JP6951297B2 - Composition for forming an organic film and an organic film - Google Patents

Description

The present invention relates to a multilayer resist film material used when forming a wiring pattern on a substrate for manufacturing a semiconductor device, and particularly to a composition for forming an organic film.

Conventionally, the improvement of the processing capacity of semiconductor devices has been driven by the miniaturization of pattern dimensions by shortening the wavelength of the light source in the lithography technology. However, in recent years, since the speed of shortening the wavelength after the ArF light source has slowed down, there has been a demand for higher performance of the processing capacity of the semiconductor device instead of miniaturization. As one of the methods, a semiconductor device having high processing capacity, in which three-dimensional transistors capable of operating at a higher speed than a planar transistor are arranged at a high density, has been proposed. A substrate for manufacturing such a semiconductor device (hereinafter referred to as a substrate) has a three-dimensional structure that has undergone complicated step processing as compared with a conventional substrate. Therefore, when attempting to form a pattern by the pattern forming method using a single-layer photoresist that was applied when forming a conventional planar transistor, the photoresist film follows the step formed during substrate processing. As a result, a step is generated on the surface of the photoresist film, and as a result, a flat resist film cannot be obtained. As a result, when the photoresist is exposed and a pattern is formed, it becomes impossible to accurately focus on the photoresist, and as a result, the yield of substrate processing decreases. There is a need for new materials and methods to prevent this.

As one of the methods for solving such a problem, there is a multilayer resist method. In this method, a substrate with a step is flattened with a lower layer film having high flattening performance, and a photoresist film is formed on the flat film, thereby widening the focal margin at the time of exposure and reducing the yield in substrate processing. Can be prevented. Further, in this method, when a lower layer film having different etching selectivity for the upper photoresist film and the substrate is selected, a pattern is formed on the resist upper layer film, and then the resist upper layer film pattern is used as a dry etching mask and intermediate by dry etching. The pattern can be transferred to the film, and the pattern can be transferred to the substrate to be processed by dry etching using the lower layer film as a dry etching mask.

As this multilayer resist method, a three-layer resist method that can be performed using a general resist composition used in the single-layer resist method is generally used. For example, an organic resist underlayer film having high flatness and sufficient dry etching resistance for substrate processing is formed on a substrate to be processed, and a silicon-containing resist underlayer film is formed as an intermediate film on the organic resist underlayer film (hereinafter, silicon-containing). A resist interlayer film), and a photoresist film is formed on the resist interlayer film as a resist upper layer film. For dry etching with a fluorine-based gas plasma, the organic resist upper layer film has a good etching selectivity with respect to the silicon-containing resist interlayer film, so dry etching with a fluorine-based gas plasma should be used for the resist pattern. Can be transferred to a silicon-containing resist interlayer film. Furthermore, for dry etching with oxygen-based gas plasma, the silicon-based resist interlayer film has a good etching selectivity with respect to the organic resist underlayer film, so the silicon-containing resist interlayer film pattern is dry with oxygen-based gas plasma. It can be transferred to the organic resist underlayer film by using etching. According to this method, it is difficult to form a pattern having a sufficient film thickness for directly processing the substrate to be processed, or a composition for forming a resist upper layer film, or dry etching resistance is sufficient for processing the substrate. Even if a composition for forming a resist upper layer film is used, if the pattern can be transferred only to the silicon-containing film, a pattern of an organic resist lower layer film having sufficient dry etching resistance for processing can be obtained. Such pattern transfer by dry etching does not cause problems such as pattern collapse due to friction caused by a developer during resist development, and therefore functions sufficiently as a dry etching mask even at a high aspect ratio. A pattern of an organic film having a thickness of the same thickness can be obtained. Then, by using the pattern of the organic resist underlayer film thus formed as a dry etching mask, it becomes possible to transfer the pattern to a substrate having a three-dimensional transistor structure having a complicated step. As the organic resist underlayer film as described above, many are already known, such as those described in Patent Document 1.

Generally, in the three-layer resist method, in order to stabilize the processing dimensions, it is necessary to leave a silicon-containing resist interlayer film having a thickness of several nm on the organic resist underlayer film pattern in the pattern transfer by dry etching to the organic resist underlayer film. be. This remaining silicon is removed by etching with a dry etching gas that processes the substrate while the pattern is being transferred to the substrate using the organic resist underlayer film pattern as a mask. Therefore, the organic resist underlayer film pattern is removed after the substrate is processed. Does not remain on top. Therefore, even if the organic resist underlayer film pattern remaining after substrate processing is dry-etched (ashed) or wet-removed, the silicon content does not remain on the substrate as a residue.

