TW202120464A - Composition for forming resist underlayer film, pattern formation method, and electronic device manufacturing method - Google Patents

Abstract

Disclosed are: a composition for forming a resist underlayer film, which comprises a resin having an aromatic ring and a compound represented by general formula (1), wherein the content of the compound represented by general formula (1) is 0.1 to 500 ppm by mass inclusive relative to the whole mass of the composition for forming a resist underlayer film; and a pattern formation method and an electronic device manufacturing method, each using the composition for forming a resist underlayer film. Accordingly, provided are; a composition for forming a resist underlayer film, which makes it possible to prevent the occurrence of coating defects after the elapse of a certain time period and can have excellent flatness after the elapse of a certain time period; and a pattern formation method and an electronic device manufacturing method, each using the composition for forming a resist underlayer film. In general formula (1), R1 to R3 independently represent an alkyl group having 1 to 5 carbon atoms.

Description

Composition for forming resist underlayer film, pattern forming method, and manufacturing method of electronic device

The present invention relates to a composition for forming a resist base film, a pattern forming method, and a manufacturing method of an electronic device. In more detail, the present invention relates to a method suitable for semiconductor manufacturing steps such as integrated circuits (IC), the manufacture of circuit substrates such as liquid crystals and thermal heads, and other photolithography processes (photofabrication). The composition for forming a resist base film, a pattern forming method, and a manufacturing method of an electronic device of the step.

After the resist for KrF excimer laser (248 nm), in order to compensate for the decrease in sensitivity caused by light absorption, a patterning method using chemical amplification is used. For example, in the positive chemical amplification method, first, the photoacid generator contained in the exposure part is decomposed by light irradiation to generate acid. In addition, in a post-exposure baking (PEB: Post Exposure Bake) process or the like, the alkali-insoluble group contained in the photosensitive composition is changed to an alkali-soluble group due to the catalytic action of the generated acid. Then, for example, an alkaline developer is used for development. Thereby, the exposure part is removed, and a desired pattern can be obtained.

In addition, in recent years, the following multilayer resist manufacturing process has been proposed: a resist underlayer film is placed between the resist film and the substrate, the resist film is exposed and developed to form a resist pattern, and then the resist pattern As a mask, the resist base film is etched to form a pattern, and the pattern is further used as a mask to etch the substrate to obtain a desired pattern (see Patent Document 1 and Patent Document 2). In Patent Document 1 and Patent Document 2, as a composition for forming a resist underlayer film (a composition for forming a resist underlayer film), a composition containing a compound having an aromatic ring and an organic solvent is described. In addition, as the organic solvent, various compounds such as propylene glycol monomethyl ether acetate (PGMEA) or propylene glycol monomethyl ether (PGME) are described. [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2019-20701 [Patent Document 2] Japanese Patent Laid-Open No. 2017-21337

[The problem to be solved by the invention] It is known that the composition for forming a resist underlayer film may be left in a preserved state after preparation for a fixed period, but in the case where the composition for forming a resist underlayer film is coated on a substrate after the preservation and fixing period, , Sometimes produce coating defects (also known as "coating defects after time"). In addition, in recent years, pattern formation on substrates having various grooves and the like has been increasing, and the composition for forming a resist underlayer film is required to have high flatness (resist formed from the composition for forming a resist underlayer film). Flat underlayer film), especially when the composition for forming a resist underlayer film is prepared and coated on a substrate after storage and a fixed period, it is required to have excellent flatness (also referred to as "flatness over time") .

The subject of the present invention is to provide a composition for forming a resist underlayer film that suppresses the occurrence of coating defects after time and has excellent flatness after time, and a composition using the composition for forming a resist underlayer film Pattern forming method and manufacturing method of electronic device. [Means to solve the problem]

The following aspects are included in the means for solving the above-mentioned problems.

＜1＞ A composition for forming a resist underlayer film, comprising: a resin having an aromatic ring and a compound represented by the following general formula (1). In the composition for forming a resist underlayer film, The content of the compound represented by the general formula (1) is 0.1 mass ppm or more and 500 mass ppm or less with respect to the total mass of the composition for forming a resist underlayer film.

[化1]

In the general formula (1), R ₁ to R ₃ each independently represent an alkyl group having 1 to 5 carbon atoms. <2> The composition for forming a resist underlayer film according to <1>, wherein the amount of the compound represented by the general formula (1) is relative to the total mass of the composition for forming a resist underlayer film The content is 1 mass ppm or more. <3> The composition for forming a resist underlayer film according to <1> or <2>, wherein the composition for forming a resist underlayer film is represented by the general formula (1) relative to the total mass of the composition for forming a resist underlayer film The content of the indicated compound is 100 mass ppm or less. <4> The composition for forming a resist base film according to any one of <1> to <3>, which contains 0.1 mass ppm relative to the total mass of the composition for forming a resist base film The compound represented by the following general formula (2) above and 500 mass ppm or less.

[化2]

In the general formula (2), R ₄ and R ₅ each independently represent an alkyl group having 1 to 5 carbon atoms. <5> The composition for forming a resist underlayer film as described in <4>, wherein the compound represented by the general formula (2) has an amount relative to the total mass of the composition for forming a resist underlayer film The content is 1 mass ppm or more. <6> The composition for forming a resist underlayer film as described in <4> or <5>, wherein the composition for forming a resist underlayer film is represented by the general formula (2) relative to the total mass of the composition for forming a resist underlayer The content of the indicated compound is 200 ppm by mass or less. <7> The composition for forming a resist base film according to any one of <1> to <6>, which contains 1 mass ppm relative to the total mass of the composition for forming a resist base film Above and below 1% by mass of water. <8> The composition for forming a resist underlayer film according to <7>, wherein the content of the water is 0.01% by mass or more with respect to the total mass of the composition for forming a resist underlayer. <9> The composition for forming a resist underlayer film according to <7> or <8>, wherein the content of the water is 0.5 mass relative to the total mass of the composition for forming a resist underlayer %the following. <10> The composition for forming a resist underlayer film according to any one of <1> to <9>, containing a compound represented by the following general formula (3), represented by the general formula (1) The content of the compound relative to the compound represented by the general formula (3) is 0.1 mass ppm or more and 0.05 mass% or less.

[化3]

In the general formula (3), R ₆ to R ₈ each independently represent an alkyl group having 1 to 5 carbon atoms. <11> The composition for forming a resist underlayer film according to <10>, wherein the content of the compound represented by the general formula (1) relative to the compound represented by the general formula (3) is 1 mass ppm or more and 0.005 mass% or less. <12> The composition for forming a resist underlayer film as described in any one of <1> to <11>, which contains a thermal acid generator and a crosslinking agent. <13> A pattern forming method, including: (1) a step of forming a resist base film on a substrate using the composition for forming a resist base film as described in any one of <1> to <12>; (2) The step of forming a resist film using a resist composition on the resist underlayer film; (3) The step of exposing the resist film; (4) The step of exposing the exposed The resist film is developed to form a resist pattern; and (5) the resist pattern is used as a mask and is etched to form a pattern. <14> A method of manufacturing an electronic device, including the pattern forming method as described in <13>. [Effects of the invention]

According to the present invention, it is possible to provide a composition for forming a resist underlayer film that suppresses the occurrence of coating defects after time and has excellent flatness after time, and a pattern using the composition for forming a resist underlayer film Forming method and manufacturing method of electronic device.

Hereinafter, the content of the present invention will be described in detail. The description of the structural elements described below may be based on representative embodiments of the present invention, and the present invention is not limited to such embodiments. In the expression of the group (atomic group) in this specification, expressions that do not describe substituted and unsubstituted also include a group (atomic group) without a substituent and a group (atomic group) with a substituent. For example, the term "alkyl" includes not only an unsubstituted alkyl group (unsubstituted alkyl group) but also a substituted alkyl group (substituted alkyl group). In addition, the "organic group" in this specification refers to a group containing at least one carbon atom.

In addition, the type of substituent, the position of the substituent, and the number of substituents when it is referred to as "may have a substituent" in this specification are not particularly limited. The number of substituents can be, for example, one, two, three, or more. Examples of the substituent include a monovalent non-metal atomic group other than a hydrogen atom. For example, it can be selected from the following substituents T.

(Substituent T) Examples of the substituent T include halogen atoms such as fluorine atom, chlorine atom, bromine atom, and iodine atom; alkoxy groups such as methoxy, ethoxy, and tert-butoxy; phenoxy and p-tolyloxy, etc. Aryloxy; alkoxycarbonyl groups such as methoxycarbonyl, butoxycarbonyl and phenoxycarbonyl; acetyloxy groups such as acetoxy, propoxy and benzyloxy; acetoxy, benzyl Anoyl, isobutyryl, acryloyl, methacryloyl and methoxalyl (methoxalyl); alkylthio groups such as methylthio and tertiary butylthio; phenylthio and p-tolylthio Alkyl; Cycloalkyl; Aryl; Heteroaryl; Hydroxyl; Carboxy; Carboxylic; Sulfo; Cyano; Alkylaminocarbonyl; Arylaminocarbonyl; Sulfonamide; Silyl group; amino group; monoalkylamino group; dialkylamino group; arylamino group; nitro group; methanoyl group; and combinations of these.

The "actinic rays" or "radiation rays" in this specification refer to, for example, the bright-ray spectrum of mercury lamps, extreme ultraviolet rays represented by excimer lasers, extreme ultraviolet rays (EUV: Extreme Ultraviolet), X-rays, and electron beams. (EB: Electron Beam) and so on. The "light" in this specification refers to actinic rays or radiation unless otherwise specified. Unless otherwise specified, the "exposure" in this manual includes not only exposure using the bright line spectrum of a mercury lamp, extreme ultraviolet, extreme ultraviolet, X-ray, EUV, etc., represented by excimer lasers, but also Exposure using particle beams such as electron beams and ion beams. In this specification, the term "~" is used to include the numerical values described before and after it as the lower limit and the upper limit.

In this specification, (meth)acrylate means acrylate and methacrylate, and (meth)acrylic means acrylic and methacrylic acid. In this specification, the weight average molecular weight (Mw), number average molecular weight (Mn), and degree of dispersion (also called molecular weight distribution) (Mw/Mn) of the resin components are defined as the use of gel permeation chromatography (Gel Permeation Chromatography). GPC measurement (solvent: tetrahydrofuran, flow rate (sample injection volume): 10 μL, column: manufactured by Tosoh (stock) HLC-8120GPC) device (Tosoh (stock) HLC-8120GPC) TSK gel Multipore HXL-M, column temperature: 40°C, flow rate: 1.0 mL/min, detector: Refractive Index Detector (Refractive Index Detector).

Regarding the amount of each component in the composition in this specification, when there are multiple types of substances corresponding to each component in the composition, unless otherwise specified, it refers to the total amount of the multiple types of conforming substances present in the composition. The term "step" in this specification includes not only independent steps, but even when it cannot be clearly distinguished from other steps, as long as the desired purpose of the step can be achieved, it is also included in this term. In this manual, "mass%" and "weight%" have the same meaning, and "parts by mass" and "parts by weight" have the same meaning. In addition, in this specification, a combination of two or more preferable aspects is a more preferable aspect.

(Composition for forming resist underlayer film) The composition for forming a resist underlayer film of the present invention (hereinafter also simply referred to as "composition") contains: a resin having an aromatic ring, and a compound represented by the following general formula (1), the resist underlayer In the composition for film formation, The content of the compound represented by the general formula (1) is 0.1 mass ppm or more and 500 mass ppm or less with respect to the total mass of the composition for forming a resist underlayer film.

[化4]

In the general formula (1), R ₁ to R ₃ each independently represent an alkyl group having 1 to 5 carbon atoms.

By adopting the above structure, the composition of the present invention can solve the problem of the present invention that the generation of coating defects after time is suppressed and the flatness after time is excellent. The reason is not clear, but the inventors of the present invention consider the following. The acid generator or crosslinking agent that can be contained in the composition for forming a resist underlayer film is usually a compound with high polarity and high hydrophilicity, so it is easy to aggregate. In particular, when the composition for forming a resist underlayer film is allowed to elapse, when the composition is used to form a resist underlayer film, the acid generator or the crosslinking agent tends to aggregate. If the acid generator or crosslinking agent aggregates in the film after the resist underlayer film is formed, in the subsequent heating step, the agglomerated part of the acid generator or crosslinking agent crosses very quickly compared to the peripheral part. Joint reaction. Therefore, it is considered that the film is deformed due to the volatilization of the desorbed component accompanying the reaction or the change in the stress of the film, and as a result, it becomes a coating defect after the heating step. The composition for forming a resist underlayer film of the present invention contains a compound represented by general formula (1). The compound represented by the general formula (1) is β-type alkanediol monoalkyl ether acetate (for example, β-type propylene glycol monomethyl ether acetate (β-PGMEA), etc.), and its boiling point is comparable to that of α-type alkanediol mono Since the alkyl ether acetate (for example, α-PGMEA (α-PGMEA), etc.) is different, it tends to remain in the film when the composition for forming a resist underlayer film is formed (before the heating step). In addition, the compound represented by the general formula (1) has a high affinity for the acid generator and the crosslinking agent, and can inhibit aggregation of the acid generator and the crosslinking agent during film formation. This allows the uniformity of the crosslinking reaction to be good, and therefore it is considered that the generation of coating defects in the composition for forming a resist base film can be suppressed over time.

In addition, the composition for forming a resist underlayer film of the present invention contains the formula (1) represented by the general formula (1) in a specific range of 0.1 mass ppm or more and 500 mass ppm or less with respect to the total mass of the resist underlayer film forming composition Compound. As mentioned above, the compound represented by the general formula (1) is β-type alkanediol monoalkyl ether acetate (for example, β-PGMEA, etc.), and its boiling point is similar to that of α-type alkanediol monoalkyl ether acetate. (For example, α-PGMEA, etc.) are different. Therefore, if it is contained in a large amount in the composition for forming a resist underlayer film, the amount of residual solvent in the resist underlayer film will be too large. Thereby, the mobility of the acid generator or the crosslinking agent in the resist underlayer film is increased, and the crosslinking reaction in the heating step is promoted. Originally, in the heating step, the film flows due to heat to obtain excellent flatness, but due to the promotion of the crosslinking reaction, fluidity is lost, and the flatness of the film is reduced. Therefore, in the present invention, the compound represented by the general formula (1) is contained in a specific range, and the composition for forming a resist underlayer film is excellent in flatness.

The resist underlayer film formed from the composition for forming a resist underlayer film of the present invention is typically a spin on carbon (SOC) layer used in a multilayer resist process for semiconductors.

Hereinafter, the details of each component contained in the composition for forming a resist underlayer film of the present invention will be described.

<The compound represented by the general formula (1)> The composition of the present invention contains the compound represented by the general formula (1).

[化5]

In the general formula (1), R ₁ to R ₃ each independently represent an alkyl group having 1 to 5 carbon atoms.

The C1-C5 alkyl group represented by R ₁ to R _{3 may be linear or branched.} The alkyl group having 1 to 5 carbon atoms represented by R ₁ to R ₃ may not have a substituent (unsubstituted alkyl group), or may have a substituent. Preferably, R ₁ to R ₃ each independently represent an alkyl group having 1 to 3 carbon atoms, more preferably each independently represent a methyl group or an ethyl group, and more preferably represent a methyl group. In the _{case where R 1} to R ₃ are methyl groups, the compound represented by the general formula (1) represents β-type PGMEA (β-PGMEA).

The composition of the present invention may contain only one compound represented by the general formula (1), or two or more kinds.

