WO2023199851A1

WO2023199851A1 - Semiconductor substrate manufacturing method, composition, and compound

Info

Publication number: WO2023199851A1
Application number: PCT/JP2023/014339
Authority: WO
Inventors: 温子永縄; 修平山田; 崇片切; 真也阿部; 大貴中津; 裕之宮内
Original assignee: Jsr株式会社
Priority date: 2022-04-13
Filing date: 2023-04-07
Publication date: 2023-10-19
Also published as: TW202406886A

Abstract

Provided are: a semiconductor substrate manufacturing method using a resist underlayer film-forming composition from which it is possible to form a film having excellent etching resistance, heat resistance, and bending resistance; a composition; and a compound. This semiconductor substrate manufacturing method comprises a step for directly or indirectly applying a resist underlayer film-forming composition on a substrate, a step for directly or indirectly forming a resist pattern on the resist underlayer film formed in the application step, and a step for performing etching by using the resist pattern as a mask. The resist underlayer film-forming composition contains a solvent and a compound represented by formula (1). (In formula (1), Ar1, Ar2, Ar3, and Ar4 each represent a substituted or unsubstituted monovalent group having an aromatic ring with 5-40 ring members, and at least one thereof has a group represented by formula (1-1) or (1-2).) (In formulae (1-1) and (1-2), Ar5, Ar6, and Ar7 each represent a substituted or unsubstituted aromatic ring that has 6-20 ring members and that forms a fused ring structure.)

Description

Manufacturing method, composition and compound of semiconductor substrate

The present invention relates to a method for manufacturing a semiconductor substrate, a composition, and a compound.

In the manufacture of semiconductor devices, for example, a multilayer resist process is used in which a resist film is formed on a substrate through a resist underlayer film such as an organic underlayer film or a silicon-containing film, and then exposed and developed to form a resist pattern. It is being In this process, a desired pattern can be formed on a semiconductor substrate by etching the resist underlayer film using this resist pattern as a mask, and further etching the substrate using the obtained resist underlayer film pattern as a mask. (See Publication No. 2004-177668).

Various studies have been conducted on materials used in such resist underlayer film forming compositions (see International Publication No. 2011/108365).

Japanese Patent Application Publication No. 2004-177668 International Publication No. 2011/108365

In the multilayer resist process, the organic underlayer film as the resist underlayer film is required to have etching resistance, heat resistance, and bending resistance.

The present invention has been made based on the above circumstances, and its object is to provide a method for manufacturing a semiconductor substrate using a composition for forming a resist underlayer film that can form a film having excellent etching resistance, heat resistance, and bending resistance. , compositions and compounds.

In one embodiment, the present invention provides:
a step of directly or indirectly applying a resist underlayer film forming composition to the substrate;
forming a resist pattern directly or indirectly on the resist underlayer film formed by the coating process;
and a step of performing etching using the resist pattern as a mask,
The resist underlayer film forming composition described above is
A compound represented by the following formula (1) (hereinafter also referred to as "[A] compound"),
A solvent (hereinafter also referred to as "[B] solvent").

(In formula (1), Ar ¹ , Ar ² , Ar ³ and Ar ⁴ are each independently a monovalent group having a substituted or unsubstituted aromatic ring having 5 to 40 ring members. ^{Ar 1} , At least one of Ar ² , Ar ³ and Ar ⁴ has a group represented by the following formula (1-1) or (1-2).The following formula (1-1) or (1-2) If there are multiple groups represented by , the multiple groups may be the same or different from each other.)

(In formulas (1-1) and (1-2), X ¹ and X ² are each independently a group represented by the following formula (i), (ii), (iii) or (iv). Ar ⁵ , Ar ⁶ and Ar ⁷ each independently represent a substituted or unsubstituted ring that forms a fused ring structure with two adjacent carbon atoms in the above formulas (1-1) and (1-2). It is an aromatic ring having 6 to 20 members. L ¹ and L ² are each independently a single bond or a divalent organic group having an aromatic ring. * represents the bond with the carbon atom in the above formula (1). It is a conjugate.)

(In formula (i), R ¹ and R ² are each independently a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms.
In formula (ii), R ³ is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. R ⁴ is a monovalent organic group having 1 to 20 carbon atoms.
In formula (iii), R ⁵ is a monovalent organic group having 1 to 20 carbon atoms.
In formula (iv), R ⁶ is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. )

As used herein, "number of ring members" refers to the number of atoms constituting the ring. For example, the biphenyl ring has 12 ring members, the naphthalene ring has 10 ring members, and the fluorene ring has 13 ring members.

In one embodiment, the present invention provides:
A compound represented by the following formula (1),
A composition comprising: a solvent;

In one embodiment, the present invention provides:
The present invention relates to a compound represented by the following formula (1).

According to the method for manufacturing a semiconductor substrate, it is possible to form a resist underlayer film with excellent etching resistance, heat resistance, and bending resistance, so that a good semiconductor substrate can be obtained. According to the composition, a film having excellent etching resistance, heat resistance, and bending resistance can be formed. According to the compound, a composition capable of forming a film having excellent etching resistance, heat resistance, and bending resistance can be provided. Therefore, these can be suitably used in the production of semiconductor devices, which are expected to be further miniaturized in the future.

FIG. 3 is a schematic plan view for explaining a method for evaluating bending resistance.

Hereinafter, a method for manufacturing a semiconductor substrate, a composition, and a compound according to each embodiment of the present invention will be explained in detail. Combinations of preferred aspects in embodiments are also preferred.

《Method for manufacturing semiconductor substrate》
The method for manufacturing the semiconductor substrate includes a step of directly or indirectly coating the substrate with a composition for forming a resist underlayer film (hereinafter also referred to as a "coating step"), and a resist underlayer film formed by the above coating step. The method includes a step of directly or indirectly forming a resist pattern on the substrate (hereinafter also referred to as a "resist pattern forming step"), and a step of performing etching using the resist pattern as a mask (hereinafter also referred to as an "etching step").

According to the method for manufacturing a semiconductor substrate, the composition containing the compound described below is used as a composition for forming a resist underlayer film in the coating process, thereby producing a resist with excellent etching resistance, heat resistance, and bending resistance. Since the lower layer film can be formed, a semiconductor substrate having a good pattern shape can be manufactured.

The method for manufacturing the semiconductor substrate may further include a step of directly or indirectly forming a silicon-containing film on the resist underlayer film (hereinafter also referred to as "silicon-containing film forming step"), if necessary. .

Hereinafter, the composition and each process used in the method for manufacturing the semiconductor substrate will be explained.

<Composition>
The composition for forming a resist underlayer film contains a [A] compound and a [B] solvent. The composition may contain optional components within a range that does not impair the effects of the present invention.

By containing the [A] compound and the [B] solvent, the composition can form a film with excellent etching resistance, heat resistance, and bending resistance. Therefore, the composition can be used as a composition for forming a film. More specifically, the composition can be suitably used as a composition for forming a resist underlayer film in a multilayer resist process.

Hereinafter, each component contained in the composition will be explained.

<[A] Compound>
[A] Compound is a compound represented by the above formula (1). The composition can contain one or more [A] compounds.

In the above formula (1), the aromatic ring having 5 to 40 ring members in Ar ¹ , Ar ² , Ar ³ and Ar ⁴ (hereinafter sometimes referred to as "Ar ¹ to Ar ⁴ ") is, for example, benzene. ring, aromatic hydrocarbon rings such as naphthalene ring, anthracene ring, phenalene ring, phenanthrene ring, pyrene ring, fluorene ring, perylene ring, coronene ring, furan ring, pyrrole ring, thiophene ring, phosphole ring, pyrazole ring, oxazole ring , aromatic heterocycles such as isoxazole ring, thiazole ring, pyridine ring, pyrazine ring, pyrimidine ring, pyridazine ring, triazine ring, or combinations thereof. The aromatic ring of Ar ¹ is at least one aromatic hydrocarbon ring selected from the group consisting of a benzene ring, a naphthalene ring, an anthracene ring, a phenalene ring, a phenanthrene ring, a pyrene ring, a fluorene ring, a perylene ring, and a coronene ring. A benzene ring, a naphthalene ring, a pyrene ring or a fluorene ring is more preferable.

In the above formula (1), the monovalent group having an aromatic ring having 5 to 40 ring members represented by Ar ¹ to Ar ⁴ is a monovalent group having an aromatic ring having 5 to 40 ring members, excluding one hydrogen atom from the aromatic ring having 5 to 40 ring members. Preferred examples include such groups.

