TW201439684A - Composition for forming anti-etching under-layer film and pattern formation method - Google Patents

Abstract

The purpose of the present invention is to provide a composition for forming an anti-etching under-layer film, which has excellent storage stability and is capable of reducing the generation of coating defects, and a pattern formation method using the composition for forming an anti-etching under-layer film. The present invention relates to a composition for forming an anti-etching under-layer film, which is an anti-etching under-layer film formation composition that comprises [A] a polysiloxane and [B] an organic solvent. The [B] organic solvent includes (B1) alkylene glycol monoalkylether acetates having a standard boiling point of lower than 150.0 DEG C and (B2) an organic solvent having a standard boiling point of 150.0 DEG C or higher. The content percentage of the (B1) alkylene glycol monoalkylether acetates in the [B] organic solvent is 50 mass% or more and 99 mass% or less, while the content percentage of the (B2) organic solvent is 1 mass% or more and 50 mass% or less. The standard boiling point of the (B2) organic solvent is preferably 180 DEG C or higher.

Description

Anti-corrosion underlayer film forming composition and pattern forming method

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

In the manufacture of a semiconductor device, a multilayer resist process has been used in accordance with the miniaturization of the pattern associated with high integration. This process is to apply a composition for forming a resist underlayer film on a substrate to be processed, to form a resist underlayer film, and apply a resist composition on the resist underlayer film to form a resist film. Next, the resist film is exposed through a mask by a reduction projection exposure apparatus (stepper) or the like, and developed as an appropriate developing liquid to form a resist pattern. Then, the resist pattern is used as a mask to dry-etch the underlayer film, and the obtained underlayer film pattern is used as a mask to further dry-etch the substrate to be processed, thereby forming a desired pattern on the substrate to be processed.

As the composition for forming a resist underlayer film, it has been disclosed that a composition containing a polyoxyalkylene can be used as a resist having a high etching selectivity for a resist film, and a resist underlayer film can be surely etched (refer to the special opening). Japanese Patent Publication No. 2004-310019 and JP-A-2005-018054.

However, the preservation stability of the above composition is insufficient, if When the storage period is lengthened, even if the film thickness of the resist underlayer film formed under the same manufacturing conditions is different, a difference occurs. Moreover, in the formation of the resist underlayer film in the past composition, the polymer component dissolved in the composition is solidified, and the coating defect is abnormal in the formed resist underlayer film due to the formed solid matter. .

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] JP-A-2004-310019

[Patent Document 2] JP-A-2005-018054

The present invention has been made in view of the above circumstances, and an object thereof is to provide a composition for forming a resist underlayer film having excellent storage stability and reducing coating defects, and a pattern for forming a composition for forming the resist underlayer film. Forming method.

The invention for solving the above problems is a composition for forming a resist underlayer film, which is a composition for forming a resist underlayer film containing [A] polydecane and [B] an organic solvent, which is characterized by [B] The organic solvent comprises (B1) an alkylene glycol monoalkyl ether acetate having a standard boiling point of less than 150.0 ° C (hereinafter also referred to as "(B1) alkanediol monoalkyl ether acetate"), and (B2) standard The boiling point is above 150.0 ° C The solvent (hereinafter also referred to as "(B2) organic solvent"), and the content of the (B1) alkanediol monoalkyl ether acetate in the organic solvent is 50% by mass or more and 99% by mass or less. (B2) The content of the organic solvent is 1% by mass or more and 50% by mass or less.

The composition for forming a resist underlayer film of the present invention has a (B1) organic solvent including the above-mentioned specific (B1) alkanediol monoalkyl ether acetate and a high boiling component (B2) organic solvent. The excellent storage stability of the film thickness of the resist underlayer film accompanying the composition is reduced, and the coating defects during the formation of the undercoat film can be reduced.

(B2) The standard boiling point of the organic solvent is preferably 180 ° C or higher. By setting the standard boiling point of the (B2) organic solvent to the above specific range, the storage stability of the composition can be further improved, and the coating defect can be further reduced.

(B2) The organic solvent is preferably at least one selected from the group consisting of esters and ethers. By making the (B2) organic solvent the above specific solvent, the solubility of the [A] polyoxyalkylene can be improved, and as a result, coating defects can be further reduced.

(B2) The organic solvent is preferably at least one selected from the group consisting of a carboxylic acid ester, a lactone, a carbonate, and a compound represented by the following formula (1).

(In the formula (1), R ¹ and R ² each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or a fluorenyl group having 1 to 4 carbon atoms; R ³ is a hydrogen atom or a methyl group, and n is 1 to 4 An integer, when n is 2 or more, a plurality of R ^{3 's} may be the same or different).

By making the (B2) organic solvent the above specific solvent, the solubility of the [A] polyoxane of the composition can be further improved.

(B2) The specific dielectric ratio of the organic solvent is preferably 13 or more and 200 or less. By setting the specific dielectric constant of the (B2) organic solvent to the above specific range, the solubility of the [A] polyoxane of the composition can be further improved.

The (B1) alkanediol monoalkyl ether acetates are preferably propylene glycol monoalkyl ether acetates. By making the (B1) alkanediol monoalkyl ether acetates propylene glycol monoalkyl ether acetates, the solubility of the [A] polyoxane can be further improved.

Since the composition for forming a resist underlayer film has the above properties, it can be preferably used in a multilayer resist process, and a resist underlayer film having less coating defects can be formed.

The composition for forming a resist underlayer film preferably further contains a [C] acid diffusion controlling agent. By further including the [C] acid diffusion controlling agent in the composition for forming a resist underlayer film, the above effect can be maintained, and on the one hand, acid diffusion of the resist film caused by the underlayer film can be effectively suppressed, and as a result, The shape of the resist pattern formed by the multilayer resist process can be improved.

The [A] polyoxyalkylene is preferably a hydrolysis condensate of a compound containing a decane compound represented by the following formula (i), [Chem. 2] R ^A _a SiX _4-a (i)

(In the formula (i), R ^A is a hydrogen atom, a fluorine atom, an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an aryl group having 6 to 20 carbon atoms or a cyano group, and the above alkyl group Part or all of a hydrogen atom may be substituted with an epoxyalkyloxy group, an epoxy group, an acid anhydride group or a cyano group, and some or all of the hydrogen atoms of the above aryl group may be substituted by a hydroxyl group, and X is a halogen atom or -OR ^B However, R ^B is a monovalent organic group, and a is an integer of 0 to 3. However, when R ^A and X are plural, respectively, the plural R ^A and X may be the same or different.

By making [A] polyoxyalkylene a hydrolysis condensate of the above specific compound, the composition can form a resist pattern having a good shape, and the adhesion between the resist underlayer film and the resist film can be improved.

The pattern forming method of the present invention has the following steps: (1) a step of forming a resist underlayer film on a substrate to be processed using the composition for forming a resist underlayer film, and (2) using a resist composition for the above-mentioned anti-corrosion a step of forming a resist film on the underlying film, (3) a step of exposing the resist film by irradiation of exposed light through the photomask, and (4) developing the exposed resist film to form an anti-etching film The step of etching the pattern, and (5) the step of sequentially etching the resist underlayer film and the substrate to be processed by using the resist pattern as a mask.

The resist underlayer film forming composition has the above properties Therefore, according to the pattern forming method of the present invention, a good resist pattern can be formed.

Here, the "standard boiling point" (hereinafter also referred to simply as "boiling point") means the boiling point at atmospheric pressure. Moreover, the "specific dielectric ratio" means the ratio of the dielectric ratio of the medium to the dielectric ratio of the vacuum. For the specific dielectric constant of the compound, refer to the values described in "Chemical Notes Basics Revision 5". The specific dielectric constant of the compound not described in the above chemical handbook is a value measured at 20 ° C by the method described in JIS C2138. Further, the "monovalent organic group" is a valent group containing at least one carbon atom.

As described above, the composition for forming a resist underlayer film of the present invention has excellent storage stability and can reduce the occurrence of coating defects. According to this, the composition for forming a resist underlayer film and the pattern forming method can be preferably used in a manufacturing process of a semiconductor device in which the pattern is refined.