The content of the compound represented by the general formula (1) is 0.1 mass ppm or more and 500 mass ppm or less with respect to the total mass of the composition for forming a resist underlayer film. Furthermore, "ppm" is the abbreviation for "parts per million". In addition, "mass ppm" means ppm on a mass basis. When the compound represented by the general formula (1) is only one compound, the content of the compound represented by the general formula (1) becomes the content of the compound. In addition, when there are two or more compounds represented by the general formula (1), the content of the compound represented by the general formula (1) is the total (total amount) of the content of each compound. If the content of the compound represented by the general formula (1) is less than 0.1 mass ppm with respect to the total mass of the composition for forming a resist underlayer film, coating defects over time are likely to occur. In addition, if the content of the compound represented by the general formula (1) exceeds 500 mass ppm with respect to the total mass of the composition for forming a resist underlayer film, the flatness is likely to decrease.

For the reason that coating defects after time can be further suppressed, the content of the compound represented by the general formula (1) is preferably 0.5 mass ppm or more relative to the total mass of the composition for forming a resist underlayer film. More preferably, it is 1 mass ppm or more, still more preferably 10 mass ppm or more, and particularly preferably 15 mass ppm or more. In addition, the content of the compound represented by the general formula (1) is preferably 400 ppm by mass relative to the total mass of the composition for forming a resist underlayer film for the reason that the coating defect after time can be further suppressed Hereinafter, it is more preferably 300 ppm by mass or less, still more preferably 200 ppm by mass or less, particularly preferably 100 ppm by mass or less, and most preferably 50 ppm by mass or less.

The method of adjusting the content of the compound represented by the general formula (1) is not particularly limited. For example, when the compound represented by the general formula (1) is β-PGMEA, a method of adding separated β-PGMEA to the composition for forming a resist base film or the solvent used for the preparation thereof can be used. In addition, as isolated β-PGMEA (cas number 70657-70-4), a commercially available product can also be used. In addition, a mixture obtained by distilling a mixture of α-PGMEA and β-PGMEA (for example, generally commercially available PGMEA, etc.) to separate α-PGMEA and β-PGMEA can also be used. Furthermore, PGMEA can be manufactured using PGME as a raw material, but the content of β-PGMEA can be adjusted by manufacturing PGMEA by using PGME that controls the production of β isomer as a raw material.

The content of the compound represented by the general formula (1) in the composition for forming a resist underlayer film can be quantified using gas chromatography/mass analysis (GC/MS).

<The compound represented by the general formula (2)> The composition of the present invention preferably further contains a compound represented by the following general formula (2). The composition of the present invention preferably contains a compound represented by the following general formula (2) in an amount of 0.1 mass ppm or more and 500 mass ppm or less with respect to the total mass of the composition of the invention.

[化6]

In the general formula (2), R ₄ and R ₅ each independently represent an alkyl group having 1 to 5 carbon atoms.

The C1-C5 alkyl group represented by R ₄ and R _{5 may be linear or branched.} The carbon number of R ₄ and R ₅ represents an alkyl group having 1 to 5 may not have a substituent (unsubstituted alkyl), may have a substituent. The R ₄ and R ₅ preferably each independently represent an alkyl group having 1 to 3 carbon atoms, more preferably each independently represent a methyl group or an ethyl group, and more preferably represent a methyl group. In the _{case where R 4} and R ₅ are methyl groups, the compound represented by the general formula (2) represents β-type propylene glycol monomethyl ether (β-PGME). When R ₄ is a methyl group and R ₅ is an ethyl group, the compound represented by the general formula (2) represents β-type propylene glycol monoethyl ether (β-PGEE).

The composition of the present invention may contain only one compound represented by the general formula (2), or two or more kinds.

By containing 0.1 mass ppm or more of the compound represented by general formula (2) with respect to the total mass of the composition of the present invention, it is possible to further suppress the occurrence of coating defects over time, which is preferable. It is believed that the reason is that the compound represented by the general formula (2) (typically a primary alcohol) has little steric hindrance, and has a high affinity for acid generators or crosslinking agents, and can inhibit acid generators during film formation. Or agglomeration of the cross-linking agent, thereby increasing the uniformity of the cross-linking reaction. In addition, by containing 1% by mass or less of the compound represented by the general formula (2) with respect to the total mass of the composition of the present invention, flatness can be further improved, which is preferable. The compound represented by the general formula (2) (β-type alkanediol monoalkyl ether) is more hydrophilic than α-type alkanediol monoalkyl ether, and has less steric hindrance, so it has the effect of promoting the crosslinking reaction. If contained in a large amount, the crosslinking reaction is promoted in the heating step, the fluidity of the film is lost, and the flatness is likely to decrease. Therefore, it is considered that by containing 1% by mass or less of the compound represented by the general formula (2) with respect to the total mass of the composition of the present invention, the decrease in flatness can be suppressed. For the reason that coating defects after time can be further suppressed, the content of the compound represented by the general formula (2) is preferably 0.5 mass ppm or more, and more preferably 1 relative to the total mass of the composition of the present invention. Mass ppm or more, more preferably 10 mass ppm or more, particularly preferably 15 mass ppm or more. In addition, the content of the compound represented by the general formula (2) is preferably 500 mass ppm or less, more preferably, for the reason that the coating defect after time can be further suppressed, relative to the total mass of the composition of the present invention It is 300 mass ppm or less, more preferably 200 mass ppm or less, particularly preferably 100 mass ppm or less, and most preferably 50 mass ppm or less.

When the compound represented by the general formula (2) is only one compound, the content of the compound represented by the general formula (2) becomes the content of the compound. In addition, when there are two or more compounds represented by the general formula (2), the content of the compound represented by the general formula (2) is the total (total) content of each compound.

The method of adjusting the content of the compound represented by general formula (2) is not particularly limited. For example, when the compound represented by the general formula (2) is β-PGME, a method of adding the separated β-PGME to the composition for forming a resist underlayer film or the solvent used for its preparation can be used. In addition, as isolated β-PGME (cas number 1589-47-5), a commercially available product can also be used. In addition, a mixture obtained by distilling a mixture of α-PGME and β-PGME (for example, generally commercially available PGME, etc.) to separate α-PGME and β-PGME may also be used. Furthermore, it can also be used for PGME which controls the production of β isomer at the time of manufacture. In addition, for example, when the compound represented by the general formula (2) is β-PGEE, a method of adding isolated β-PGEE to the composition for forming a resist underlayer film or the solvent used for its preparation can be used . In addition, as isolated β-PGEE (cas number 19089-47-5), a commercially available product can also be used. In addition, a mixture obtained by distilling a mixture of α-PGEE and β-PGEE (for example, generally commercially available PGEE, etc.) to separate α-PGEE and β-PGEE can also be used. Furthermore, it can also be used for PGEE which controls the production of β isomers at the time of manufacture.

The content of the compound represented by the general formula (2) in the composition for forming a resist underlayer film can be quantified using gas chromatography/mass analysis (GC/MS).

＜Water＞ The composition of the present invention preferably further contains water. Water has a high affinity for the compound represented by the general formula (1) or the compound represented by the general formula (2), and the composition of the present invention contains water, thereby forming a corrosion inhibitor using the composition of the present invention. In the case of a base film, water is likely to remain in the film together with the compound represented by the general formula (1) or the compound represented by the general formula (2), and the effects brought by these compounds are more likely to be exerted , Therefore better.

The composition of the present invention preferably contains 1 mass ppm or more and 2 mass% or less of water with respect to the total mass of the composition of the present invention, and more preferably contains 1 mass ppm or more and 1 mass% or less of water.

In terms of making the flatness better, the content of water relative to the total mass of the composition of the present invention is preferably 1 mass ppm or more, more preferably 10 mass ppm or more, and still more preferably 0.01 mass% (100 Mass ppm) or more, particularly preferably 0.1 mass% (1000 mass ppm) or more. With respect to the total mass of the composition of the present invention, the water content is preferably 2% by mass (20,000 mass ppm) or less, more preferably 1% by mass (10,000 mass ppm) or less, and still more preferably 0.5% by mass (5,000 mass ppm) )the following. If a large amount of water is contained, the reaction field becomes hydrophilic, and therefore the cross-linking reaction in the heating step is promoted, and the fluidity of the film is lost and the flatness sometimes decreases. If the water content is within the above range, the decrease in flatness can be suppressed .

As the water, for example, pure water and ultrapure water can be used.

The method of adjusting the content of water is not particularly limited. For example, a method of preliminarily mixing a predetermined amount of water in a solvent used for preparing a composition for forming a resist underlayer film, or using, for example, a molecular sieve for a composition for forming a resist underlayer film containing water And other general dehydration methods.

The content of water in the composition for forming a resist underlayer film can be measured using a Karl Fischer moisture meter.

<The compound represented by the general formula (3)> The composition of the present invention preferably further contains a compound represented by the following general formula (3). The composition of the present invention preferably contains a compound represented by the following general formula (3), and the content of the compound represented by the general formula (1) relative to the compound represented by the following general formula (3) is 0.1 mass ppm or more and 0.05 mass% or less, more preferably 1 mass ppm or more and 0.005 mass% or less.

[化7]

In the general formula (3), R ₆ to R ₈ each independently represent an alkyl group having 1 to 5 carbon atoms.

The alkyl group having 1 to 5 carbon atoms represented by R ₆ to R _{8 may be linear or branched.} The alkyl group having 1 to 5 carbon atoms represented by R ₆ to R ₈ may not have a substituent (unsubstituted alkyl group), or may have a substituent. Preferably, R ₆ to R ₈ each independently represent an alkyl group having 1 to 3 carbon atoms, more preferably each independently represents a methyl group or an ethyl group, and more preferably each independently represents a methyl group. When R ₆ to R ₈ are methyl groups, the compound represented by the general formula (3) represents α-PGMEA (α-PGMEA).

The compound represented by the general formula (3) has a structure similar to the compound represented by the general formula (1), and therefore has high affinity with the compound represented by the general formula (1). In addition, if the compound represented by the general formula (1) and the compound represented by the general formula (3) coexist, the solubility of the acid generator or the crosslinking agent becomes high, and the composition of the present invention is used to form a resist underlayer film In this case, the aggregation of the acid generator or the crosslinking agent is easily suppressed, and the effect is easily exhibited, which is preferable.

When the composition of the present invention contains not only the compound represented by the general formula (1) but also the compound represented by the general formula (3), R ₆ in the general formula (3) is preferably the same as the general formula (1) R ₁ in the general formula (3) is the same, R ₇ in the general formula (3) is preferably the _{same as R 2} in the general formula (1), and R ₈ in the general formula (3) is preferably the same as that in the general formula (1). R _{3 is the} same. Thereby, the affinity of the compound represented by general formula (3) and the compound represented by general formula (1) is very high, and the said effect can be exhibited more easily.

The composition of the present invention may contain only one compound represented by the general formula (3), or two or more kinds.

When the compound represented by the general formula (3) is only one compound, the content of the compound represented by the general formula (3) becomes the content of the compound. In addition, when there are two or more compounds represented by the general formula (3), the content of the compound represented by the general formula (3) is the total (total amount) of the content of each compound.

The compound represented by the general formula (3) can be used, for example, as a solvent described later. When the compound represented by the general formula (3) is used as a solvent, it is preferable to use the compound represented by the general formula (3) so that the solid content concentration of the composition of the present invention becomes 0.1% by mass to 55% by mass The solvent of the compound is more preferably a solvent containing the compound represented by the general formula (3) so as to be 1% by mass to 50% by mass, and it is more preferred to use a solvent containing the compound represented by the general formula (3) so as to be 2% by mass to 50% by mass. The solvent of the compound represented by the formula (3) is particularly preferably a solvent containing the compound represented by the general formula (3) so as to be 3% to 45% by mass, and it is most preferable to be 3% to 40% by mass The% method uses a solvent containing the compound represented by the general formula (3). In the case of using the compound represented by the general formula (3) as the solvent in the composition of the present invention, the mass of the compound represented by the general formula (3) relative to the total mass of the solvent is preferably 50% by mass or more and 100% by mass or less. The so-called "solid content" in the composition of the present invention means removing the solvent, water, the compound represented by the general formula (1), and the compound represented by the general formula (2) from all the components contained in the composition of the present invention The compound and the components after the compound represented by the general formula (3) may be solid or liquid at 25°C, for example. In addition, the "total solid content" in the composition of the present invention means removing the solvent, water, the compound represented by the general formula (1), the compound represented by the general formula (2), and the And the total mass of the components after the compound represented by the general formula (3).

The method of adjusting the content of the compound represented by general formula (3) is not particularly limited. For example, when the compound represented by the general formula (3) is α-PGMEA, the separated α-PGMEA can be added to the preparation of the resist base film formation composition or used as a solvent. In addition, as isolated α-PGMEA (cas number 108-65-6), a commercially available product can also be used. In addition, a mixture obtained by distilling a mixture of α-PGMEA and β-PGMEA (for example, generally commercially available PGMEA, etc.) to separate α-PGMEA and β-PGMEA can also be used.

The content of the compound represented by the general formula (3) in the composition for forming a resist underlayer film can be quantified using gas chromatography/mass analysis (GC/MS).

＜Resin with aromatic ring＞ The composition for forming a resist underlayer film of the present invention contains a resin having an aromatic ring. As the resin having an aromatic ring, conventionally known materials can be suitably used. A resin having an aromatic ring typically does not have an acid-decomposable group (specifically, an acid-decomposable group in the resin (A) described later). Among them, the resin having an aromatic ring may have an acid-decomposable group. As the resin having an aromatic ring, for example, (meth)acrylic resin, styrene resin, cellulose resin, phenol resin (novolak resin), and the like can be used. In addition, as other resins, aromatic polyester resins, aromatic polyimide resins, polybenzoxazole resins, aromatic polyamide resins, acenaphthylene resins, isocyanuric acid resins, and the like can be used.

In particular, as the aromatic polyimide resin and aromatic polyimide resin, for example, the resin compound described in Japanese Patent No. 4120584, the resin compound described in Japanese Patent No. 4466877 [0021] to [0053], Resin compounds described in Japanese Patent No. 4525940 [0025] to [0050]. In addition, as the novolak resin, resin compounds described in Japanese Patent Nos. 5215825 [0015] to [0058] and Japanese Patent Nos. 5257009 [0023] to [0041] can be used. In addition, as the acenaphthene-based resin, for example, the resin compound described in Japanese Patent No. 4666166 [0032] to [0052], the resin compound described in Japanese Patent No. 04388429 [0037] to [0043], and Japanese Patent No. 5040839 [ 0026] to [0065], the polymer described in Japanese Patent No. 4892670 [0015] to [0032], and the like.

The resin having an aromatic ring is also preferably a resin containing a repeating unit having a hydroxyl group as a crosslinking reaction group. Moreover, it is also preferable that the resin which has an aromatic ring contains the repeating unit which has a lactone structure mentioned later in resin (A). In the resin having an aromatic ring, a non-crosslinkable monomer can also be copolymerized, thereby allowing fine adjustments of dry etching rate, reflectance, and the like. As such a comonomer, the following can be mentioned. For example, it is selected from acrylic esters, acrylamides, methacrylates, methacrylamides, allyl compounds, vinyl ethers, vinyl esters, styrenes, crotonates, etc. A compound with one addition polymerizable unsaturated bond.

As acrylic esters, for example, alkyl acrylates having 1 to 10 carbon atoms in the alkyl group can be cited.

Examples of the methacrylates include alkyl methacrylates having 1 to 10 carbon atoms in the alkyl group.

Examples of acrylamides include: acrylamide, or N-alkylacrylamide, N-arylacrylamide, N,N-dialkylacrylamide, and N,N-diarylacrylamide Amine, N-methyl-N-phenylacrylamide, N-2-acetamide ethyl-N-acetylacrylamide, etc.

Examples of methacrylamides include: methacrylamide, N-alkylmethacrylamide, N-arylmethacrylamide, and N,N-dialkylmethacrylamide , N,N-diarylmethacrylamide, N-methyl-N-phenylmethacrylamide, N-ethyl-N-phenylmethacrylamide, etc.

Examples of vinyl ethers include alkyl vinyl ethers and vinyl aryl ethers.

Examples of vinyl esters include vinyl butyrate, vinyl isobutyrate, and vinyl trimethyl acetate.

