WO2019208212A1

WO2019208212A1 - Resist underlayer film formation composition, resist underlayer film and method for forming same, and method for forming pattern

Info

Publication number: WO2019208212A1
Application number: PCT/JP2019/015534
Authority: WO
Inventors: 毅由安陪; 大貴中津; 信也峯岸; 直矢野坂; 慎也中藤; 翼阿部; 崇片切
Original assignee: Jsr株式会社
Priority date: 2018-04-23
Filing date: 2019-04-10
Publication date: 2019-10-31
Also published as: JP7255589B2; KR20210005595A; JPWO2019208212A1

Abstract

The purpose of the present invention is to provide a resist underlayer film formation composition with which it is possible to form a resist underlayer film having excellent heat resistance, etching resistance, and film defect inhibition. The present invention is a resist underlayer film formation composition containing: a compound having an aromatic ring, and a nitrogen atom that is bonded with a carbon atom of the aromatic ring; and a solvent, wherein the compound is represented by formula (1) or (2). In formula (1), R¹ is a substituted or unsubstituted C1-70 n-valent hydrocarbon group. R³ and R⁴ are each independently a substituted or unsubstituted C1-20 monovalent hydrocarbon group or a hydrogen atom, or R³ and R⁴ are part of a 3- to 20-member ring structure constituted by joining the same to each other and bonding these with a nitrogen atom. At least one of R¹, R³, and R⁴ is a group having an aromatic ring, the group being bonded to the nitrogen atom in formula (1) by a carbon atom of the aromatic ring.

Description

Resist underlayer film forming composition, resist underlayer film, method for forming the same, and pattern forming method

The present invention relates to a resist underlayer film forming composition, a resist underlayer film, a forming method thereof, and a pattern forming method.

In the manufacture of semiconductor devices, for example, a multilayer resist process is used in which a resist film formed on a substrate via a resist underlayer such as an organic underlayer film or a silicon-containing film is exposed and developed to form a resist pattern. . In this process, the resist underlayer film is etched using the resist pattern as a mask, and the substrate is further etched using the obtained resist underlayer film pattern as a mask, thereby forming a desired pattern on the substrate and obtaining a patterned substrate. (See JP 2004-177668 A).

JP 2004-177668 A

The resist underlayer film and the composition for forming a resist underlayer film of the present invention are the above-described organic underlayer film and a composition for forming the same. The resist underlayer film forming composition used for the formation of the organic underlayer film in the multilayer resist process is required to have good coating properties, and the formed resist underlayer film (organic underlayer film) has heat resistance and etching. It is required to have excellent resistance. In addition, in the multilayer resist process, it is also necessary to be excellent in suppressing the occurrence of defects such as cracks and peeling on the surface of the silicon-containing film, that is, excellent in the film defect suppression of the silicon-containing film.

The present invention has been made based on the circumstances as described above, and its purpose is to provide a resist underlayer film forming composition capable of forming a resist underlayer film having excellent heat resistance, etching resistance, and film defect suppression properties, and a resist underlayer. An object of the present invention is to provide a method for forming a film and a resist underlayer film and a pattern forming method.

The invention made in order to solve the above problems includes an aromatic ring, a compound having a nitrogen atom bonded to a carbon atom of the aromatic ring (hereinafter also referred to as “[A] compound”), a solvent (hereinafter referred to as “[B ] [Solvent] ", and the above-mentioned [A] compound is a composition for forming a resist underlayer film represented by the following formula (1) or the following formula (2).

(In Formula (1), R ¹ is a substituted or unsubstituted n-valent hydrocarbon group having 1 to 70 carbon atoms. R ³ and R ⁴ are each independently a substituted or unsubstituted carbon number. A monovalent hydrocarbon group of 1 to 20 or a hydrogen atom, or a part of a ring structure of 3 to 20 ring members composed of R ³ and R ⁴ together with the nitrogen atom to which they are bonded However, at least one of R ¹ , R ³ and R ⁴ has an aromatic ring, and is a group bonded to the nitrogen atom in the above formula (1) at a carbon atom of the aromatic ring. It is an integer of ~ 10. When n is 2 or more, the plurality of R ³ are the same or different, and the plurality of R ⁴ are the same or different.
In the formula (2), R ^{2 ′} is a substituted or unsubstituted divalent hydrocarbon group having 1 to 20 carbon atoms. R ^{3 ′} is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms or a hydrogen atom. However, at least one of R ^{2 ′} and R ^{3 ′} has an aromatic ring and is a group bonded to the nitrogen atom in the above formula (2) at the carbon atom of the aromatic ring. m is an integer of 1 to 10. When m is 2 or more, the plurality of R ^{2 ′} are the same or different and the plurality of R ^{3 ′} are the same or different. )

Another invention made to solve the above problems is a resist underlayer film formed from the resist underlayer film forming composition.

Still another invention made in order to solve the above-mentioned problem comprises a step of directly or indirectly applying a resist underlayer film forming composition to a substrate, wherein the resist underlayer film forming composition comprises a compound [A] And [B] a method for forming a resist underlayer film containing a solvent.

Still another invention made in order to solve the above-described problems includes a step of directly or indirectly applying a composition for forming a resist underlayer film on a substrate, and a resist underlayer film formed by the above coating step directly or indirectly. A pattern forming method comprising a step of indirectly forming a resist pattern and a step of performing etching using the resist pattern as a mask, wherein the composition for forming a resist underlayer film contains a compound [A] and a solvent [B] It is.

The composition for forming a resist underlayer film of the present invention can form a resist underlayer film having excellent heat resistance, etching resistance, and film defect suppression properties. The resist underlayer film of the present invention is excellent in heat resistance, etching resistance and film defect suppression. According to the method for forming a resist underlayer film of the present invention, a resist underlayer film having excellent heat resistance, etching resistance, and film defect suppression properties can be formed. According to the pattern forming method of the present invention, a patterned substrate having a good pattern shape can be obtained by using such an excellent resist underlayer film. Therefore, these can be suitably used for manufacturing semiconductor devices and the like that are expected to be further miniaturized in the future.

<Composition for forming resist underlayer film>
The resist underlayer film forming composition (hereinafter also simply referred to as “composition”) contains a compound [A] and a solvent [B]. The said composition may contain arbitrary components in the range which does not impair the effect of this invention. Hereinafter, each component will be described.

<[A] Compound>
The compound [A] is a compound represented by the following formula (1) or the following formula (2) (hereinafter, the compound represented by the formula (1) is also referred to as “[A1] compound”, and represented by the formula (2)). The compound obtained is also referred to as “[A2] compound”).