<Resist composition for forming an underlayer film>

The composition for forming a resist underlayer film of the present invention contains [A] a polysiloxane and a solvent [B]. Further, the composition for forming a resist underlayer film may further contain a [C] acid diffusion controlling agent as a preferable component. Further, the composition for forming a resist underlayer film may contain any other constituents as long as the effects of the present invention are not impaired. Minute.

Further, since the composition for forming a resist underlayer film is excellent in coating defects, it can be preferably used in a multilayer resist process as shown in the pattern forming method described later, and can form less coating defects. The underlying film of the resist. Hereinafter, each component will be described in detail.

<[A]polyoxane>

[A] Polysiloxane is not particularly limited as long as it has a polymer having a decane bond, but is preferably a compound hydrolysis condensate containing a decane compound represented by the above formula (i). Here, the "hydrolysis condensate of a compound containing a decane compound" means a hydrolysis condensate of a decane compound represented by the above formula (i), or a decane compound represented by the above formula (i) and the formula (i) A hydrolysis condensate of a decane compound other than a decane compound (hereinafter also referred to as "another decane compound"). The other decane compound is not particularly limited as long as it can form a hydrolyzed stanol group. By making [A] polyoxyalkylene a hydrolysis condensate of the compound represented by the above formula (i), the composition can be formed into a shape having a good shape and a resist underlayer film and a resist film can be improved. The closeness.

In the above formula (i), R ^A is a hydrogen atom, a fluorine atom, an alkyl group having 1 to 5 carbon atoms, the carbon atoms of the alkenyl group having 2 to 10 carbon atoms or an aryl group having 6 to 20 of the cyano group. Some or all of one of the hydrogen atoms of the above alkyl group may be substituted with an epoxyalkyloxy group, an epoxy group, an acid anhydride group or a cyano group. Some or all of one of the hydrogen atoms of the above aryl group may be substituted with a hydroxyl group. X is a halogen atom or -OR ^B . However, R ^B is a monovalent organic group. a is an integer from 0 to 3. However, when R ^A and X are each plural, the plural R ^A and X may be the same or different.

The alkyl group having 1 to 5 carbon atoms represented by the above R ^A is exemplified by a linear alkyl group such as a methyl group, an ethyl group, a n-propyl group, a n-butyl group or a n-pentyl group; an isopropyl group and an isobutyl group; A branched alkyl group such as a second butyl group, a tert-butyl group or an isopentyl group. Among these, a methyl group and an ethyl group are more preferable, and a methyl group is more preferable.

The alkenyl group having 2 to 10 carbon atoms represented by the above R ^A is exemplified by, for example, a vinyl group, a 1-propen-1-yl group, a 1-propen-2-yl group, a 1-propen-3-yl group, and a 1-butene-1. -yl, 1-buten-2-yl, 1-buten-3-yl, 1-buten-4-yl, 2-buten-1-yl, 2-buten-2-yl, 1- Pentene-5-yl, 2-penten-1-yl, 2-penten-2-yl, 1-hexen-6-yl, 2-hexen-1-yl, 2-hexene-2- Base.

The aryl group having 6 to 20 carbon atoms represented by the above R ^A is exemplified by, for example, a phenyl group, a naphthyl group, a methylphenyl group, an ethylphenyl group, a chlorophenyl group, a bromophenyl group, a fluorophenyl group or the like.

In the present specification, the above "epoxy group" includes both an epoxy group and an oxetanyl group.

The above alkyl group substituted with an epoxyalkyloxy group is exemplified by an epoxyethyl group such as 2-glycidoxyethyl group, 3-glycidoxypropyl group or 4-glycidoxybutyl group; 3-ethyl-3-oxetanyloxypropyl, 3-methyl-3-oxetanyloxypropyl, 3-ethyl-2-oxetanyloxypropyl And an oxetanyloxyalkyl group such as 2-oxetanyloxyethyl group. Among these, 3-glycidoxypropyl group and 3-ethyl-3-oxetanyloxypropyl group are preferred.

The above alkyl group substituted with an epoxy group is preferably an epoxy group having 2 to 10 carbon atoms, and is exemplified by, for example, 1,2-epoxyethyl group, 1,2-epoxypropyl group. Base, 1,2-epoxybutyl, 1,2-epoxypentyl and the like.

The alkyl group substituted with an acid anhydride group is exemplified by an ethyl group substituted with a 2-succinic anhydride group, a propyl group substituted with a 3-succinic anhydride group, a butyl group substituted with a 4-succinic anhydride group, and the like. Among these, a propyl group substituted with a 3-succinic anhydride group is more preferred.

The above alkyl group substituted with a cyano group is exemplified by, for example, 2-cyanoethyl, 3-cyanopropyl, 4-cyanobutyl or the like.

The above aryl group substituted with a hydroxy group is exemplified by, for example, a 4-hydroxyphenyl group, a 4-hydroxy-2-methylphenyl group, a 4-hydroxynaphthyl group or the like. Among these, a 4-hydroxyphenyl group is preferred.

The halogen atom represented by X above is, for example, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom or the like.

The one-valent organic group in the above R ^B is preferably an alkyl group or an alkylcarbonyl group. The above alkyl group is preferably a methyl group, an ethyl group, a n-propyl group, an isopropyl group, a n-butyl group, an isobutyl group, a second butyl group or a t-butyl group, more preferably a methyl group or an ethyl group, and most preferably methyl. Further, the above alkylcarbonyl group is preferably a methylcarbonyl group or an ethylcarbonyl group.