Examples of styrenes include styrene, alkyl styrene, alkoxy styrene, halogen styrene, and the like.

Examples of crotonates include alkyl crotonates such as butyl crotonate, hexyl crotonate, and glyceryl monocrotonate.

In addition, dialkyl esters of itaconic acid, dialkyl esters or monoalkyl esters of maleic acid or fumaric acid, crotonic acid, itaconic acid, maleic anhydride, maleimide, Acrylonitrile, methacrylonitrile, maleonitrile, etc. In addition, generally, it can be used as long as it is an addition polymerizable unsaturated compound that can be copolymerized with a polymer containing at least one crosslinking reaction group, that is, a hydroxyl group per repeating unit.

The resin having an aromatic ring may be any of a random polymer, a block polymer, or a graft polymer. Resins with aromatic rings can be synthesized by methods such as radical polymerization, anionic polymerization, and cationic polymerization. The form can be various methods such as solution polymerization, suspension polymerization, emulsion polymerization, and bulk polymerization.

In addition, as the resin having an aromatic ring, various phenolic polymers having a phenolic structure can be preferably used. Preferably, a novolak resin, a p-hydroxystyrene homopolymer, a meta-hydroxystyrene homopolymer, a copolymer polymer having a p-hydroxystyrene structure, and a copolymer polymer having a meta-hydroxystyrene structure are mentioned. In these copolymerization polymers, it is preferable to have a repeating unit represented by the following general formula (1P) as a copolymerization part.

[化8]

In the formula, R ₁₀ represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, a cyano group, or a halogen atom, and is preferably a hydrogen atom or a methyl group. L ₁ represents a single bond, -COO-, -CON(R ₃ )-, or an arylene group, and R ₃ represents a hydrogen atom and an alkyl group having 1 to 3 carbon atoms. L ₁ is preferably a single bond, -COO-, or phenylene. L ₂ represents a single bond, a C1-C10 alkylene group, a C6-C18 arylene group, -COO-, -O-, preferably a single bond, a C1-C4 alkylene group, Phenylene. Rb represents an alkyl group having 1 to 10 carbons, a cycloalkyl group having 4 to 30 carbons, a bridged cycloalicyclic hydrocarbon group having 5 to 25 carbons, an aryl group having 6 to 18 carbons, and preferably represents a carbon number of 1 ～8 alkyl (methyl, ethyl, butyl, tertiary butyl, etc.), carbon 5-8 cycloalkyl (cyclohexyl, cyclooctyl, etc.), carbon 5-20 bridged cycloaliphatic Cyclic hydrocarbon groups, aryl groups with 6 to 12 carbons (phenyl, naphthyl, etc.). These groups may have substituents. Examples of substituents include halogen atoms (Cl, Br, etc.), cyano groups, alkyl groups having 1 to 4 carbons, hydroxyl groups, alkoxy groups having 1 to 4 carbons, An acyl group having 1 to 4 carbons, and an aryl group having 6 to 12 carbons. The preferable skeleton of the bridged cycloalicyclic hydrocarbon group having 5 to 20 carbon atoms is listed below.

[化9]

[化10]

Particularly good examples of these bases include: (5), (6), (7), (8), (9), (10), (13), (14), (15), ( 23), (28), (36), (37), (40) (42), (47).

In the case where the resin having an aromatic ring is the copolymerized polymer, the content of the repeating unit represented by the general formula (1P) is preferably 0 mol% to 80 mol% relative to all repeating units of the copolymerized polymer , More preferably 0 mol%～60 mol%. In addition, the copolymer may be a copolymer having other repeating units for the purpose of improving film-forming properties, adhesiveness, developability, etc., in addition to the repeating units described above.

The resin having an aromatic ring may be a copolymer that contains, in addition to the repeating unit represented by the general formula (1P), other repeating units for the purpose of improving film-forming properties, adhesiveness, developability, and the like. As a monomer corresponding to such other repeating unit, for example, it can be selected from acrylates, methacrylates, acrylamides, methacrylamides, allyl compounds, vinyl ethers, Compounds with one addition polymerizable unsaturated bond among vinyl esters.

Specifically, for example, there are acrylic acid esters, such as acrylic acid alkyl (preferably an alkyl group having 1 to 10 carbon atoms) esters (for example, methyl acrylate, ethyl acrylate, propyl acrylate, acrylic acid). Amyl ester, cyclohexyl acrylate, ethylhexyl acrylate, octyl acrylate, third octyl acrylate, chloroethyl acrylate, trimethylolpropane monoacrylate, pentaerythritol monoacrylate, benzyl acrylate, methyl acrylate Oxybenzyl, furfuryl acrylate, tetrahydrofurfuryl acrylate, etc.);

Methacrylates, such as alkyl methacrylate (preferably an alkyl group with 1 to 10 carbon atoms) esters (such as methyl methacrylate, ethyl methacrylate, propyl methacrylate) , Isopropyl methacrylate, amyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, chlorobenzyl methacrylate, octyl methacrylate, trimethylol Propane monomethacrylate, pentaerythritol monomethacrylate, furfuryl methacrylate, tetrahydrofurfuryl methacrylate, etc.);

Acrylic amines, such as acrylamide, N-alkyl acrylamide (as the alkyl group, there are alkyl groups with 1 to 10 carbon atoms, such as methyl, ethyl, propyl, butyl, tertiary butyl , Heptyl, octyl, cyclohexyl, hydroxyethyl, etc.), N,N-dialkylacrylamide (as the alkyl group, there are alkyl groups with 1 to 10 carbon atoms, such as methyl, ethyl, butyl Group, isobutyl, ethylhexyl, cyclohexyl, etc.), N-hydroxyethyl-N-methacrylamide, N-2-acetamide ethyl-N-acetylacrylamide, etc.;

Methacrylamides, such as methacrylamide, N-alkylmethacrylamide (as the alkyl group, there are alkyl groups with 1 to 10 carbon atoms, such as methyl, ethyl, tertiary butyl , Ethylhexyl, hydroxyethyl, cyclohexyl, etc.), N,N-dialkylmethacrylamide (as an alkyl group, there are ethyl, propyl, butyl, etc.), N-hydroxyethyl-N -Methacrylamide, etc.;

Allyl compounds, such as allyl esters (for example, allyl acetate, allyl caproate, allyl octanoate, allyl laurate, allyl palmitate, allyl stearate Propyl ester, allyl benzoate, allyl acetoacetate, allyl lactate, etc.), allyloxyethanol, etc.;

Vinyl ethers, such as alkyl vinyl ethers (such as hexyl vinyl ether, octyl vinyl ether, decyl vinyl ether, ethylhexyl vinyl ether, methoxyethyl vinyl ether, ethoxy ethyl Vinyl ether, chloroethyl vinyl ether, 1-methyl-2,2-dimethylpropyl vinyl ether, 2-ethylbutyl vinyl ether, hydroxyethyl vinyl ether, diethylene Alcohol vinyl ether, dimethylaminoethyl vinyl ether, diethylaminoethyl vinyl ether, butylaminoethyl vinyl ether, benzyl vinyl ether, tetrahydrofurfuryl vinyl ether Wait);

Vinyl esters, such as vinyl butyrate, vinyl isobutyrate, vinyl trimethyl acetate, vinyl diethyl acetate, vinyl pivalate, vinyl caproate, chloroacetic acid Vinyl ester, vinyl dichloroacetate, vinyl methoxyacetate, vinyl butoxyacetate, vinyl acetylacetate, vinyl lactate, vinyl β-phenylbutyrate, ring Vinyl hexyl carboxylate, etc.;

Dialkyl itaconate esters (such as dimethyl itaconate, diethyl itaconate, dibutyl itaconate, etc.); dialkyl fumarate (such as dibutyl fumarate) Etc.) or monoalkyl esters; acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic anhydride, maleimide, acrylonitrile, methacrylonitrile, maleonitrile, etc. In addition to this, it is sufficient as long as it is an addition polymerizable unsaturated compound copolymerizable with the various repeating units described above.

As a preferable example of a phenolic polymer, the following can be mentioned. In the following specific examples, the ratio of repeating units is molar ratio.

[化11]

[化12]

As a preferable specific example of the resin which has an aromatic ring, A-1 to A-15 used in an Example can also be mentioned.

The weight average molecular weight (Mw) of the resin having an aromatic ring is not particularly limited, but is preferably 1,000 to 100,000, more preferably 2,000 to 50,000, and still more preferably 3,000 to 20,000.

One type of resin having an aromatic ring may be used, or two or more types may be used. The content of the resin having an aromatic ring relative to the total solid content of the composition for forming a resist underlayer film of the present invention is preferably 20% by mass or more, more preferably 40% by mass or more, and still more preferably 60% by mass or more, Particularly preferred is 80% by mass or more. The upper limit is not particularly limited, but is preferably 99.5% by mass or less, more preferably 99% by mass or less, and still more preferably 97% by mass or less.

In a preferred embodiment, the composition for forming a resist underlayer film of the present invention may include a solvent, an acid generator, a crosslinking agent, a surfactant, etc., in addition to a resin having an aromatic ring. In this case, it is preferable to form a cross-linked film by exposing or heating the coating film formed from the composition for forming a resist underlayer film, which is used as a resist underlayer film. The composition for forming a resist underlayer film of the present invention particularly preferably contains a thermal acid generator and a crosslinking agent. When the composition for forming a resist underlayer film of the present invention contains a thermal acid generator and a crosslinking agent, the composition for forming a resist underlayer film is applied to a substrate to form a coating film, and then heated (preferably at Heating above 200°C), by which cross-linking reaction (preferably a cross-linking reaction in which the acid generated by the thermal acid generator is used as a catalyst and the cross-linking agent reacts with the hydroxyl group in the resin having an aromatic ring) can be used. A resist underlayer film is formed.

<Acid Generator> The composition for forming a resist underlayer film of the present invention preferably contains an acid generator (typically at least one of a photoacid generator and a thermal acid generator). The acid generator is a component that generates acid by exposure or heating. By including an acid generator in the composition for forming a resist underlayer film, the acid generated by the acid generator can be used as a catalyst to perform a crosslinking reaction. In addition, by including an acid generator in the resist underlayer film formation composition, it is possible to eliminate the crosslinking reaction hindrance in the resist underlayer film (due to substances generated from the substrate (especially low-dielectric film) (for example, (Substances having basic groups such as OH-, CH ₃ -, NH ₂ -) diffuse into the resist underlayer film, deactivate the acid in the resist underlayer film, and hinder the crosslinking reaction). That is, by reacting the acid generator in the formed resist underlayer film with the barrier substance, it is possible to prevent the barrier substance from diffusing into the resist underlayer film. Among the acid generators, the acid generators that generate acid by exposure (hereinafter also referred to as "photoacid generators") include, for example, those described in the paragraphs of International Publication No. 07/105776 pamphlet [0076] to [0081] The compound and so on.

Among these photoacid generators, diphenylidium trifluoromethanesulfonate, diphenylinium nonafluoro-n-butanesulfonate, diphenylipyrene sulfonate, and diphenylinium-n-dodecane are preferred. Benzene sulfonate, diphenylidium 10-camphorsulfonate, diphenylinium naphthalenesulfonate, bis(4-tertiary butylphenyl) iodotrifluoromethanesulfonate, bis(4-th Tributylphenyl) iodonium nonafluoro-n-butanesulfonate, bis(4-tertiary butylphenyl) iododecylbenzenesulfonate, bis(4-tertiarybutylphenyl) iodonium 10 -Camphorsulfonate, bis(4-tert-butylphenyl) naphthalene sulfonate, more preferably bis(4-tert-butylphenyl) nonafluoro-n-butanesulfonate. In addition, these photoacid generators can be used individually or in mixture of 2 or more types. As a photoacid generator, the photoacid generator mentioned later can also be used suitably in a resist composition.

In addition, examples of acid generators (thermal acid generators) that generate acid by heating include 2,4,4,6-tetrabromocyclohexadienone, benzoin tosylate, and 2-nitro Benzyl toluene sulfonate, alkyl sulfonate, etc. These thermal acid generators can be used alone or in combination of two or more. Furthermore, as an acid generator, a photoacid generator and a thermal acid generator can also be used together.

As a preferable specific example of an acid generator, T-1 to T-9 used in an Example can also be mentioned.

The content of the acid generator is preferably 100 parts by mass or less relative to 100 parts by mass of the resin having an aromatic ring, more preferably 0.1 parts by mass to 30 parts by mass, and particularly preferably 0.1 parts by mass to 10 parts by mass.

＜Crosslinking agent＞ When the composition for forming a resist underlayer film of the present invention contains a crosslinking agent, the resist underlayer film can be cured at a lower temperature to form a protective film with respect to the substrate to be processed. As such a crosslinking agent, in addition to polynuclear phenols, various hardeners can be used. Examples of the polynuclear phenols include binuclear phenols such as 4,4'-biphenyldiol, 4,4'-methylene bisphenol, 4,4'-ethylene bisphenol, and bisphenol A. ; 4,4',4''-Methylene triphenol, 4,4'-[1-[4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl]ethylene Base] trinuclear phenols such as bisphenol; polyphenols such as novolac. Among these, 4,4'-[1-[4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl]ethylene]bisphenol and novolac are preferred. Moreover, these polynuclear phenols can be used individually or in mixture of 2 or more types. In addition, examples of the curing agent include diisocyanates, epoxy compounds, melamine curing agents, benzoguanamine curing agents, glycoluril curing agents, and the like. Among these, melamine-based hardeners and glycoluril-based hardeners are preferred, and 1,3,4,6-tetra(methoxymethyl)glycururil is more preferred. Furthermore, these hardeners can be used alone or in combination of two or more kinds. In addition, as a crosslinking agent, a polynuclear phenol and a hardener may be used in combination.

As preferred specific examples of the crosslinking agent, CL-1 to CL-10 used in the examples can also be cited.

The content of the crosslinking agent is preferably 100 parts by mass or less with respect to 100 parts by mass of the resin having an aromatic ring, more preferably 1 part by mass to 20 parts by mass, and particularly preferably 1 part by mass to 10 parts by mass.

＜Solvent＞ The composition for forming a resist underlayer film of the present invention may contain any solvent. As the solvent, for example, alkanediol monoalkyl ether carboxylate, alkanediol monoalkyl ether, alkyl lactate, alkyl alkoxypropionate, cyclic lactone (preferably carbon number 4-10), monoketone compounds that may have a ring (preferably carbon number 4-10), organic solvents such as alkylene carbonate, alkyl alkoxyacetate, alkyl pyruvate, etc. Specific examples of these solvents include those described in [0441] to [0455] in the specification of U.S. Patent Application Publication No. 2008/0187860.

In the present invention, a mixed solvent obtained by mixing a solvent containing a hydroxyl group in a structure and a solvent not containing a hydroxyl group can be used as an organic solvent. As a solvent containing a hydroxyl group and a solvent not containing a hydroxyl group, the exemplified compounds can be appropriately selected. As the solvent containing a hydroxyl group, an alkanediol monoalkyl ether, an alkyl lactate, etc. are preferred, and propylene glycol monomethyl is more preferred. Ether (alias 1-methoxy-2-propanol), ethyl lactate, methyl 2-hydroxyisobutyrate. In addition, as a solvent that does not contain a hydroxyl group, an alkanediol monoalkyl ether acetate, an alkyl alkoxy propionate, a ring-containing monoketone compound, a cyclic lactone, an alkyl acetate, etc. are preferred. Among these, particularly preferred are propylene glycol monomethyl ether acetate (alias 1-methoxy-2-acetoxypropane), ethyl ethoxy propionate, 2-heptanone, and γ-butyrolactone , Cyclohexanone, butyl acetate, most preferably propylene glycol monomethyl ether acetate, ethyl ethoxy propionate, 2-heptanone. The mixing ratio (mass) of the hydroxyl-containing solvent and the hydroxyl-free solvent is 1/99 to 99/1, preferably 10/90 to 90/10, and more preferably 20/80 to 60/40. In terms of coating uniformity, a mixed solvent containing 50% by mass or more of a solvent that does not contain a hydroxyl group is particularly preferable. The solvent preferably contains propylene glycol monomethyl ether acetate, more preferably propylene glycol monomethyl ether acetate alone or a mixed solvent of two or more containing propylene glycol monomethyl ether acetate. As preferred specific examples of the solvent, F-1 to F-9 used in the examples can also be cited.