In the above formula (1), R ¹ is a substituted or unsubstituted n-valent hydrocarbon group having 1 to 70 carbon atoms. R ³ and R ⁴ are each independently a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms or a hydrogen atom, or R ³ and R ⁴ are combined with each other and bonded to each other. It is a part of a ring structure having 3 to 20 ring members that is formed with a nitrogen atom. However, at least one of R ¹ , R ³ and R ⁴ has an aromatic ring and is a group bonded to the nitrogen atom in the above formula (1) at the carbon atom of the aromatic ring. n is an integer of 1 to 10. When n is 2 or more, the plurality of R ³ are the same or different, and the plurality of R ⁴ are the same or different.

In the above formula (2), R ^{2 ′} is a substituted or unsubstituted divalent hydrocarbon group having 1 to 20 carbon atoms. R ^{3 ′} is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms or a hydrogen atom. However, at least one of R ^{2 ′} and R ^{3 ′} has an aromatic ring and is a group bonded to the nitrogen atom in the above formula (2) at the carbon atom of the aromatic ring. m is an integer of 1 to 10. When m is 2 or more, the plurality of R ^{2 ′} are the same or different and the plurality of R ^{3 ′} are the same or different.

By containing the [A] compound, the composition can form a resist underlayer film that is excellent in heat resistance, etching resistance, and film defect suppression. The reason why the composition exhibits the above-described effect by having the above-described configuration is not necessarily clear, but can be estimated as follows, for example. That is, the [A] compound has an aromatic ring to which an amino group having a high electron donating ability is bonded. The compound [A] having such a structure is easily oxidized and easily generates radical active species. As a result, the resist underlayer film forming composition can form a resist underlayer film having a denser crosslink. It is considered that a resist underlayer film having excellent heat resistance and etching resistance and excellent film defect suppression properties can be formed.
Hereinafter, the [A1] compound and the [A2] compound will be described.

[[A1] Compound]
[A1] The compound is a compound represented by the above formula (1).

Examples of the n-valent hydrocarbon group having 1 to 70 carbon atoms represented by R ¹ include 1 to 70 carbon atoms such as alkanes such as methane, ethane, propane and butane, and alkenes such as ethene, propene, butene and pentene. Chain hydrocarbons, cyclopropanes such as cyclopropane, cyclobutane, cyclopentane, cycloalkane such as cyclohexane, norbornane and adamantane, cycloalkenes such as cyclopropene, cyclobutene, cyclopentene, cycloalkene such as cyclohexene and norbornene, etc. Groups obtained by removing n hydrogen atoms from hydrocarbons such as aromatic hydrocarbons having 6 to 70 carbon atoms such as hydrogen, benzene, toluene, xylene, mesitylene, naphthalene, methylnaphthalene, dimethylnaphthalene, anthracene, and other arenes. Can be mentioned.

Examples of the substituent for the n-valent hydrocarbon group include halogen atoms such as fluorine atom, chlorine atom, bromine atom and iodine atom, alkoxy groups such as methoxy group, ethoxy group and propoxy group, methoxycarbonyl group and ethoxycarbonyl. Examples include alkoxycarbonyl groups such as alkoxycarbonyl groups such as methoxycarbonyloxy group and ethoxycarbonyloxy group, acyl groups such as formyl group, acetyl group, propionyl group, butyryl group and benzoyl group, cyano group, nitro group and the like. It is done.

R ¹ is preferably a group containing an aromatic ring (hereinafter also referred to as “group (1)”). As the aromatic ring, an aromatic carbocyclic ring is preferable. Examples of the aromatic carbocycle include a benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, pyrene ring, tetracene ring, pentacene ring, and fluorene ring.

The group (1) is preferably a group in which the nitrogen atom in the above formula (1) is bonded to the aromatic carbocycle of R ¹ (hereinafter also referred to as “group (1-1)”).

Examples of the group (1-1) include a group represented by the following formula (3).

In the above formula (3), Ar ¹ is a group obtained by removing (p + a) hydrogen atoms on the aromatic ring from an arene having 6 to 70 carbon atoms. R ^A is a monovalent organic group having 1 to 20 carbon atoms, a hydroxy group, or a halogen atom. p is an integer of 0 to 20. When p is 2 or more, a plurality of ^RA are the same or different. a is an integer of 1 to 10. * Indicates a binding site with the nitrogen atom in the above formula (1).

Examples of the C6-C70 arene that gives Ar ¹ include benzene, naphthalene, anthracene, phenanthrene, tetracene, pyrene, biphenyl, dimethylbiphenyl, diphenylbiphenyl, fluorene, and the like.

“Organic group” refers to a group containing at least one carbon atom. Examples of the monovalent organic group having 1 to 20 carbon atoms represented by ^RA include, for example, a monovalent hydrocarbon group having 1 to 20 carbon atoms and a divalent hetero atom between carbon-carbon of the hydrocarbon group. A group having a group, a group obtained by substituting a part or all of the hydrogen atoms of the hydrocarbon group and the group having a divalent heteroatom-containing group with a monovalent heteroatom-containing group, and the like.

Examples of the divalent heteroatom-containing group include —CO—, —CS—, —NH—, —O—, —S—, and combinations thereof.

Examples of the monovalent heteroatom-containing group include a hydroxy group, a sulfanyl group, a cyano group, a nitro group, and a halogen atom.

p is preferably 0 to 2, more preferably 0 or 1, and still more preferably 0.
a is preferably from 1 to 5, and more preferably 2 or 3.

Examples of the group (1-1) include groups represented by the following formulas.

In the above formula, each R is independently a hydrogen atom or a monovalent hydrocarbon group having 1 to 20 carbon atoms. * Is synonymous with the above formula (3).

Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms represented by R ³ or R ⁴ include carbons such as alkanes such as methane, ethane, propane, and butane, alkenes such as ethene, propene, butene, and pentene. 1-20 chain hydrocarbons, cycloalkanes such as cyclopropane, cyclobutane, cyclopentane, cyclohexane, norbornane, adamantane, etc., and cycloalkenes such as cycloalkene such as cyclopropene, cyclobutene, cyclopentene, cyclohexene, norbornene, etc. One hydrogen atom was removed from hydrocarbons such as aromatic hydrocarbons having 6 to 20 carbon atoms such as cyclic hydrocarbons, arenes such as benzene, toluene, xylene, mesitylene, naphthalene, methylnaphthalene, dimethylnaphthalene and anthracene. Groups and the like.