Ar ¹ to Ar ⁴ may have a substituent. Examples of the substituent include a monovalent chain hydrocarbon group having 1 to 10 carbon atoms, a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, an alkoxy group such as a methoxy group, an ethoxy group, a propoxy group, Alkoxycarbonyl groups such as methoxycarbonyl group and ethoxycarbonyl group, alkoxycarbonyloxy groups such as methoxycarbonyloxy group and ethoxycarbonyloxy group, acyl group such as formyl group, acetyl group, propionyl group, butyryl group, cyano group, nitro group Examples include.

In the above formulas (i), (ii), (iii) and (iv), R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ (hereinafter referred to as "R ¹ to R ⁶ ") Examples of monovalent organic groups having 1 to 20 carbon atoms include monovalent hydrocarbon groups having 1 to 20 carbon atoms; Examples include a group having a divalent heteroatom-containing group, a group in which part or all of the hydrogen atoms of the above hydrocarbon group are substituted with a monovalent heteroatom-containing group, or a combination thereof.

Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms include a monovalent chain hydrocarbon group having 1 to 20 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, and a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms. Examples include 6 to 20 monovalent aromatic hydrocarbon groups or combinations thereof.

In this specification, the "hydrocarbon group" includes a chain hydrocarbon group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group. This "hydrocarbon group" includes a saturated hydrocarbon group and an unsaturated hydrocarbon group. The term "chain hydrocarbon group" refers to a hydrocarbon group that does not contain a ring structure and is composed only of a chain structure, and includes both linear hydrocarbon groups and branched hydrocarbon groups. "Alicyclic hydrocarbon group" means a hydrocarbon group that contains only an alicyclic structure as a ring structure and does not contain an aromatic ring structure, and includes monocyclic alicyclic hydrocarbon groups and polycyclic alicyclic hydrocarbon groups. (However, it does not need to be composed only of an alicyclic structure, and may include a chain structure as part of it.) "Aromatic hydrocarbon group" means a hydrocarbon group containing an aromatic ring structure as a ring structure (however, it does not need to be composed only of an aromatic ring structure, and some of it may have an alicyclic structure or a chain structure). structure).

Examples of the monovalent chain hydrocarbon group having 1 to 20 carbon atoms include methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, sec-butyl group, tert-butyl group, etc. Alkyl groups; alkenyl groups such as ethenyl, propenyl and butenyl; alkynyl groups such as ethynyl, propynyl and butynyl; and the like.

Examples of the monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms include cycloalkyl groups such as cyclopentyl group and cyclohexyl group; cycloalkenyl groups such as cyclopropenyl group, cyclopentenyl group, and cyclohexenyl group; norbornyl group; Examples include bridged ring saturated hydrocarbon groups such as adamantyl group and tricyclodecyl group; bridged ring unsaturated hydrocarbon groups such as norbornenyl group and tricyclodecenyl group.

Examples of the monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms include phenyl group, tolyl group, naphthyl group, anthracenyl group, and pyrenyl group.

Examples of the heteroatom constituting the divalent or monovalent heteroatom-containing group include an oxygen atom, a nitrogen atom, a sulfur atom, a phosphorus atom, a silicon atom, a halogen atom, a boron atom, and the like. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

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

Examples of the monovalent heteroatom-containing group include a hydroxy group, a sulfanyl group, a cyano group, a nitro group, a halogen atom, a boronic acid group (-B(OH) ₂ ), or an ester structure thereof.

In the above formulas (1-1) and (1-2), Ar ⁵ , Ar ⁶ and Ar ⁷ (hereinafter sometimes referred to as "Ar ⁵ to Ar ⁷ ") are each independently represented by the above formula It is a substituted or unsubstituted aromatic ring having 6 to 20 ring members that forms a fused ring structure together with two adjacent carbon atoms in (1-1) and (1-2). The aromatic ring having 6 to 20 ring members in Ar ⁵ to Ar ⁷ is an aromatic ring corresponding to 6 to 20 ring members among the aromatic rings having 5 to 40 ring members in Ar ¹ to Ar ⁴ of the above formula (1). Preferred examples include:

Ar ⁵ to Ar ⁷ may have a substituent. As the substituent, the above-mentioned substituents that Ar ¹ to Ar ⁴ may have can be suitably employed.

In the above formulas (1-1) and (1-2), the divalent organic group having an aromatic ring in L ¹ and L ² includes two aromatic rings from Ar ¹ to Ar ⁴ having 5 to 40 ring members. A substituted or unsubstituted group (hereinafter also referred to as "group (α)") excluding a hydrogen atom is preferably mentioned. The divalent organic group having an aromatic ring represented by L ¹ and L ² is one of the group (α) and the monovalent organic group having 1 to 20 carbon atoms represented by R ¹ to R ⁶ above. It may also be a group that is a combination of groups with hydrogen atoms removed. The divalent organic group having an aromatic ring represented by L ¹ and L ² includes a substituted or unsubstituted arenediyl group having 6 to 12 ring members, a substituted or unsubstituted alkenediyl group having 2 to 10 carbon atoms, a carbon Alkyndiyl groups of 2 to 10 or a combination thereof are preferred, benzenediyl groups, naphthalenediyl groups, ethylenediyl groups, ethinediyl groups or combinations thereof are more preferred, and benzenediyl groups or a combination of benzenediyl groups and ethinediyl groups are preferred. More preferred.

The carbon atom in the above formula (1) is preferably bonded to the aromatic ring possessed by Ar ¹ to Ar ⁴ in terms of heat resistance and bending resistance.

It is preferable that at least two of the above Ar ¹ to Ar ⁴ have a group represented by the above formula (1-1) or (1-2). More preferably, at least three of Ar ¹ to Ar ⁴ have groups represented by formula (1-1) or (1-2). More preferably, all of the above Ar ¹ to Ar ⁴ have a group represented by the above formula (1-1) or (1-2).

At least one of Ar ¹ to Ar ⁴ is a substituent selected from the group consisting of a hydroxy group, a group represented by the following formula (2-1), and a group represented by the following formula (2-2). It is preferable to have at least one group. Thereby, the etching resistance and heat resistance of the resulting resist underlayer film can be improved.

(In formulas (2-1) and (2-2), R ⁷ is each independently a divalent organic group having 1 to 20 carbon atoms or a single bond. * indicates a bond with a carbon atom in an aromatic ring. It is a conjugate.)

In the above formulas (2-1) and (2-2), the divalent organic group having 1 to 20 carbon atoms represented by R ⁷ includes the above formulas (i), (ii), (iii) and ( Examples include a group obtained by removing one hydrogen atom from the monovalent organic group in R ¹ to R ⁶ in iv). R ⁷ is preferably a divalent hydrocarbon group having 1 to 10 carbon atoms such as a methanediyl group, ethanediyl group, or phenylene group, or a combination thereof and -O-; A combination with is more preferable.

Examples of the compound represented by the above formula (1) include compounds represented by the following formulas (1-1) to (1-48).

Among these, compounds represented by the above formulas (1-1) to (1-36) are preferred.

[A] The lower limit of the molecular weight of the compound is preferably 500, more preferably 600, even more preferably 800, and particularly preferably 1000. The upper limit of the molecular weight is preferably 3,000, more preferably 2,500, even more preferably 2,200, and particularly preferably 2,000. Note that the molecular weight is determined from the chemical formula.

The lower limit of the content of the [A] compound in the composition is preferably 2% by mass, more preferably 4% by mass, and even more preferably 6% by mass, based on the total mass of the [A] compound and the [B] solvent. Particularly preferred is 8% by weight. The upper limit of the content ratio is preferably 30% by mass, more preferably 25% by mass, even more preferably 20% by mass, and particularly preferably 15% by mass, based on the total mass of the compound [A] and the solvent [B].

<[A] Synthesis method of compound>
[A] Compound can be typically synthesized according to the scheme below. [A] A case where the compound has a group containing a fluorene structure in the above formula (1-1) will be explained as an example. Through a cross-coupling reaction between a boronic acid derivative (i) having an aromatic ring structure around the central carbon atom of the above formula (1) and a fluorene derivative (i-1), a compound expressed by the following formula (1-α) is obtained. [A] Compound can be synthesized. Furthermore, it is also possible to modify the carbon atom or substituent at the 9-position of the fluorene structure. Other structures include the aromatic ring structure around the central carbon of the starting material boronic acid derivative (i), the structure including substituents of the partner compound in the cross-coupling reaction, and the modification of the 9-position carbon atom of the fluorene structure. It can be synthesized by appropriately changing the structure and the like.

(In the above scheme, Ar ^a , Ar ^b , Ar ^c and Ar ^d are divalent aromatic rings. Y is -OH or -OR'. R' is a monovalent organic group. Z is a It is a leaving group.R' is a hydrogen atom or a monovalent substituent.)

