or two or more can be used in combination.

[0223] When using an acid-generating agent, its proportion is 0.01 to 10 parts by mass, 0.1 to 8 parts by mass, or 0.5 to 5 parts by mass relative to 100 parts by mass of the solid component of the composition for forming the lower layer of the resist film.

[0224] In addition to the above, the composition for forming the resist underlayer film, as one aspect of the present invention, may also include, as needed, a crosslinking agent, a surfactant, a light absorber, a rheology modifier, an adhesive aid, etc.

[0225] Representative crosslinking agents include amino plastic crosslinking agents and phenolic plastic crosslinking agents.

[0226] As the aforementioned crosslinking agent, a crosslinking agent with high heat resistance can be used. As a crosslinking agent with high heat resistance, a compound containing crosslinking-forming substituents with aromatic rings (e.g., benzene rings, naphthalene rings) within the molecule is preferred.

[0227] Examples of crosslinking agents for amino plastics include highly alkylated, alkoxylated, or alkoxyalkylated melamine, benzoguanidine, glycourea, urea, and their polymers. Preferably, crosslinking agents have at least two crosslinking-forming substituents, such as compounds like methoxymethylated glycourea, butoxymethylated glycourea, methoxymethylated melamine, butoxymethylated melamine, methoxymethylated benzoguanidine, butoxymethylated benzoguanidine, methoxymethylated urea, butoxymethylated urea, methoxymethylated thiourea, or methoxymethylated thiourea. Condensates of these compounds can also be used.

[0228] Preferably, it is selected from at least one of tetramethoxymethyl glycourea and hexamethoxymethyl melamine.

[0229] If we give some specific examples, they are as follows.

[0230]

[0231] Examples of crosslinking agents for phenolic plastics include highly alkylated, alkoxylated, or alkoxyalkylated aromatic compounds and their polymers. Preferably, crosslinking agents have at least two crosslinking-forming substituents in one molecule, such as 2,6-dihydroxymethyl-4-methylphenol, 2,4-dihydroxymethyl-6-methylphenol, bis(2-hydroxy-3-hydroxymethyl-5-methylphenyl)methane, bis(4-hydroxy-3-hydroxymethyl-5-methylphenyl)methane, 2,2-bis(4-hydroxy-3,5-dihydroxymethylphenyl)propane, bis(3-formyl-4-hydroxyphenyl)methane, bis(4-hydroxy-2,5-dimethylphenyl)formylmethane, and α,α-bis(4-hydroxy-2,5-dimethylphenyl)-4-formyltoluene. Condensates of these compounds can also be used.

[0232] In addition to the above, other examples of such compounds include compounds having a partial structure of the following formula (4), polymers or oligomers having repeating units of the following formula (5).

[0233]

[0234] The above R 11 R 12 R 13 and R 14 Alkyl groups having 1 to 10 hydrogen or carbon atoms can be used as illustrated above. n1 is an integer from 1 to 4, n2 is an integer from 1 to (5-n1), and (n1+n2) represents an integer from 2 to 5. n3 is an integer from 1 to 4, n4 is from 0 to (4-n3), and (n3+n4) represents an integer from 1 to 4. Oligomers and polymers can be used in the range of 2 to 100 or 2 to 50 repeating unit structures.

[0235] If we give some specific examples, they are as follows.

[0236]

[0237] Crosslinking agents such as amino plastic crosslinking agents and phenolic plastic crosslinking agents can be used alone or in combination. Amino plastic crosslinking agents can be manufactured by methods known to them or equivalent methods; in addition, commercially available products can be used.

[0238] Furthermore, the amount of crosslinking agents such as amino plastic crosslinking agents and phenolic plastic crosslinking agents used varies depending on the coating solvent used, the substrate used, the required solution viscosity, and the required film shape, but the total solid content of the composition for forming the resist underlayer film involved in this invention is 0.001% by mass or more, 0.01% by mass or more, 0.05% by mass or more, 0.5% by mass or more, or 1.0% by mass or more, and is 80% by mass or less, 50% by mass or less, 40% by mass or less, 20% by mass or less, or 10% by mass or less.