The decane compound represented by the above formula (i) is exemplified by, for example, a trialkoxy decane containing an aromatic ring, which is phenyltrimethoxydecane, 4-methylphenyltrimethoxydecane, or 4-ethylphenyl. Trimethoxydecane, 4-hydroxyphenyltrimethoxydecane, 3-methylphenyltrimethoxydecane, 3-ethylphenyltrimethoxydecane, 3-hydroxyphenyltrimethoxydecane, 2-methyl Phenyltrimethoxydecane, 2-ethylphenyltrimethoxyindole An alkane, 2-hydroxyphenyltrimethoxydecane, 2,4,6-trimethylphenyltrimethoxydecane, etc.; as an alkyltrialkoxydecane, a methyltrimethoxydecane, a methyl three Ethoxy decane, methyl tri-n-propoxy decane, methyl triisopropoxy decane, methyl tri-n-butoxy decane, methyl tri-second butoxy decane, methyl tri-tertiary Oxydecane, methyltriphenoxydecane, methyltriethoxydecane, methyltrichlorodecane, methyltriisopropenyloxydecane, methylglyoxime (dimethylmethoxyoxy)decane, A Ginseng (methoxyethoxy) decane, methyl gin (methyl ethyl ketoxime) decane, methyl ginseng (trimethyl decyloxy) decane, methyl decane, ethyl trimethoxy decane, B Triethoxy decane, ethyl tri-n-propoxy decane, ethyl triisopropoxy decane, ethyl tri-n-butoxy decane, ethyl tri-second butoxy decane, ethyl tri- Tributoxydecane, ethyltriphenoxydecane, ethyl bis-(trimethyldecyloxy)decane, ethyldichlorodecane, ethyltriethoxydecane, ethyltrichlorodecane, positive Propyltrimethoxydecane, positive Propyl triethoxy decane, n-propyl tri-n-propoxy decane, n-propyl triisopropoxy decane, n-propyl tri-n-butoxy decane, n-propyl tri-second butoxy decane, N-propyl tri-t-butoxydecane, n-propyltriphenoxydecane, n-propyltriethoxydecane, n-propyltrichlorodecane, isopropyltrimethoxydecane, isopropyl trisole Ethoxy decane, isopropyl tri-n-propoxy decane, isopropyl triisopropoxy decane, isopropyl tri-n-butoxy decane, isopropyl tri-second butoxy decane, isopropyl Tri-t-butoxy decane, isopropyl triphenoxy decane, n-butyl trimethoxy decane, n-butyl triethoxy decane, n-butyl tri-n-propoxy decane, n-butyl triiso Propoxydecane, n-butyltri-n-butoxy Decane, n-butyltri-t-butoxydecane, n-butyltri-t-butoxydecane, n-butyltriphenoxydecane, n-butyltrichlorodecane, 2-methylpropyltrimethoxy Baseline, 2-methylpropyltriethoxydecane, 2-methylpropyltri-n-propoxydecane, 2-methylpropyltriisopropoxydecane, 2-methylpropyltri-n-butyl Oxydecane, 2-methylpropyltri-t-butoxydecane, 2-methylpropyltri-t-butoxydecane, 2-methylpropyltriphenoxydecane, 1-methyl Propyltrimethoxydecane, 1-methylpropyltriethoxydecane, 1-methylpropyltri-n-propoxydecane, 1-methylpropyltriisopropoxydecane, 1-methylpropane Tri-n-butoxy decane, 1-methylpropyltri-t-butoxydecane, 1-methylpropyltri-t-butoxydecane, 1-methylpropyltriphenoxydecane, Third butyl trimethoxy decane, tert-butyl triethoxy decane, tert-butyl tri-n-propoxy decane, tert-butyl triisopropoxy decane, tert-butyl tri-n-butoxy Decane, tert-butyltri-t-butoxydecane, tert-butyltri-tert-butoxydecane, Tributyltriphenoxydecane, tert-butyltrichlorodecane, tert-butyldichlorodecane, etc.; as alkenyl trialkoxydecanes, vinyltrimethoxydecane, vinyltriethoxy Decane, vinyl tri-n-propoxy decane, vinyl triisopropoxy decane, vinyl tri-n-butoxy decane, vinyl tri-second butoxy decane, vinyl tri-tert-butoxy decane , vinyl triphenoxydecane, allyl trimethoxy decane, allyl triethoxy decane, allyl tri-n-propoxy decane, allyl triisopropoxy decane, allyl tri N-butoxy decane, allyl tri-second butoxy decane, allyl tri-t-butoxy decane, allyl triphenoxy decane, etc.; as tetraalkoxy decane, four Methoxy decane, tetraethoxy hydrazine Alkane, tetra-n-propoxy decane, tetraisopropoxy decane, tetra-n-butoxy decane, tetra-butoxy decane, tetra-tert-butoxy decane, etc.; as tetraaryl decane, Tetraphenoxydecane, etc.; as an epoxy group-containing decane, 3-oxetanylmethyloxypropyltrimethoxydecane, 3-oxetanylethyloxypropyltrimethoxydecane , 3-glycidoxypropyltrimethoxydecane, etc.; as an acid anhydride-containing decane, 3-(trimethoxydecyl)propyl succinic anhydride, 2-(trimethoxydecyl)ethyl amber An acid anhydride, 3-(trimethoxydecyl)propyl succinic anhydride, 2-(trimethoxydecyl)ethyl succinic anhydride, etc.; tetrachloro decane, etc. are tetrachloro decane, etc..

The above other decane compounds are exemplified by, for example, benzyltrimethoxydecane, phenethyltrimethoxydecane, 4-phenoxyphenyltrimethoxydecane, 4-aminophenyltrimethoxydecane, 4-dimethylamine. Phenyltrimethoxydecane, 4-ethenylaminophenyltrimethoxydecane, 3-methoxyphenyltrimethoxydecane, 3-phenoxyphenyltrimethoxydecane, 3-amino Phenyltrimethoxydecane, 3-dimethylaminophenyltrimethoxydecane, 3-ethenylaminophenyltrimethoxydecane, 2-methoxyphenyltrimethoxydecane, 2-phenoxy Phenyltrimethoxydecane, 2-aminophenyltrimethoxydecane, 2-dimethylaminophenyltrimethoxydecane, 2-ethenylaminophenyltrimethoxydecane, 4-methyl Benzyltrimethoxydecane, 4-ethylbenzyltrimethoxydecane, 4-methoxybenzyltrimethoxydecane, 4-phenoxybenzyltrimethoxydecane, 4-hydroxybenzyltrimethoxy Decane, 4-aminobenzyltrimethoxydecane, 4-dimethylaminobenzyltrimethoxydecane, 4-ethylguanidinobenzyl-3- Methoxydecane, etc.

Hydrolysis condensation of the above-described long as the conditions allow to hydrolyse at least a portion of the silicon alkoxy compound represented by the above formula (I), to convert the hydrolyzable group (-OR ^B) to silicon alkoxide group, i.e. by causing a condensation reaction is not particularly limited, and example thereof It can be implemented in the following ways.

The water used for the hydrolytic condensation is preferably water which has been purified by reverse osmosis membrane treatment, ion exchange treatment, distillation or the like. By using the purified water, side reactions can be suppressed and hydrolysis reactivity can be improved. The amount of water used is 1 mol, more preferably 0.1 to 3 mol, more preferably 0.3 to 2 mol, more preferably 0.5, based on the total amount of the hydrolyzable group of the decane compound represented by the above formula (i). ~1.5 moles. Hydrolysis can be achieved by using this amount of water. The reaction rate of the condensation is optimized.

The solvent to be used in the above hydrolysis condensation is not particularly limited, but is preferably ethylene glycol monoalkyl ether acetate, diethylene glycol dialkyl ether, propylene glycol monoalkyl ether, propylene glycol monoalkyl ether acetate. Ester, propionate. Among these, it is more preferably diethylene glycol dimethyl ether, diethylene glycol ethyl methyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monomethyl ether acetate or 3-methyl Methyl oxypropionate, 4-hydroxy-4-methyl-2-pentanone (diacetone alcohol).

The above hydrolysis condensation reaction is preferably carried out in an acid catalyst (for example, hydrochloric acid, sulfuric acid, nitric acid, formic acid, oxalic acid, acetic acid, trifluoroacetic acid, trifluoromethanesulfonic acid, phosphoric acid, acidic ion exchange resin, various Lewis acids), alkali catalyst (for example, ammonia, primary amines, secondary amines, tertiary amines, nitrogen-containing compounds such as pyridine; basic ion exchange resins; hydroxides such as sodium hydroxide And a carbonate such as potassium carbonate; a carboxylate such as sodium acetate; various Lewis bases; or an alkoxide (for example, zirconium alkoxide, titanium alkoxide, or alkane oxide). For example, aluminum aluminoxide can be used for the aluminum alkoxide. The amount of the catalyst used is preferably 0.2 mol or less, more preferably 0.00001 to 0.1 mol, based on the monomer 1 mol of the hydrolyzable decane compound, from the viewpoint of promoting the hydrolysis condensation reaction.

The reaction temperature and reaction time in the above hydrolysis condensation are appropriately set. For example, the following conditions can be employed. The reaction temperature is preferably from 40 ° C to 200 ° C, more preferably from 50 ° C to 150 ° C. The reaction time is preferably from 30 minutes to 24 hours, more preferably from 1 hour to 12 hours. By setting the reaction temperature and the reaction time, the hydrolysis condensation reaction can be carried out most efficiently. In the hydrolysis condensation reaction, a hydrolyzable decane compound, water, and a catalyst may be added to the reaction system at a time, and the reaction may be carried out in one stage, or a hydrolyzable decane compound, water, and a catalyst may be added to the reaction system in portions. The hydrolysis condensation reaction is carried out in multiple stages. Further, after the hydrolysis condensation reaction, a dehydrating agent may be added, followed by evaporation, and water and the produced alcohol are removed from the reaction system.

The content of the [A] polyoxyalkylene is preferably 80% by mass or more, more preferably 90% by mass or more, and still more preferably 95% by mass or more based on the total solid content in the composition for forming a resist underlayer film. Further, the composition for forming a resist underlayer film may contain only one kind of [A] polyoxyalkylene, and may contain two or more kinds.

[A] polyoxyalkylene has a weight average molecular weight (Mw) in terms of polystyrene measured by a gel permeation chromatography (GPC) of usually 500 to 50,000, preferably 1,000 to 30,000, more preferably 1,000 to 15,000, and even better, 1,000 to 5,000.