<[B] Solvent>
The [B] solvent is not particularly limited as long as it can dissolve or disperse the [A] compound and optional components contained therein.

Examples of the [B] solvent include hydrocarbon solvents, ester solvents, alcohol solvents, ketone solvents, ether solvents, and nitrogen-containing solvents. [B] Solvents can be used alone or in combination of two or more.

Examples of the hydrocarbon solvent include aliphatic hydrocarbon solvents such as n-pentane, n-hexane, and cyclohexane, and aromatic hydrocarbon solvents such as benzene, toluene, and xylene.

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, diethylene glycol monomethyl acetate, and propylene glycol monomethyl ether acetate. Examples include alcohol partial ether carboxylate solvents and lactic acid ester solvents such as methyl lactate and ethyl lactate.

Examples of alcoholic solvents include monoalcoholic solvents such as methanol, ethanol, and n-propanol, and polyhydric alcoholic 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, polyhydric alcohol ether solvents such as propylene glycol dimethyl ether, and polyhydric alcohol partial ether solvents such as diethylene glycol monomethyl ether. Examples include.

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

[B] The solvent is preferably an ester solvent or a ketone solvent, more preferably a polyhydric alcohol partial ether carboxylate solvent or a cyclic ketone solvent, and even more preferably propylene glycol monomethyl ether acetate or cyclohexanone.

The lower limit of the content of the [B] solvent in the composition is preferably 50% by mass, more preferably 60% by mass, and even more preferably 70% by mass. The upper limit of the content ratio is preferably 99.9% by mass, more preferably 99% by mass, and even more preferably 95% by mass.

[Optional ingredients]
The composition may contain optional components within a range that does not impair the effects of the present invention. Examples of optional components include acid generators, crosslinking agents, surfactants, and polymers. The optional components can be used alone or in combination of two or more. The content ratio of the optional component in the composition can be determined as appropriate depending on the type of the optional component.

[Method for preparing composition]
The composition is prepared by mixing [A] the compound, [B] the solvent, and optional components in a predetermined ratio, and preferably filtering the resulting mixture using a membrane filter or the like with a pore size of 0.5 μm or less. It can be prepared by

[Coating process]
In this step, a composition for forming a resist underlayer film is applied directly or indirectly to the substrate. In this step, the above-mentioned composition is used as the resist underlayer film forming composition.

The method of applying the composition for forming a resist underlayer film is not particularly limited, and can be carried out by any suitable method such as spin coating, casting coating, roll coating, etc. A coating film is thereby formed, and a resist underlayer film is formed by volatilization of the [B] solvent.

Examples of the substrate include metal or semimetal substrates such as silicon substrates, aluminum substrates, nickel substrates, chromium substrates, molybdenum substrates, tungsten substrates, copper substrates, tantalum substrates, and titanium substrates, and among these, silicon substrates are preferred. . The substrate may be a substrate on which a silicon nitride film, an alumina film, a silicon dioxide film, a tantalum nitride film, a titanium nitride film, or the like is formed.

Examples of cases in which the composition for forming a resist underlayer film is indirectly applied to the substrate include cases in which the composition for forming a resist underlayer film is applied onto a silicon-containing film, which will be described later, formed on the substrate.

[Heating process]
The method for manufacturing the semiconductor substrate may include a step of heating the coating film formed by the above coating step. Heating the coating film promotes the formation of the resist underlayer film. More specifically, heating the coating film promotes volatilization of the [B] solvent.

Heating of the above-mentioned coating film may be performed under an air atmosphere or under a nitrogen atmosphere. The lower limit of the heating temperature is preferably 200°C, more preferably 250°C, and even more preferably 300°C. The upper limit of the heating temperature is preferably 600°C, more preferably 500°C. The lower limit of the heating time is preferably 15 seconds, more preferably 30 seconds. The upper limit of the above time is preferably 1,200 seconds, more preferably 600 seconds.

Note that the resist underlayer film may be exposed to light after the above coating step. After the above coating step, the resist underlayer film may be exposed to plasma. After the above coating step, ions may be implanted into the resist underlayer film. Exposure of the resist underlayer film improves the etching resistance of the resist underlayer film. Exposure of the resist underlayer film to plasma improves the etching resistance of the resist underlayer film. Ion implantation into the resist underlayer film improves the etching resistance of the resist underlayer film.

The radiation used for exposing the resist underlayer film is appropriately selected from electromagnetic waves such as visible light, ultraviolet rays, deep ultraviolet rays, X-rays, and γ-rays; and particle beams such as electron beams, molecular beams, and ion beams.

Examples of methods for exposing the resist underlayer film to plasma include a direct method in which the substrate is placed in each gas atmosphere and plasma is discharged. The conditions for plasma exposure are usually a gas flow rate of 50 cc/min or more and 100 cc/min or less, and a supply power of 100 W or more and 1,500 W or less.

The lower limit of the plasma exposure time is preferably 10 seconds, more preferably 30 seconds, and even more preferably 1 minute. The upper limit of the above time is preferably 10 minutes, more preferably 5 minutes, and even more preferably 2 minutes.

For example, plasma is generated in an atmosphere of a mixed gas of H ₂ gas and Ar gas. Further, in addition to H ₂ gas and Ar gas, a carbon-containing gas such as CF ₄ gas or CH ₄ gas may be introduced. Note that instead of either or both of H ₂ gas and Ar gas, CF ₄ gas, NF ₃ gas, CHF ₃ gas, CO ₂ gas, CH ₂ F ₂ gas, CH ₄ gas, and C ₄ F ₈ gas may be used. At least one of them may be introduced.

Ion implantation into the resist underlayer film involves injecting dopants into the resist underlayer film. The dopant may be selected from the group consisting of boron, carbon, nitrogen, phosphorous, arsenic, aluminum, and tungsten. The implant energy utilized to energize the dopant can range from approximately 0.5 keV to 60 keV, depending on the type of dopant utilized and the depth of implantation desired.

The lower limit of 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. Note that the method for measuring the average thickness is as described in Examples.

[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 or the heating step. Examples of the case where a silicon-containing film is indirectly formed on the resist underlayer film include a case where a surface modification film of the resist underlayer film is formed on the resist underlayer film. The surface-modified film of the resist underlayer film is, for example, a film that has a different contact angle with water from that of the resist underlayer film.

The silicon-containing film can be formed by coating a silicon-containing film-forming composition, chemical vapor deposition (CVD), atomic layer deposition (ALD), or the like. As a method for forming a silicon-containing film by coating a silicon-containing film-forming composition, for example, a coated film formed by directly or indirectly applying a silicon-containing film-forming composition to the resist underlayer film is used. , a method of curing by exposure and/or heating, and the like. As commercially available silicon-containing film-forming compositions, for example, "NFC SOG01", "NFC SOG04", "NFC SOG080" (all manufactured by JSR Corporation), etc. can be used. 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 in the exposure include electromagnetic waves such as visible light, ultraviolet rays, deep ultraviolet rays, X-rays, and γ-rays, and particle beams such as electron beams, molecular beams, and ion beams.

The lower limit of the temperature when heating the coating film is preferably 90°C, more preferably 150°C, and even more preferably 200°C. The upper limit of the above temperature is preferably 550°C, more preferably 450°C, and even more preferably 300°C.

The lower limit of the average thickness of the silicon-containing film is preferably 1 nm, more preferably 10 nm, and even more preferably 20 nm. The above upper limit is preferably 20,000 nm, more preferably 1,000 nm, and even more preferably 100 nm. The average thickness of the silicon-containing film, like the average thickness of the resist underlayer film, is a value measured using the spectroscopic ellipsometer described above.

[Resist pattern formation process]
In this step, a resist pattern is formed directly or indirectly on the resist underlayer film. Examples of methods for performing this step include a method using a resist composition, a method using a nanoimprint method, a method using a self-assembling composition, and the like. An example of a case where a resist pattern is indirectly formed on the resist underlayer film is a case where a resist pattern is formed on the silicon-containing film.

Examples of the above resist compositions include positive or negative chemically amplified resist compositions containing a radiation-sensitive acid generator, positive resist compositions containing an alkali-soluble resin and a quinone diazide photosensitizer, and alkali-soluble Examples include negative resist compositions containing a resin and a crosslinking agent, and metal-containing resist compositions containing metals such as tin, zirconium, and hafnium.

Examples of the coating method for the resist composition include a spin coating method. The temperature and time of prebaking can be adjusted as appropriate depending on the type of resist composition used.