The lower limit of the solid content concentration of the resist base film forming composition is preferably 0.1% by mass or more, more preferably 1% by mass or more, still more preferably 2% by mass or more, and particularly preferably 3% by mass or more. The upper limit of the solid content concentration is preferably 55% by mass or less, more preferably 50% by mass or less, still more preferably 45% by mass or less, and particularly preferably 40% by mass or less.

＜Other optional ingredients＞ In addition to the above-mentioned components, the composition for forming a resist underlayer film may contain other optional components such as a thermosetting polymer, a radiation absorber, a storage stabilizer, an antifoaming agent, and an adhesive agent as necessary.

(Pattern forming method) Next, the pattern forming method of the present invention will be described. The pattern forming method of the present invention preferably includes: (1) A step of forming a resist underlayer film on a substrate using the composition for forming a resist underlayer film of the present invention; (2) The step of forming a resist film with a resist composition on the resist underlayer film; (3) The step of exposing the resist film; (4) The step of developing the exposed resist film to form a resist pattern; and (5) A step of etching the resist pattern as a mask to form a pattern.

[Step (1)] Step (1) of the pattern forming method of the present invention is to form a resist base film on a substrate (also referred to as a "substrate to be processed") using the resist base film forming composition of the present invention A step of. The substrate to be processed in step (1) may be disposed on the base layer. The base layer, and the material substrate to be processed is not particularly limited, each may be used, for example silicon, SiN, SiO ₂ and other inorganic substrates, SOG (Spin on Glass, SOG) substrate or the like based inorganic coating and the like, integrated circuit (Integrated Circuit, IC) and other semiconductor manufacturing steps, circuit boards such as liquid crystals, thermal heads, and other circuit substrates, and other substrates generally used in photolithography steps of photosensitive etching processing. In particular, as the substrate to be processed, a silicon (Si) substrate can be preferably cited.

In addition, the substrate to be processed may also be a stepped substrate. The so-called stepped substrate is a substrate in which at least one stepped shape is formed on the substrate. When the substrate to be processed is a stepped substrate, the thickness of the resist underlayer film refers to the height from the bottom surface on the stepped substrate to the upper surface of the formed resist underlayer film. For example, in the form of implanting ions into the substrate to be processed, as a stepped substrate, a substrate having fins or gates patterned on a flat substrate can be used. In the case of coating a resist underlayer film on a stepped substrate with patterned fins or gates in this way, the thickness of the resist underlayer film refers to the bottom layer on the stepped substrate as described above. The height from the surface to the upper surface of the formed resist underlayer film, rather than the height from the upper surface of the fin or gate to the upper surface of the formed resist underlayer film. Regarding the dimensions (width, length, height, etc.), spacing, structure, and composition of fins and gates, for example, "Journal of the Society of Electronic Information and Communications" Vol. 91, No. 1, 2008, pp. 25-29, "Front-end FinFET" Process, Integrated Technology", or "Jpn. J. Appl. Phys." Vol. 42 (2003) Pages 4142 to 4146, Part 1, Issue 6B, June 2003 Fin-Type Double-Gate Metal-Oxide-Semiconductor Field-Effect Transistors Fabricated by Orientation-Dependent Etching and Electron Beam Lithography Recorded in ".

As a stepped substrate, for example, a groove having a groove width of less than or equal to the exposure wavelength (preferably 100 nm or less, more preferably 40 nm or less, and usually 15 nm or more) and a depth of 100 nm or less (preferably 50 nm to 50 nm) can be mentioned. 100 nm, more preferably 65 nm-100 nm) of the stepped substrate of the groove part, or having a diameter of less than the exposure wavelength (preferably 100 nm or less, more preferably 40 nm or less, usually 15 nm or more), depth It is a stepped substrate or the like of a cylindrical concave portion of 100 nm or less (preferably 50 nm to 100 nm, more preferably 65 nm to 100 nm). As the step substrate having the groove portion, for example, a step having a plurality of grooves is repeated at equal intervals at a pitch of 20 nm to 200 nm (preferably 50 nm to 150 nm, more preferably 70 nm to 120 nm). Poor substrate, etc. In addition, as a stepped substrate having the cylindrical concave portion, for example, there can be mentioned that there are multiple repetitions at equal intervals at a pitch of 20 nm to 200 nm (preferably 50 nm to 150 nm, more preferably 70 nm to 120 nm). A stepped substrate with a cylindrical recess, etc.

The thickness of the resist underlayer film is not particularly limited, and as the lower limit, it is preferably 10 nm or more, more preferably 30 nm or more, and still more preferably 50 nm or more. As the upper limit, it is preferably 3000 nm or less, more preferably 2000 nm or less, and still more preferably 500 nm or less.

The formation of the substrate to be processed and the resist underlayer film can be performed by appropriately employing a known method according to the type of material used. In the case of forming the substrate to be processed on the base layer, the method may include: coating the base layer with materials that constitute the substrate to be processed based on a conventionally known spin coating method, spray method, roll coating method, dipping method, etc. The method of drying the liquid, or the method of depositing the material constituting the substrate to be processed by the chemical vapor deposition (Chemical Vapor Deposition, CVD) method. As a method of forming a resist underlayer film, it can be exemplified that the composition for forming a resist underlayer film is applied and dried on the substrate to be processed based on a conventionally known spin coating method, spray method, roll coating method, dipping method, etc. Method and so on.

In this step, it is preferable to heat the coating film formed by applying the composition for forming a resist base film. In this way, a resist underlayer film is formed. The heating of the coating film is usually performed under the atmosphere. The lower limit of the heating temperature is preferably 150°C or higher, more preferably 200°C or higher. The upper limit of the heating temperature is preferably 500°C or lower, more preferably 450°C or lower, and still more preferably 420°C or lower. When the heating temperature is in the above range, the crosslinking reaction can proceed satisfactorily. The lower limit of the heating time is not particularly limited, but it is preferably 15 seconds or more, more preferably 30 seconds or more, and still more preferably 45 seconds or more. The upper limit of the heating time is not particularly limited, but it is preferably 1200 seconds or less, more preferably 600 seconds or less, and still more preferably 300 seconds or less.

Before heating the coating film at a temperature above 150°C and below 500°C, preheating may be performed at a temperature above 60°C and below 250°C. The lower limit of the heating time in the preheating is preferably 10 seconds or more, and more preferably 30 seconds or more. The upper limit of the heating time is preferably 300 seconds or less, and more preferably 180 seconds or less. By performing this preheating, the solvent is vaporized in advance to make the coating film dense, and thereby the dehydrogenation reaction caused during the heating described later can be efficiently performed.

[Step (2)] The step (2) of the pattern forming method of the present invention is a step of forming a resist film on the resist base film using the resist composition.

(Resist composition) The resist composition will be described below. The resist composition may be a positive resist composition or a negative resist composition. In addition, the resist composition is typically a chemically amplified resist composition.

In the pattern forming method of the present invention, more than one intermediate film may be provided between the resist base film and the resist film. In the case where an intermediate film is provided between the resist underlayer film and the resist film, the intermediate film preferably has at least one atom selected from the group consisting of Si atoms and Ti atoms, as the intermediate film is formed Examples of methods include a method of coating and drying by a conventionally known spin coating method, spray method, roll coating method, dipping method, etc., or a method of depositing materials constituting the interlayer film using the CVD method. In the case where an intermediate film is not provided between the resist underlayer film and the resist film, the resist composition is not particularly limited, and preferably contains a composition selected from the group consisting of Si atoms and Ti atoms. At least one atom of resin.

Hereinafter, each component of the resist composition that can be preferably used in the pattern forming method of the present invention will be described.

·Resin (A) The resist composition usually contains resin (also referred to as "resin (A)"). The resin (A) preferably contains a repeating unit having an acid-decomposable group. Here, the acid-decomposable group refers to a group that is decomposed by the action of an acid to generate a polar group. The acid-decomposable group preferably has a structure in which the polar group is protected by a group that is decomposed and released by the action of an acid (a leaving group). Examples of polar groups include: phenolic hydroxyl groups, carboxyl groups, fluorinated alcohol groups (preferably hexafluoroisopropanol groups), sulfonic acid groups, sulfonamide groups, sulfonamide groups, (alkylsulfonyl groups) (Alkyl)(alkylcarbonyl)methylene, (alkylsulfonyl)(alkylcarbonyl)imino, bis(alkylcarbonyl)methylene, bis(alkylcarbonyl)imino, Acidic groups such as bis(alkylsulfonyl)methylene, bis(alkylsulfonyl)imino, tris(alkylcarbonyl)methylene, and tris(alkylsulfonyl)methylene ( The groups dissociated in 2.38% by mass tetramethylammonium hydroxide aqueous solution), alcoholic hydroxyl groups, and the like.

In addition, the alcoholic hydroxyl group refers to a hydroxyl group other than the hydroxyl group (phenolic hydroxyl group) that is directly bonded to the aromatic ring and is bonded to a hydrocarbon group. As a hydroxyl group, the α-position is substituted with an electron-withdrawing group such as a fluorine atom. Except for group alcohol groups (for example, fluorinated alcohol groups (hexafluoroisopropanol groups, etc.)). The alcoholic hydroxyl group is preferably a hydroxyl group having a pKa (acid dissociation constant) of 12 to 20.

Examples of preferred polar groups include carboxyl groups, fluorinated alcohol groups (preferably hexafluoroisopropanol groups), and sulfonic acid groups.

A preferable group as an acid-decomposable group is a group obtained by substituting a hydrogen atom of these groups with groups detached by acid. Examples of the group to be removed by acid (a leaving group) include -C(R ₃₆ )(R ₃₇ )(R ₃₈ ), -C(R ₃₆ )(R ₃₇ )(OR ₃₉ ), and -C( R ₀₁ )(R ₀₂ )(OR ₃₉ ) and so on. In the formula, R ₃₆ to R ₃₉ each independently represent an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, or an alkenyl group. R ₃₆ and R ₃₇ may be bonded to each other to form a ring. R ₀₁ and R ₀₂ each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, or an alkenyl group.

The acid-decomposable group is preferably a cumyl ester group, an enol ester group, an acetal ester group, or a tertiary alkyl ester group, and more preferably a tertiary alkyl ester group.

The resin (A) preferably has a repeating unit represented by the following general formula (AI) as a repeating unit having an acid-decomposable group. The repeating unit represented by the general formula (AI) generates a carboxyl group as a polar group due to the action of an acid.

[化13]

In the general formula (AI), Xa ₁ represents a hydrogen atom, an alkyl group, a cyano group, or a halogen atom. T represents a single bond or a divalent linking group. Rx ₁ to Rx ₃ each independently represent an alkyl group or a cycloalkyl group. Two of Rx ₁ to Rx ₃ may be bonded to form a ring structure.

In addition, the resin (A) also preferably contains a repeating unit having a structure in which a phenolic hydroxyl group is protected by a leaving group that is decomposed and detached by the action of an acid, as a repeating unit having an acid-decomposable group. In addition, in this specification, a phenolic hydroxyl group is a group which substituted the hydrogen atom of an aromatic hydrocarbon group by a hydroxyl group. The aromatic ring of the aromatic hydrocarbon group is a monocyclic or polycyclic aromatic ring, and examples thereof include a benzene ring and a naphthalene ring.

The repeating unit having a structure in which the phenolic hydroxyl group is decomposed and removed by the action of an acid is preferably a repeating unit represented by the following general formula (AII).

[化14]

In the general formula (AII), R ₆₁ , R ₆₂ and R ₆₃ each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group, or an alkoxycarbonyl group. However, R ₆₂ may be _{bonded to Ar 6} to form a ring. In this case, R ₆₂ represents a single bond or an alkylene group. X ₆ represents a single bond, -COO-, or -CONR ₆₄ -. R ₆₄ represents a hydrogen atom or an alkyl group. L ₆ represents a single bond or an alkylene group. Ar ₆ represents an (n+1)-valent aromatic hydrocarbon group, and when it _{bonds with R 62} to form a ring, it represents an (n+2)-valent aromatic hydrocarbon group. In the case of n≧2, Y ₂ each independently represents a hydrogen atom or a group released by the action of an acid. Among them, _{at least one of Y 2} represents a group that is detached by the action of an acid. The group that is detached by the action of an acid as Y _{2 is preferably the group exemplified as the detaching group.} n represents an integer of 1-4.

Each of the above groups may have a substituent. Examples of the substituent include an alkyl group (carbon number 1 to 4), a halogen atom, a hydroxyl group, an alkoxy group (carbon number 1 to 4), a carboxyl group, and an alkoxycarbonyl group. (C2-6), etc., a group having 8 or less carbon atoms is preferred.

The repeating unit having an acid-decomposable group may be one type, or two or more types may be used in combination.

Relative to all the repeating units of the resin (A), the content of the acid-decomposable group-containing repeating unit contained in the resin (A) (in the case where there are multiple acid-decomposable group-containing repeating units, the total is relatively high) It is preferably 20 mol% to 90 mol%, more preferably 40 mol% to 80 mol%. Among them, it is preferable that the resin (A) has the repeating unit represented by the general formula (AI), and more preferably the content of the repeating unit represented by the general formula (AI) relative to all the repeating units of the resin (A) It is more than 40 mol%.

The resin (A) preferably has at least one selected from the group consisting of a lactone structure, a sultone structure, and a carbonate structure, and more preferably contains a resin (A) selected from the group consisting of a lactone structure, a sultone structure, and A repeating unit of at least one of the group consisting of the carbonate structure.

As the lactone structure or sultone structure, any one may be used as long as it has a lactone structure or a sultone structure, preferably a 5-membered to 7-membered cyclic lactone structure or a 5-membered to 7-membered cyclic sultone The ester structure is more preferably a structure formed by condensing other ring structures to form a bicyclic structure and/or a spiro ring structure with a 5- to 7-membered ring lactone structure, or other ring structures to form a bicyclic structure and/or A structure formed by condensing the form of the spiro ring structure with the 5-membered to 7-membered cyclic sultone structure. It is more preferable to contain a lactone structure represented by any one of the following general formula (LC1-1) to general formula (LC1-21), or the following general formula (SL1-1) to general formula (SL1-3 The repeating unit of the sultone structure represented by any one of ). In addition, the lactone structure or sultone structure may be directly bonded to the main chain. Among them, as the lactone structure, the general formula (LC1-1), the general formula (LC1-4), the general formula (LC1-5), the general formula (LC1-6), the general formula (LC1-13), General formula (LC1-14), or general formula (LC1-17), more preferably a lactone structure represented by general formula (LC1-4). By using this specific lactone structure, line edge roughness (LER) and development defects become better.

[化15]

The lactone moiety or the sultone moiety may have a substituent (Rb ₂ ) or may not have a substituent (Rb ₂ ). Examples of the substituent (Rb ₂ ) include alkyl groups having 1 to 8 carbons, cycloalkyl groups having 4 to 7 carbons, alkoxy groups having 1 to 8 carbons, and alkoxycarbonyl groups having 2 to 8 carbons. , Carboxyl group, halogen atom, hydroxyl group, cyano group, acid-decomposable group, etc., preferably C1-C4 alkyl group, cyano group, or acid-decomposable group. n ₂ represents an integer of 0-4. When n ₂ is 2 or more, a plurality of substituents (Rb ₂ ) may be the same or different. In addition, a plurality of substituents (Rb ₂ ) may be bonded to each other to form a ring.

When the resin (A) contains a repeating unit having a lactone structure or a sultone structure, the content of the repeating unit having a lactone structure or a sultone structure is preferable relative to all the repeating units in the resin (A) It is 5 mol% to 60 mol%, more preferably 5 mol% to 55 mol%, and still more preferably 10 mol% to 50 mol%.