Examples of the substituent for the monovalent hydrocarbon group for R ³ and R ⁴ include the same groups as those exemplified as the substituent for the n-valent hydrocarbon group for R ¹ . Examples of the substituent when the monovalent hydrocarbon group of R ³ and R ⁴ is an aromatic hydrocarbon group include alkanes such as methane, ethane, propane, and butane, alkenes such as ethene, propene, butene, and pentene C 1-20 chain hydrocarbons such as cycloalkanes such as cyclopropane, cyclobutane, cyclopentane, cyclohexane, norbornane, adamantane, etc., cycloalkenes such as cyclopropene, cyclobutene, cyclopentene, cyclohexene, norbornene, etc. A group obtained by removing one hydrogen atom from a hydrocarbon of 20 alicyclic hydrocarbons is preferred, and a group obtained by removing one hydrogen atom from an alkane such as methane, ethane, propane, or butane is more preferred.

Examples of the ring structure having 3 to 20 ring members constituted by R ³ and R ⁴ include azacycloalkane structures such as an azacyclopentane structure and an azacyclohexane structure.

At least one of R ³ and R ⁴ is a substituted or unsubstituted monovalent hydrocarbon having 1 to 20 carbon atoms, or R ³ and R ⁴ are bonded to each other by combining R ³ and R ⁴ with each other. It is preferably a part of a ring structure having 3 to 20 ring members formed together with a nitrogen atom, and R ³ and R ⁴ are substituted or unsubstituted monovalent hydrocarbon having 1 to 20 carbon atoms, Or, it is more preferable that R ³ and R ⁴ are part of a ring structure having 3 to 20 ring members formed together with the nitrogen atom to which they are combined with each other.

When the monovalent hydrocarbon group of R ³ and R ⁴ is a chain hydrocarbon group or an alicyclic hydrocarbon group, an unsubstituted chain hydrocarbon group or an unsubstituted alicyclic hydrocarbon group It is preferable that

At least one of R ¹ , R ³ and R ⁴ has an aromatic ring, and is bonded to the nitrogen atom in the above formula (1) at the carbon atom of the aromatic ring.

As the lower limit of n, 2 is preferable. As an upper limit of n, 5 is preferable and 3 is more preferable.

Examples of the compound [A1] include compounds represented by the following formulas (i1-1) to (i1-10) (hereinafter also referred to as “compounds (i1-1) to (i1-10)”). .

Of these, compounds (i1-1) to (i1-4) are preferred.

[[A2] Compound]
[A2] The compound is a compound represented by the above formula (2).

Examples of the divalent hydrocarbon group having 1 to 20 carbon atoms represented by R ^{2 ′} include those exemplified as the n-valent hydrocarbon group having 1 to 70 carbon atoms of R ^{1 in} the above formula (1). , N is 2 and the group has 1 to 20 carbon atoms.

Examples of the substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms represented by R ^{3 ′} include, for example, monovalent hydrocarbon having 1 to 20 carbon atoms exemplified as R ³ in the above formula (1). Examples thereof include the same group as the group.

Examples of the substituent of the divalent hydrocarbon group of R ^{2 ′ and} the monovalent hydrocarbon group of R ^{3 ′} include the groups exemplified as the substituent of the n-valent hydrocarbon group of R1 in the above formula (1) The same group etc. are mentioned.

R ^{2 ′} is preferably a substituted or unsubstituted divalent hydrocarbon group, and more preferably a substituted or unsubstituted arenediyl group.
R ^{3 ′} is preferably a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms, and more preferably an unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms.

At least one of R ^{2 ′} and R ^{3 ′} has an aromatic ring, and is bonded to the nitrogen atom in the above formula (2) at the carbon atom of the aromatic ring.

As the lower limit of m, 2 is preferable and 3 is more preferable. As an upper limit of m, 6 is preferable and 5 is more preferable.

Examples of the compound [A2] include compounds represented by the following formulas (i2-1) to (i2-5) (hereinafter also referred to as “compounds (i2-1) to (i2-5)”). .

The lower limit of the molecular weight of the [A] compound is preferably 300, more preferably 400, and even more preferably 500. The upper limit of the molecular weight is preferably 4,000, more preferably 2,000, and further preferably 1,500. By setting the molecular weight of the compound [A] within the above range, the film defect suppression property of the resist underlayer film can be further improved. [A] A compound can be used individually by 1 type or in combination of 2 or more types. [A] When there are two or more compounds, the molecular weight of the [A] compound refers to the number average molecular weight.

[[A] Compound Synthesis Method]
The compound [A] can be synthesized by a known method. The compound [A1] is, for example, a method in which an aldehyde compound such as 1-pyrenecarbaldehyde and an aromatic amine compound such as N, N-diethylaniline are subjected to dehydration condensation in the presence of an acid such as sulfuric acid, N, N′— An aromatic secondary amine compound such as di-p-tolyl-3,3′-dimethylbenzidine, an aromatic halide such as 4-ethyliodobenzene, copper powder and a base such as potassium carbonate in the presence of 3 A method of forming a secondary amino group, a fluorene compound such as 1,3,5-tri (fluoren-2-yl) benzene and an aldehyde compound such as N, N-dimethylaminobenzaldehyde, an ammonium salt such as tetrabutylammonium bromide And a method of dehydration condensation in the presence of a base such as sodium hydroxide. The [A2] compound is, for example, 2 such as 5,11,17,23-tetra-t-butyl-25,26,27,28-tetramethoxy-2,8,14,20-tetraazacalix [4] arene. Synthesize a tertiary amino group-containing azacalixarene compound with an organic halide such as butyl iodide in the presence of a base such as 2,6-t-butyl-4-methylpyridine. be able to.

The upper limit of the hydrogen atom content constituting the [A] compound is preferably 12.0% by mass, more preferably 11.0% by mass, and even more preferably 10.0% by mass. As a minimum of the content rate of the above-mentioned hydrogen atom, it is 0.1 mass%, for example. [A] By making the hydrogen atom content rate which comprises a compound into the said range, the heat resistance of a resist underlayer film can be improved more. [A] The content of hydrogen atoms constituting the compound is a value calculated from the molecular formula of the [A] compound.

The lower limit of the content ratio of the [A] compound is preferably 50% by mass, more preferably 70% by mass, and still more preferably 85% by mass with respect to all components other than the [B] solvent of the composition. The upper limit of the content is, for example, 100% by mass.

The lower limit of the content ratio of the [A] compound in the composition is preferably 1% by mass, more preferably 3% by mass, and still more preferably 5% by mass. As an upper limit of the said content rate, 50 mass% is preferable, 30 mass% is more preferable, and 15 mass% is further more preferable.

<[B] Solvent>
[B] A solvent will not be specifically limited if it can melt | dissolve or disperse | distribute the [A] compound and the arbitrary component contained as needed.

[B] Examples of the solvent include alcohol solvents, ketone solvents, ether solvents, ester solvents, nitrogen-containing solvents, and the like. [B] A solvent can be used individually by 1 type or in combination of 2 or more types.