Next, the formed resist film is exposed to selective radiation. The radiation used for exposure can be appropriately selected depending on the type of radiation-sensitive acid generator used in the resist composition, and includes visible light, ultraviolet rays, far ultraviolet rays, X-rays, γ-rays, etc. Examples include electromagnetic waves, electron beams, molecular beams, and particle beams such as ion beams. Among these, far ultraviolet light is preferable, and KrF excimer laser light (wavelength 248 nm), ArF excimer laser light (wavelength 193 nm), _F2 excimer laser light (wavelength 157 nm), _Kr2 excimer laser light (wavelength 147 nm), ArKr excimer laser light Laser light (wavelength: 134 nm) or extreme ultraviolet light (wavelength: 13.5 nm, etc., hereinafter also referred to as "EUV") is more preferred, and KrF excimer laser light, ArF excimer laser light, or EUV is even more preferred.

After the above exposure, post-baking can be performed to improve resolution, pattern profile, developability, etc. The temperature and time of this post-baking can be determined as appropriate depending on the type of resist composition used.

Next, the exposed resist film is developed with a developer to form a resist pattern. This development may be alkaline development or organic solvent development. In the case of alkaline development, examples of the developer include basic aqueous solutions such as ammonia, triethanolamine, tetramethylammonium hydroxide (TMAH), and tetraethylammonium hydroxide. To these basic aqueous solutions, suitable amounts of water-soluble organic solvents such as alcohols such as methanol and ethanol, surfactants, and the like may be added. Further, in the case of organic solvent development, examples of the developer include various organic solvents exemplified as the [B] solvent of the above-mentioned composition.

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

[Etching process]
In this step, etching is performed using the resist pattern as a mask. The etching may be performed once or multiple times, that is, the etching may be performed sequentially using the pattern obtained by etching as a mask. From the viewpoint of obtaining a pattern with a better shape, it is preferable to repeat the process multiple times. When etching is performed multiple times, for example, the silicon-containing film, the resist underlayer film, and the substrate are etched in this order. Examples of the etching method include dry etching, wet etching, and the like. From the viewpoint of improving the shape of the pattern on the substrate, dry etching is preferable. This dry etching uses, for example, gas plasma such as oxygen plasma. Through the above etching, a semiconductor substrate having a predetermined pattern is obtained.

Dry etching can be performed using, for example, a known dry etching device. 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, etc. For example, _CHF3 , _CF4 , _C2F6 , _C3F8 _, _SF6, etc. Fluorine gas, chlorine gas such as _Cl2 , _BCl3 , oxygen gas such as _O2 , _O3 , _H2O , H2, _NH3 _, CO, _CO2 , _CH4 _, _C2H2 , 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, BCl ₃ and other reducing gases, He, N ₂ , Ar, etc. Examples include inert gas. These gases can also be used in combination. When etching a substrate using a pattern of a resist underlayer film as a mask, a fluorine-based gas is usually used.

"Composition"
The composition contains a [A] compound and a [B] solvent. As the composition, a composition used in the method for manufacturing a semiconductor substrate described above can be suitably employed.

"Compound"
The compound is a compound represented by the above formula (1). As the compound, the [A] compound used in the method for manufacturing the semiconductor substrate described above can be suitably employed.

Hereinafter, the present invention will be specifically explained based on Examples, but the present invention is not limited to these Examples.

[Weight average molecular weight (Mw)]
The Mw of the polymer was determined using Tosoh Corporation GPC columns (2 G2000HXL, 1 G3000HXL, and 1 G4000HXL), flow rate: 1.0 mL/min, elution solvent: tetrahydrofuran, column. Measurement was performed by gel permeation chromatography (detector: differential refractometer) using monodisperse polystyrene as a standard under analysis conditions of temperature: 40°C.

[Average thickness of resist lower layer film]
The average thickness of the resist underlayer film was measured using a spectroscopic ellipsometer (“M2000D” manufactured by J.A. WOOLLAM) at arbitrary intervals of 5 cm including the center of the resist underlayer film formed on a 12-inch silicon wafer (substrate). The film thickness was measured at nine positions, and the average value of these film thicknesses was determined as the calculated value.

[Synthesis Example 1] (Synthesis of compound (a-1))
2.00 g of tetrakis(4-bromophenyl)methane and 30 g of tetrahydrofuran were added to the reaction vessel under a nitrogen atmosphere, and the mixture was cooled to -78°C. Next, 15.7 mL of n-butyllithium (1.6M hexane solution) was added dropwise, and the mixture was stirred at -78°C for 2 hours. Thereafter, 4.73 g of triisopropyl borate was added, and the mixture was stirred for 10 hours while returning to room temperature. After adding 50 g of a 5% aqueous oxalic acid solution to the reaction solution, the organic solvent was distilled off using an evaporator, 100 g of a 10% aqueous sodium hydroxide solution was added to the remaining solution, and the precipitate was removed by filtration. 100 g of a 5% aqueous oxalic acid solution was added to the filtrate, and the resulting solid was collected by filtration and dried to obtain a compound (a-1) represented by the following formula (a-1).

[Synthesis Example 2] (Synthesis of compound (A-1))
In a reaction vessel, under a nitrogen atmosphere, 4.96 g of the above compound (a-1), 12.29 g of 2-bromo-7-(2-trimethylsilylethynyl)fluorene, 0.32 g of tetrabutylammonium bromide, 6.91 g of potassium carbonate, 259 g of toluene and 52 g of water were added, and the mixture was stirred at room temperature for 30 minutes. Next, 0.23 g of tetrakis(triphenylphosphine)palladium was added, heated to 120° C., and stirred for 24 hours. After the reaction was completed, the mixture was cooled to room temperature, the organic phase was separated, and the aqueous phase was extracted twice with 100 g of methyl isobutyl ketone. Next, the organic phase was washed three times with 200 g of a 5% aqueous oxalic acid solution, and then three times with 200 g of water. The organic phase was concentrated using an evaporator, and the residue was added dropwise to n-hexane to obtain a precipitate. After washing the obtained precipitate with n-hexane, the solid was collected by suction filtration and dried to obtain a compound (A-1) represented by the following formula (A-1).

[Synthesis Example 3] (Synthesis of compound (A-2))
Instead of reacting 12.29 g of 2-bromo-7-(2-trimethylsilylethynyl)fluorene, 9.40 g of 7-bromo-2-fluorenol was added, and since deprotection of the trimethylsilyl group was not required, potassium carbonate 6. A compound represented by the following formula (A-2) was obtained by reacting under the same conditions as [Synthesis Example 2] except that 4.15 g was used instead of 91 g, heated to 120 ° C. and stirred for 5 hours. (A-2) was obtained.

[Synthesis Example 4] (Synthesis of compound (A-3))
10.41 g of the above compound (A-2), 11.05 g of potassium carbonate, and 350 g of N,N-dimethylacetamide were added to a reaction vessel under a nitrogen atmosphere, and the mixture was stirred at 0° C. for several minutes. Next, 7.13 g of propargyl bromide was slowly added dropwise, and after the addition was completed, the mixture was stirred at room temperature for 5 hours. After the reaction was completed, 200 g of methyl isobutyl ketone and 200 g of water were added to the reaction solution for washing. Thereafter, the organic phase was separated, and the aqueous phase was washed three times with 200 g of methyl isobutyl ketone. The organic phase was concentrated using an evaporator, and the residue was added dropwise to n-hexane to obtain a precipitate. After washing the obtained precipitate with n-hexane, the solid was collected by suction filtration and dried to obtain a compound (A-3) represented by the following formula (A-3).

[Synthesis Example 5] (Synthesis of compound (a-2))
In a reaction vessel, under a nitrogen atmosphere, add 4.96 g of the above compound (a-1), 8.82 g of 2-bromofluorene, 0.32 g of tetrabutylammonium bromide, 4.15 g of potassium carbonate, 208 g of toluene, and 41 g of water. The mixture was stirred at room temperature for 30 minutes. Next, 0.23 g of tetrakis(triphenylphosphine)palladium was added, heated to 120° C., and stirred for 5 hours. After the reaction was completed, the mixture was cooled to room temperature, the organic phase was separated, and the aqueous phase was extracted twice with 100 g of methyl isobutyl ketone. Next, the organic phase was washed three times with 200 g of a 5% aqueous oxalic acid solution, and then three times with 200 g of water. The organic phase was concentrated using an evaporator, and the residue was added dropwise to n-hexane to obtain a precipitate. After washing the obtained precipitate with n-hexane, the solid was collected by suction filtration and dried to obtain a compound (a-2) represented by the following formula (a-2).