[0239] In the resist underlayer film forming composition of the present invention, in order to avoid the generation of pinholes, streaks, etc., and to further improve the coating performance on uneven surfaces, a surfactant can be mixed in.

[0240] Examples of surfactants include, for instance, polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, and polyoxyethylene oil-based ether; polyoxyethylene alkyl aryl ethers such as polyoxyethylene octylphenol ether and polyoxyethylene nonylphenol ether; polyoxyethylene / polyoxypropylene block copolymers; sorbitol fatty acid esters such as sorbitol monolaurate, sorbitol monopalmitate, sorbitol monostearate, sorbitol monooleate, sorbitol trioleate, and sorbitol tristearate; polyoxyethylene sorbitol fatty acid esters such as polyoxyethylene sorbitol monolaurate, polyoxyethylene sorbitol monopalmitate, polyoxyethylene sorbitol monostearate, polyoxyethylene sorbitol trioleate, and polyoxyethylene sorbitol tristearate; and nonionic surfactants. EF301, EF303, EF352 (manufactured by EF30F Co., Ltd., trade name), EF303, EF352 171. F173, R-30, R-40 (manufactured by Dainippon Co., Ltd., trade name), Fururo FC430, FC43 1 (trade name manufactured by Sumitomo Solar Co., Ltd.), ASUNALA AG710, SALENA S-382, SC101, S Fluorine-based surfactants such as C102, SC103, SC104, SC105, SC106 (trade name manufactured by Asahi Glass Co., Ltd.), Organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.), etc.

[0241] The amount of these surfactants mixed in is typically 2.0% by mass or less, preferably 1.0% by mass or less, relative to the total solid content of the resist underlayer film forming composition involved in this invention. These surfactants can be added individually or in combination of two or more.

[0242] As light absorbers, commercially available light absorbers listed in publications such as "Technology and Market of Industrial Pigments" (CMC Publishing) and "Dye Handbook" (Organic Synthetic Chemistry Society) are suitable, including CI Disperse Yellow 1, 3, 4, 5, 7, 8, 13, 23, 31, 49, 50, 51, 54, 60, 64, 66, 68, 79, 82, 88, 90, 93, 102, 114, and 124; CI Disperse Orange 1, 5, 13, 25, etc. 29, 30, 31, 44, 57, 72 and 73; CI Disperse Red 1, 5, 7, 13, 17, 19, 43, 50, 54, 58, 65, 72, 73, 88, 117, 137, 143, 199 and 210; CI Disperse Violet 43; CI Disperse Blue 96; CI Fluorescent Whitening Agent 112, 135 and 163; CI Solvent Orange 2 and 45; CI Solvent Red 1, 3, 8, 23, 24, 25, 27 and 49; CI Pigment Green 10; CI Pigment Brown 2, etc. The above-mentioned light absorbers are generally blended in a ratio of 10% by mass or less, preferably 5% by mass or less, relative to the total solid components of the resist underlayer film forming composition involved in this invention.

[0243] Rheology modifiers are primarily added to improve the flowability of the composition for forming the resist underlayer film, especially during the baking process, to improve the uniformity of the resist underlayer film thickness and the filling ability of the composition for forming the resist underlayer film into pores. Specific examples include phthalic acid derivatives such as dimethyl phthalate, diethyl phthalate, diisobutyl phthalate, dihexyl phthalate, and butyl isodecyl phthalate; adipic acid derivatives such as di-n-butyl adipate, diisobutyl adipate, diisooctyl adipate, and octyldecyl adipate; maleic acid derivatives such as di(n-butyl) maleate, diethyl maleate, and dinonyl maleate; oleic acid derivatives such as methyl oleate, butyl oleate, and tetrahydrofurfuryl oleate; or stearic acid derivatives such as n-butyl stearate and glyceryl stearate. These rheology modifiers are typically blended in proportions of less than 30% by mass relative to the total solid components of the resist underlayer film forming composition involved in this invention.