The repeating unit having a carbonate structure (cyclic carbonate structure) is preferably a repeating unit represented by the following general formula (A-1).

[化16]

In the general formula (A-1), R _A ¹ represents a hydrogen atom or an alkyl group. When n is 2 or more, _{R A} ^{2 each independently represents a substituent.} A represents a single bond or a divalent linking group. Z represents an atomic group that forms a monocyclic or polycyclic structure together with the group represented by -OC(=O)-O- in the formula. n represents an integer of 0 or more. In the resin (A), the content of the repeating unit having a cyclic carbonate structure (preferably the repeating unit represented by the general formula (A-1)) relative to all the repeating units constituting the resin (A) is better It is 3 mol%～80 mol%, more preferably 3 mol%～60 mol%, further preferably 3 mol%～45 mol%, particularly preferably 3 mol%～30 mol%, The best range is 10 mol% to 15 mol%. By setting such a content rate, it is possible to improve the developability as a resist, low defectivity, low line width roughness (LWR), and low post exposure bake (PEB) temperature dependence Sex, profile, etc.

The resin (A) may contain a repeating unit having a phenolic hydroxyl group. Examples of the repeating unit having a phenolic hydroxyl group include a hydroxystyrene repeating unit or a hydroxystyrene (meth)acrylate repeating unit. Among them, the repeating unit having a phenolic hydroxyl group is preferably a repeating unit represented by the following general formula (I).

[化17]

In the formula, R ₄₁ , R ₄₂ and R ₄₃ each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group, or an alkoxycarbonyl group. Among them, R ₄₂ may be _{bonded to Ar 4} to form a ring. In this case, R ₄₂ represents a single bond or an alkylene group. X ₄ represents a single bond, -COO-, or -CONR ₆₄ -, and R ₆₄ represents a hydrogen atom or an alkyl group. L ₄ represents a single bond or a divalent linking group. Ar ₄ represents an (n+1)-valent aromatic hydrocarbon group, and when it _{bonds with R 42} to form a ring, it represents an (n+2)-valent aromatic hydrocarbon group. n represents an integer of 1-5. For the purpose of increasing the polarity of the repeating unit represented by the general formula (I), it is also preferable that n is an integer of 2 or more, or X ₄ is -COO- or -CONR ₆₄ -.

In the resin (A), relative to all the repeating units in the resin (A), the content of the repeating unit having a phenolic hydroxyl group is preferably 40 mol% or more, more preferably 50 mol% or more, and still more preferably 60 More than mol%. In addition, in the resin (A), the content of the repeating unit having a phenolic hydroxyl group is preferably 85 mol% or less, and more preferably 80 mol% or less with respect to all the repeating units in the resin (A).

The resin (A) preferably contains a repeating unit having a hydroxyl group or a cyano group other than the repeating unit. This improves the substrate adhesion and developer affinity. The repeating unit having a hydroxyl group or a cyano group is preferably a repeating unit having an alicyclic hydrocarbon structure substituted with a hydroxyl group or a cyano group, and preferably does not have an acid-decomposable group. The alicyclic hydrocarbon structure in the alicyclic hydrocarbon structure substituted with a hydroxyl group or a cyano group is preferably an adamantyl group, a diadamantyl group, and a norbornyl group.

Relative to all the repeating units in the resin (A), the content of the repeating unit having a hydroxyl group or a cyano group is preferably 5 mol% to 40 mol%, more preferably 5 mol% to 30 mol%, and more preferably It is 10 mol%～25 mol%.

The resin (A) may contain a repeating unit having an alkali-soluble group. As the alkali-soluble group, for example, a carboxyl group, a sulfonamido group, a sulfonamidoimino group, a bissulfonamidoimino group, and an aliphatic alcohol group substituted with an electron withdrawing group at the α position (for example, six The fluoroisopropanol group) preferably contains a repeating unit having a carboxyl group. By containing a repeating unit having an alkali-soluble group, the resolution for contact hole applications is increased. The repeating unit having an alkali-soluble group is preferably a repeating unit having an alkali-soluble group directly bonded to the main chain of the resin such as a repeating unit formed of acrylic acid and methacrylic acid, or a repeating unit having an alkali-soluble group directly bonded to the main chain of the resin via a linking group. Any one of the repeating unit to which an alkali-soluble group is bonded to the chain, and a polymerization initiator or a chain transfer agent having an alkali-soluble group is used during polymerization to be introduced to the end of the polymer chain, and the linking group may have a single ring or Polycyclic cyclic hydrocarbon structure. It is also preferable to use repeating units derived from (meth)acrylic acid. Relative to all the repeating units in the resin (A), the content of the repeating unit having an alkali-soluble group is preferably 0 mol% to 20 mol%, more preferably 3 mol% to 15 mol%, and still more preferably 5mol%～10mol%.

The resin (A) of the present invention may further contain a repeating unit that has an alicyclic hydrocarbon structure that does not contain a polar group (for example, the alkali-soluble group, hydroxyl group, cyano group, etc.) and does not show acid decomposability. As such a repeating unit, the repeating unit represented by general formula (IV) can be mentioned.

[化18]

In the general formula (IV), R ₅ represents a hydrocarbon group having at least one cyclic structure and no polar group. Ra represents a hydrogen atom, an alkyl group, or a -CH ₂ -O-Ra ₂ group. In the formula, Ra ₂ represents a hydrogen atom, an alkyl group or an acyl group. Ra is preferably a hydrogen atom, a methyl group, a hydroxymethyl group, or a trifluoromethyl group, and more preferably a hydrogen atom or a methyl group. The cyclic structure of R ₅ includes a monocyclic hydrocarbon group and a polycyclic hydrocarbon group. Examples of monocyclic hydrocarbon groups include cycloalkyl groups having 3 to 12 carbon atoms such as cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl; and cycloalkenyl groups having 3 to 12 carbon atoms such as cyclohexenyl. The monocyclic hydrocarbon group is preferably a monocyclic hydrocarbon group having 3 to 7 carbon atoms, more preferably a cyclopentyl group or a cyclohexyl group.

Resin (A) may contain a repeating unit which has an alicyclic hydrocarbon structure which does not contain a polar group and does not show acid-decomposability, and may not contain it. In the case of including these repeating units, relative to all repeating units in the resin (A), the content of the repeating unit is preferably 1 mol% to 40 mol%, more preferably 2 mol% to 20 mol% ear%.

When the resist composition is used for ArF exposure, it is also preferable that the resin (A) does not substantially have an aromatic group in terms of transparency to ArF light. More specifically, among all the repeating units of the resin (A), the repeating unit having an aromatic group is preferably 5 mol% or less of the whole, more preferably 3 mol% or less, and still more preferably 0 mol%, That is, it does not contain a repeating unit having an aromatic group. In addition, the resin (A) preferably has a monocyclic or polycyclic alicyclic hydrocarbon structure.

The resin (A) is also preferably a resin containing all of the repeating units (meth)acrylate-based repeating units. In this case, a resin in which all repeating units are methacrylate-based repeating units, resins in which all repeating units are acrylate-based repeating units, and all repeating units are formed of methacrylate-based repeating units and acrylate-based repeating units. Any kind of resin. Among them, a resin in which the acrylate-based repeating unit is 50 mol% or less of all repeating units is preferred.

The resin (A) can be synthesized according to a conventional method (for example, radical polymerization). The weight average molecular weight of the resin (A) is preferably 1,000 to 200,000, more preferably 2,000 to 40,000, still more preferably 3,000 to 30,000, particularly preferably 4,000 to 25,000. By setting the weight average molecular weight to 1,000 to 200,000, deterioration of heat resistance or dry etching resistance can be prevented, and deterioration of developability or increase in viscosity can be prevented, resulting in deterioration of film forming properties. The degree of dispersion (molecular weight distribution) of the resin (A) is usually 1.0 to 3.0, preferably 1.0 to 2.6, more preferably 1.0 to 2.0, and still more preferably 1.1 to 2.0. The smaller the molecular weight distribution, the better the resolution and the shape of the resist, and the sidewalls of the resist pattern are smooth and the roughness is excellent.

The content of the resin (A) relative to the total solid content of the resist composition is preferably 20% by mass or more, more preferably 40% by mass or more, still more preferably 60% by mass or more, and particularly preferably 80% by mass or more. The content of the resin (A) is preferably 99% by mass or less with respect to the total solid content of the resist composition. In this specification, the total solid content of the resist composition refers to the total mass of the components after removing the solvent from all the compositions of the resist composition. In addition, the so-called "solid content" of the resist composition is a component obtained by removing the solvent from the resist composition as described above. For example, it may be solid or liquid at 25°C. One type of resin (A) may be used, or two or more types may be used.

·Photoacid generator The resist composition preferably contains a photoacid generator (a compound that generates an acid by irradiation with actinic rays or radiation). The photoacid generator is not particularly limited, but is preferably a compound that generates an organic acid by irradiation with actinic rays or radiation. As the photoacid generator, a photoinitiator for photocation polymerization, a photoinitiator for photoradical polymerization, a photodecolorizer for pigments, a photochromic agent, or a microresist can be appropriately selected and used. The well-known compounds that generate acid by irradiation with actinic rays or radiation and mixtures of these include, for example, the compounds described in paragraph [0039] to paragraph [0103] of JP 2010-61043 A , Japanese Patent Laid-Open No. 2013-4820, the compound described in paragraph [0284] to paragraph [0389], but the present invention is not limited thereto. For example, a diazonium salt, a phosphonium salt, a sulfonium salt, an iodonium salt, an imine sulfonate, an oxime sulfonate, diazodisulfonate, disulfonate, and o-nitrobenzyl sulfonate are mentioned.

As the photoacid generator contained in the resist composition, for example, a compound represented by the following formula (3) that generates an acid by irradiation with actinic rays or radiation (specific photoacid generator).

[化19]

·· In the anionic formula (3), Xf each independently represents a fluorine atom or an alkyl group substituted with at least one fluorine atom. R ₄ and R ₅ each independently represent a hydrogen atom, a fluorine atom, an alkyl group, or an alkyl group substituted with at least one fluorine atom, and when there are a plurality of R ₄ and R ₅ , each may be the same or different. L represents a divalent linking group, and L may be the same or different when there are multiple. W represents an organic group containing a cyclic structure. o represents an integer of 1-3. p represents an integer of 0-10. q represents an integer of 0-10.

··Cation In formula (3), X ⁺ represents a cation. X ⁺ is not particularly limited as long as it is a cation. As a preferred aspect, for example, the cation (other than ^{Z -} ) in the general formula (ZI), general formula (ZII) or general formula (ZIII) described later can be cited ).

··Better appearance As a preferable aspect of the specific photoacid generator, the compound represented by the following general formula (ZI), general formula (ZII), or general formula (ZIII) is mentioned, for example.

[化20]

In the general formula (ZI), R ₂₀₁ , R ₂₀₂ and R ₂₀₃ each independently represent an organic group. The carbon number of the organic group as R ₂₀₁ , R ₂₀₂ and R _{203 is generally 1-30, preferably 1-20.} In addition, two of R ₂₀₁ to R ₂₀₃ may be bonded to form a ring structure, and an oxygen atom, a sulfur atom, an ester bond, an amide bond, and/or a carbonyl group may be included in the ring. Examples of the group formed by bonding two of R ₂₀₁ to R ₂₀₃ include an alkylene group (for example, a butylene group and a pentylene group). Z ^- represents an anion, preferably an anion in the formula (3).

Next, the general formula (ZII) and the general formula (ZIII) will be explained. In general formula (ZII) and general formula (ZIII), R ₂₀₄ to R ₂₀₇ each independently represent an aryl group, an alkyl group, or a cycloalkyl group.

The photoacid generator (including the specific photoacid generator. The same applies below) may be in the form of a low-molecular compound, or may be in the form of being incorporated into a part of the polymer. In addition, the form of the low-molecular compound and the form incorporated into a part of the polymer may be used in combination. When the photoacid generator is in the form of a low-molecular compound, the molecular weight is preferably 580 or more, more preferably 600 or more, still more preferably 620 or more, and particularly preferably 640 or more. The upper limit is not particularly limited, but is preferably 3000 or less, more preferably 2000 or less, and still more preferably 1000 or less. In the case where the photoacid generator is incorporated into a part of the polymer, it may be incorporated into a part of the resin, or may be incorporated into a resin different from the resin. The photoacid generator can be synthesized by a known method, for example, it can be synthesized according to the method described in Japanese Patent Laid-Open No. 2007-161707. The photoacid generator can be used individually by 1 type or in combination of 2 or more types. Based on the total solid content of the resist composition, the content of the photoacid generator in the resist composition (in the case of multiple types, the total amount) is preferably 0.1% by mass to 30% by mass, and more preferably It is 0.5% by mass to 25% by mass, more preferably 3% by mass to 20% by mass, and particularly preferably 3% by mass to 15% by mass.

·Acid diffusion control agent The resist composition preferably contains an acid diffusion control agent. The acid diffusion control agent functions as a quencher that captures the acid generated by the photoacid generator during exposure, and suppresses the reaction of the acid-decomposable resin in the unexposed portion caused by the excessive generation of acid . As the acid diffusion control agent, basic compounds can be used; low-molecular compounds having nitrogen atoms and groups that are detached by the action of acid; basic compounds whose basicity decreases or disappears by irradiation with actinic rays or radiation ; Or relatively weak acid onium salt for the photoacid generator. One kind of acid diffusion control agent may be used alone, or two or more kinds may be used in combination. Based on the total solid content of the resist composition, the content of the acid diffusion control agent in the resist composition (the total when there are multiple types) is preferably 0.1% by mass to 10% by mass, more preferably It is 0.1% by mass to 5% by mass.

·Hydrophobic resin Independently of the resin (A), the resist composition may include a hydrophobic resin different from the resin (A). The hydrophobic resin is preferably designed to be localized on the surface of the resist film, but unlike surfactants, it does not necessarily have a hydrophilic group in the molecule, and it may not contribute to the uniform mixing of polar and non-polar substances. As the effect brought by the addition of the hydrophobic resin, control of the static and dynamic contact angle of the surface of the resist film with respect to water, suppression of outgassing, and the like can be cited.

In terms of localization to the film surface layer, the hydrophobic resin preferably has any one or more of _{"fluorine atom", "silicon atom", and "CH 3 partial structure contained in the side chain part of the resin",} It is more preferable to have two or more types. In addition, the hydrophobic resin preferably has a hydrocarbon group having a carbon number of 5 or more. These groups may exist in the main chain of the resin, or may be substituted in the side chain.

When the hydrophobic resin contains fluorine atoms and/or silicon atoms, the fluorine atoms and/or silicon atoms in the hydrophobic resin may be included in the main chain of the resin, or may be included in the side chain.

When the resist composition contains a hydrophobic resin, the content of the hydrophobic resin is preferably 0.01% by mass to 20% by mass, and more preferably 0.1% by mass to 15%, relative to the total solid content of the resist composition. quality%.

·Solvent The resist composition also preferably contains a solvent. Examples of solvents that can be used when preparing the resist composition include: alkane glycol monoalkyl ether carboxylate, alkane glycol monoalkyl ether, alkyl lactate, and alkyl alkoxy propionate. , Cyclic lactone (preferably carbon number 4-10), monoketone compound which may have a ring (preferably carbon number 4-10), alkylene carbonate, alkyl alkoxy acetate, and acetone Organic solvents such as acid alkyl esters. Specific examples of these solvents include the solvents described in [0441] to [0455] in the specification of U.S. Patent Application Publication No. 2008/0187860.

·Surfactant The resist composition may or may not further contain a surfactant. The surfactant is preferably a fluorine-based and/or silicon-based surfactant (a fluorine-based surfactant, a silicon-based surfactant, a surfactant having both a fluorine atom and a silicon atom). These surfactants may be used singly, or two or more may be used. When the resist composition contains a surfactant, relative to the total solid content of the resist composition, the amount of the surfactant used is preferably 0.0001% by mass to 2% by mass, more preferably 0.0005% by mass to 1% by mass.