Examples of the alcohol solvent include monoalcohol solvents such as methanol, ethanol and n-propanol, and polyhydric alcohol solvents such as ethylene glycol and 1,2-propylene glycol.

Examples of ketone solvents include chain ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone, and cyclic ketone solvents such as cyclohexanone.

Examples of ether solvents include chain ether solvents such as n-butyl ether, cyclic ether solvents such as tetrahydrofuran, and polyhydric alcohol partial ether solvents such as diethylene glycol monomethyl ether.

Examples of ester solvents include carbonate solvents such as diethyl carbonate, acetic acid monoester solvents such as methyl acetate and ethyl acetate, lactone solvents such as γ-butyrolactone, acetic acid diethylene glycol monomethyl ether, and acetic acid propylene glycol monomethyl ether. Examples thereof include monohydric alcohol partial ether carboxylate solvents, and lactic acid ester solvents such as methyl lactate and ethyl lactate.

Examples of the nitrogen-containing solvent include chain nitrogen-containing solvents such as N, N-dimethylacetamide and cyclic nitrogen-containing solvents such as N-methylpyrrolidone.

[B] The solvent preferably contains an ester solvent or a ketone solvent. As the ester solvent, an ester solvent having a glycol structure is more preferable from the viewpoint of improving coatability.

Examples of the ester solvent having a glycol structure include propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, and propylene glycol monopropyl ether acetate. Among these, propylene glycol monomethyl ether acetate is particularly preferable.

<Optional component>
The composition may contain an oxidizing agent, a crosslinking agent, an acid generator, a surfactant, an adhesion assistant, and the like as optional components. These optional components can be used alone or in combination of two or more.

[Oxidant]
The oxidizing agent is a component that promotes crosslinking of the [A] compound by an oxidation reaction. When the composition contains an oxidizing agent, the crosslinking reaction of the [A] compound is promoted, and the hardness of the resist underlayer film to be formed can be further increased. An oxidizing agent can be used individually by 1 type or in combination of 2 or more types.

Examples of the oxidizing agent include oxopiperidinium salt compounds such as 4-acetamido-2,2,6,6-tetramethyl-1-oxopiperidinium trifluoromethanesulfonate, bis (4-t-butylphenyl) iodonium trifluoro Examples include onium salt compounds such as romethanesulfonate.

When the said composition contains an oxidizing agent, as an upper limit of content of an oxidizing agent, 30 mass parts is preferable with respect to 100 mass parts of [A] compounds, and 10 mass parts is more preferable. As a minimum of the above-mentioned content, 1 mass part is preferred and 3 mass parts is more preferred.

[Crosslinking agent]
The cross-linking agent is a component that forms a cross-linking bond between components such as the compound [A] in the composition by the action of heat or acid, or that forms a cross-linked structure by itself. When the composition contains a crosslinking agent, the hardness of the resist underlayer film to be formed can be increased. A crosslinking agent can be used individually by 1 type or in combination of 2 or more types.

Examples of the crosslinking agent include polyfunctional (meth) acrylate compounds, epoxy compounds, hydroxymethyl group-substituted phenol compounds, alkoxyalkyl group-containing phenol compounds, and compounds having an alkoxyalkylated amino group.

When the said composition contains a crosslinking agent, as an upper limit of content of a crosslinking agent, 100 mass parts is preferable with respect to 100 mass parts of [A] compounds, and 50 mass parts is more preferable. As a minimum of the above-mentioned content, 5 mass parts is preferred and 10 mass parts is more preferred.

[Method for Preparing Composition]
In the composition, the [A] compound, the [B] solvent, and, if necessary, optional components are mixed in a predetermined ratio, and preferably the obtained mixture is filtered through a membrane filter of 0.1 μm or less. Can be prepared. The lower limit of the concentration of the composition is preferably 0.1% by mass, more preferably 1% by mass, further preferably 3% by mass, and particularly preferably 5% by mass. As an upper limit of the said density | concentration, 50 mass% is preferable, 30 mass% is more preferable, 20 mass% is further more preferable, 15 mass% is especially preferable.

<Resist underlayer film>
The resist underlayer film is formed from the composition. Since the resist underlayer film is formed from the composition, it has excellent heat resistance, film defect suppression properties, and etching resistance.

<Method for forming resist underlayer film>
The method of forming the resist underlayer film includes a step of coating the composition directly or indirectly on a substrate (hereinafter, also referred to as “coating step”), and a coating film formed by the above coating step. A heating step (hereinafter also referred to as “heating step”).

According to the method for forming the resist underlayer film, since the above-described composition is used, it is possible to form a resist underlayer film having excellent heat resistance, film defect suppression properties, and etching resistance. Hereinafter, each step will be described.

[Coating process]
In this step, the composition is applied directly or indirectly to the substrate.

Examples of the substrate include a silicon wafer and a wafer coated with aluminum. Moreover, the coating method of the said composition is not specifically limited, For example, it can implement by appropriate methods, such as spin coating, cast coating, and roll coating.

[Heating process]
This step is an arbitrary step of heating the coating film formed by the coating step.

The heating of the coating film is usually performed in the air, but may be performed in a nitrogen atmosphere. As a minimum of heating temperature of the above-mentioned coating film, 100 ° C is preferred and 200 ° C is preferred. As an upper limit of the heating temperature of the said coating film, 600 degreeC is preferable and 500 degreeC is preferable. As a minimum of the heating time of the above-mentioned coating film, 15 seconds are preferred and 30 seconds are preferred. The upper limit of the heating time of the coating film is preferably 600 seconds, and more preferably 300 seconds.

Before the coating film is heated at a temperature of 200 ° C. or higher and 600 ° C. or lower, it may be preheated at a temperature of 60 ° C. or higher and 150 ° C. or lower. As a minimum of heating time in preliminary heating, 10 seconds are preferred and 30 seconds are more preferred. The upper limit of the heating time is preferably 300 seconds, and more preferably 180 seconds.

The lower limit to the average thickness of the resist underlayer film to be formed is preferably 30 nm, more preferably 50 nm, and even more preferably 100 nm. The upper limit of the average thickness is preferably 3,000 nm, more preferably 2,000 nm, and even more preferably 500 nm.

<Pattern formation method>
The pattern forming method includes a step of applying the composition directly or indirectly to the substrate (coating step) and a step of forming a resist pattern directly or indirectly on the resist underlayer film formed by the coating step. (Hereinafter also referred to as “resist pattern forming step”) and a step of performing etching using the resist pattern as a mask (hereinafter also referred to as “etching step”).