[0244] Adhesive aids are mainly used to improve the adhesion between the substrate or resist and the composition for forming the underlying film of the resist, especially during development in order to prevent the resist from peeling off. Specific examples include chlorosilanes such as trimethylchlorosilane, dimethylvinylchlorosilane, methyldiphenylchlorosilane, and chloromethyldimethylchlorosilane; alkoxysilanes such as trimethylmethoxysilane, dimethyldiethoxysilane, methyldimethoxysilane, dimethylvinylethoxysilane, diphenyldimethoxysilane, and phenyltriethoxysilane; silazanes such as hexamethyldisilazane, N,N'-bis(trimethylsilyl)urea, dimethyltrimethylsilylamine, and trimethylsilylimidazolium; silanes such as vinyltrichlorosilane, γ-chloropropyltrimethoxysilane, γ-aminopropyltriethoxysilane, and γ-epoxypropoxypropyltrimethoxysilane; and silanes such as benzotriazole, benzimidazole, indazole, imidazole, 2-mercaptobenzimidazole, 2-mercaptobenzothiazole, and 2-mercaptobenzo[]. Heterocyclic compounds such as azoles, urazoles, thiouracil, mercaptoimidazoles, and mercaptopyrimidines, and urea or thiourea compounds such as 1,1-dimethylurea and 1,3-dimethylurea. These adhesive aids are typically blended in proportions of less than 5% by mass, preferably less than 2% by mass, relative to the total solids content of the resist underlayer film forming composition involved in this invention.

[0245] The solid content of the resist underlayer film forming composition of the present invention is 0.1 to 70% by mass or 0.1 to 60% by mass. The solid content refers to the proportion of all components in the resist underlayer film forming composition after the solvent has been removed. A crosslinkable resin may be contained in the solid content at a proportion of 1 to 99.9% by mass, 50 to 99.9% by mass, 50 to 95% by mass, or 50 to 90% by mass.

[0246] [Underlying film of resist]

[0247] The resist underlayer film can be formed using the resist underlayer film forming composition of the present invention, for example as follows.

[0248] A resist underlayer film formation composition, as described in one aspect of the present invention, is formed by coating a substrate used in the manufacture of semiconductor devices (e.g., silicon wafer substrate, silicon dioxide coated substrate (SiO2 substrate), silicon nitride substrate (SiN substrate), silicon oxide nitride substrate (SiON substrate), titanium nitride substrate (TiN substrate), tungsten substrate (W substrate), glass substrate, ITO substrate, polyimide substrate, and low-k material coated substrate, etc.) with a suitable coating method such as a spin coater or coating machine, and then firing it using a heating means such as a hot plate. The firing conditions are appropriately selected from a firing temperature of 80°C to 800°C and a firing time of 0.3 to 60 minutes. Preferably, the firing temperature is 150°C to 500°C and the firing time is 0.5 to 2 minutes. The atmosphere gas used during firing can be air, or inactive gases such as nitrogen or argon. In one aspect, an oxygen concentration of 1% or less is particularly preferred. Here, the thickness of the underlying film formed is, for example, 10–1000 nm, or 20–500 nm, or 30–400 nm, or 50–300 nm. Furthermore, if a quartz substrate is used as the substrate, a replica of the quartz embossing mold (mold replica) can be fabricated.

[0249] Furthermore, an adhesive layer and / or a silicon-containing layer containing 99% by mass or less or 50% by mass or less of Si can also be formed on the resist underlayer film, which is an aspect of the present invention, by coating or vapor deposition. For example, in addition to the method of forming the adhesive layer described in Japanese Patent Application Publication No. 2013-202982, Japanese Patent No. 5827180, and the silicon-containing resist underlayer film (inorganic resist underlayer film) forming composition described in International Publication No. 2009 / 104552 (A1) by spin coating, Si-based inorganic material films can also be formed by CVD or the like.

[0250] Furthermore, by coating a resist underlayer film forming composition, which is one aspect of the present invention, onto a semiconductor substrate (so-called high-low difference substrate) containing portions having high-low differences and portions not having high-low differences and then firing it, the high-low difference between the portions having high-low differences and the portions not having high-low differences can be reduced.

[0251] [Method for forming resist patterns]

[0252] The method for forming a resist pattern according to the present invention includes at least the step of coating a resist underlayer film forming composition of the present invention onto a semiconductor substrate and firing it to form a resist underlayer film.