·Other additives The resist composition may or may not contain the onium carboxylate salt. Examples of such onium carboxylates include those described in paragraph [0605] to paragraph [0606] of the specification of U.S. Patent Application Publication No. 2008/0187860. These onium carboxylates can be synthesized by reacting sulfonium hydroxide, iodonium hydroxide, ammonium hydroxide, and carboxylic acid with silver oxide in a suitable solvent.

When the resist composition contains an onium carboxylate, its content is preferably 0.1% by mass to 20% by mass relative to the total solid content of the composition, more preferably 0.5% by mass to 10% by mass, and still more preferably It is 1% by mass to 7% by mass. The resist composition may further contain acid multiplying agents, dyes, plasticizers, photosensitizers, light absorbers, alkali-soluble resins, dissolution inhibitors, and compounds that promote solubility in developer ( For example, phenol compounds having a molecular weight of 1,000 or less, alicyclic or aliphatic compounds having a carboxyl group), and the like.

Such a phenol compound with a molecular weight of 1000 or less can refer to the methods described in Japanese Patent Laid-Open No. 4-122938, Japanese Patent Laid-Open No. 2-28531, U.S. Patent No. 4,916,210, European Patent No. 219294, etc., for example, by those skilled in the art. Easily synthesized. Examples of the alicyclic or aliphatic compound having a carboxyl group include carboxylic acid derivatives having a steroid structure such as cholic acid, deoxycholic acid, and lithocholic acid, adamantane carboxylic acid derivatives, adamantane dicarboxylic acid, Although cyclohexane carboxylic acid, cyclohexane dicarboxylic acid, etc. are not limited to these.

The solid content concentration of the resist composition is not particularly limited, but is preferably 1.0% by mass to 20% by mass, more preferably 2.0% by mass to 15% by mass, and still more preferably 2.0% by mass to 10% by mass. The solid content of the resist composition refers to components other than the solvent of the resist composition. The solid content concentration of the resist composition is the ratio (percentage) of the mass of other resist components excluding the solvent to the total mass of the composition.

The preparation method of the resist composition is not particularly limited, but it is preferable to dissolve the respective components in a predetermined organic solvent, preferably the mixed solvent, and filter it. The filter used in filter filtration is preferably made of polytetrafluoroethylene, polyethylene, or nylon with a pore size of 0.1 μm or less (preferably 0.05 μm or less, more preferably 0.03 μm or less) Filter. In filter filtration, for example, as in Japanese Patent Laid-Open No. 2002-62667, it is possible to perform cyclic filtration, or to connect multiple filters in series or in parallel to perform filtration. In addition, the composition may be filtered multiple times. Furthermore, the composition may be degassed before and after filtration by the filter.

[Procedure of step (2)] The procedure of step (2) is not particularly limited. Examples include: coating the resist composition on the resist underlayer film and, if necessary, hardening treatment (coating method), or forming on a dummy support Resist film, the method of transferring the resist film to the substrate, etc. Among them, the coating method is preferred in terms of excellent productivity.

〔Resist Film〕 The thickness of the resist film is not particularly limited, but is preferably 1 μm or less, more preferably 700 nm or less, and still more preferably 500 nm or less. In addition, the thickness of the resist film is preferably 1 nm or more, more preferably 10 nm or more, and still more preferably 30 nm or more. By setting the solid content concentration in the composition to an appropriate range, making it have an appropriate viscosity, and improving coating properties and film forming properties, such a film thickness can be achieved.

In order to reduce peeling or collapse of the resist pattern, an adhesion auxiliary layer may be provided between the resist underlayer film and the resist film.

As a method of forming the adhesion auxiliary layer, a method of forming an adhesion auxiliary layer having a polymerizable group on a resist base film is preferably cited. The polymerizability in the adhesion auxiliary layer formed by this method is based on the formation of a chemical or physical bond between the resist underlayer film and the resist film, so it is considered that the result is between the resist underlayer film and the resist film Shows excellent adhesion.

The adhesion auxiliary layer preferably has a polymerizable group. More specifically, it is preferable that the material (particularly preferably a resin) forming the adhesion auxiliary layer has a polymerizable group. The type of polymerizable group is not particularly limited, and examples include (meth)acrylic acid groups, epoxy groups, oxetanyl groups, maleimino groups, itaconate groups, crotonate groups, Isocrotonic acid ester group, maleic acid ester group, styryl group, vinyl group, acrylamide group, methacrylamide group, etc. Among them, a (meth)acryloyl group, an epoxy group, an oxetanyl group, and a maleimino group are preferred, and a (meth)acryloyl group is more preferred.

The thickness of the adhesion auxiliary layer is not particularly limited. For the reason that a finer pattern can be formed with higher accuracy, it is preferably 1 nm to 100 nm, more preferably 1 nm to 50 nm, and still more preferably 1 nm to 10 nm. , Particularly preferably 1 nm～5 nm.

The method for forming the adhesion auxiliary layer is not particularly limited, and examples thereof include: coating the composition for forming the adhesion auxiliary layer on the resist underlayer film and, if necessary, hardening treatment to form the adhesion auxiliary layer (coating Cloth method), or a method of forming an adhesion auxiliary layer on the dummy support and transferring the adhesion auxiliary layer to the resist underlayer film, etc. Among them, the coating method is preferred in terms of excellent productivity. There is no particular limitation on the method of applying the composition for forming an adhesion auxiliary layer to the resist underlayer film, and a known method can be used, but spin coating can be preferably used in the field of semiconductor manufacturing.

After coating the composition for forming an adhesion auxiliary layer on the resist underlayer film, a hardening treatment may be performed as necessary. The hardening treatment is not particularly limited, and for example, exposure treatment, heat treatment, and the like can be mentioned.

For the exposure treatment, light irradiation with ultraviolet (UV) lamps, visible rays, etc. can be used. As the light source, for example, there are mercury lamps, metal halide lamps, xenon lamps, chemical lamps, carbon arc lamps, and the like. As radiation, there are electron beams, X-rays, ion beams, far infrared rays, and the like. As a specific aspect, scanning exposure using infrared laser, high-illuminance flash exposure such as a xenon discharge lamp, or infrared lamp exposure, etc. are preferably mentioned. The exposure time varies depending on the reactivity of the polymer and the light source, but it is usually between 10 seconds and 5 hours. The exposure energy may be about 10 mJ/cm ² to 10000 mJ/cm ² , and is preferably in the range of 100 mJ/cm ² to 8000 mJ/cm ² . In addition, in the case of heat treatment, a blower dryer, oven, infrared dryer, heating drum, etc. can be used. It is also possible to combine exposure treatment and heating treatment.

[Step (3)] Step (3) is a step of exposing the resist film formed in step (2). Here, exposing the resist film means irradiating the resist film with actinic rays or radiation.

The light used for exposure is not particularly limited, and examples thereof include infrared light, visible light, ultraviolet light, extreme ultraviolet light, extreme ultraviolet light, X-rays, and electron beams. Examples include extreme ultraviolet light or electron beams preferably having a wavelength of 250 nm or less, more preferably extreme ultraviolet light or electron beams having a wavelength of 220 nm or less, and further preferably extreme ultraviolet light or electrons having a wavelength of 1 nm to 200 nm. bundle. More specifically, include: KrF excimer laser (248 nm), ArF excimer laser (193 nm), F ₂ excimer laser (157 nm), X-ray, EUV (13 nm), electron beam Among them, KrF excimer laser, ArF excimer laser, EUV or electron beam is preferred, and ArF excimer laser, EUV or electron beam is more preferred.

A liquid immersion exposure method can be used in the exposure step. The liquid immersion exposure method can be combined with super-resolution techniques such as phase shift method and anamorphic illumination method. The liquid immersion exposure can be performed in accordance with the method described in paragraph [0594] to paragraph [0601] of JP 2013-242397 A, for example.

In step (3), it is preferable to expose the resist film by any one of KrF exposure, ArF exposure, and ArF immersion exposure, and it is more preferable to perform exposure by KrF exposure.

After step (3) and before step (4) described later, heat treatment (PEB: Post Exposure Bake) may be performed on the (exposed) film irradiated with actinic rays or radiation in step (3). This step promotes the reaction of the exposure part. Heat treatment (PEB) can be performed multiple times. The temperature of the heat treatment is preferably 70°C to 130°C, more preferably 80°C to 120°C. The heat treatment time is preferably 30 seconds to 300 seconds, more preferably 30 seconds to 180 seconds, and still more preferably 30 seconds to 90 seconds. The heat treatment can be performed by a mechanism included in a normal exposure machine or a developing machine, or a hot plate or the like can be used.

[Step (4)] Step (4) is a step of developing the (exposed) film irradiated with actinic rays or radiation in step (3) to form a resist pattern.

Step (4) is preferably a step of developing the exposed resist film with a developer to form a resist pattern. The developer may be an alkaline developer or a developer containing an organic solvent. As the alkaline developer, a quaternary ammonium salt represented by tetramethylammonium hydroxide is generally used. In addition to this, alkaline aqueous solutions such as inorganic bases, primary to tertiary amines, alcohol amines, and cyclic amines may also be used. Specifically, as the alkaline developer, for example, inorganic bases such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and ammonia; primary amines such as ethylamine and n-propylamine; Secondary amines such as ethylamine and di-n-butylamine; tertiary amines such as triethylamine and methyldiethylamine; alcohol amines such as dimethylethanolamine and triethanolamine; tetramethylammonium hydroxide, hydroxide Quaternary ammonium salts such as tetraethylammonium; alkaline aqueous solutions of cyclic amines such as pyrrole and piperidine. Among these, it is preferable to use an aqueous solution of tetraethylammonium hydroxide. Furthermore, an appropriate amount of alcohols and surfactants may be added to the alkaline developer. The alkali concentration of the alkaline developer is usually 0.1% by mass to 20% by mass. The pH of the alkaline developer is usually 10.0 to 15.0. The development time using an alkaline developer is usually 10 seconds to 300 seconds. The alkali concentration (and pH) and development time of the alkaline developer can be appropriately adjusted according to the pattern formed. It is also possible to wash with a rinse liquid after development using an alkaline developer, and pure water may be used as the rinse liquid, and an appropriate amount of surfactant may be added and used. In addition, after the development process or the rinsing process, a process of using a supercritical fluid to remove the developer or rinsing liquid adhering to the pattern may be performed. Furthermore, after rinsing treatment or treatment with a supercritical fluid, heat treatment may be performed in order to remove water remaining in the pattern.

As the organic developer, polar solvents and hydrocarbon solvents such as ketone solvents, ester solvents, alcohol solvents, amide solvents, ether solvents, etc. can be used. Specifically, for example, in addition to Japanese Patent Laid-Open No. 2014-048500 In addition to those described in paragraph [0461] to paragraph [0463] of the bulletin, examples include methyl 2-hydroxyisobutyrate, butyl butyrate, isobutyl isobutyrate, butyl propionate, butyl butyrate, and Isoamyl acetate. The said solvent may mix multiple types, and may mix and use with the solvent or water other than the said. Among them, the organic developer preferably has a moisture content of less than 10% by mass as the entire developer, and more preferably contains substantially no moisture. That is, the use amount of the organic solvent with respect to the organic developer is preferably 90% by mass or more and 100% by mass or less, and more preferably 95% by mass or more and 100% by mass or less with respect to the total amount of the developer.

In particular, the organic developer is preferably a developer containing at least one organic solvent selected from the group consisting of ketone solvents, ester solvents, alcohol solvents, amide solvents, and ether solvents.

The vapor pressure of the organic developer is preferably 5 kPa or less at 20°C, more preferably 3 kPa or less, and particularly preferably 2 kPa or less. By setting the vapor pressure of the organic developer to 5 kPa or less, the evaporation of the developer on the substrate or in the developing cup is suppressed, the temperature uniformity in the wafer surface is improved, and the dimensional uniformity in the wafer surface is reduced. good.

In the organic developer, an appropriate amount of surfactant can be added as necessary. The surfactant is not particularly limited. For example, ionic or nonionic fluorine-based and/or silicon-based surfactants can be used. As these fluorine-based and/or silicon-based surfactants, for example, Japanese Patent Laid-Open No. 62-36663, Japanese Patent Laid-Open No. 61-226746, Japanese Patent Laid-Open No. 61-226745, Japanese Patent Laid-Open No. 62-170950, Japanese Patent Laid-Open No. 63-34540, Japanese Patent Laid-Open No. 7-230165, Japanese Patent Laid-Open No. 8-62834, Japanese Patent Laid-Open No. 9-54432 Bulletin, Japanese Patent Laid-Open No. 9-5988, U.S. Patent No. 5,405,720, U.S. Patent No. 5360692, U.S. Patent No. 5,529,881, U.S. Patent No. 5296330, U.S. Patent No. 5,436,098, U.S. Patent No. The surfactants described in specification No. 5576143, US Patent No. 5,294,511, and US Patent No. 5,824,451 are preferably nonionic surfactants. The nonionic surfactant is not particularly limited, and it is more preferable to use a fluorine-based surfactant or a silicon-based surfactant.

The amount of the surfactant used is usually 0.001% by mass to 5% by mass relative to the total amount of the developer, preferably 0.005% by mass to 2% by mass, and more preferably 0.01% by mass to 0.5% by mass.

The organic developer may also contain an alkaline compound. Specific examples and preferred examples of alkaline compounds that can be contained in the organic developer used in the present invention, and specific examples and preferred examples of alkaline compounds that can be contained in the composition as an acid diffusion control agent The case is the same.

As a development method, for example, a method of immersing a substrate in a tank filled with a developer solution for a fixed period of time (dipping method); a method of performing development by depositing the developer solution on the surface of the substrate using surface tension and standing still for a fixed period of time (covering Puddle method); a method of spraying the developer onto the surface of the substrate (spray method); a method in which the developer spray nozzle is scanned at a fixed speed, and the developer is continuously sprayed onto the substrate rotating at a fixed speed (dynamic distribution Law) and so on. In addition, there are no particular limitations on the preferable range of the discharge pressure of the discharged developer and the method of adjusting the discharge pressure of the developer. For example, the paragraph of Japanese Patent Laid-Open No. 2013-242397 can be used [ 0631] ~ Scope and method described in paragraph [0636].

In the pattern forming method of the present invention, a step of developing using an alkaline developer (alkaline development step) and a step of developing using a developer containing an organic solvent may be used in combination. Thereby, a finer pattern can be formed. In the present invention, the part with weak exposure intensity is removed by the organic solvent development step, and the part with strong exposure intensity is also removed by the alkali development step. By performing the multiple development process in which multiple developments are performed in this manner, pattern formation is performed without dissolving only the area of the intermediate exposure intensity, so that a finer pattern than usual can be formed (in accordance with Japanese Patent Laid-Open No. 2008-292975 The same mechanism as the paragraph [0077]). In the pattern forming method of the present invention, the order of the alkali development step and the organic solvent development step is not particularly limited, and it is more preferable to perform alkali development before the organic solvent development step.

Preferably, after the step of performing development using a developer containing an organic solvent, a step of washing with a rinse solution is included. The rinsing liquid used in the rinsing step after the step of performing development using a developer containing an organic solvent is not particularly limited as long as it does not dissolve the resist pattern, and a solution containing a general organic solvent can be used. As the rinse liquid, it is preferable to use a rinse liquid containing at least one organic solvent selected from the group consisting of hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents, and ether solvents. Specific examples of hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents, and ether solvents include the same ones as those described in the developer containing an organic solvent.