According to the pattern forming method, since the resist underlayer film having excellent heat resistance, etching resistance and film defect suppression property is used, a patterned substrate having a good pattern shape can be obtained.

The pattern forming method may include a step of forming a silicon-containing film directly or indirectly on the resist underlayer film (hereinafter also referred to as “silicon-containing film forming step”) as necessary. Hereinafter, each step will be described.

[Coating process]
In this step, the composition is applied directly or indirectly to the substrate. The pattern forming method usually includes a step of heating the coating film formed by the coating step (hereinafter also referred to as “heating step”). Thereby, a resist underlayer film is formed. This step is the same as the coating step in the resist underlayer film forming method described above.

[Heating process]
In this step, the coating film formed by the coating step may be heated. This step is the same as the heating step in the method for forming the resist underlayer film described above.

[Silicon-containing film formation process]
In this step, a silicon-containing film is formed directly or indirectly on the resist underlayer film formed by the coating step.

The silicon-containing film can be formed by coating a composition for forming a silicon-containing film, chemical vapor deposition (CVD), atomic layer deposition (ALD), or the like. Examples of a method for forming a silicon-containing film by coating a silicon-containing film-forming composition include, for example, a coating film formed by directly or indirectly applying a silicon-containing film-forming composition to the resist underlayer film. Can be cured by exposure and / or heating. As a commercial item of the said composition for silicon-containing film formation, "NFC SOG01", "NFC SOG04", "NFC SOG080" (above, JSR Corporation) etc. can be used, for example. A silicon oxide film, a silicon nitride film, a silicon oxynitride film, and an amorphous silicon film can be formed by chemical vapor deposition (CVD) or atomic layer deposition (ALD).

Examples of the radiation used for the exposure include electromagnetic waves such as visible light, ultraviolet rays, far ultraviolet rays, X-rays and γ rays, particle beams such as electron beams, molecular beams and ion beams.

As a minimum of the temperature at the time of heating a coating film, 90 ° C is preferred, 150 ° C is more preferred, and 200 ° C is still more preferred. As an upper limit of the said temperature, 550 degreeC is preferable, 450 degreeC is more preferable, and 300 degreeC is further more preferable. As a minimum of time to heat a coating film, 10 seconds are preferred and 30 seconds are more preferred. The upper limit of the time is preferably 600 seconds, and more preferably 300 seconds. As a minimum of average thickness of a silicon content film formed, 1 nm is preferred, 10 nm is more preferred, and 20 nm is still more preferred. The upper limit of the average thickness is preferably 20,000 nm, more preferably 1,000 nm, and even more preferably 100 nm.

[Resist pattern formation process]
In this step, a resist pattern is formed directly or indirectly on the resist underlayer film. Examples of the method for performing this step include a method using a resist composition.

In the method using the resist composition, specifically, after the resist composition is applied so that the obtained resist film has a predetermined thickness, the solvent in the coating film is volatilized by pre-baking. Then, a resist film is formed.

Examples of the resist composition include a positive or negative chemically amplified resist composition containing a radiation-sensitive acid generator, a positive resist composition containing an alkali-soluble resin and a quinonediazide-based photosensitizer, and an alkali-soluble composition. Examples thereof include a negative resist composition containing a resin and a crosslinking agent.

The lower limit of the concentration of the resist composition is preferably 0.3% by mass, and more preferably 1% by mass. As an upper limit of the said density | concentration, 50 mass% is preferable and 30 mass% is more preferable. In addition, the resist composition is generally filtered through a filter having a pore size of 0.2 μm or less, for example, and used for forming a resist film. In this step, a commercially available resist composition can be used as it is.

The coating method of the resist composition is not particularly limited, and examples thereof include a spin coating method. The pre-baking temperature is appropriately adjusted according to the type of resist composition to be used, but the lower limit of the temperature is preferably 30 ° C., more preferably 50 ° C. As an upper limit of the said temperature, 200 degreeC is preferable and 150 degreeC is more preferable. The lower limit of the pre-baking time is preferably 10 seconds, and more preferably 30 seconds. The upper limit of the time is preferably 600 seconds, and more preferably 300 seconds.

Next, the formed resist film is exposed by selective radiation irradiation. As radiation used for exposure, depending on the type of radiation-sensitive acid generator used in the resist composition, electromagnetic waves such as visible light, ultraviolet light, far ultraviolet light, X-rays, γ-rays, electron beams, molecular beams, It is appropriately selected from particle beams such as ion beams. Among these, far ultraviolet rays are preferable, and KrF excimer laser light (248 nm), ArF excimer laser light (193 nm), F ₂ excimer laser light (wavelength 157 nm), Kr ₂ excimer laser light (wavelength 147 nm), ArKr excimer laser light. (Wavelength 134 nm) or extreme ultraviolet light (wavelength 13.5 nm, etc., EUV) is more preferable, and KrF excimer laser light, ArF excimer laser light, or EUV is more preferable.

After the exposure, post-baking can be performed to improve resolution, pattern profile, developability, and the like. The post-baking temperature is appropriately adjusted according to the type of resist composition to be used, but the lower limit of the temperature is preferably 50 ° C., more preferably 70 ° C. As an upper limit of the said temperature, 200 degreeC is preferable and 150 degreeC is more preferable. The lower limit of the post-bake time is preferably 10 seconds, and more preferably 30 seconds. The upper limit of the time is preferably 600 seconds, and more preferably 300 seconds.

Next, the exposed resist film is developed with a developer to form a resist pattern. This development may be alkali development or organic solvent development. As the developer, in the case of alkali development, for example, sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, methyl Diethylamine, dimethylethanolamine, triethanolamine, tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide, pyrrole, piperidine, choline, 1,8-diazabicyclo [5.4.0] -7-undecene, 1,5 -Basic aqueous solutions such as diazabicyclo [4.3.0] -5-nonene. An appropriate amount of a water-soluble organic solvent such as alcohols such as methanol and ethanol, a surfactant, and the like can be added to these basic aqueous solutions. In the case of organic solvent development, examples of the developer include various organic solvents exemplified as the [B] solvent of the above composition.

After development with the developer, the resist pattern is formed by washing and drying.

As a method for performing the resist pattern forming step, in addition to the method using the resist composition described above, a method using a nanoimprint method, a method using a self-organizing composition, and the like can also be used.

[Etching process]
In this step, etching is performed using the resist pattern as a mask. The number of times of etching may be one time or a plurality of times, that is, the etching may be sequentially performed using a pattern obtained by etching as a mask, but a plurality of times is preferable from the viewpoint of obtaining a pattern having a better shape. When performing the etching a plurality of times, the etching is sequentially performed in the order of the silicon-containing film, the lower layer film, and the substrate. Examples of the etching method include dry etching and wet etching. Among these, dry etching is preferable from the viewpoint of improving the shape of the substrate pattern. For this dry etching, for example, gas plasma such as oxygen plasma is used. After the etching, a patterned substrate having a predetermined pattern is obtained.