[0253] The method for forming the resist pattern of the present invention may include the following steps.

[0254] The process of forming a resist film on the resist underlayer film; The process of irradiating a resist film with light or an electron beam, followed by developing the resist film to obtain a resist pattern; and The process of using a resist pattern as a mask and etching the underlying resist film.

[0255] [Method for manufacturing semiconductor devices]

[0256] (i)

[0257] A method for manufacturing a semiconductor device, as one aspect of the present invention, includes the following steps: The process of forming a photoresist underlayer film on a semiconductor substrate using a photoresist underlayer film forming composition as an aspect of the present invention; The process of forming a resist film on the resist underlayer film; The process of forming a resist pattern by irradiating a resist film with light or an electron beam and developing it; The process of etching the aforementioned resist underlayer film through a resist pattern to form a patterned resist underlayer film; and The process of processing a semiconductor substrate through a patterned resist underlayer film.

[0258] (ii)

[0259] Furthermore, the method for manufacturing a semiconductor device as an aspect of the present invention includes the following steps: The process of forming a photoresist underlayer film on a semiconductor substrate using a photoresist underlayer film forming composition as an aspect of the present invention; The process of forming a hard mask on the underlying resist film; The next step is to form a resist film on the hard mask. The process of forming a resist pattern by irradiating a resist film with light or an electron beam and developing it; The process of etching a hard mask using a resist pattern to form a patterned hard mask; The process of etching the aforementioned resist underlayer film through a patterned hard mask to form a patterned resist underlayer film; and The process of processing a semiconductor substrate through a patterned resist underlayer film.

[0260] (iii)

[0261] Furthermore, the method for manufacturing a semiconductor device as an aspect of the present invention includes the following steps: The process of forming a photoresist underlayer film on a semiconductor substrate using a photoresist underlayer film forming composition as an aspect of the present invention; The process of forming a hard mask on the underlying resist film; The next step is to form a resist film on the hard mask. The process of forming a resist pattern by irradiating a resist film with light or an electron beam and developing it; The process of etching a hard mask using a resist pattern to form a patterned hard mask; The process of etching the above-mentioned photoresist underlayer film through a patterned hard mask to form a patterned photoresist underlayer film. The process of removing the hard mask; and The process of processing a semiconductor substrate through a patterned resist underlayer film.

[0262] (iv)

[0263] Furthermore, the method for manufacturing a semiconductor device as an aspect of the present invention includes the following steps: The process of forming a photoresist underlayer film on a semiconductor substrate using a photoresist underlayer film forming composition as an aspect of the present invention; The process of forming a hard mask on the underlying resist film; The next step is to form a resist film on the hard mask. The process of forming a resist pattern by irradiating a resist film with light or an electron beam and developing it; The process of etching a hard mask using a resist pattern to form a patterned hard mask; The process of etching the above-mentioned photoresist underlayer film through a patterned hard mask to form a patterned photoresist underlayer film. The process of removing the hard mask; The process of forming a vapor-deposited film (spacer) on the resist underlayer film after the hard mask is removed; The process of etching a vapor-deposited film (spacer); The process of removing the patterned resist underlayer, leaving the patterned vapor-deposited film (spacers); and The process of processing a semiconductor substrate by depositing a patterned vapor-deposited film (spacer).

[0264] The semiconductor substrate can be processed using the manufacturing methods described in (i) to (iv) above.

[0265] The process of forming a photoresist underlayer film using the photoresist underlayer film forming composition as an aspect of the present invention is as described in the above [Photoresist Underlayer Film].

[0266] A hard mask containing silicon, or a film, can be formed on the resist lower layer film formed by the above process as a second resist lower layer film, and a resist pattern can be formed on it [as described in (ii) to (iv) above].

[0267] Hard masks can be coatings of inorganic materials, or vapor-deposited films of inorganic materials formed by vapor deposition methods such as CVD and PVD. Examples include SiON films, SiN films, or SiO2 films.

[0268] An anti-reflective film (BARC) can be further formed on the hard mask, and a resist shape correction film without anti-reflective capability can be formed.