After the step of performing development using a developer containing an organic solvent, it is more preferable to use at least one selected from the group consisting of ketone solvents, ester solvents, alcohol solvents, amide solvents, and hydrocarbon solvents. An organic solvent-based rinsing liquid is used for cleaning, and it is more preferable to implement a cleaning step using a rinsing liquid containing an alcohol-based solvent or an ester-based solvent, and it is particularly preferable to implement a cleaning step using a rinsing liquid containing a monohydric alcohol. To implement the step of washing using a washing liquid containing a monohydric alcohol with a carbon number of 5 or more. The rinsing liquid containing a hydrocarbon solvent is preferably a hydrocarbon compound having 6 to 30 carbon atoms, more preferably a hydrocarbon compound having 8 to 30 carbon atoms, and particularly preferably a hydrocarbon compound having 10 to 30 carbon atoms. Among them, by using a rinse liquid containing decane and/or undecane, pattern collapse can be suppressed. When using an ester-based solvent as an organic solvent, in addition to the ester-based solvent (one type or two or more types), a glycol ether-based solvent may also be used. As a specific example in this case, an ester solvent (preferably butyl acetate) is used as a main component and a glycol ether solvent (preferably propylene glycol monomethyl ether (PGME)) is used as a subcomponent. Thereby, residue defects can be further suppressed.

Here, as the monohydric alcohol used in the rinsing step, linear, branched, and cyclic monohydric alcohols can be cited. Specifically, 1-butanol, 2-butanol, and 3-methyl-1 can be used. -Butanol, tertiary butanol, 1-pentanol, 2-pentanol, 1-hexanol, 4-methyl-2-pentanol, 1-heptanol, 1-octanol, 2-hexanol, cyclo Pentanol, 2-heptanol, 2-octanol, 3-hexanol, 3-heptanol, 3-octanol, 4-octanol, etc. As particularly preferred monohydric alcohols with 5 or more carbon atoms, 1- Hexanol, 2-hexanol, 4-methyl-2-pentanol, 1-pentanol, 3-methyl-1-butanol, etc.

Each component may mix multiple types, and may mix and use with organic solvents other than the said. The water content in the rinse liquid is preferably 10% by mass or less, more preferably 5% by mass or less, and particularly preferably 3% by mass or less. By setting the moisture content to 10% by mass or less, good development characteristics can be obtained.

The vapor pressure of the rinse liquid used after the step of developing using a developer containing an organic solvent is preferably 0.05 kPa or more and 5 kPa or less at 20°C, more preferably 0.1 kPa or more and 5 kPa or less, and most preferably 0.12 kPa or more and 3 kPa or less. By setting the vapor pressure of the rinsing liquid to 0.05 kPa or more and 5 kPa or less, the temperature uniformity in the wafer surface is improved, and the swelling caused by the penetration of the rinsing liquid is suppressed, and the dimensional uniformity in the wafer surface is changed. good.

In the rinse liquid, an appropriate amount of surfactant can also be added for use. In the rinsing step, the rinsing liquid containing the organic solvent is used to perform a cleaning process on the wafer that has been developed using the developer containing the organic solvent. The method of cleaning treatment is not particularly limited. For example, a method of continuously spraying a rinse liquid onto a substrate rotating at a fixed speed (spin coating method); a method of immersing the substrate in a bath filled with rinse liquid for a fixed period of time (dipping Method); the method of spraying the rinse liquid onto the surface of the substrate (spray method), etc., among which, it is preferable to perform the cleaning process by a spin coating method. After cleaning, the substrate is subjected to 2000 rpm to 4000 rpm (revolutions per minute). (Rotations per minute) rotations per minute) to remove the rinse liquid from the substrate. In addition, it is also preferable to include a heating step (Post Bake) after the washing step. Baking is used to remove the developer and rinsing liquid remaining between the patterns and inside the patterns. The heating step after the rinsing step is usually carried out at 40°C to 160°C, preferably 70°C to 95°C, for usually 10 seconds to 3 minutes, preferably 30 seconds to 90 seconds.

The resist composition of the present invention and the various materials used in the pattern forming method of the present invention (for example, a developer, a rinse liquid, etc.) preferably do not contain impurities such as metals. Examples of metal impurity components include Na, K, Ca, Fe, Cu, Mn, Mg, Al, Cr, Ni, Zn, Ag, Sn, Pb, and Li. The total content of impurities contained in these materials is preferably 1 ppm (parts per million) or less, more preferably 10 ppb or less, and still more preferably 100 ppt (parts per trillion, trillion points). 1) Below, particularly preferably below 10 ppt, most preferably below 1 ppt. Examples of methods for removing impurities such as metals from the various materials include filtration using a filter. The pore diameter of the filter is preferably 50 nm or less, more preferably 10 nm or less, and still more preferably 5 nm or less. As the material of the filter, a filter made of polytetrafluoroethylene, polyethylene, or nylon is preferable. In the filter filtration step, multiple filters can also be connected in series or in parallel for use. When multiple filters are used, filters with different pore sizes and/or materials can also be used in combination. In addition, various materials can be filtered multiple times, and the step of filtering multiple times can be a cyclic filtering step. In addition, as methods for reducing impurities such as metals contained in the various materials, methods such as selecting a raw material with a low metal content as the raw material constituting the various materials, filtering the raw materials constituting the various materials, and the like can be cited. The preferable conditions in the filter filtration of the raw materials constituting the various materials are the same as the above-mentioned conditions. In addition to filter filtration, the adsorption material can be used to remove impurities, and the filter can also be used in combination with the adsorption material. As the adsorbent, well-known adsorbents can be used. For example, inorganic adsorbents such as silica gel and zeolite, and organic adsorbents such as activated carbon can be used. In order to reduce impurities such as metals contained in the various materials, it is necessary to prevent the incorporation of metal impurities in the manufacturing process. Whether or not the metal impurities have been sufficiently removed from the manufacturing device can be confirmed by measuring the content of the metal component contained in the cleaning liquid used in the cleaning of the manufacturing device. The content of the metal component contained in the cleaning solution after use is more preferably 100 ppt (parts per trillion, one trillion) or less, further preferably 10 ppt or less, particularly preferably 1 ppt or less. In order to prevent malfunctions of the chemical solution piping or various parts (filters, O-rings, tubes, etc.) associated with electrostatic charging and subsequent electrostatic discharge, the resist composition of the present invention and the pattern forming method of the present invention The organic treatment liquid (resist solvent, developer, rinsing liquid, etc.) used can be added with a conductive compound. The conductive compound is not particularly limited, and for example, methanol can be mentioned. The addition amount is not particularly limited, but from the viewpoint of maintaining better development characteristics, it is preferably 10% by mass or less, and more preferably 5% by mass or less. Regarding the components of the chemical liquid piping, SUS (stainless steel), or various piping coated with antistatic polyethylene, polypropylene, or fluororesin (polytetrafluoroethylene, perfluoroalkoxy resin, etc.) can be used . The same applies to filters or O-rings, and antistatically treated polyethylene, polypropylene, or fluororesin (polytetrafluoroethylene, perfluoroalkoxy resin, etc.) can be used.

A method of improving the surface roughness of the pattern can also be applied to the pattern formed by the method of the present invention. As a method of improving the surface roughness of the pattern, for example, a method of processing a resist pattern using a plasma of a hydrogen-containing gas disclosed in WO2014/002808A1 can be cited. In addition to this, it can also be applied such as Japanese Patent Laid-Open No. 2004-235468, US2010/0020297A, Japanese Patent Laid-Open No. 2008-83384, Proceeding of Society of Photo-optical Instrumentation Engineers, Proc. of SPIE) Vol. 8328 83280N-1 "Line Width Roughness (LWR) Reduction and Etch Selectivity Enhancement EUV Resist Curing Technique for LWR Reduction and Etch Selectivity Enhancement" described in The general well-known method. The pattern formation method of the present invention can also be used for the formation of guided patterns in Directed Self-Assembly (DSA) (for example, refer to "American Chemical Society Nano (ACS Nano)" Volume 4, 8 Issue 4815-4823). In addition, the resist pattern formed by the method can be used as a core material for the spacer process disclosed in Japanese Patent Laid-Open No. 3-270227 and Japanese Patent Laid-Open No. 2013-164509, for example.

In addition, a pattern refining process can also be applied to the pattern formed by the method of the present invention. As the pattern refining process, for example, as shown in Japanese Patent Laid-Open No. 2013-145290 and Japanese Patent Laid-Open No. 2014-071424, the pattern is coated with a refining composition and heated to make the resist The method of widening the width of the agent pattern. Furthermore, in order to maintain the etching resistance of the resist pattern after the miniaturization process, the miniaturization composition preferably contains silicon atoms.

[Step (5)] Step (5) is a step of forming a pattern by etching the resist pattern as a mask. As a more specific aspect of step (5), for example, the following steps can be cited: the resist pattern formed in step (4) is used as a mask to etch (preferably dry etching), and the resist underlayer film is etched Processed to form patterns.

The etching method is not particularly limited, and step (5) is preferably a step of forming a pattern by using the resist pattern as a mask and dry etching the resist base film. Dry etching may be one-stage etching, or may include multiple-stage etching. When the etching includes multiple stages of etching, the etching of each stage may be the same treatment or different treatments. The method of the dry etching device is not particularly limited, and it is more preferably an inductively coupled plasma (ICP (Inductive Coupled Plasma), inductive coupling) type, a two-frequency conductively coupled plasma (CCP (Conductive Coupled Plasma), capacitive coupling) type , Electron cyclotron resonance (ECR) type and other methods that can independently control plasma density and bias voltage. Etching can use any of the well-known methods, and various conditions and the like are appropriately determined according to the type and use of the substrate. For example, etching can be performed in accordance with Proc. of SPIE Vol. 6924, 692420 (2008), Japanese Patent Laid-Open No. 2009-267112, and the like. In addition, you can also follow the method described in the "Chapter 4 Etching" of "Semiconductor Process Textbook Fourth Edition 2007 Issuer: Japan International Semiconductor Equipment and Materials Association (Semiconductor Equipment and Materials International, SEMI)".

Among them, the dry etching of the resist underlayer film is preferably oxygen plasma etching. The oxygen plasma etching described here refers to plasma etching using a gas containing oxygen atoms. Specifically, it is selected from O ₂ , O ₃ , CO, CO ₂ , NO, NO ₂ , N ₂ O, SO, At least one of the group consisting of SO _{2 and COS.} In addition, in addition to adding the oxygen-containing gas, at least one of the group consisting of _{Ar, He, Xe, Kr, N 2 and the like can be added as a diluent gas, and then Cl 2} , HBr, BCl ₃ , CH _4. At least one of the group consisting of NH _{4 is used as an additive gas.} If a gas containing oxygen atoms is used, the irradiating effect of oxygen radicals and oxygen ions generated in the plasma promotes the etching of the resist underlayer film. On the other hand, regarding the silicon-containing resist film, The oxidation and aggregation of silicon components in the resist film improves the etching resistance, and can increase the selection ratio of the silicon-containing resist film to the resist base film. In the case of suppressing changes in the pattern size before and after etching, by increasing the oxygen-containing gas containing oxygen atoms and at least one of C, N, S, etc. (for example, CO, CO ₂ , NO, NO ₂ , N ₂ O, SO , SO ₂ , COS), the accumulation component generated in the plasma adheres to the sidewall of the etching pattern, suppresses the side etching effect caused by oxygen radicals, and can reduce the narrowing of the line width before and after etching. _{By adding CH 4} or NH ₄ as an additive gas in an oxygen-containing gas (such as O ₂ , O ₃ , CO, CO ₂ , NO, NO ₂ , N ₂ O, SO, SO ₂ , COS), the same can be done Play the effect. In addition, if _{a gas containing a halogen element other than fluorine such as Cl 2} or HBr is used, a high-boiling carbon chloride or carbon bromide is formed as an etching product of the underlying film, and the adhesion to the sidewall of the processed pattern is improved. In this case, the inhibitory effect of side corrosion due to oxygen radicals can also be expected. On the other hand, by appropriately selecting _{the mixing ratio of O 2} or O ₃ gas and the diluent gas, the amount of side etching of the silicon-containing resist film and the resist underlayer film can also be controlled, and the etching can be performed at the same time. The trimming of the desired size.

The present invention also relates to a manufacturing method of an electronic device including the pattern forming method of the present invention, and an electronic device manufactured by the manufacturing method. The electronic device of the present invention is an electronic device that is preferably mounted on electrical and electronic equipment (home appliances, Office Automation (OA), media-related equipment, optical equipment, communication equipment, etc.). [Example]

Examples are given below to more specifically explain the embodiments of the present invention. As long as it does not deviate from the gist of the embodiment of the present invention, the materials, usage amount, ratio, processing content, processing procedure, etc. shown in the following examples can be appropriately changed. Therefore, the scope of the embodiments of the present invention is not limited to the specific examples shown below. In addition, unless otherwise specified, "parts" and "%" are quality standards.

(Purification of β-PGMEA and α-PGMEA) Put propylene glycol monomethyl ether acetate (PGMEA) (manufactured by Kanto Chemical Co., Ltd.) into a flask containing a distillation apparatus, reduce the pressure to 100 mmHg and slowly heat. After removing the fraction (1-methoxy-2-propyl acetate (α-PGMEA)) (solvent F-1) obtained near 80°C, the fraction obtained near 110°C (2-methoxy -1-propanol acetate (β-PGMEA)). In this way, α-PGMEA and β-PGMEA are obtained. The obtained distillates were α-PGMEA and β-PGMEA, respectively, which were ^{confirmed by 1} H-NMR (Nuclear Magnetic Resonance, NMR).

Using the same method as described above, 1-methoxy-2-propanol (α-PGME) (solvent F-2) and 2-methoxy-1-propanol were obtained from commercially available propylene glycol monomethyl ether (PGME). Propanol (β-PGME). In addition, using the same method as described above, 1-ethoxy-2-propanol (α-PGEE) (solvent F-3) and 2-ethoxy-1 were obtained from commercially available propylene glycol monoethyl ether (PGEE). -Propanol (β-PGEE).

<Resin having an aromatic ring> The resins (A-1 to A-15) having an aromatic ring to be used each have the structure shown below. The composition ratio of the repeating units contained in the resin is the molar ratio. The weight average molecular weight (Mw) of the resin having an aromatic ring is shown in Table 1 below. However, for resin A-6, the ratio of the number of substituted phenolic hydroxyl groups to the number of non-substituted phenolic hydroxyl groups is shown instead of Mw. In addition, the weight average molecular weight (Mw) of the resin which has an aromatic ring is measured by GPC (carrier: tetrahydrofuran (THF)) as mentioned above (it is a polystyrene conversion amount). In addition, the composition ratio (molar ratio) of the repeating units contained in the resin is ^{measured by 13} C-nuclear magnetic resonance (NMR).

[化21]

[化22]

[化23]

[Table 1] Resin with aromatic ring Mw Number of substituted phenolic hydroxyl groups/Number of non-substituted phenolic hydroxyl groups A-1 7000 - A-2 5000 - A-3 6500 - A-4 4500 - A-5 11000 - A-6 - 70/30 A-7 9000 - A-8 13000 - A-9 8300 - A-10 8000 - A-11 5000 - A-12 6000 - A-13 4000 - A-14 7000 - A-15 9000

＜Crosslinking agent＞ The structure of the crosslinking agent (CL-1 to CL-10) used is shown below.

[化24]

[化25]

[化26]

[化27]

＜Acid Generator＞ The acid generators (T-1 to T-9) used are shown below. T-5 and T-6 are manufactured by KING INDUSTRIES. T-1～T-9 are all thermal acid generators.