[Synthesis Example 6] (Synthesis of compound (A-4))
In a reaction vessel, under a nitrogen atmosphere, add 9.77 g of the above compound (a-2), 16.0 g of sodium hydroxide (50% aqueous solution), 0.32 g of tetrabutylammonium bromide, and 100 g of N,N-dimethylacetamide. Allowed to stir for several minutes at °C. Next, 14.28 g of propargyl bromide was slowly added dropwise, and after the addition was completed, the mixture was heated to 60° C. and stirred for 24 hours. After the reaction was completed, it was cooled to room temperature, 200 g of a 5% aqueous oxalic acid solution was added to the reaction solution, and the aqueous phase was extracted three times with 200 g of methyl isobutyl ketone. Thereafter, the organic phase was washed three times with 150 g of water. The organic phase was concentrated using an evaporator, and the residue was added dropwise to n-hexane to obtain a precipitate. After washing the obtained precipitate with n-hexane, the solid was collected by suction filtration and dried to obtain a compound (A-4) represented by the following formula (A-4).

[Synthesis Example 7] (Synthesis of compound (A-5))
9.77 g of the above compound (a-2), 8.00 g of paraformaldehyde, 60 g of N,N-dimethylacetamide, and 5 g of methanol were added to a reaction vessel under a nitrogen atmosphere, and the mixture was cooled to 0°C. Next, 23.2 g of sodium methoxide (28% methanol solution) was slowly added dropwise, and the mixture was stirred at 0° C. for 1 hour. After the reaction was completed, 100 g of a 5% aqueous oxalic acid solution was added to the reaction solution, and the aqueous phase was extracted three times with 150 g of methyl isobutyl ketone. Thereafter, the organic phase was washed three times with 200 g of water. The organic phase was concentrated using an evaporator, and the residue was added dropwise to n-hexane to obtain a precipitate. After washing the obtained precipitate with n-hexane, the solid was collected by suction filtration and dried to obtain a compound (A-5) represented by the following formula (A-5).

[Synthesis Example 8] (Synthesis of compound (A-7))
The following formula ( A compound (A-7) represented by A-7) was obtained.

[Synthesis Example 9] (Synthesis of compound (a-3))
10.41 g of the above compound (A-2), 5.45 g of imidazole, and 50 g of N,N-dimethylacetamide were added to a reaction vessel under a nitrogen atmosphere, and the mixture was stirred at room temperature for several minutes. Then, 9.04 g of tert-butyldimethylsilyl chloride was added dropwise, and the mixture was stirred at room temperature for 1 hour. After the reaction was completed, 100 g of water was added, and the reaction solution was extracted three times with 200 g of methyl isobutyl ketone. The organic phase was concentrated using an evaporator, and the residue was added dropwise to n-hexane to obtain a precipitate. After washing the obtained precipitate with n-hexane, the solid was collected by suction filtration and dried to obtain a compound (a-3) represented by the following formula (a-3).

[Synthesis Example 10] (Synthesis of compound (A-8))
In a reaction vessel, under a nitrogen atmosphere, add 14.98 g of the above compound (a-3), 16.0 g of sodium hydroxide (50% aqueous solution), 0.32 g of tetrabutylammonium bromide, and 100 g of N,N-dimethylacetamide. Allowed to stir for several minutes at °C. Next, 14.28 g of propargyl bromide was slowly added dropwise, and after the addition was completed, the mixture was heated to 60° C. and stirred for 24 hours. After the reaction was completed, it was cooled to room temperature, 200 g of a 5% aqueous oxalic acid solution was added to the reaction solution, and the aqueous phase was extracted three times with 200 g of methyl isobutyl ketone. Thereafter, the organic phase was washed three times with 150 g of water. The organic phase was concentrated using an evaporator, poured into 200 g of hexane, and reprecipitated. After washing the obtained precipitate with hexane, the solid was collected by suction filtration and dried. Subsequently, in order to deprotect the tert-butyldimethylsilyl group, 11.5 g of tetrabutylammonium fluoride and 200 g of tetrahydrofuran were added to 18.03 g of the dried solid, and the mixture was stirred at room temperature for 30 minutes. 50 g of ice was added to the reaction solution, and the mixture was extracted three times with 200 g of methyl isobutyl ketone. Thereafter, the organic phase was washed three times with 100 g of water. The organic phase was concentrated using an evaporator, and the residue was added dropwise to n-hexane to obtain a precipitate. After washing the obtained precipitate with n-hexane, the solid was collected by suction filtration and dried to obtain a compound (A-8) represented by the following formula (A-8).

[Synthesis Example 11] (Synthesis of compound (A-9))
[Synthesis Example 6] Except that 10.41 g of the above compound (A-2) was added instead of reacting 9.77 g of the above compound (a-2) and 28.54 g of propargyl bromide was reacted. By reacting under the same conditions as above, a compound (A-9) represented by the following formula (A-9) was obtained.

[Synthesis Example 12] (Synthesis of compound (A-10))
The following formula ( A compound (A-10) represented by A-10) was obtained.

[Synthesis Example 13] (Synthesis of compound (A-11))
14.98 g of the above compound (a-3), 8.01 g of paraformaldehyde, 90 g of N,N-dimethylacetamide, and 10 g of methanol were added to a reaction vessel under a nitrogen atmosphere, and the mixture was cooled to 0°C. Next, 23.2 g of sodium methoxide (28% methanol solution) was slowly added dropwise, and the mixture was stirred at 0° C. for 1 hour. 150 g of a 5% aqueous oxalic acid solution was added to the reaction solution, and the aqueous phase was extracted three times with 150 g of methyl isobutyl ketone. Thereafter, the organic phase was washed three times with 200 g of water. The organic phase was concentrated using an evaporator, poured into 150 g of hexane, and reprecipitated. After washing the obtained precipitate with hexane, the solid was collected by suction filtration and dried. Subsequently, in order to deprotect the tert-butyldimethylsilyl group, 11.5 g of tetrabutylammonium fluoride and 200 g of tetrahydrofuran were added to 17.38 g of the dried solid, and the mixture was reacted at room temperature for 30 minutes. 50 g of ice was added to the reaction solution, and the mixture was extracted three times with 200 g of methyl isobutyl ketone. Thereafter, the organic phase was washed three times with 100 g of water. The organic phase was concentrated using an evaporator, and the residue was added dropwise to n-hexane to obtain a precipitate. After washing the obtained precipitate with n-hexane, the solid was collected by suction filtration and dried to obtain a compound (A-11) represented by the following formula (A-11).

[Synthesis Example 14] (Synthesis of compound (A-12))
The following formula (A- A compound (A-12) represented by 12) was obtained.

[Synthesis Example 15] (Synthesis of compound (A-16))
10.73 g of the above compound (A-1), 100 g of tetrahydrofuran, 10.13 g of 1-pyrenecarboxaldehyde, and 0.97 g of tetrabutylammonium bromide were added to a reaction vessel under a nitrogen atmosphere and stirred for several minutes. Then, 29.16 g of tetramethylammonium hydroxide (25% aqueous solution) was slowly added dropwise at room temperature. After the dropwise addition was completed, the mixture was stirred at room temperature for 8 hours. After the reaction was completed, 200 g of a 5% aqueous oxalic acid solution was added to the reaction solution, and the aqueous phase was extracted three times with 200 g of cyclohexanone. Thereafter, the organic phase was washed three times with 150 g of water. The organic phase was concentrated using an evaporator, and the residue was added dropwise to n-hexane to obtain a precipitate. After washing the obtained precipitate with n-hexane, the solid was collected by suction filtration and dried to obtain a compound (A-16) represented by the following formula (A-16).

[Synthesis Example 16] (Synthesis of compound (A-17))
14.98 g of compound (a-3), 130 g of tetrahydrofuran, 10.13 g of 1-pyrenecarboxaldehyde, and 0.97 g of tetrabutylammonium bromide were added to a reaction vessel under a nitrogen atmosphere and stirred for several minutes. Then, 29.17 g of tetramethylammonium hydroxide (25% aqueous solution) was slowly added dropwise at room temperature. After the dropwise addition was completed, the mixture was stirred at room temperature for 8 hours. After the reaction was completed, 200 g of a 5% aqueous oxalic acid solution was added to the reaction solution, and the aqueous phase was extracted three times with 200 g of cyclohexanone. Thereafter, the organic phase was washed three times with 150 g of water. The organic phase was concentrated using an evaporator, poured into 200 g of hexane, and reprecipitated. After washing the obtained precipitate with hexane, the solid was collected by suction filtration and dried. Subsequently, in order to deprotect the tert-butyldimethylsilyl group, 11.51 g of tetrabutylammonium fluoride and 200 g of tetrahydrofuran were added to 23.48 g of the dried solid, and the mixture was reacted at room temperature for 30 minutes. 50 g of ice was added to the reaction solution, and the mixture was extracted three times with 200 g of cyclohexanone. Thereafter, the organic phase was washed three times with 100 g of water. The organic phase was concentrated using an evaporator, and the residue was added dropwise to n-hexane to obtain a precipitate. After washing the obtained precipitate with n-hexane, the solid was collected by suction filtration and dried to obtain a compound (A-17) represented by the following formula (A-17).