[0269] In the above-described process of forming the resist pattern, exposure is performed either by using a mask (photomask) to form the specified pattern or by direct drawing. Exposure sources can include, for example, gamma rays, i-rays, KrF excimer lasers, ArF excimer lasers, EUV, and electron beams. After exposure, post-exposure baking is performed as needed. Then, development is carried out with a developer (e.g., 2.38% by mass tetramethylammonium hydroxide aqueous solution, butyl acetate), followed by rinsing with a rinsing solution or pure water to remove the used developer. Finally, post-baking is performed to dry the resist pattern and improve adhesion to the substrate.

[0270] The etching process performed after the above-mentioned resist pattern is formed is carried out by dry etching.

[0271] Additionally, the following gases—CF4, CHF3, CH2F2, CH3F, C4F6, C4F8, O2, N2O, NO2, H2, and He—can be used in the processing of the hard mask (containing a silicon layer), the underlayer of the resist, and the substrate. These gases can be used alone or in mixtures of two or more. Furthermore, argon, nitrogen, carbon dioxide, carbonyl sulfide, sulfur dioxide, neon, or nitrogen trifluoride can be mixed with these gases.

[0272] The aforementioned resist film can be patterned using nanoimprinting or self-assembly film methods.

[0273] For nanoimprinting, a resist composition is formed using a mold (type) that is transparent to the light and has been patterned. Furthermore, for self-assembled film methods, patterning is achieved using self-assembled films with naturally formed nanoscale regular structures, such as diblock polymers (polystyrene-polymethyl methacrylate, etc.).

[0274] In nanoimprint lithography, a silicon-containing layer (hard mask layer) can be selectively formed on a photoresist underlayer by coating or vapor deposition before applying a curable composition that becomes a photoresist film. A bonding layer is then formed on the photoresist underlayer or the silicon-containing layer (hard mask layer) by coating or vapor deposition, and the curable composition that becomes a photoresist film is applied on the bonding layer.

[0275] In addition, wet etching is sometimes performed to simplify the process and reduce damage to the substrate. This suppresses dimensional variations and reduces pattern roughness, resulting in a high yield rate for substrate processing. Therefore, in (iii) to (iv) above, hard masks can be removed by either etching or an alkaline solution. In particular, when using an alkaline solution, there are no restrictions on the composition, but the following components are preferred as the alkaline component.

[0276] Examples of alkaline components include, for example, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, methyltripropylammonium hydroxide, methyltributylammonium hydroxide, ethyltrimethylammonium hydroxide, dimethyldiethylammonium hydroxide, benzyltrimethylammonium hydroxide, hexadecyltrimethylammonium hydroxide and (2-hydroxyethyl)trimethylammonium hydroxide, monoethanolamine, diethanolamine, triethanolamine, 2-(2-aminoethoxy)ethanol, N,N-dimethylethanolamine, N,N-diethylethanolamine, N,N-dibutylethanolamine, N... Methylethanolamine, N-ethylethanolamine, N-butylethanolamine, N-methyldiethanolamine, monoisopropanolamine, diisopropanolamine, triisopropanolamine, tetrahydrofurfurylamine, N-(2-aminoethyl)piperazine, 1,8-diazabicyclo[5.4.0]undecene-7, 1,4-diazabicyclo[2.2.2]octane, hydroxyethylpiperazine, piperazine, 2-methylpiperazine, trans-2,5-dimethylpiperazine, cis-2,6-dimethylpiperazine, 2-piperidinemethanol, cyclohexylamine, 1,5-diazabicyclo[4,3,0]nonene-5, etc. Furthermore, especially from an operational point of view, tetramethylammonium hydroxide and tetraethylammonium hydroxide are particularly preferred, as an inorganic base can be used in combination with a quaternary ammonium hydroxide. As the inorganic base, hydroxides of alkali metals such as potassium hydroxide, sodium hydroxide, and rubidium hydroxide are preferred, with potassium hydroxide being more preferred.

[0277] Example

[0278] The following examples illustrate the content of the present invention in detail, but the present invention is not limited to these examples.