<[B]organic solvent>

[B] The organic solvent contains (B1) alkanediol monoalkyl ether acetates and (B2) an organic solvent, and [B] an organic solvent (B1) alkanediol monoalkyl ether acetates. 50% by mass or more and 99% by mass or less, and the content of the organic solvent (B2) is 1% by mass or more and 50% by mass or less. In addition, the [B] organic solvent may contain other components (organic solvent) such as an organic solvent (hereinafter also referred to as "(B3) organic solvent"), which will be described later, within the range which does not impair the effects of the present invention. Each of the above components may be used alone or in combination of two or more. The components are detailed below.

[(B1) alkanediol monoalkyl ether acetates)

(B1) The alkanediol monoalkyl ether acetate is an organic solvent having a standard boiling point of less than 150.0 °C. The (B1) alkanediol monoalkyl ether acetates are preferably propylene glycol monoalkyl ether acetates. By making the (B1) alkanediol monoalkyl ether acetates propylene glycol monoalkyl ether acetates, the solubility of the [A] polyoxane can be further improved.

The above (B1) alkanediol monoalkyl ether acetates are exemplified by, for example, ethylene glycol monoalkyl ethers being ethylene glycol monomethyl ether acetate (boiling point: 145 ° C), etc.; as propylene glycol monoalkyl ether The acetate is propylene glycol monomethyl ether acetate (boiling point: 146 ° C) and the like. Among these, propylene glycol monoalkyl ether acetate is preferred, and propylene glycol monomethyl ether acetate is more preferred.

[B] (B1) alkanediol monoalkyl ether acetate in an organic solvent The content of the ester is 50% by mass or more and 99% by mass or less. The content ratio is preferably 70% by mass or more and 99% by mass or less, more preferably 80% by mass or more and 99% by mass or less. When the content of the (B1) alkanediol monoalkyl ether acetate is in the above range, storage stability and coating defects can be effectively improved.

[(B2) organic solvent]

(B2) The organic solvent is an organic solvent having a normal boiling point of 150.0 ° C or more. By making the [B] organic solvent contain a [B2] organic solvent having a high boiling point component, it has excellent storage stability which can reduce the change in the thickness of the resist underlayer film due to storage of the composition, and can be reduced in the resist. Coating defects in the formation of the underlying film.

(B2) The standard boiling point of the organic solvent is preferably 160 ° C or higher, more preferably 170 ° C or higher, and still more preferably 180 ° C or higher. By setting the standard boiling point of the (B2) organic solvent to the above range, the storage stability and coating defects of the composition can be more effectively improved.

The standard boiling point of the organic solvent (B2) is preferably 300 ° C or lower, more preferably 280 ° C or lower, still more preferably 250 ° C or lower, and most preferably 220 ° C or lower. By setting the standard boiling point of the above (B2) organic solvent to the above range, the residue of the organic solvent after the formation of the undercoat film can be reduced.

(B2) The component of the organic solvent is exemplified by esters, alcohols, ethers, ketones, guanamine-based solvents, and the like. In the above, at least one selected from the group consisting of esters and ethers is preferably more preferably composed of a carboxylate, a lactone, a carbonate, and a compound represented by the above formula (1). At least one of the group selections. By making the (B2) organic solvent into the above solvent, the solubility of the [A] polyoxane of the composition can be further improved.

In the above formula (1), R ¹ and R ² each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or a mercapto group having 1 to 4 carbon atoms. R ³ is a hydrogen atom or a methyl group. n is an integer from 1 to 4. n is 2 or more, plural R ³ may be identical or different.

In the above-described R ¹ and R ² represents an alkyl group of 1 to 4 carbon atoms include, for example, the methyl, ethyl, n-propyl, n-butyl linear alkyl group; an isopropyl group, an isobutyl group, a second a branched alkyl group such as a butyl group or a tributyl group.

The fluorenyl group having 1 to 4 carbon atoms represented by the above R ¹ and R ² is exemplified by a methyl group, an ethyl group, a propyl group or the like.

The above esters are exemplified by, for example, as a carboxylic acid ester, 3-methoxybutyl acetate (boiling point: 172 ° C), 2-ethylbutyl acetate (boiling point: 160 ° C), 2-ethylhexyl acetate (boiling point: 199 ° C), benzyl acetate (boiling point: 212 ° C), cyclohexyl acetate (boiling point: 172 ° C), methylcyclohexyl acetate (boiling point: 201 ° C), n-decyl acetate (boiling point: 208 ° C ), ethyl acetoxyacetate (boiling point: 169 ° C), ethyl acetoacetate (boiling point: 181 ° C), isoamyl propionate (boiling point: 156 ° C), diethyl oxalate (boiling point: 185 ° C) , di-n-butyl oxalate (boiling point: 239 ° C), ethyl lactate (boiling point: 151 ° C), n-butyl lactate (boiling point: 185 ° C), diethyl malonate (boiling point: 199 ° C), phthalic acid Dimethyl ester (boiling point: 283 ° C); etc.; as for lactones, β-propiolactone (boiling point: 162 ° C), γ-butyrolactone (boiling point: 204 ° C), γ-valerolactone (boiling point: 207 ° C), γ-undecene lactone (boiling point: 286 ° C).

The carbonates are exemplified by ethyl carbonate (boiling point: 244 ° C), propylene carbonate (boiling point: 242 ° C), and the like.

The above alcohols are exemplified by, for example, 3-methoxybutanol (boiling point: 157 ° C), n-hexanol (boiling point: 157 ° C), n-octanol (boiling point: 194 ° C), and second octanol (boiling point). : 174 ° C), n-nonanol (boiling point: 215 ° C), n-nonanol (boiling point: 228 ° C), phenol (boiling point: 182 ° C), cyclohexanol (boiling point: 161 ° C), benzyl alcohol (boiling point: 205 ° C )Wait.

As the polyol, ethylene glycol (boiling point: 197 ° C), 1,2-propanediol (boiling point: 188 ° C), 1,3-butanediol (boiling point: 208 ° C), 2,4-pentanediol ( Boiling point: 201 ° C), 2-methyl-2,4-pentanediol (boiling point: 196 ° C), 2,5-hexanediol (boiling point: 216 ° C), triethylene glycol (boiling point: 165 ° C), etc. As a part of the polyol ether, it is ethylene glycol monobutyl ether (boiling point: 171 ° C), ethylene glycol monophenyl ether (boiling point: 244 ° C), diethylene glycol monomethyl ether (boiling point: 194 ° C ), diethylene glycol monoethyl ether (boiling point: 202 ° C), triethylene glycol monomethyl ether (boiling point: 249 ° C), diethylene glycol monoisopropyl ether (boiling point: 207 ° C), two Glycol monobutyl ether (boiling point: 231 ° C), triethylene glycol monobutyl ether (boiling point: 271 ° C), ethylene glycol monoisobutyl ether (boiling point: 161 ° C), diethylene glycol monoisobutyl Ether (boiling point: 220 ° C), ethylene glycol monohexyl ether (boiling point: 208 ° C), diethylene glycol monohexyl ether (boiling point: 259 ° C), ethylene glycol mono-2-ethylhexyl Ether (boiling point: 229 ° C), diethylene glycol mono 2-ethylhexyl ether (boiling point: 272 ° C), ethylene glycol monoallyl ether (boiling point: 159 ° C), diethylene glycol monophenyl ether ( Boiling point: 283 ° C), ethylene glycol monobenzyl ether (boiling point: 256 ° C), diethylene glycol monobenzyl ether (boiling point: 302 ° C), dipropylene glycol monomethyl ether (boiling point: 187 ° C), tripropylene glycol Monomethyl ether (boiling point: 242 ° C), dipropylene glycol monopropyl ether (boiling point: 212 ° C), propylene glycol monobutyl ether (boiling point: 170 ° C), dipropylene glycol monobutyl ether (boiling point: 231 ° C), propylene glycol Monophenyl ether (boiling point: 243 ° C) and the like.