Dry etching can be performed using, for example, a known dry etching apparatus. The etching gas used for dry etching can be appropriately selected depending on the mask pattern, the elemental composition of the film to be etched, and the like. For example, CHF ₃ , CF ₄ , C ₂ F ₆ , C ₃ F ₈ , SF ₆ Fluorine gas such as Cl ₂ , chlorine gas such as Cl ₂ and BCl ₃ , oxygen gas such as O ₂ , O ₃ and H ₂ O, H ₂ , NH ₃ , CO, CO ₂ , CH ₄ and C ₂ H ₂ Reducing gases such as C ₂ H ₄ , C ₂ H ₆ , C ₃ H ₄ , C ₃ H ₆ , C ₃ H ₈ , HF, HI, HBr, HCl, NO, NH ₃ , BCl ₃ , He, N _2. An inert gas such as Ar is used. These gases can also be mixed and used. When the substrate is etched using the resist underlayer film pattern as a mask, a fluorine-based gas is usually used. For example, the mask pattern of the resist underlayer film is used in a process of forming a via hole in a silicon oxide film (interlayer insulating film) on the substrate by fluorine-based gas etching, and therefore is required to have excellent fluorine-based gas etching resistance.

Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. The measuring method of various physical property values is shown below.

[Average thickness of resist underlayer]
The average thickness of the resist underlayer film was measured using a spectroscopic ellipsometer (“M2000D” manufactured by JA WOOLLAM).

<Synthesis of [A] Compound>
Compounds (A-1) to (A-5) as [A] compounds were synthesized by the following method.

[Synthesis Example 1-1]
Under a nitrogen atmosphere, 20.0 g of 1-pyrenecarbaldehyde and 259.3 g of N, N-diethylaniline were charged in a three-necked flask equipped with a thermometer, a condenser and a magnetic stirrer and dissolved at room temperature. 0.4 g of 96 mass% sulfuric acid was added dropwise over 30 minutes. After completion of dropping, the mixture was heated to 60 ° C. and reacted for 10 hours. After completion of the reaction, the reaction solution was added to a large amount of water, and then extracted by adding 60 g of methyl isobutyl ketone (MIBK) and 30 g of tetrahydrofuran (THF). After washing three times with water, the organic phase was poured into 600 g of hexane and reprecipitated. The resulting precipitate was dried under reduced pressure at 60 ° C. overnight to obtain the following compound (A-1) (molecular weight 511).

[Synthesis Example 1-2]
In a three-necked flask equipped with a thermometer, a condenser and a magnetic stirrer, 3.93 g of N, N′-di-p-tolyl-3,3′-dimethylbenzidine and 4.73 g of 4-ethyliodobenzene were added under an argon atmosphere. Then, 0.1 g of copper powder, 1.38 g of potassium carbonate and 20 mL of nitrobenzene were added, stirred while bubbling argon, and refluxed for 24 hours while removing water by azeotropy with nitrobenzene. After the reaction solution was filtered, nitrobenzene was distilled off and purified by alumina column chromatography to obtain the following compound (A-2) (molecular weight 601).

[Synthesis Example 1-3]
In a nitrogen atmosphere, 20.0 g of 2-acetylfluorene and 20.0 g of m-xylene were charged in a reaction vessel and dissolved at 110 ° C. Next, 3.14 g of dodecylbenzenesulfonic acid was added and heated to 140 ° C. to react for 16 hours. After completion of the reaction, the reaction solution was diluted by adding 80 g of xylene, cooled to 50 ° C., and poured into 500 g of methanol for reprecipitation. The obtained precipitate was washed with toluene, and then the solid was collected with a filter paper and dried to obtain a compound (b-1) represented by the following formula (b-1).

Under a nitrogen atmosphere, 10.0 g of the above compound (b-1), 8.23 g of N, N-dimethylaminobenzaldehyde and 50 g of toluene were added to the reaction vessel and stirred, and then 25.2 g of a 50 mass% aqueous sodium hydroxide solution and 1.7 g of tetrabutylammonium bromide was added and reacted at 92 ° C. for 12 hours. After cooling the reaction solution to 50 ° C., 25 g of tetrahydrofuran was added. After removing the aqueous phase, 50 g of a 1% by mass oxalic acid aqueous solution was added to perform liquid separation extraction, and the resultant was poured into hexane for reprecipitation. The resulting precipitate was collected with a filter paper and dried to obtain the following compound (A-3) (molecular weight 964).

[Synthesis Example 1-4]
Under a nitrogen atmosphere, 5.00 g of 2,7-di- (N, N-diphenylamino) -9H-fluorene, 3.63 g of 1-bromohexane and 50 g of toluene were added to the reaction vessel and stirred, and then 50 masses. 25.2 g of a sodium hydroxide aqueous solution and 1.7 g of tetrabutylammonium bromide were added and reacted at 92 ° C. for 12 hours. After cooling the reaction solution to 50 ° C., 25 g of tetrahydrofuran was added. After removing the aqueous phase, 50 g of a 1% by mass oxalic acid aqueous solution was added to perform liquid separation extraction, and the resultant was poured into hexane for reprecipitation. The resulting precipitate was collected with a filter paper and dried to obtain the following compound (A-4) (molecular weight 669).

[Synthesis Example 1-5]
In a reaction vessel, 10 g of 5,11,17,23-tetra-t-butyl-25,26,27,28-tetramethoxy-2,8,14,20-tetraazacalix [4] arene in a nitrogen atmosphere Then, 20 g of butyl iodide, 11.5 g of 2,6-t-butyl-4-methylpyridine and 100 g of N, N-dimethylacetamide were charged and reacted at 40 ° C. for 48 hours. After cooling, each was washed with 60 g of cyclohexanone, 40 g of MIBK, and 5% by mass hydrochloric acid, and MIBK was distilled off and diluted with cyclohexanone to obtain a 10% by mass solution of the following compound (A-5) (molecular weight 933).

[Synthesis Example 2-1]
A resin represented by the following formula (a-1) was synthesized by the following method. Under a nitrogen atmosphere, 250.0 g of 4-cresol, 125.0 g of 37% by mass formalin and 2 g of oxalic anhydride were added to the reaction vessel, reacted at 100 ° C. for 3 hours, and at 180 ° C. for 1 hour, and then under reduced pressure. Unreacted monomer was removed to obtain a resin represented by the following formula (a-1).