[化28]

[化29]

＜Solvent＞ The solvents used are shown below. F-1: 1-Methoxy-2-propyl acetate (α-PGMEA) F-2: 1-Methoxy-2-propanol (α-PGME) F-3: 1-Ethoxy-2-propanol (α-PGEE) F-4: Cyclohexanone F-5: Cyclopentanone F-6: 2-Heptanone F-7: Ethyl lactate F-8: γ-butyrolactone F-9: Propyl Carbonate

(Example 1 to Example 16, and Comparative Example 1 to Comparative Example 3) <Preparation of composition for forming resist base film> The respective components shown in Table 2 below were used in the amounts (parts by mass) shown in Table 2 and mixed so that the solid content concentration became 5% by mass to obtain a solution. However, the contents of β-PGMEA, β-PGME, β-PGEE, and water were adjusted so as to become the values shown in Table 3 below. Then, the obtained solution was filtered with a polyethylene filter having a pore diameter of 0.03 μm, thereby preparing a composition for forming a resist underlayer film. The contents of β-PGMEA, β-PGME, and β-PGEE were obtained by adding β-PGMEA, β-PGME, and β-PGEE obtained by the method to the composition for forming a resist underlayer film, respectively The preparation of the solvent can be adjusted. The content of water is adjusted by adding pure water or performing a dehydration operation to α-PGMEA (F-1) used in the composition for forming a resist underlayer film. In addition, in the composition for forming a resist underlayer film, the so-called solid content means removing the solvent, water, the compound represented by the general formula (1), and the compound represented by the general formula (2) from the composition for forming a resist underlayer film. ) And all components after the compound represented by the general formula (3). The obtained resist underlayer film formation composition was used in Examples and Comparative Examples.

[Table 2] Composition for forming resist underlayer film Resin with aromatic ring Crosslinking agent Acid generator Solvent species Mass parts species Mass parts species Mass parts species Mixed mass ratio UL-1 A-1 1 CL-1 0.08 T-1 0.02 F-1 100 UL-2 A-2 1 CL-2 0.1 T-2 0.03 F-1/F-2 60/40 UL-3 A-3 1 CL-3 0.07 T-3 0.02 F-1/F-3 80/20 UL-4 A-4 1 CL-4 0.09 T-4 0.04 F-1/F-4 90/10 UL-5 A-5 1 CL-5 0.11 T-5 0.05 F-1/F-5 70/30 UL-6 A-6 1 CL-6 0.05 T-6 0.01 F-1/F-6 80/20 UL-7 A-7 1 CL-7 0.08 T-1 0.07 F-1/F-7 60/40 UL-8 A-8 1 CL-8 0.07 T-2 0.06 F-1/F-8 95/5 UL-9 A-9 1 CL-9 0.1 T-3 0.1 F-1/F-9 99/1 UL-10 A-10 1 CL-1 0.12 T-4 0.04 F-1 100 UL-11 A-11 1 CL-3 0.09 T-5 0.03 F-1/F-2 40/60 UL-12 A-12 1 CL-5 0.05 T-6 0.01 F-1/F-4 30/70 UL-13 A-13 1 CL-7 0.06 T-7 0.02 F-1/F-7 20/80 UL-14 A-14 1 CL-9 0.05 T-8 0.03 F-1 100 UL-15 A-15 1 CL-10 0.08 T-9 0.05 F-1 100 UL-16 A-1 1 CL-1 0.08 T-1 0.02 F-1 100 UL-17 A-2 1 CL-2 0.08 T-2 0.02 F-1/F-2 60/40 UL-18 A-5 1 CL-5 0.11 T-5 0.05 F-1/F-5 70/30 UL-19 A-5 1 CL-5 0.11 T-5 0.05 F-1/F-5 70/30

<Measurement of β-PGMEA content in resist base film formation composition> The content of β-PGMEA in the composition for forming a resist base film is measured as follows. Using a heating adsorption device μ-CTE250 manufactured by MARKES, the solvent component in the sample is heated and vaporized at a heating temperature of 170°C and adsorbed in a dedicated sample tube. After that, the heating and desorption device HandyTD TD265 manufactured by GL Sciences (GL Sciences) was used to desorb the solvent components adsorbed in the sample tube at a heating temperature of 170°C, and then the gas chromatography mass analyzer JMS manufactured by JEOL was used. -Q1500GC for quantitative analysis.

<Measurement of the content of β-PGME and β-PGEE in the composition for forming a resist base film> The content of β-PGME and β-PGEE in the composition for forming a resist underlayer film is also measured in the same manner as the above-mentioned "Measurement of the content of β-PGMEA in the composition for forming a resist underlayer".

<Measurement of the water content in the composition for forming a resist base film> The content of water in the composition for forming a resist underlayer film was measured using a Karl Fischer moisture meter MKC-510N manufactured by Kyoto Electronics Industry Co., Ltd. HYDRANAL-Coulomat AK (manufactured by Honeywell) was used as the anolyte, and HYDRANAL-Coulomat CG (manufactured by Honeywell) was used as the catholyte, and 5 g of the sample was injected to measure the moisture content.

＜Performance evaluation＞ The coating defects after time and the flatness after time were evaluated as follows. In addition, the composition for forming a resist underlayer film is used for storing in a thermostat at 35°C for six months after preparation.

[Coating Defects after Time] Using a spin coater ("CLEAN TRACK ACT12" of Tokyo Electronics Co., Ltd.), the composition for forming a resist underlayer film was applied to the silicon wafer at a rotation speed of 1500 rpm using a spin coating method . Then, heating is performed at 205° C. for 60 seconds in an atmospheric environment to form a resist underlayer film with a thickness of 100 nm on the silicon wafer. Use UVision5 (manufactured by AMAT) to detect the distribution of defects on the silicon wafer, and use SEMVisionG4 (manufactured by AMAT) to determine the number of defects. A: The number of defects per wafer is less than 10 B: The number of defects per wafer is 11-50 C: The number of defects per wafer is 51-100 D: The number of defects per wafer is more than 101

[Flatness after time] Using a spin coater (“CLEAN TRACK ACT12” of Tokyo Electronics Co., Ltd.), the composition for forming a resist underlayer film was applied to a depth of 100 at a rotation speed of 1500 rpm using a spin coating method. On a silicon wafer with a groove pattern of 10 μm and a groove width of 10 μm (the interval between the grooves is 10 μm). Then, heating is performed at 205° C. for 60 seconds in an atmospheric environment to form a resist underlayer film with a thickness of 100 nm on the silicon wafer. A scanning electron microscope (Hitachi High-technologies’ "S-4800") was used to observe the cross-sectional shape of the silicon wafer with the resist underlayer film, and The difference (ΔFT) between the height of the central portion of the groove pattern and the height of the non-groove pattern portion at a position 5 μm from the end of the groove pattern (ΔFT) is used as an index of flatness over time. For the flatness after time, the case where the ΔFT is less than 30 nm is evaluated as "A", the case where the ΔFT is more than 30 nm and less than 40 nm is evaluated as "B", and the case where the ΔFT is greater than 40 nm is evaluated as "C" .

Table 3 shows the obtained evaluation results. The "content of β-PGMEA" shown in Table 3 is the content of β-PGMEA with respect to the total mass of the composition for forming a resist base film. The "content of β-PGME" shown in Table 3 is the content of β-PGME with respect to the total mass of the composition for forming a resist underlayer film. The "content of β-PGEE" shown in Table 3 is the content of β-PGEE with respect to the total mass of the composition for forming a resist base film. The "water content" shown in Table 3 is the content of water with respect to the total mass of the composition for forming a resist underlayer film. The “ratio of β-PGMEA to α-PGMEA” shown in Table 3 is the ratio (mass %) of β-PGMEA to the content of α-PGMEA in the composition for forming a resist base film. The “content of β-PGMEA” in Table 3 is “undetected”, which means that the content of β-PGMEA with respect to the total mass of the resist base film forming composition is less than 0.1 mass ppm. "The content of β-PGME" in Table 3 is "-", which means that the content of β-PGME with respect to the total mass of the resist base film formation composition is less than 0.1 mass ppm. The "content of β-PGEE" in Table 3 is "-", which means that the content of β-PGEE with respect to the total mass of the resist base film formation composition is less than 0.1 mass ppm. The "content of water" in Table 3 is "-", which means that the content of water relative to the total mass of the composition for forming a resist base film is less than 0.1 mass ppm.

[化30]

[table 3] Composition for forming resist underlayer film The content of β-PGMEA [mass ppm] The content of β-PGME [mass ppm] The content of β-PGEE [mass ppm] Water content [mass ppm] Ratio of β-PGMEA to α-PGMEA [mass%] Coating defects after time Flatness after time Example 1 UL-1 0.8 - - 90 0.00008 C B Example 2 UL-2 0.4 0.4 - 2500 0.00007 C A Example 3 UL-3 0.5 - 50 6000 0.00007 C A Example 4 UL-4 0.9 - - 7500 0.00011 B A Example 5 UL-5 20 30 - 60 0.00301 A B Example 6 UL-6 40 - - 3000 0.00526 B A Example 7 UL-7 30 - - 8000 0.00526 B A Example 8 UL-8 20 - - 15000 0.00222 A C Example 9 UL-9 300 - - 75 0.03191 B B Example 10 UL-10 450 - - 1500 0.04739 B A Example 11 UL-11 200 200 - 6300 0.05266 B A Example 12 UL-13 25 - - 95 0.01316 B B Example 13 UL-14 15 20 - 4100 0.00158 A A Example 14 UL-15 35 30 - - 0.00368 A C Comparative example 1 UL-16 Not detected - - 1000 - D A Comparative example 2 UL-12 2500 - - - 0.88496 D C Comparative example 3 UL-17 600 600 - 20000 0.10537 D C Example 15 UL-18 20 210 - 60 0.00301 B B Example 16 UL-19 37 30 - 60 0.00556 B B

From the results shown in Table 3, it can be seen that the composition for forming a resist underlayer film of the present invention can suppress coating defects over time and is excellent in flatness over time.

[Example of multilayer resist manufacturing process] <Preparation of resist composition> Use the following components in the amounts (parts by mass) shown below, using a mixture of propylene glycol monomethyl ether acetate/cyclohexanone/γ-butyrolactone=70/29/1 (mass ratio) As the solvent, the solvent was mixed so that the solid content concentration became 4% by mass to obtain a solution. Then, the obtained solution was filtered with a polyethylene filter having a pore diameter of 0.03 μm, thereby preparing a resist composition Re-1.

(Ingredients (solid content) used in the preparation of resist composition Re-1) Acid decomposable resin P-1 1 part by mass Photoacid generator PAG-1 0.11 parts by mass Acid diffusion control agent D-1 0.03 parts by mass Hydrophobic resin E-1 0.008 parts by mass Surfactant H-1 0.002 parts by mass

The ingredients used are described below. In addition, the composition ratio of the repeating unit contained in the resin is a molar ratio.

[化31]

Surfactant H-1 is Megafac F176 (manufactured by DIC (stock), fluorine-based surfactant).

＜Pattern formation method＞ The composition UL-1 for forming a resist underlayer film was coated on a silicon wafer, and baked at 205°C for 60 seconds to form a resist underlayer film with a thickness of 100 nm. SHB-A940 (silicon-containing spin hard mask manufactured by Shin-Etsu Chemical Co., Ltd.) was coated on it, and baked at 220°C for 60 seconds to form an intermediate film with a thickness of 30 nm. Furthermore, a resist composition Re-1 was applied thereon, and baked at 100°C for 60 seconds to form a resist film with a film thickness of 90 nm. For the resist film, use an ArF excimer laser immersion scanner (manufactured by ASML; XT1950i, NA1.35, C-Quad, external sigma 0.930, internal sigma 0.730, XY deflection). Expose with a 6% halftone mask of a 1:1 line and a space pattern with a line width of 50 nm. The liquid immersion liquid is ultrapure water. After the exposed resist film was baked at 100°C for 60 seconds, it was developed with a 2.38% by mass tetramethylammonium hydroxide (TMAH) aqueous solution for 30 seconds, and then rinsed with pure water for 30 seconds. After that, it was spin-dried to obtain a positive 1:1 line and space pattern (resist pattern) with a line width of 50 nm. For the silicon wafer on which the resist pattern is formed, the parallel plate type reactive ion etching device DES-245R manufactured by Plasma System is used to etch the intermediate film under the following etching condition 1 using the resist pattern as a mask. . Using the obtained pattern of the intermediate film as a mask, the resist base film was further etched under the following etching conditions 2 to obtain a good pattern. In addition, the resist base film forming composition used in Example 2 to Example 16 also obtained a good pattern after etching.

(Etching condition 1) Etching gas: CF ₄ Pressure: 20 mTorr Applied power: 100 mW/cm ²

(Etching condition 2) Etching gas: O ₂ Pressure: 20 mTorr Applied power: 100 mW/cm ² [Industrial applicability]

According to the present invention, it is possible to provide a composition for forming a resist underlayer film that suppresses the occurrence of coating defects after time and has excellent flatness after time, and a pattern using the composition for forming a resist underlayer film Forming method and manufacturing method of electronic device.

The present invention has been described in detail with reference to specific embodiments, and it is clear to those skilled in the art that various changes or modifications can be added without departing from the spirit and scope of the present invention. This application is based on a Japanese patent application (Japanese Patent Application No. 2019-217608) filed on November 29, 2019, and the content is incorporated herein as a reference.

no

no

no.

Claims (14)

A composition for forming a resist underlayer film, comprising: a resin having an aromatic ring and a compound represented by the following general formula (1); The total mass of the composition for forming an etchant underlayer film, and the content of the compound represented by the general formula (1) is 0.1 mass ppm or more and 500 mass ppm or less,

In the general formula (1), R ₁ to R ₃ each independently represent an alkyl group having 1 to 5 carbon atoms. The composition for forming a resist underlayer film according to claim 1, wherein the content of the compound represented by the general formula (1) is 1 relative to the total mass of the composition for forming a resist underlayer film Mass ppm or more. The composition for forming a resist underlayer film according to claim 1, wherein the content of the compound represented by the general formula (1) is 100 relative to the total mass of the composition for forming a resist underlayer film Mass ppm or less. The composition for forming a resist underlayer film according to claim 1, wherein the composition for forming a resist underlayer film contains the following general formula of 0.1 mass ppm or more and 500 mass ppm or less relative to the total mass of the resist underlayer film forming composition (2) The compound represented,

In the general formula (2), R ₄ and R ₅ each independently represent an alkyl group having 1 to 5 carbon atoms. The composition for forming a resist underlayer film according to claim 4, wherein the content of the compound represented by the general formula (2) is 1 relative to the total mass of the composition for forming a resist underlayer film Mass ppm or more. The composition for forming a resist underlayer film according to claim 4, wherein the content of the compound represented by the general formula (2) is 200 relative to the total mass of the composition for forming a resist underlayer. Mass ppm or less. The composition for forming a resist underlayer film according to any one of claims 1 to 6, wherein the composition for forming a resist underlayer film contains 1 mass ppm or more and 1 mass ppm relative to the total mass of the composition for forming a resist underlayer film. Water below mass%. The composition for forming a resist underlayer film according to claim 7, wherein the content of the water is 0.01% by mass or more with respect to the total mass of the composition for forming a resist underlayer. The composition for forming a resist underlayer film according to claim 7, wherein the content of the water is 0.5% by mass or less with respect to the total mass of the composition for forming a resist underlayer. The composition for forming a resist underlayer film according to any one of claims 1 to 6, containing a compound represented by the following general formula (3), and the compound represented by the general formula (1) is relatively The content of the compound represented by the general formula (3) is 0.1 mass ppm or more and 0.05 mass% or less,

In the general formula (3), R ₆ to R ₈ each independently represent an alkyl group having 1 to 5 carbon atoms. The composition for forming a resist underlayer film according to claim 10, wherein the content of the compound represented by the general formula (1) relative to the compound represented by the general formula (3) is 1 mass ppm or more and 0.005 mass% or less. The composition for forming a resist underlayer film according to any one of claims 1 to 6 contains a thermal acid generator and a crosslinking agent. A pattern forming method includes: (1) A step of forming a resist underlayer film on a substrate using the composition for forming a resist underlayer film according to any one of claims 1 to 12; (2) A step of forming a resist film using a resist composition on the resist underlayer film; (3) The step of exposing the resist film; (4) The step of developing the exposed resist film to form a resist pattern; and (5) A step of etching the resist pattern as a mask to form a pattern. A manufacturing method of an electronic device includes the pattern forming method as described in claim 13.