The above ethers are exemplified by, for example, diethylene glycol dimethyl ether (boiling point: 162 ° C), triethylene glycol dimethyl ether (boiling point: 216 ° C), diethylene glycol methyl ethyl ether (boiling point: 176). °C), diethylene glycol diethyl ether (boiling point: 189 ° C), diethylene glycol dibutyl ether (boiling point: 255 ° C), dipropylene glycol dimethyl ether (boiling point: 171 ° C), diethylene glycol Monoethyl ether acetate (boiling point: 217 ° C), ethylene glycol monobutyl ether acetate (boiling point: 188 ° C), 1,8-cineole (boiling point: 176 ° C), two different Amyl ether (boiling point: 171 ° C), anisole (boiling point: 155 ° C), ethyl benzyl ether (boiling point: 189 ° C), diphenyl ether (boiling point: 259 ° C), dibenzyl ether (boiling point: 297 ° C), phenylethyl alcohol (boiling point: 170 ° C), dihexyl ether (boiling point: 226 ° C), and the like.

The ketones are exemplified by, for example, ethyl amyl ketone (boiling point: 167 ° C), dibutyl ketone (boiling point: 186 ° C), dipentyl ketone (boiling point: 228 ° C), and the like.

The above amide-based solvent is exemplified as, for example, N-methylpyrrolidone (boiling point: 204 ° C), N,N-dimethylacetamide (boiling point: 165 ° C), formamide (boiling point: 210 ° C), N-ethylacetamide (boiling point: 206) °C), N-methylacetamide (boiling point: 206 ° C), and the like.

Other (B2) organic solvents are decyl alcohol (boiling point: 162 ° C), dimethyl hydrazine (boiling point: 189 ° C), cyclobutyl hydrazine (boiling point: 287 ° C), glycerin (boiling point: 290 ° C), succinonitrile ( Boiling point: 265 ° C), nitrobenzene (boiling point: 211 ° C), and the like.

(B2) The specific dielectric ratio of the organic solvent is preferably from 13 to 200, more preferably from 15 to 150, still more preferably from 20 to 100. By making the specific dielectric constant of the (B2) organic solvent into the specific dielectric ratio in the above range, the solubility of the [A] polyoxane of the composition can be improved.

The (B2) organic solvent having a specific dielectric ratio in the above range is exemplified by, for example, ethyl acetoxyacetate (specific dielectric ratio: 16), N-methylpyrrolidone (specific dielectric ratio: 33), N, N- Dimethylacetamide (specific dielectric ratio: 39), formamide (specific dielectric ratio: 111), N-ethylacetamide (specific dielectric ratio: 135), N-methylacetamide (specific dielectric ratio: 179), furfural (specific dielectric ratio: 42), propylene carbonate (specific dielectric ratio: 63), ethyl carbonate (specific dielectric ratio: 90), dimethyl adenine (specific dielectric ratio: 49), cyclobutyl hydrazine (specific dielectric ratio: 42), ethylene glycol (specific dielectric ratio: 41), glycerin (specific dielectric ratio: 47), succinonitrile (specific dielectric) Rate: 63), nitrobenzene (specific dielectric ratio: 36), γ-butyrolactone (specific dielectric ratio: 39) Wait.

[B] The content of the (B2) organic solvent in the organic solvent is 1% by mass or more and 50% by mass or less. The content ratio is preferably 2% by mass or more and 40% by mass or less, more preferably 2% by mass or more and 30% by mass or less. By setting the content of the (B2) organic solvent in the above range, storage stability and coating defects can be more effectively improved.

[(B3) Organic Solvent]

(B3) The organic solvent is an alcohol having a standard boiling point of less than 150.0 ° C, and the composition for forming a base film for a resist underlayer may contain the organic solvent (B3) within a range not impairing the effects of the present invention.

(B3) The organic solvent is exemplified by, for example, methanol (boiling point: 65 ° C), ethanol (boiling point: 78 ° C), n-propanol (boiling point: 97 ° C), and isopropanol (boiling point: 82 ° C). Butanol (boiling point: 117 ° C), isobutanol (boiling point: 108 ° C), second butanol (boiling point: 99 ° C), third butanol (boiling point: 82 ° C), n-pentanol (boiling point: 138 ° C) , isoamyl alcohol (boiling point: 132 ° C), 2-methylbutanol (boiling point: 136 ° C), second pentanol (boiling point: 118 ° C), third pentanol (boiling point: 102 ° C), 2-methyl Pentanol (boiling point: 148 ° C), 2-ethylbutanol (boiling point: 146 ° C), etc.; part of the polyol ether is ethylene glycol monomethyl ether (boiling point: 125 ° C), ethylene glycol monoethyl ether (boiling point: 135 ° C), propylene glycol-1-methyl ether (boiling point: 120 ° C), propylene glycol-1-ethyl ether (boiling point: 133 ° C), propylene glycol-1-propyl ether (boiling point: 149.8 ° C), and the like.

[B] The content of the (B3) organic solvent in the organic solvent is preferably from 0% by mass to 10% by mass, more preferably from 0% by mass to 5% by mass, even more preferably from 0% by mass to 3% by mass. Hereinafter, it is preferably 0% by mass or more and 0.5% by mass or less.

<[C] Acid Diffusion Control Agent>

The [C] acid diffusion controlling agent is a component that suppresses acid diffusion generated in the resist film upon exposure. When the composition for forming a resist underlayer film of the present invention further contains a [C] acid diffusion controlling agent, it is possible to effectively suppress acid diffusion of the resist film caused by the resist underlayer film while maintaining the above effects. The shape of the resist pattern formed by the multilayer resist process can be improved. Further, the [C] acid diffusion controlling agent may be used singly or in combination of two or more.

The [C] acid diffusion controlling agent is exemplified by, for example, an amine compound, a guanamine group-containing compound, a urea compound, a nitrogen-containing heterocyclic compound, and the like.

The above amine compounds are exemplified by, for example, mono(cyclo)alkylamines; di(cyclo)alkylamines; tri(cyclo)alkylamines; substituted alkylanilines or derivatives thereof; ethylenediamine, N, N,N',N'-tetramethylethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diamino Diphenyl ether, 4,4'-diaminobenzophenone, 4,4'-diaminodiphenylamine, 2,2-bis(4-aminophenyl)propane, 2-(3 -aminophenyl)-2-(4-aminophenyl)propane, 2-(4-aminophenyl)-2-(3-hydroxyphenyl)propane, 2-(4-aminophenyl) )-2-(4-hydroxyphenyl)propane, 1,4-bis(1-(4-aminophenyl)-1-methylethyl)benzene, 1,3-bis(1-(4- Aminophenyl)-1-methylethyl)benzene, bis(2-dimethylamino) Ether, bis(2-diethylaminoethyl)ether, 1-(2-hydroxyethyl)-2-imidazolidinone, 2-quinoxalinol, N,N,N',N'- Bis(2-hydroxypropyl)ethylenediamine, N,N,N',N",N"-pentamethyldiethylenetriamine, and the like.

The above-mentioned amidino group-containing compound is exemplified by, for example, N-tert-butoxycarbonyl-4-hydroxypiperidine, N-tert-butoxycarbonyl-2-carboxy-4-hydroxypyrrolidine, and N-third butoxide. Amine compound containing N-tert-butoxycarbonyl group, such as carbonylcarbonyl-2-carboxypyrrolidine; amine containing N-third pentyloxycarbonyl group, such as N-third pentyloxycarbonyl-4-hydroxypiperidine Base compound; N-(9-o-aminobenzylmethyloxycarbonyl) piperidine and the like; N-(9-o-aminobenzylmethyloxycarbonyl)-containing amine compound; formamide, N- Methylformamide, N,N-dimethylformamide, acetamide, N-methylacetamide, N,N-dimethylacetamide, acetamide, benzamide, pyrrolidone , N-methylpyrrolidone, N-ethinyl-1-adamantylamine, and the like.

The above urea compounds are exemplified by, for example, urea, methyl urea, 1,1-dimethylurea, 1,3-dimethylurea, 1,1,3,3-tetramethylurea, 1,3-diphenyl. Urea, tri-n-butyl thiourea, and the like.