<Preparation of composition for forming resist underlayer film>
The [A] compound, [B] solvent, [C] oxidizing agent and [D] cross-linking agent used for the preparation of the resist underlayer film forming composition are shown below.

[[A] Compound]
Example: Compounds (A-1) to (A-5) synthesized above
Comparative example: Resin (a-1) synthesized above

[[B] solvent]
B-1: Propylene glycol monomethyl ether acetate B-2: Cyclohexanone

[[C] oxidizing agent]
C-1: 4-acetamido-2,2,6,6-tetramethyl-1-oxopiperidinium trifluoromethanesulfonate (compound represented by the following formula (C-1))
C-2: Bis (4-t-butylphenyl) iodonium trifluoromethanesulfonate (compound represented by the following formula (C-2))

[[D] Crosslinking agent]
D-1: 1,3,4,6-tetrakis (methoxymethyl) glycoluril (compound represented by the following formula (D-1))

[Example 1-1]
[A] 10 parts by mass of (A-1) as a compound was dissolved in 90 parts by mass of (B-1) as a [B] solvent. The obtained solution was filtered through a membrane filter having a pore diameter of 0.1 μm to prepare a resist underlayer film forming composition (J-1).

[Examples 1-2 to 1-10 and Comparative Example 1-1]
Resist underlayer film forming compositions (J-2) to (J-10) and (CJ) were prepared in the same manner as in Example 1-1 except that the components of the types and contents shown in Table 1 were used. -1) was prepared. “-” In Table 1 indicates that the corresponding component was not used.

<Formation of resist underlayer film>
[Examples 2-1 to 2-10 and Comparative Example 2-1]
The prepared resist underlayer film forming composition was coated on a silicon wafer (substrate) by a spin coating method using a spin coater (“CLEAN TRACK ACT12” from Tokyo Electron Ltd.). Next, after heating (baking) at a heating temperature (° C.) and a heating time (sec) shown in Table 2 below in an air atmosphere, the resist underlayer film having an average thickness of 200 nm is cooled at 23 ° C. for 60 seconds. The substrate with the resist underlayer film in which the resist underlayer film was formed on the substrate was obtained.

<Evaluation>
Using the obtained composition for forming a resist underlayer film and a substrate with a resist underlayer film, the following items were evaluated by the following methods. The evaluation results are shown in Table 2 below.

[Heat-resistant]
The prepared resist underlayer film forming composition is applied onto a silicon wafer having a diameter of 8 inches by spin coating, and baked at 250 ° C. for 60 seconds in an air atmosphere to form a resist underlayer film. Thus, a substrate with a resist underlayer film was obtained. Next, the resist underlayer film of the substrate with the resist underlayer film is scraped to recover the powder, and the resist underlayer film powder is used for measurement by a TG-DTA apparatus ("TG-DTA2000SR" from NETZSCH). The mass before heating was measured. Next, using the above TG-DTA apparatus, the sample was heated to 400 ° C. at a temperature increase rate of 10 ° C./min in a nitrogen atmosphere, and the mass of the powder at 400 ° C. was measured. And mass reduction rate (%) was measured by the following formula, and this mass reduction rate was used as a measure of heat resistance.
M _L = {(m1−m2) / m1} × 100
Here, in the above formula, _{M L} is a mass reduction rate (%), m1 is the pre-heating the mass (mg), m @ 2 is the mass (mg) at 400 ° C..
The heat resistance is better as the mass reduction rate of the powder as the sample is smaller, because there are fewer sublimates and decomposition products of the resist underlayer film that are generated when the resist underlayer film is heated. That is, the smaller the mass reduction rate, the higher the heat resistance. The heat resistance is “A” (very good) when the mass reduction rate is less than 5%, “B” (good) when it is 5% or more and less than 10%, and “C” (when it is 10% or more). Bad).

[Etching resistance]
The resist underlayer film in the substrate with the resist underlayer film obtained above was subjected to CF ₄ / Ar = 110/440 sccm, PRESS. Using an etching apparatus (“TACTRAS” of Tokyo Electron Ltd.). = 30 MT, HF RF (High Frequency Power for Plasma Generation) = 500 W, LF RF (High Frequency Power for Bias) = 3000 W, DCS = -150 V, RDC (Gas Center Flow Ratio) = 50%, 30 sec. The etching rate (nm / min) was calculated from the average thickness of the resist underlayer films before and after. Next, a ratio with respect to Comparative Example 2-1 was calculated based on the etching rate of Comparative Example 2-1, and used as a measure of etching resistance. The etching resistance was evaluated as “A” (good) when the ratio was 0.98 or more and less than 1.00, and “B” (bad) when the ratio was 1.00 or more. “-” In the column of etching resistance in Table 2 indicates that it is a criterion for evaluation.

[Membrane defect suppression]
A silicon-containing film-forming composition (“NFC SOG080” from JSR Co., Ltd.) was applied on the obtained substrate with a resist underlayer film by a spin coating method, and then at 200 ° C. for 60 seconds in an air atmosphere. Heating (firing) was performed to form a silicon-containing film having an average thickness of 50 nm to obtain a substrate with a silicon-containing film. The obtained substrate with a silicon-containing film was further heated (baked) at 450 ° C. for 60 seconds, and then the surface of the silicon-containing film was observed with an optical microscope. Film defect suppression was evaluated as “A” (good) when no cracking or peeling of the silicon-containing film was observed, and “B” (bad) when cracking or peeling of the silicon-containing film was observed. .

As can be seen from the results in Table 2, the resist underlayer film formed from the resist underlayer film forming composition of the example is excellent in heat resistance, etching resistance, and film defect suppression. On the other hand, the resist underlayer film formed from the composition for forming a resist underlayer film of the comparative example has poor heat resistance and film defect suppression properties, and has poor etching resistance.

[Resist pattern formation]
On the substrate with the resist underlayer film formed using the resist underlayer film forming compositions (J-1) to (J-10) obtained above, a silicon-containing film forming composition (“JSR Co., Ltd.” NFC SOG080 ") was applied by a spin coating method, and then heated (fired) at 200 ° C for 60 seconds in an air atmosphere to form a silicon-containing film having an average thickness of 50 nm, thereby obtaining a substrate with a silicon-containing film. Next, a resist composition for ArF (“AR1682J” from JSR Co., Ltd.) is applied on the silicon-containing film by a spin coating method, and heated (baked) at 130 ° C. for 60 seconds in an air atmosphere. A resist film having an average thickness of 200 nm was formed. Thereafter, the resist film was passed through a one-to-one line-and-space mask pattern with a target size of 100 nm using a Nikon ArF excimer laser exposure apparatus (lens numerical aperture 0.78, exposure wavelength 193 nm). Then, after changing the exposure amount, the exposure was performed (heating) at 130 ° C. for 60 seconds in an air atmosphere, and using an aqueous 2.38 mass% tetramethylammonium hydroxide (TMAH) solution at 25 ° C. for 1 minute. Developed, washed with water and dried. By observing the resist film with a scanning electron microscope (“CG-4000” manufactured by Hitachi High-Technologies Corporation), a line-and-space resist pattern having a line width of 30 nm to 100 nm and having a line width of 30 nm to 100 nm. It was confirmed that was formed.