[0279] The weight-average molecular weights (Mw) of the polymers shown in Synthetic Examples 1-7 and Comparative Synthetic Example 1 below are the results obtained by gel permeation chromatography (hereinafter referred to as GPC). A GPC apparatus manufactured by Toso Corporation was used in the determination, and the determination conditions are as follows.

[0280] GPC column: TSKgel Super-MultiporeHZ-N (2 columns)

[0281] Column temperature: 40℃

[0282] Solvent: Tetrahydrofuran (THF)

[0283] Flow rate: 0.35 ml / min

[0284] Standard sample: Polystyrene (manufactured by Tosoo Corporation)

[0285] (1) Polymer synthesis

[0286] The synthesis of polymers (S1) to (S7) used in the lower layer of the resist film, and the synthesis of polymer (SS1) as a comparative example, used the following compound groups A, B, C, D, and E: redeposition solvents.

[0287] (1-1) Compound group A~B

[0288] (1-2) Catalyst group C, solvent group D, and reprecipitation solvent group E

[0289] Mesylate: C1

[0290] Propylene glycol monomethyl ether acetate (PGMEA): D1

[0291] Propylene glycol monomethyl ether (PGME): D2

[0292] Methanol: E1

[0293] Methanol / Water: E2

[0294] [Synthesis Example 1] (Synthesis of polymer (S1))

[0295] (A1 / B1 / B2 = 50 / 35 / 15 (molar ratio))

[0296] 10.0 g of A1, 6.8 g of B1, 2.3 g of B2, 0.6 g of methanesulfonic acid, 30.8 g of PGMEA, and 3.2 g of PGME1 were added to a flask. The mixture was then heated under nitrogen to 120 °C and reacted for approximately 15 hours. After the reaction was stopped, the mixture was redetermined with methanol (E1) and dried to obtain polymer (S1). The weight-average molecular weight (Mw), determined by GPC to be equivalent to polystyrene, was approximately 4,000. The resulting resin (polymer) was dissolved in PGMEA, and ion exchange was performed for 4 hours using both cation and anion exchange resins to obtain a solution of the target compound.

[0297] [Synthesis Examples 2 to 7]

[0298] Polymers (S2) to (S7) were synthesized under the conditions shown in Synthesis Examples 2 to 7 in Table 1 below, using the same procedures as in Synthesis Example 1.

[0299]

[0300] The following shows the structural formulas and weight-average molecular weights of the obtained resins S1 to S7.

[0301]

[0302] [Comparative Synthesis Example 1]

[0303] Comparative resin SS1 was synthesized under the conditions shown in Comparative Synthesis Example 1 in Table 2 below, using the same procedures as in Synthesis Example 1.

[0304]

[0305] The following shows the structural formula and weight-average molecular weight of the obtained resin SS1.

[0306]

[0307] [Examples 1-7, Comparative Example 1]

[0308] (2) Modulation of the underlayer film of the resist

[0309] Polymers (S1) to (S7) and (SS1), crosslinking agent (CL1), acid-generating agent (Ad1), solvent (D1 and D2), and surfactant Megafac (registered trademark) R-40 (manufactured by DIC Co., Ltd., G1) were mixed in the following weight proportions (as shown in Table 3 below; the weight of crosslinking agent, acid-generating agent, and surfactant is indicated when the weight of polymer is set to 100 parts; regarding solvent, the weight of each solvent is indicated independently of the weight of polymer when the total solvent weight is set to 100% by weight) and filtered using a 0.1 μm polytetrafluoroethylene microfilter to prepare the resist underlayer film forming compositions of each example.

[0310] The following shows the structural formulas of the crosslinking agent (CL1) and the acid-producing agent (Ad1). In the formula, "Me" refers to a methyl group.

[0311]

[0312] [Determination of optical constants]

[0313] The resist underlayer film forming compositions prepared in Examples 1-7 and Comparative Example 1 were respectively coated onto silicon wafers using a spin coater. Then, they were baked on a hot plate at 240°C for 60 seconds to form a resist underlayer film (film thickness 50 nm). The refractive index (n-value) and optical absorption coefficient (also known as k-value or attenuation coefficient) at a wavelength of 193 nm were measured using a spectroscopic ellipsometry as the optical constants of these resist underlayer films. The results are shown in Table 4.