The above nitrogen-containing heterocyclic compounds are exemplified by, for example, imidazoles; pyridines; piperazines; pyrazine, pyrazole, pyridazine, quinazoline, hydrazine, pyrrolidine, piperidine, piperidine ethanol, 3-(N-piperidin Iridyl)-1,2-propanediol, morpholine, 4-methylmorpholine, 1-(4-morpholinyl)ethanol, 4-ethylmercaptomorpholine, 3-(N-morpholinyl)-1 , 2-propanediol, 1,4-dimethylpiperazine, 1,4-diazabicyclo[2.2.2]octane, and the like.

In the above, the compound containing a guanamine group and the nitrogen-containing heterocyclic compound are preferred, and the compound containing a guanamine group preferably contains N- An amine compound of a tributoxycarbonyl group, an amine compound containing an N-third pentyloxycarbonyl group, more preferably an amine compound of N-(9-o-aminobenzyloxycarbonyl), preferably N -T-butoxycarbonyl-4-hydroxypiperidine, N-tert-butoxycarbonyl-2-carboxy-4-hydroxypyrrolidine, N-tert-butoxycarbonyl-2-carboxy-pyrrolidine, N - Third pentyloxycarbonyl-4-hydroxypiperidine, N-(9-o-aminobenzyloxycarbonyl)piperidine. The above nitrogen-containing heterocyclic compound is more preferably 3-(N-piperidinyl)-1,2-propanediol.

Further, as the [C] acid diffusion controlling agent, a photo-cracking base which generates a base by exposure to light can also be used. One example of the photocracking base is decomposed by exposure to lose the onium salt compound which is controlled by acid diffusion. The onium salt compound is, for example, an onium salt compound represented by the following formula (2-1), an onium salt compound represented by the formula (2-2), and the like.

In the above formula (2-1) and formula (2-2), R ^c1 to R ^{c5 are} each independently a hydrogen atom, an alkyl group, an alkoxy group, a hydroxyl group or a halogen atom. Z ^- and E ^{- are} each independently OH ^- , R ^c6 -COO ^- or R ^c6 -SO ₃ ^- . R ^c6 is an alkyl group, an aryl group, an alkylaryl group or an anion represented by the following formula (2').

In the above formula (2'), R ^c7 is a linear or branched alkyl group having 1 to 12 carbon atoms or a linear or branched alkoxy group having 1 to 12 carbon atoms. However, some or all of the hydrogen atoms of the above alkyl group and alkoxy group may be substituted by a fluorine atom, and u is an integer of 0-2.

The alkyl group represented by R ^c1 to R ^c7 is exemplified by, for example, a methyl group, an ethyl group, a n-propyl group, an isopropyl group, a n-butyl group, an isobutyl group, a t-butyl group or the like.

The alkoxy group represented by R ^c1 to R ^c5 and R ^c7 is exemplified by, for example, a methoxy group, an ethoxy group, a third butoxy group or the like.

The halogen atom represented by R ^c1 to R ^c5 is exemplified by a fluorine atom, a chlorine atom, a bromine atom, an iodine atom or the like.

The aryl group represented by R ^c6 to include, for example, phenyl, naphthyl, anthryl and the like.

The alkaryl group represented by R ^c6 is exemplified by, for example, a benzyl group, a phenethyl group, a phenylpropyl group or the like.

The photocracking base is exemplified by, for example, the following formula. Compounds, etc.

Among these, a triphenylsulfonium salicylate represented by the formula (2-1-1) and a triphenylphosphonium 10-camphorsulfonate represented by the formula (2-1-2) are preferably used. Triphenylsulfonium N-butyltrifluoromethylsulfonamide represented by the formula (2-1-3).

The content of the [C] acid diffusion controlling agent is preferably from 0.1 part by mass to 10 parts by mass, more preferably from 1 part by mass to 5 parts by mass, per 100 parts by mass of the [A] polyoxazane. By setting the content of the [C] acid diffusion controlling agent in the above range, a resist underlayer film having high etching selectivity to the resist film can be formed, and the shape of the resist pattern can be improved.

<Other optional ingredients>

The composition for forming a resist underlayer film of the present invention may contain other optional components such as water, colloidal cerium oxide, colloidal alumina, an organic polymer, and a surfactant, as long as the effects of the present invention are not impaired. Other optional components may be used alone or in combination of two or more. Further, the content of other optional components may be appropriately selected depending on the purpose thereof.

[D]water

[D] Water is a component which can be contained in the composition for forming a resist underlayer film. By containing water in the composition for forming a resist underlayer film, the storage stability of the composition can be improved. As for the water, it is preferably deionized water, distilled water or ultrapure water.

The content of water [D] is preferably 1 part by mass or more and 1,000 parts by mass or less, more preferably 5 parts by mass or more and 500 parts by mass or less, and still more preferably 10 parts by mass based on 100 parts by mass of the [A] polyoxane. More than 200 parts by mass or less. By setting the content of [D] water to the above range, the storage stability can be effectively improved.

[Organic Polymers]

The organic polymer is exemplified by a polymer such as an acrylate compound, a methacrylate compound, or an aromatic vinyl compound; a vinyl amide-based polymer, a dendrimer, a polyimine, a poly-proline, and a poly Polyarylenes, polyamines, polyquinoxaline, polyoxadiazoles, fluorine-based polymers, and the like.

[Surfactant]

The surfactant is exemplified by, for example, a nonionic surfactant, an anionic surfactant, a cationic surfactant, an amphoteric surfactant, a polyoxon surfactant, a polyalkylene oxide surfactant, and a fluorine-containing surfactant. Surfactant and the like.

<Modulation method of composition for forming a resist underlayer film>

The composition for forming a resist underlayer film of the present invention can be prepared by mixing [A] polyoxoxane, [B] an organic solvent, an optional [C] acid diffusion controlling agent, other optional components, and the like in a specific ratio. .

<Graphic formation method>

The pattern forming method of the present invention has the following steps: (1) a step of forming a resist underlayer film on the substrate to be processed using the composition for forming a resist underlayer film, and (2) using a resist composition, a step of forming a resist film on the resist underlayer film, (3) a step of exposing the resist film by irradiation of exposed light through a mask, and (4) developing the exposed resist film to form an exposed resist film. a step of resisting the pattern, and (5) a step of sequentially etching the resist underlayer film and the substrate to be processed by using the resist pattern as a mask.

Since the composition for forming a resist underlayer film has the above properties, it is possible to form a good resist pattern according to the pattern forming method of the present invention.

[step 1)]

In this step, the resist underlayer film forming composition is used to form a resist underlayer film on the substrate to be processed. The substrate to be processed is exemplified by, for example, a tantalum wafer, a wafer coated with aluminum, or the like.

The method for forming the resist underlayer film can be applied to a surface of a substrate to be processed or another underlayer film to be described later, for example, to form a coating film for forming a composition for forming a resist underlayer film, and heating the coating film. It is formed by treatment or hardening by ultraviolet light irradiation and heat treatment. The method of applying the composition for forming a resist underlayer film is, for example, a spin coating method, a roll coating method, a dipping method, or the like. Further, the heating temperature is usually from 50 ° C to 450 ° C, preferably from 150 ° C to 300 ° C. The heating time is usually from 5 seconds to 600 seconds.

Further, another underlayer film (hereinafter also referred to as "other underlayer film") different from the resist underlayer film formed using the composition for forming a resist underlayer film of the present invention may be formed in advance on the substrate to be processed. The other anti-reflection film disclosed in, for example, Japanese Patent Publication No. Hei 6-12452 or JP-A-59-93448.

The film thickness of the above-mentioned resist underlayer film is usually from 10 nm to 1,000 nm, preferably from 10 nm to 500 nm.

[Step (2)]

In this step, a resist film is formed on the resist underlayer film by using a resist composition. Specifically, after the resist composition is applied so that the obtained resist film has a specific film thickness, the solvent in the coating film is volatilized by prebaking to form a resist film.

The resist composition is exemplified by a positive or negative chemically amplified resist composition containing an acid generator, a positive resist composition composed of an alkali-soluble resin and a quinone-based sensitizer, and alkali-soluble. A negative resist composition composed of a resin and a crosslinking agent.

The total solid content concentration of the above resist composition is usually from 1% by mass to 50% by mass. Further, the above-mentioned resist composition is generally filtered by a filter having a pore diameter of, for example, about 0.2 μm, and is provided in the formation of a resist film. Moreover, in this step, the anticorrosive composition of a commercial item can also be used as it is.