[Synthesis Example 17] (Synthesis of compound (A-18))
The following formula ( A compound (A-18) represented by A-18) was obtained.

[Synthesis Example 18] (Synthesis of compound (A-19))
By reacting under the same conditions as in [Synthesis Example 15] except that 6.87 g of 2-naphthaldehyde was added instead of reacting 10.13 g of 1-pyrenecarboxaldehyde, the following formula (A-19) was obtained. The represented compound (A-19) was obtained.

[Synthesis Example 19] (Synthesis of compound (A-20))
By reacting under the same conditions as [Synthesis Example 16] except that 6.87 g of 2-naphthaldehyde was added instead of reacting 10.13 g of 1-pyrenecarboxaldehyde, the following formula (A-20) was obtained. The represented compound (A-20) was obtained.

[Synthesis Example 20] (Synthesis of compound (A-21))
Except that instead of reacting 10.73 g of the above compound (A-1) and 10.13 g of 1-pyrenecarboxaldehyde, 11.93 g of the above compound (A-3) and 6.87 g of 2-naphthaldehyde were added, respectively. By reacting under the same conditions as in [Synthesis Example 15], a compound (A-21) represented by the following formula (A-21) was obtained.

[Synthesis Example 21] (Synthesis of compound (A-22))
Instead of reacting 10.13 g of 1-pyrenecarboxaldehyde and 29.16 g of tetramethylammonium hydroxide (25% aqueous solution), 6.39 g of indole-3-carboxaldehyde and 1,8-diazabicyclo[5.4. A compound (A-22) represented by the following formula (A-22) was obtained by reacting under the same conditions as [Synthesis Example 15] except that 12.18 g of [0]-7-undecene was added. .

[Synthesis Example 22] (Synthesis of compound (A-23))
Instead of reacting 10.13 g of 1-pyrenecarboxaldehyde and 29.17 g of tetramethylammonium hydroxide (25% aqueous solution), 6.39 g of indole-3-carboxaldehyde and 1,8-diazabicyclo[5.4. A compound (A-23) represented by the following formula (A-23) was obtained by reacting under the same conditions as [Synthesis Example 16] except that 12.18 g of [0]-7-undecene was added. Ta.

[Synthesis Example 23] (Synthesis of compound (A-24))
Instead of reacting 10.73 g of the above compound (A-1), 10.13 g of 1-pyrenecarboxaldehyde, and 29.16 g of tetramethylammonium hydroxide (25% aqueous solution), 11.93 g of (A-3), By reacting under the same conditions as [Synthesis Example 15] except that 6.39 g of indole-3-carboxaldehyde and 12.18 g of 1,8-diazabicyclo[5.4.0]-7-undecene were added. , a compound (A-24) represented by the following formula (A-24) was obtained.

[Synthesis Example 24] (Synthesis of compound (A-25))
By reacting under the same conditions as [Synthesis Example 15] except that 4.93 g of 2-thiophenecarboxaldehyde was added instead of reacting 10.13 g of 1-pyrenecarboxaldehyde, the following formula (A-25) was obtained. A compound (A-25) represented by was obtained.

[Synthesis Example 25] (Synthesis of compound (A-26))
By reacting under the same conditions as [Synthesis Example 16] except that 4.94 g of 2-thiophenecarboxaldehyde was added instead of reacting 10.13 g of 1-pyrenecarboxaldehyde, the following formula (A-26) was obtained. A compound (A-26) represented by was obtained.

[Synthesis Example 26] (Synthesis of compound (A-27))
Instead of reacting 10.73 g of the above compound (A-1) and 10.13 g of 1-pyrenecarboxaldehyde, 11.93 g of the above compound (A-3) and 4.93 g of 2-thiophenecarboxaldehyde were added, respectively. A compound (A-27) represented by the following formula (A-27) was obtained by reacting under the same conditions as in [Synthesis Example 15] except for this.

[Synthesis Example 27] (Synthesis of compound (A-28))
Instead of reacting 10.13 g of 1-pyrenecarboxaldehyde and 29.16 g of tetramethylammonium hydroxide (25% aqueous solution), 4.18 g of pyrrole-2-carboxaldehyde and 1,8-diazabicyclo[5.4. A compound (A-28) represented by the following formula (A-28) was obtained by reacting under the same conditions as [Synthesis Example 15] except that 12.18 g of [0]-7-undecene was added. .

[Synthesis Example 28] (Synthesis of compound (A-29))
Instead of reacting 10.13 g of 1-pyrenecarboxaldehyde and 29.17 g of tetramethylammonium hydroxide (25% aqueous solution), 4.18 g of pyrrole-2-carboxaldehyde and 1,8-diazabicyclo[5.4. A compound (A-29) represented by the following formula (A-29) was obtained by reacting under the same conditions as in [Synthesis Example 16] except that 12.18 g of [0]-7-undecene was added. Ta.

[Synthesis Example 29] (Synthesis of compound (A-30))
Instead of reacting 10.73 g of the above compound (A-1), 10.13 g of 1-pyrenecarboxaldehyde, and 29.16 g of tetramethylammonium hydroxide (25% aqueous solution), the above compound (A-3) 11. The reaction was carried out under the same conditions as [Synthesis Example 15] except that 93 g, 4.18 g of pyrrole-2-carboxaldehyde, and 12.18 g of 1,8-diazabicyclo[5.4.0]-7-undecene were added. As a result, a compound (A-30) represented by the following formula (A-30) was obtained.

[Synthesis Example 30] (Synthesis of compound (A-31))
The following formula (A- A compound (A-31) represented by 31) was obtained.

[Synthesis Example 31] (Synthesis of compound (A-32))
The following formula (A- A compound (A-32) represented by 32) was obtained.

[Synthesis Example 32] (Synthesis of compound (A-33))
Instead of reacting 10.73 g of the above compound (A-1) and 10.13 g of 1-pyrenecarboxaldehyde, 11.93 g of the above compound (A-3) and 6.60 g of 3-formylphenylboronic acid were added, respectively. A compound (A-33) represented by the following formula (A-33) was obtained by reacting under the same conditions as in [Synthesis Example 15] except for the above.

[Synthesis Example 33] (Synthesis of compound (a-4))
4.96 g of tetrakis(4-ethynylphenyl)methane, 0.28 g of copper(I) iodide, 0.42 g of dichlorobis(triphenylphosphine)palladium, 150 g of triethylamine, and 100 g of tetrahydrofuran were added to a reaction vessel under a nitrogen atmosphere, and the mixture was heated to room temperature. The mixture was stirred for 30 minutes. Next, 20.3 g of 2-bromo-7-(2-trimethylsilylethynyl)fluorene was added, heated to 60° C., and stirred for 16 hours. After the reaction was completed, the mixture was cooled to room temperature and washed three times with 200 g of methyl isobutyl ketone and 200 g of a 5% aqueous oxalic acid solution, and then the organic phase was washed three times with 150 g of water. The organic phase was concentrated using an evaporator, and the residue was added dropwise to n-hexane to obtain a precipitate. After washing the obtained precipitate with n-hexane, the solid was collected by suction filtration and dried to obtain a compound (a-4) represented by the following formula (a-4).

[Synthesis Example 34] (Synthesis of compound (A-34))
To deprotect the trimethylsilyl group, 11.5 g of tetrabutylammonium fluoride and 200 g of tetrahydrofuran were added to 14.58 g of the above compound (a-4), and the mixture was stirred at room temperature for 30 minutes. 50 g of ice was added to the reaction solution, and the mixture was extracted three times with 200 g of methyl isobutyl ketone. Thereafter, the organic phase was washed three times with 100 g of water. The organic phase was concentrated using an evaporator, and the residue was added dropwise to n-hexane to obtain a precipitate. After washing the obtained precipitate with n-hexane, the solid was collected by suction filtration and dried to obtain a compound (A-34) represented by the following formula (A-34).

[Synthesis Example 35] (Synthesis of compound (A-35))
React under the same conditions as [Synthesis Example 33] except that 15.54 g of 7-bromo-2-fluorenol was added instead of 20.3 g of 2-bromo-7-(2-trimethylsilylethynyl)fluorene. As a result, a compound (A-35) represented by the following formula (A-35) was obtained.