[0314]

[0315] [Coating performance test / planarization performance test on substrates with uneven surfaces]

[0316] In the case of substrates with uneven surfaces, the coating properties of the resist underlayer film sometimes deteriorate compared to silicon wafers without uneven surfaces. Therefore, tests were conducted to determine whether it is possible to coat the substrate with uneven surfaces without unevenness. As part of the coating property test for substrates with uneven surfaces, a SiO2 substrate with a film thickness of 200 nm was used. The uneven surface of the substrate after coating with the resist underlayer film formation composition was visually confirmed, and cases where coating was achieved without unevenness were marked as "0", while cases where it was not were marked as "×".

[0317] Next, the planarization performance was evaluated in the wide trench region with a trench width of 800 nm present in the aforementioned high-low difference substrate. The film thickness of the wide trench region and the unpatterned region (open region) was compared. The resist underlayer film forming compositions prepared in Examples 1-7 and Comparative Example 1 were respectively coated onto the aforementioned high-low difference substrate, and then fired on a hot plate at the specified temperature / specified time as described in Table 5 to form a resist underlayer film with a thickness of 150 nm. The planarization performance of the substrate was observed using a scanning electron microscope (S-4800) manufactured by Hitachi Hightech Noroges Co., Ltd., and the film thickness difference between the trench region (patterned area) and the open region (unpatterned area) of the high-low difference substrate was measured (the difference in coating height between the trench region and the open region, referred to as "deviation") to evaluate the planarization performance. Here, planarization refers to the small difference in film thickness (iso-dense deviation) between the patterned area (groove area (patterned area)) and the unpatterned area (open area (unpatterned area)). Compared to Comparative Example 1, cases where the deviation was improved were marked as "0", and cases where the deviation was the same as or worsened compared to Comparative Example 1 were marked as "×". The results are shown in Table 5.

[0318]

[0319] As can be seen above, if an aldehyde with a flexible portion is introduced, it will have good coating properties and good planarization properties even on substrates with varying elevations from which vapor-deposited films are applied. By changing the monomers during synthesis, the optical constant can be adjusted to suppress reflection during exposure, depending on the device.

Claims

1. A composition for forming a resist underlayer film, comprising a resin (G) having a plurality of composite unit structures and a solvent, The composite unit structure has the following characteristics: Unit structures containing a naphthalene ring with one or two phenolic hydroxyl groups (A), and Unit structures with one or more carbon atoms (B), The resin (G) is a resin obtained by reacting carbon atoms of the naphthalene ring constituting the unit structure (A) with carbon atoms in the unit structure (B) to form covalent bonds. The first composite unit structure includes a unit structure (BI) having a naphthalene ring as the unit structure (B). The second composite unit structure includes a unit structure (B-II) having an aliphatic hydrocarbon group as said unit structure (B).

2. The composition for forming a resist underlayer film according to claim 1, wherein the structure of the first composite unit is represented by the following formula (1), The second composite unit structure is represented by at least one of the following equations (2) and (3); In equation (1), n1 represents 1 or 2; In equation (2), n2 represents 1 or 2, and R 2 R represents an alkyl group with 1 to 10 carbon atoms, an alkenyl group with 2 to 10 carbon atoms, an alkynyl group with 2 to 10 carbon atoms, or an alkoxy group with 1 to 10 carbon atoms, where m represents an integer from 1 to 5. When m is 2 or more, R... 2 They can be different or the same; In equation (3), n3 represents 1 or 2, and R 3 It represents an alkyl group with 1 to 10 carbon atoms, an alkenyl group with 2 to 10 carbon atoms, or an alkynyl group with 2 to 10 carbon atoms.

3. The composition for forming a resist underlayer film according to claim 1, wherein the molar ratio of the unit structure (BI) to the unit structure (B-II) in the resin (G) is 20:80 to 80:

20.

4. The composition for forming a resist underlayer film according to claim 1, wherein the resin (G) is a resin synthesized from the following reactants, wherein the reactants comprise: Hydroxynaphthalene with one or two phenolic hydroxyl groups, Naphthalene formaldehyde, and Aldehyde compounds containing aliphatic hydrocarbon groups, The aliphatic hydrocarbon group is selected from one or more of the following: alkyl with 1 to 10 carbon atoms, alkenyl with 2 to 10 carbon atoms, and alkynyl with 2 to 10 carbon atoms.