Claims

A compound having an aromatic ring and a nitrogen atom bonded to a carbon atom of the aromatic ring;
Containing a solvent and
A composition for forming a resist underlayer film, wherein the compound is represented by the following formula (1) or the following formula (2).

(In Formula (1), R 1 is a substituted or unsubstituted n-valent hydrocarbon group having 1 to 70 carbon atoms. R 3 and R 4 are each independently a substituted or unsubstituted carbon number. A monovalent hydrocarbon group of 1 to 20 or a hydrogen atom, or a part of a ring structure of 3 to 20 ring members composed of R 3 and R 4 together with the nitrogen atom to which they are bonded However, at least one of R 1 , R 3 and R 4 has an aromatic ring, and is a group bonded to the nitrogen atom in the above formula (1) at a carbon atom of the aromatic ring. It is an integer of ~ 10. When n is 2 or more, the plurality of R 3 are the same or different, and the plurality of R 4 are the same or different.
In the formula (2), R 2 ′ is a substituted or unsubstituted divalent hydrocarbon group having 1 to 20 carbon atoms. R 3 ′ is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms or a hydrogen atom. However, at least one of R 2 ′ and R 3 ′ has an aromatic ring and is a group bonded to the nitrogen atom in the above formula (2) at the carbon atom of the aromatic ring. m is an integer of 1 to 10. When m is 2 or more, the plurality of R 2 ′ are the same or different and the plurality of R 3 ′ are the same or different. )
In the above formula (1), at least one of R 3 and R 4 is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms, or R 3 and R 4 are R 3 and R 4 are The composition for forming a resist underlayer film according to claim 1, wherein the composition is a part of a ring structure having 3 to 20 ring members constituted together with nitrogen atoms to which they are bonded.
R 3 and R 4 in the above formula (1) are substituted or unsubstituted monovalent hydrocarbon groups having 1 to 20 carbon atoms, or nitrogen atoms to which R 3 and R 4 are combined with each other and bonded to each other The composition for forming a resist underlayer film according to claim 2, wherein the composition is a part of a ring structure having 3 to 20 ring members.
4. The resist underlayer film forming composition according to claim 1, wherein n in the above formula (1) is 2 or more.
The composition for forming a resist underlayer film according to any one of claims 1 to 4, wherein R 1 in the formula (1) includes an aromatic carbocyclic ring.
Resist underlayer film forming composition according to claim 5 wherein the nitrogen atom in the formula (1) is attached to an aromatic carbocyclic ring R 1.
The composition for forming a resist underlayer film according to any one of claims 1 to 6, wherein the compound has a molecular weight of 4,000 or less.
The composition for forming a resist underlayer film according to any one of claims 1 to 7, wherein a content ratio of the compound is 50% by mass or more based on all components other than the solvent.
A resist underlayer film formed from the resist underlayer film forming composition according to any one of claims 1 to 8.
A step of applying a resist underlayer film forming composition directly or indirectly to a substrate,
The resist underlayer film forming composition is
An aromatic ring and a compound having a nitrogen atom bonded to a carbon atom of the aromatic ring, and a solvent,
A method for forming a resist underlayer film, wherein the compound is represented by the following formula (1) or the following formula (2).

(In Formula (1), R 1 is a substituted or unsubstituted n-valent hydrocarbon group having 1 to 70 carbon atoms. R 3 and R 4 are each independently a substituted or unsubstituted carbon number. A monovalent hydrocarbon group of 1 to 20 or a hydrogen atom, or a part of a ring structure of 3 to 20 ring members composed of R 3 and R 4 together with the nitrogen atom to which they are bonded However, at least one of R 1 , R 3 and R 4 has an aromatic ring, and is a group bonded to the nitrogen atom in the above formula (1) at a carbon atom of the aromatic ring. It is an integer of ~ 10. When n is 2 or more, the plurality of R 3 are the same or different, and the plurality of R 4 are the same or different.
In the formula (2), R 2 ′ is a substituted or unsubstituted divalent hydrocarbon group having 1 to 20 carbon atoms. R 3 ′ is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms or a hydrogen atom. However, at least one of R 2 ′ and R 3 ′ has an aromatic ring and is a group bonded to the nitrogen atom in the above formula (2) at the carbon atom of the aromatic ring. m is an integer of 1 to 10. When m is 2 or more, the plurality of R 2 ′ are the same or different and the plurality of R 3 ′ are the same or different. )
Applying the resist underlayer film forming composition directly or indirectly to the substrate;
Forming a resist pattern directly or indirectly with respect to the resist underlayer film formed by the coating step;
Etching using the resist pattern as a mask, and
The resist underlayer film forming composition is
An aromatic ring and a compound having a nitrogen atom bonded to a carbon atom of the aromatic ring, and a solvent,
The pattern formation method by which the said compound is represented by following formula (1) or following formula (2).

(In Formula (1), R 1 is a substituted or unsubstituted n-valent hydrocarbon group having 1 to 70 carbon atoms. R 3 and R 4 are each independently a substituted or unsubstituted carbon number. A monovalent hydrocarbon group of 1 to 20 or a hydrogen atom, or a part of a ring structure of 3 to 20 ring members composed of R 3 and R 4 together with the nitrogen atom to which they are bonded However, at least one of R 1 , R 3 and R 4 has an aromatic ring, and is a group bonded to the nitrogen atom in the above formula (1) at a carbon atom of the aromatic ring. It is an integer of ~ 10. When n is 2 or more, the plurality of R 3 are the same or different, and the plurality of R 4 are the same or different.
In the formula (2), R 2 ′ is a substituted or unsubstituted divalent hydrocarbon group having 1 to 20 carbon atoms. R 3 ′ is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms or a hydrogen atom. However, at least one of R 2 ′ and R 3 ′ has an aromatic ring and is a group bonded to the nitrogen atom in the above formula (2) at the carbon atom of the aromatic ring. m is an integer of 1 to 10. When m is 2 or more, the plurality of R 2 ′ are the same or different and the plurality of R 3 ′ are the same or different. )
Before the process of forming the resist pattern,
The pattern formation method of Claim 11 provided with the process of forming a silicon-containing film directly or indirectly with respect to the resist underlayer film formed by the said coating process.