[Synthesis Example 36] (Synthesis of compound (A-36))
The following formula ( A compound (A-36) represented by A-36) was obtained.

[Synthesis Example 37] (Synthesis of polymer (x-1))
250.0 g of m-cresol, 125.0 g of 37% by mass formalin, and 2 g of oxalic anhydride were added to a reaction vessel under a nitrogen atmosphere, and after stirring at 100°C for 3 hours and at 180°C for 1 hour, the The reaction monomer was removed to obtain a polymer (x-1) represented by the following formula (x-1). The Mw of the obtained polymer (x-1) was 11,000.

[Synthesis Example 38] (Synthesis of polymer (x-2))
8.0 g of 9,9-bis(4-hydroxyphenyl)fluorene, 0.8 g of paraformaldehyde, and 21.5 g of methyl isobutyl ketone were added to a reaction container under a nitrogen atmosphere, and the mixture was heated to 80° C. to dissolve the compound. Ta. After adding 5.0 g of a solution of 0.8 g of p-toluenesulfonic acid monohydrate in methyl isobutyl ketone to the reaction vessel, the mixture was heated to 115° C. and stirred for 15 hours. After the reaction was completed, 100 g of methyl isobutyl ketone and 200 g of water were added to wash the organic phase. The organic phase was concentrated using an evaporator, and the residue was added dropwise to methanol to obtain a precipitate. After washing the obtained precipitate with methanol, the solid was collected by suction filtration and dried to obtain a polymer (x-2) represented by the following formula (x-2). The Mw of the obtained polymer (x-2) was 8,000.

<Preparation of composition>
The [A] compound, polymer, [B] solvent, [C] acid generator, and [D] crosslinking agent used in the preparation of the composition are shown below.

[[A] Compound]
[A] Compound: Compounds (A-1) to (A-5), (A-7) to (A-12), (A-16) to (A-36) synthesized above

[Polymer]
Polymer: The polymers (x-1) to (x-2) synthesized above, and the polymers (E-1) to (E-2) represented by the following formulas (E-1) to (E-2) ) (The number next to the repeating unit represents the content ratio (mol%) of each repeating unit.)

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

[[C] Acid generator]
C-1: Bis(4-t-butylphenyl)iodonium nonafluoro-n-butanesulfonate (compound represented by the following formula (C-1))

[[D] Crosslinking agent]
D-1: Compound represented by the following formula (D-1)

D-2: Compound represented by the following formula (D-2)

D-3: Compound represented by the following formula (D-3)

[Example 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 resulting solution was filtered through a polytetrafluoroethylene (PTFE) membrane filter with a pore size of 0.45 μm to prepare a composition (J-1).

[Examples 1 to 37 and Comparative Examples 1 to 2]
Compositions (J-2) to (J-37) and (CJ-1) to (CJ-2) were prepared in the same manner as in Example 1, except that the types and contents of each component shown in Table 1 below were used. ) was prepared. In Table 1, "-" in the columns of "[A] Compound,""Polymer,""[C] Acid Generator," and "[D] Crosslinking Agent" indicates that the corresponding component was not used. show.

<Evaluation>
Using the composition obtained above, the etching resistance, heat resistance, and bending resistance were evaluated by the following methods. The evaluation results are also shown in Table 2 below.

[Etching resistance]
The composition prepared above was applied onto a silicon wafer (substrate) by a spin coating method using a spin coater ("CLEAN TRACK ACT12" manufactured by Tokyo Electron Ltd.). Next, a film with an average thickness of 200 nm was formed by heating at 350°C for 60 seconds in an air atmosphere and cooling at 23°C for 60 seconds, and a film-coated substrate with a resist underlayer film formed on the substrate was formed. Obtained. The film on the film-coated substrate obtained above was etched using an etching apparatus ("TACTRAS" manufactured by Tokyo Electron Ltd.) at CF ₄ /Ar=110/440 sccm, PRESS. = 30MT, HF RF (high frequency power for plasma generation) = 500W, LF RF (high frequency power for bias) = 3000W, DCS = -150V, RDC (gas center flow rate ratio) = 50%, processed for 30 seconds, The etching rate (nm/min) was calculated from the average thickness of the film before and after the treatment. Next, the ratio to Comparative Example 1 was calculated based on the etching rate of Comparative Example 1, and this ratio was used as a measure of etching resistance. Etching resistance is rated "A" (very good) if the above ratio is 0.90 or less, "B" (good) if it is more than 0.90 and less than 0.92, and "B" (good) if it is 0.92 or more. It was evaluated as "C" (poor). Note that "-" in Table 2 indicates that it is an evaluation criterion for etching resistance.

[Heat-resistant]
The composition prepared above was applied onto a silicon wafer (substrate) by a spin coating method using a spin coater ("CLEAN TRACK ACT12" manufactured by Tokyo Electron Ltd.). Next, a film with an average thickness of 200 nm was formed by heating at 200°C for 60 seconds in an air atmosphere and cooling at 23°C for 60 seconds, and a film-coated substrate with a resist underlayer film formed on the substrate was formed. Obtained. The powder was collected by scraping the film of the film-coated substrate obtained above, and the collected powder was placed in a container used for measurement with a TG-DTA device (NETZSCH's "TG-DTA2000SR"), and the powder was placed before heating. The mass was measured. Next, using the above TG-DTA apparatus, the powder was heated to 400°C at a temperature increase rate of 10°C/min in a nitrogen atmosphere, and the mass of the powder when the temperature reached 400°C was measured. Then, the mass reduction rate (%) was measured using 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 the mass reduction rate (%), m1 is the mass (mg) before heating, and m2 is the mass (mg) at 400°C.
Regarding heat resistance, the smaller the mass reduction rate of the sample powder, the less sublimate and film decomposition products are generated during heating of the film, which is better. That is, the smaller the mass reduction rate, the higher the heat resistance. Heat resistance is rated "A" (very good) if the mass reduction rate is less than 5%, "B" (good) if it is 5% or more and less than 10%, and "C" (good) if it is 10% or more. Poor).

[Bending resistance]
The composition prepared above was coated on a silicon substrate on which a silicon dioxide film with an average thickness of 500 nm was formed by a spin coating method using a spin coater ("CLEAN TRACK ACT12" manufactured by Tokyo Electron Ltd.). Next, the substrate was heated at 400° C. for 60 seconds in an air atmosphere and then cooled at 23° C. for 60 seconds to obtain a film-coated substrate on which a resist underlayer film with an average thickness of 200 nm was formed. A silicon-containing film-forming composition ("NFC SOG080" by JSR Corporation) was coated on the film-coated substrate obtained above by a spin coating method, and then heated at 200°C for 60 seconds in an air atmosphere. , and further heated at 300° C. for 60 seconds to form a silicon-containing film with an average thickness of 50 nm. An ArF resist composition ("AR1682J" manufactured by JSR Corporation) was coated on the silicon-containing film using a spin coating method, and heated (baked) at 130°C for 60 seconds in an air atmosphere to reduce the average thickness. A 200 nm resist film was formed. The resist film was coated using an ArF excimer laser exposure device (lens numerical aperture 0.78, exposure wavelength 193 nm) by changing the exposure amount through a one-to-one line-and-space mask pattern with a target size of 100 nm. After exposure, it was heated (baked) at 130°C for 60 seconds in an air atmosphere, developed with a 2.38% by mass tetramethylammonium hydroxide (TMAH) aqueous solution at 25°C for 1 minute, washed with water, and dried. Thus, a substrate was obtained on which a line-and-space resist pattern with a line width of 30 nm to 100 nm and a pitch of 200 nm was formed.

Using the above resist pattern as a mask and using the above etching apparatus, CF ₄ =200 sccm, PRESS. The silicon-containing film was etched under the following conditions: = 85 mT, HF RF (high frequency power for plasma generation) = 500 W, LF RF (high frequency power for bias) = 0 W, DCS = -150 V, RDC (gas center flow rate ratio) = 50%. , a substrate having a pattern formed on a silicon-containing film was obtained. Next, using the silicon-containing film pattern as a mask, using the etching apparatus described above, O ₂ =400 sccm, PRESS. Etching the resist underlayer film under the following conditions: = 25 mT, HF RF (high frequency power for plasma generation) = 400 W, LF RF (high frequency power for bias) = 0 W, DCS = 0 V, RDC (gas center flow rate ratio) = 50%, A substrate on which a pattern was formed on the resist underlayer film was obtained. Using the resist underlayer film pattern as a mask and using the etching apparatus described above, CF ₄ =180 sccm, Ar=360 sccm, PRESS. = 150 mT, HF RF (high frequency power for plasma generation) = 1,000 W, LF RF (high frequency power for bias) = 1,000 W, DCS = -150 V, RDC (gas center flow rate ratio) = 50%, under the conditions of 60 seconds The silicon dioxide film was etched to obtain a substrate in which a pattern was formed on the silicon dioxide film.