The coating method of the resist composition is not particularly limited, and examples thereof include a spin coating method. Further, the prebaking temperature is appropriately adjusted depending on the type of the resist composition to be used, etc., but is usually 30 ° C to 200 ° C, preferably 50 ° C to 150 ° C.

[Step (3)]

In this step, the mask is exposed through exposure of the exposed light. The light to be exposed is appropriately selected from visible light, ultraviolet light, far ultraviolet light, X-ray, or the like depending on the type of photoacid generator used in the resist composition. Among these, far ultraviolet rays are preferred, and more preferably KrF excimer laser light (248 nm), ArF excimer laser light (193 nm), F ₂ excimer laser light (wavelength 157 nm), Kr ₂ excimer laser light (wavelength 147 nm) ), ArKr excimer laser light (wavelength 134 nm), extreme ultraviolet light (wavelength 13 nm), and the like. It is preferably an ArKr excimer laser light (wavelength 134 nm).

After the above exposure, post-baking can be performed to improve resolution, pattern profile, development, and the like. The post-baking temperature is appropriately adjusted depending on the type of the resist composition to be used, etc., but is usually 50 ° C to 200 ° C, preferably 70 ° C to 150 ° C.

[Step (4)]

In this step, the exposed resist film is developed to form a photoresist pattern. The developing liquid used in this step can be appropriately selected depending on the kind of the resist composition to be used. The developing liquid is exemplified by, for example, sodium hydroxide, potassium hydroxide, sodium carbonate, sodium citrate, sodium metasilicate, ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethyl ethane. Amine, methyldiethylamine, dimethylethanolamine, triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, pyrrole, piperidine, choline, 1,8-diazabicyclo[5.4 .0] an aqueous alkaline solution such as 7-undecene or 1,5-diazabicyclo-[4.3.0]-5-decene. A water-soluble organic solvent such as an alcohol such as methanol or ethanol, a surfactant, or the like may be added to the alkaline aqueous solution in an appropriate amount.

After developing with the above developing solution, a specific resist pattern is formed by washing and drying.

[Step 5]

In this step, the resist pattern and the substrate to be processed are sequentially dry-etched by using the resist pattern as a mask. Dry etching can be performed using a conventional dry etching apparatus. In addition, the gas source during dry etching depends on the elemental composition of the object to be etched, and a gas containing oxygen atoms such as O ₂ , CO, CO ₂ , an inert gas such as He, N ₂ or Ar, Cl ₂ or BCl _{4 may be used.} and other chlorine-based gas, CHF _3, CF ₄ fluorine-based gas, H _2, NH ₃ gas and the like of. Moreover, these gases can also be used in combination.

Moreover, after the processes, the step of removing the underlying resist film remaining on the substrate to be processed may be provided. Further, the formation of the resist pattern may be a development step without a nanoimprint method or the like.

[Examples]

Hereinafter, the present invention will be more specifically described by examples of the invention, but the invention is not limited to the examples. Further, the measurement of the solid content concentration of the polyoxyalkylene and the weight average molecular weight (Mw) in terms of polystyrene was carried out by the following method.

<solid content concentration of polyoxyalkylene>

0.5 g of the polyoxyalkylene-containing solution was baked at 250 ° C for 30 minutes, and the mass of the obtained solid component was measured to determine the solid content concentration (% by mass) of the polyoxymethane.

<weight average molecular weight (Mw) in terms of polystyrene>

Use GPC pipe column made by TOSOH (G2000HXL: 2 Root, G3000HXL: 1 piece, G4000HXL: 1 piece), flow rate: 1.0 ml/min, dissolution solvent: tetrahydrofuran, column temperature: 40 ° C analysis conditions, monodisperse polystyrene as standard, gel permeation layer The weight average molecular weight (Mw) in terms of polystyrene was measured by a GPC.

<[A] Synthesis of polyoxyalkylene>

The [A] polyoxane was synthesized using the following decane compound.

M-1: tetramethoxy decane

M-2: Phenyltrimethoxydecane

M-3: 4-methylphenyltrimethoxydecane

M-4: methyltrimethoxydecane

[Synthesis Example 1]

1.28 g of oxalic acid was dissolved in 12.85 g of water by heating to prepare an aqueous oxalic acid solution. Subsequently, a cooling tube was placed on the flask in which (M-1) 25.05 g (90 mol%), (M-2) 3.63 g (10 mol%), and methanol 43.21 g were placed, and the above aqueous oxalic acid solution was fed. Drop the funnel. Next, the flask was heated to 60 ° C in an oil bath, and the aqueous oxalic acid solution was slowly added dropwise thereto, followed by a reaction at 60 ° C for 4 hours. After the completion of the reaction, the flask to which the reaction solution was added was allowed to cool, and 129.00 g of propylene glycol monomethyl ether acetate was added to the reaction solution, and the mixture was placed on an evaporator to remove residual water and methanol, thereby obtaining a solid content. A solution of polyoxyalkylene (A-1) was 86.0 g. The solid concentration of the polyoxyalkylene (A-1) of the above solution was 18.0% by mass, and the Mw of the polyoxyalkylene (A-1) was 2,000.

[Synthesis Example 2]

2.92 g of tetramethylammonium hydroxide was dissolved in 8.75 g of water by heating to prepare an aqueous solution of tetramethylammonium hydroxide. Subsequently, a cooling tube was placed on the flask in which 11.67 g of the tetramethylammonium hydroxide aqueous solution, 4.53 g of water, and 20 g of methanol were placed, and (M-1) 10.66 g (70 mol%), (M-3) was placed. A dropping funnel of 2.12 g (10 mol%), (M-4) 2.72 g (20 mol%) and methanol 20 g of a methanol solution. Next, the flask was heated to 50 ° C in an oil bath, and the above methanol solution was slowly added dropwise thereto, followed by a reaction at 50 ° C for 2 hours. After the reaction was completed, the flask to which the reaction solution was added was allowed to cool.

Subsequently, 36.67 g of a methanolic solution of maleic acid, which was prepared by dissolving 4.39 g of maleic anhydride in 16.14 g of water and 16.14 g of methanol, was added dropwise to the reaction solution as described above, and stirred for 30 minutes. Next, 50 g of 4-methyl-2-pentenone was added, and the mixture was placed on a rotary evaporator to remove residual water, a reaction solvent, and methanol formed by the reaction to obtain a 4-methyl-2-pentenone resin solution. After the resin solution was transferred to a separatory funnel, 80 g of water was added to carry out the first water washing, and 40 g of water was added thereto to carry out a second water washing. Subsequently, 50 g of propylene glycol monomethyl ether acetate was added to the 4-methyl-2-pentenone resin solution from the separatory funnel, and then mounted on a rotary evaporator to remove 4-methyl- 2-pentenone, 51 g of a propylene glycol monomethyl ether acetate solution containing a polyoxyalkylene (A-2) as a solid component was obtained. The solid content concentration of the polyoxyalkylene (A-2) in the above solution was 14.5% by mass, and the Mw of the polyoxyalkylene (A-2) was 4,000.

[Synthesis Example 3~5]

The polypyroxane-containing (A-3) to (A-5) was synthesized in the same manner as in Synthesis Example 1, except that various monomers of [A] polyoxane were used in the amounts shown in Table 1. ) a solution. Further, the solid content concentration of [A] polyoxane in the obtained solution containing each [A] polyoxane and the Mw of [A] polyoxyalkylene are shown in Table 1.

[Synthesis Example 6]

1.28 g of oxalic acid was dissolved in 12.85 g of water by heating to prepare an aqueous oxalic acid solution. Subsequently, a cooling tube was placed on a flask filled with (M-1) 25.05 g (90 mol%), (M-2) 3.63 g (10 mol%), and propylene glycol-1-ethyl ether 57.19 g. A dropping funnel having the above aqueous oxalic acid solution was fed. Next, the flask was heated to 60 ° C in an oil bath, and the aqueous oxalic acid solution was slowly added dropwise thereto, followed by a reaction at 60 ° C for 4 hours. After completion of the reaction, the flask to which the reaction solution was added was allowed to cool, and then placed on a rotary evaporator to remove residual water and methanol, thereby obtaining 97.3 g of a solution containing a polyoxane (A-6) as a solid component. The solid content concentration of the polyoxyalkylene (A-6) in the above solution was 18.0% by mass, and the Mw of the polyoxyalkylene (A-6) was 2,000.