5. The composition for forming a resist underlayer film according to claim 1, wherein the solvent comprises a solvent with a boiling point of 160°C or higher.

6. The composition for forming a resist underlayer film according to claim 1, further comprising at least one selected from acids and their salts, and acid-generating agents.

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

8. The composition for forming a resist underlayer film according to claim 7, wherein the crosslinking agent is at least one selected from amino plastic crosslinking agents and phenolic plastic crosslinking agents.

9. The composition for forming a resist underlayer film according to claim 1, further comprising a surfactant.

10. A resist underlayer film on a semiconductor substrate, which is a cured product of the resist underlayer film forming composition according to any one of claims 1 to 9.

11. A method for forming a resist pattern for manufacturing a semiconductor, comprising the step of coating a resist underlayer film forming composition according to any one of claims 1 to 9 onto a semiconductor substrate and firing it to form a resist underlayer film.

12. A method for manufacturing a semiconductor device, comprising the following steps: The process of forming a photoresist underlayer film on a semiconductor substrate using the photoresist underlayer film forming composition according to any one of claims 1 to 9; The process of forming a resist film on the lower resist film; The process of forming a resist pattern by irradiating the resist film with light or an electron beam and developing it; The process of etching the resist underlayer film via the resist pattern to form a patterned resist underlayer film; and The process of processing a semiconductor substrate via the patterned resist underlayer film.

13. A method for manufacturing a semiconductor device, comprising the following steps: The process of forming a photoresist underlayer film on a semiconductor substrate using the photoresist underlayer film forming composition according to any one of claims 1 to 9; The process of forming a hard mask on the underlying resist film; The next step is to form a resist film on the hard mask; The process of forming a resist pattern by irradiating the resist film with light or an electron beam and developing it; The process of etching the hard mask through the resist pattern to form a patterned hard mask; The process of etching the patterned photoresist underlayer film via the patterned hard mask to form the patterned photoresist underlayer film; and The process of processing a semiconductor substrate via the patterned resist underlayer film.

14. A method for manufacturing a semiconductor device, comprising the following steps: The process of forming a photoresist underlayer film on a semiconductor substrate using the photoresist underlayer film forming composition according to any one of claims 1 to 9; The process of forming a hard mask on the lower layer of the resist film; The next step is to form a resist film on the hard mask; The process of forming a resist pattern by irradiating the resist film with light or an electron beam and developing it; The process of etching the hard mask through the resist pattern to form a patterned hard mask; The process of etching the resist underlayer film through the patterned hard mask to form the patterned resist underlayer film; The process of removing the hard mask; as well as The process of processing a semiconductor substrate via the patterned resist underlayer film.

15. A method for manufacturing a semiconductor device, comprising the following steps: The process of forming a photoresist underlayer film on a semiconductor substrate using the photoresist underlayer film forming composition according to any one of claims 1 to 9; The process of forming a hard mask on the underlying resist film; The next step is to form a resist film on the hard mask; The process of forming a resist pattern by irradiating the resist film with light or an electron beam and developing it; The process of etching the hard mask through the resist pattern to form a patterned hard mask; The process of etching the resist underlayer film through the patterned hard mask to form the patterned resist underlayer film; The process of removing the hard mask; The process of forming a vapor-deposited film on the resist underlayer after the hard mask is removed; The process of processing the vapor-deposited film by etching; The process of removing the patterned resist underlayer film, leaving the patterned vapor-deposited film; and The process of processing a semiconductor substrate via the patterned vapor deposition film.

16. The method of manufacturing a semiconductor device according to claim 13, wherein the hard mask is formed by coating a composition comprising an inorganic material or by vapor deposition of an inorganic material.

17. The method for manufacturing a semiconductor device according to claim 12, wherein the resist film is patterned by nanoimprinting or self-assembling film.

18. The method of manufacturing a semiconductor device according to claim 14, wherein the hard mask is removed by either etching or an alkaline solution.

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