After that, for the substrate on which the pattern was formed on the silicon dioxide film, the shape of the resist underlayer film pattern for each line width was examined using a scanning electron microscope (“CG-4000” manufactured by Hitachi High-Technologies Corporation) at a magnification of 250,000 times. By obtaining an enlarged image and performing image processing, measurements were taken at 10 locations at 100 nm intervals on the side surface 3a of the resist underlayer film pattern 3 (line pattern) with a length of 1,000 nm, as shown in FIG. The 3-sigma value obtained by multiplying the standard deviation calculated from the position Xn (n = 1 to 10) in the line width direction and the position Xa of the average value of these positions in the line width direction is calculated as LER (line edge roughness). ). LER, which indicates the degree of curvature of the resist underlayer film pattern, increases as the line width of the resist underlayer film pattern becomes thinner. The bending resistance is rated "A" (good) when the line width of the film pattern with LER of 5.5 nm is less than 35.0 nm, and "B" (fair) when it is 35.0 nm or more and less than 40.0 nm. Good), and cases where it was 40.0 nm or more were evaluated as "C" (poor). Note that the degree of curvature of the film pattern shown in FIG. 1 is exaggerated compared to the actual state.

As can be seen from the results in Table 2, the resist underlayer film formed from the composition of the example has superior etching resistance, heat resistance, and bending resistance compared to the resist underlayer film formed from the composition of the comparative example. was.

According to the method for manufacturing a semiconductor substrate of the present invention, a substrate that is well patterned can be obtained. The composition of the present invention can form a resist underlayer film having excellent etching resistance, heat resistance, and bending resistance. The compound of the present invention can provide a composition capable of forming a film having excellent etching resistance, heat resistance, and bending resistance. Therefore, these can be suitably used in the production of semiconductor devices, which are expected to be further miniaturized in the future.

3 Resist lower layer film pattern 3a Lateral side of resist lower layer film pattern

Claims

a step of directly or indirectly applying a resist underlayer film forming composition to the substrate;
forming a resist pattern directly or indirectly on the resist underlayer film formed by the coating process;
and a step of performing etching using the resist pattern as a mask,
The resist underlayer film forming composition described above is
A compound represented by the following formula (1),
A method for manufacturing a semiconductor substrate, the method comprising: a solvent;

(In formula (1), Ar 1 , Ar 2 , Ar 3 and Ar 4 are each independently a monovalent group having a substituted or unsubstituted aromatic ring having 5 to 40 ring members. Ar 1 , At least one of Ar 2 , Ar 3 and Ar 4 has a group represented by the following formula (1-1) or (1-2).The following formula (1-1) or (1-2) If there are multiple groups represented by , the multiple groups may be the same or different from each other.)

(In formulas (1-1) and (1-2), X 1 and X 2 are each independently a group represented by the following formula (i), (ii), (iii) or (iv). Ar 5 , Ar 6 and Ar 7 each independently represent a substituted or unsubstituted ring that forms a fused ring structure with two adjacent carbon atoms in the above formulas (1-1) and (1-2). It is an aromatic ring having 6 to 20 members. L 1 and L 2 are each independently a single bond or a divalent organic group having an aromatic ring. * represents the bond with the carbon atom in the above formula (1). It is a conjugate.)

(In formula (i), R 1 and R 2 are each independently a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms.
In formula (ii), R 3 is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. R 4 is a monovalent organic group having 1 to 20 carbon atoms.
In formula (iii), R 5 is a monovalent organic group having 1 to 20 carbon atoms.
In formula (iv), R 6 is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. )
Before forming the above resist pattern,
The method for manufacturing a semiconductor substrate according to claim 1, further comprising the step of forming a silicon-containing film directly or indirectly on the resist underlayer film.
A compound represented by the following formula (1),
A composition comprising: a solvent;

(In formula (1), Ar 1 , Ar 2 , Ar 3 and Ar 4 are each independently a monovalent group having a substituted or unsubstituted aromatic ring having 5 to 40 ring members. Ar 1 , At least one of Ar 2 , Ar 3 and Ar 4 has a group represented by the following formula (1-1) or (1-2).The following formula (1-1) or (1-2) If there are multiple groups represented by , the multiple groups may be the same or different from each other.)

(In formulas (1-1) and (1-2), X 1 and X 2 are each independently a group represented by the following formula (i), (ii), (iii) or (iv). Ar 5 , Ar 6 and Ar 7 each independently represent a substituted or unsubstituted ring that forms a fused ring structure with two adjacent carbon atoms in the above formulas (1-1) and (1-2). It is an aromatic ring having 6 to 20 members. L 1 and L 2 are each independently a single bond or a divalent organic group having an aromatic ring. * represents the bond with the carbon atom in the above formula (1). It is a conjugate.)

(In formula (i), R 1 and R 2 are each independently a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms.
In formula (ii), R 3 is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. R 4 is a monovalent organic group having 1 to 20 carbon atoms.
In formula (iii), R 5 is a monovalent organic group having 1 to 20 carbon atoms.
In formula (iv), R 6 is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. )
The composition according to claim 3, wherein the carbon atom in the above formula (1) is bonded to an aromatic ring possessed by Ar1 , Ar2 , Ar3, and Ar4 .
The composition according to claim 3 or 4, wherein at least two of the Ar 1 , Ar 2 , Ar 3 and Ar 4 have a group represented by the formula (1-1) or (1-2). .
At least one of the above Ar 1 , Ar 2 , Ar 3 and Ar 4 is a group consisting of a hydroxy group, a group represented by the following formula (2-1), and a group represented by the following formula (2-2) The composition according to claim 3 or 4, having at least one group selected from:

(In formulas (2-1) and (2-2), R 7 is each independently a divalent organic group having 1 to 20 carbon atoms or a single bond. * indicates a bond with a carbon atom in an aromatic ring. It is a conjugate.)
The composition according to claim 6, wherein at least two of the Ar 1 , Ar 2 , Ar 3 and Ar 4 have a group represented by the formula (2-1) or (2-2).
The composition according to claim 3 or 4, which is used for forming a resist underlayer film.
A compound represented by the following formula (1).

(In formula (1), Ar 1 , Ar 2 , Ar 3 and Ar 4 are each independently a monovalent group having a substituted or unsubstituted aromatic ring having 5 to 40 ring members. Ar 1 , At least one of Ar 2 , Ar 3 and Ar 4 has a group represented by the following formula (1-1) or (1-2).The following formula (1-1) or (1-2) If there are multiple groups represented by , the multiple groups may be the same or different from each other.)

(In formulas (1-1) and (1-2), X 1 and X 2 are each independently a group represented by the following formula (i), (ii), (iii) or (iv). Ar 5 , Ar 6 and Ar 7 each independently represent a substituted or unsubstituted ring that forms a fused ring structure with two adjacent carbon atoms in the above formulas (1-1) and (1-2). It is an aromatic ring having 6 to 20 members. L 1 and L 2 are each independently a single bond or a divalent organic group having an aromatic ring. * represents the bond with the carbon atom in the above formula (1). It is a conjugate.)

(In formula (i), R 1 and R 2 are each independently a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms.
In formula (ii), R 3 is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. R 4 is a monovalent organic group having 1 to 20 carbon atoms.
In formula (iii), R 5 is a monovalent organic group having 1 to 20 carbon atoms.
In formula (iv), R 6 is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. )
10. The compound according to claim 9, wherein the carbon atom in the above formula (1) is bonded to an aromatic ring possessed by Ar1 , Ar2 , Ar3, and Ar4 .
The compound according to claim 9 or 10, wherein at least two of the Ar 1 , Ar 2 , Ar 3 and Ar 4 have a group represented by the formula (1-1) or (1-2).
At least one of the above Ar 1 , Ar 2 , Ar 3 and Ar 4 is a group consisting of a hydroxy group, a group represented by the following formula (2-1), and a group represented by the following formula (2-2) The compound according to claim 9 or 10, having at least one group selected from.

(In formulas (2-1) and (2-2), R 7 is each independently a divalent organic group having 1 to 20 carbon atoms or a single bond. * indicates a bond with a carbon atom in an aromatic ring. It is a conjugate.)
The compound according to claim 12, wherein at least two of the Ar 1 , Ar 2 , Ar 3 and Ar 4 have a group represented by the formula (2-1) or (2-2).