<Preparation of composition for forming a resist underlayer film>

The components other than [A] polyoxyalkylene are shown below.

[B]Organic solvent (B1) component

B1-1: Propylene glycol monomethyl ether acetate

(B2) organic solvent

B2-1: Ethyl acetonitrile

(standard boiling point: 180.8 ° C, specific dielectric ratio: 15.9)

B2-2: γ-butyrolactone

(standard boiling point: 204 ° C, specific dielectric ratio: 39)

B2-3: Dimethyl Adenine

(standard boiling point: 189.0 ° C, specific dielectric ratio: 48.9)

(B3) component

B3-1: propylene glycol-1-methyl ether (standard boiling point: 120 ° C)

B3-2: Propylene glycol-1-ethyl ether (standard boiling point: 133 ° C)

B3-3: propylene glycol-1-propyl ether (standard boiling point: 149.8 ° C)

[C] acid diffusion control agent

a compound represented by the following formula (C-1) to (C-6)

[D]water

D-1: distilled water

[Example 1]

(B-1) 68.56 parts by mass of (B1) alkanediol monoalkyl ether acetate (B1) as a (B2) organic solvent, prepared as (A-1) 2.01 parts by mass of [A] polyoxyalkylene oxide (B2-1) 29.38 parts by mass and (C-1) 0.05 parts by mass of the [C] acid diffusion controlling agent were used to prepare a composition for forming a resist underlayer film.

[Examples 2 to 16, Comparative Examples 1 to 3]

The composition for forming each of the underlying resist films was prepared in the same manner as in Example 1 except that the types and the amounts of the components to be blended were as described in Table 2. Further, "-" in Table 2 indicates that the component is not formulated.

<evaluation>

The composition for forming each of the resist underlayer films prepared as described above was evaluated for storage stability, initial coating defects, and coating defects after storage according to the following method. The evaluation results are shown in Table 3.

[Initial coating defect evaluation]

Each of the resist underlayer film forming compositions immediately after the preparation was applied onto a tantalum wafer by a spin coating method using a coating/developing device (CLEAN TRACK ACT12, manufactured by Tokyo Electronics Co., Ltd.), and then the resulting coating film was applied. After drying at 220 ° C for 60 seconds, it was cooled to 23 ° C to form a coating film having a film thickness of 30 nm. Subsequently, the coating defect was measured by a surface defect observation apparatus (trade name "KLA2800", manufactured by KLA TENCOL), and the measurement result was evaluated as a coating defect. At this time, when the coating defect was 100 or less, the initial coating defect was evaluated as "○", and when it was more than 100, it was evaluated as "X".

[Save stability]

Each of the resist underlayer film forming compositions immediately after preparation was applied onto a tantalum wafer by a spin coating method using the above coating/developing apparatus, and the obtained coating film was dried at 215 ° C for 1 minute, and then cooled. To 23 ° C. After cooling, the film thickness of the resist underlayer film was measured using a film thickness measuring device (M-2000D, manufactured by J.A. Woolam) to be 30 nm (the film thickness was used as the initial film thickness (T0)).

Next, the composition for forming the resist underlayer film to be prepared is kept at 35 ° C After the storage for 30 days, the resist underlayer film was formed by the same method as described above, and the film thickness (the film thickness (T) after storage) was measured.

Next, the film thickness change rate after storage (∣T-T0∣/T0×100 (%)) was calculated, and the calculated value was used as the storage stability. In this case, when the calculated value is within 2%, the storage stability evaluation is very good "◎", and when it exceeds 2% and within 5%, it is evaluated as "○", and when it exceeds 5%, it is evaluated as "X".

[Evaluation of coating defects after storage]

After each of the prepared resist underlayer film forming compositions was stored at 40 ° C for one week, the composition for forming each of the resist underlayer films after storage was used in the same manner as the method described in "Evaluation of initial coating defects". The coating defects of the undercoat film were measured, and the measurement results were evaluated as coating defects after storage. In this case, when the coating defect was 100 or less, the coating defect after storage was evaluated as "○", and when it was more than 100, it was evaluated as "X".

From the results of Table 3, it was found that the storage stability of the examples and the evaluation of the coating defects after the initial stage and the storage were good. On the other hand, the above evaluation items of the comparative examples were all bad.

[Industrial availability]

The present invention can provide a composition for forming a resist underlayer film which has excellent storage stability and can reduce the occurrence of coating defects. According to this, The composition for forming a resist underlayer film and the pattern forming method can be applied to a manufacturing process of a semiconductor device in which the pattern is refined.

Claims (10)

A composition for forming a resist underlayer film, which comprises a composition for forming a resist underlayer film of [A] polydecane and [B] an organic solvent, characterized in that [B] an organic solvent contains (B1) a standard boiling point. Alkanediol monoalkyl ether acetates up to 150.0 ° C, and (B2) organic solvents having a normal boiling point of 150.0 ° C or higher, [B] (B1) alkanediol monoalkyl ether acetates in organic solvents The content of the organic solvent is not less than 50% by mass and not more than 99% by mass, and the content of the organic solvent (B2) is 1% by mass or more and 50% by mass or less. The composition for forming a resist underlayer film according to claim 1, wherein the (B2) organic solvent has a normal boiling point of 180 ° C or higher. The composition for forming a resist underlayer film according to claim 1 or 2, wherein the (B2) organic solvent is at least one selected from the group consisting of esters and ethers. The composition for forming a resist underlayer film according to claim 3, wherein the (B2) organic solvent is selected from the group consisting of a carboxylic acid ester, a lactone, a carbonate, and a compound represented by the following formula (1). At least one, (In the formula (1), R ¹ and R ² each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or a fluorenyl group having 1 to 4 carbon atoms; R ³ is a hydrogen atom or a methyl group, and n is 1 to 4 An integer, when n is 2 or more, a plurality of R ^{3 's} may be the same or different). The composition for forming a resist underlayer film according to any one of claims 1 to 4, wherein the (B2) organic solvent has a specific dielectric constant of 13 or more and 200 or less. The composition for forming a resist underlayer film according to any one of claims 1 to 5, wherein the (B1) alkanediol monoalkyl ether acetate is a propylene glycol monoalkyl ether acetate. The composition for forming a resist underlayer film according to any one of claims 1 to 6, which is used for a multilayer resist process. The composition for forming a resist underlayer film according to any one of claims 1 to 7, which further comprises a [C] acid diffusion controlling agent. The composition for forming a resist underlayer film according to any one of claims 1 to 8, wherein [A] polyoxyalkylene is a hydrolysis condensate of a compound containing a decane compound represented by the following formula (i), R ^A _a SiX _4-a (i) (In the formula (i), R ^A is a hydrogen atom, a fluorine atom, an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, and a carbon number of 6 to 20 Any one or all of the hydrogen atoms of the above alkyl group may be substituted with an epoxy group, an epoxy group, an acid anhydride group or a cyano group, and some or all of the hydrogen atoms of the above aryl group may be Substituted by a hydroxy group, X is a halogen atom or -OR ^B , but R ^B is a monovalent organic group, and a is an integer of 0 to 3. However, when R ^A and X are plural, respectively, the plural R ^A and X may be the same respectively. Can be different). A pattern forming method comprising the steps of: (1) forming a resist underlayer film on a substrate to be processed using the composition for forming a resist underlayer film according to any one of claims 1 to 9, (2) a step of forming a resist film on the resist underlayer film using a resist composition, (3) a step of exposing the resist film by irradiation of exposed light through a photomask, and (4) making the above-mentioned film The step of exposing the exposed resist film to form a resist pattern, and (5) the step of sequentially etching the resist underlayer film and the substrate to be processed by using the resist pattern as a mask.