As described above, the multilayer resist method is used for a wide range of substrate processing because it can be applied to a substrate on which a large step is formed as a substrate processing method. Therefore, by utilizing this feature, it is expected to be used as an ion implantation shielding mask in the ion implantation process, which is a part of the three-dimensional transistor forming process. However, in the organic resist underlayer film pattern for ion implantation formed by the three-layer resist method, the substrate is not processed using the organic resist underlayer film pattern as a mask, so that the organic resist underlayer film is actually as described above. Silicon remains on the pattern. Therefore, when ions are implanted using such an organic resist underlayer film pattern as a shielding mask, the silicon content remaining on the organic resist underlayer film is denatured by the implanted ions, and the organic resist is used in the cleaning step after the casting step is completed. It cannot be removed at the same time as the underlayer film pattern, and what cannot be removed remains as foreign matter on the substrate, causing a decrease in the yield of the ion implantation process. In order to prevent this, the silicon content remaining on the organic resist underlayer film pattern must be selectively washed and removed without affecting the organic resist underlayer film pattern before ion implantation. However, this silicon content is modified by dry etching gas when the pattern is transferred to the organic resist underlayer film, and is a hydrogen peroxide-containing ammonia aqueous solution that is generally applied in the semiconductor manufacturing process as a cleaning liquid that does not damage the substrate. (Hereinafter, also referred to as ammonia peroxide) cannot be washed and removed. In order to completely clean and remove the modified silicon content, it is necessary to apply a hydrofluoric acid-based cleaning liquid, but this cleaning liquid also damages the surface of the semiconductor substrate and reduces the yield in the processing process. Therefore, there is a demand for a method capable of removing silicon remaining on the organic resist underlayer film pattern without damaging the substrate after the pattern transfer to the organic resist underlayer film by dry etching is completed, and a material suitable for the method. ..

JP-A-2016-094612 (US Patent Application Publication No. 2013/0337649 (A1))

The present invention has been made in view of the above problems, and is generally used in a stripping solution that does not damage the semiconductor device substrate or the organic resist underlayer film required in the patterning process, for example, in a semiconductor manufacturing process. To provide an organic film forming composition capable of forming an organic film that can be easily wet-removed together with a silicon residue modified by dry etching using a hydrogen peroxide-containing aqueous ammonia solution called SC1 (Standard Cleaner 1). The purpose.

（式中、Ｒ_１は炭素数１〜１９の炭化水素基、ハロゲン原子、アルコキシ基、カルボキシ基、スルホ基、メトキシカルボニル基、ヒドロキシフェニル基、又はアミノ基であり、Ｒ_２は水素原子又はＡＬである。ＡＬは加熱又は酸の作用により酸性の官能基を生じる基である。Ｒ_３は水素原子、フラニル基、又は塩素原子もしくはニトロ基を有していてもよい炭素数１〜１６の炭化水素基である。ｋ_１、ｋ_２、及びｋ_３は１〜２であり、ｌは１〜３であり、ｍは０〜３であり、ｎは０又は１である。） In order to solve the above problems, in the present invention, the composition for forming an organic film is one of the repeating units represented by the following general formulas (1) to (4). Organic film formation containing the above-mentioned polymer compound and an organic solvent, in which the total of one or more selected from propylene glycol esters, ketones, and lactones accounts for more than 30 wt% of the total organic solvent. The composition for use is provided.

(In the formula, R ₁ is a hydrocarbon group having 1 to 19 carbon atoms, a halogen atom, an alkoxy group, a carboxy group, a sulfo group, a methoxycarbonyl group, a hydroxyphenyl group, or an amino group, and R ₂ is a hydrogen atom or AL. AL is a group that produces an acidic functional group by heating or the action of an acid. R ₃ is a hydrocarbon having 1 to 16 carbon atoms which may have a hydrogen atom, a phenylyl group, or a chlorine atom or a nitro group. Hydrogen groups. K _{1 , k 2} , and k ₃ are 1-2, l is 1-3, m is 0-3, and n is 0 or 1.)

Such an organic film forming composition can be used with a stripping solution that does not damage the semiconductor device substrate or the organic resist underlayer film required in the patterning process, for example, SC1 generally used in the semiconductor manufacturing process. A composition for forming an organic film capable of forming an organic film that can be easily wet-removed together with a silicon residue modified by dry etching using a so-called hydrogen peroxide-containing aqueous ammonia solution. Further, such an organic film forming composition can be applied as a material for an ion implantation shielding mask at the time of forming a three-dimensional transistor.

At this time, the organic film to be introduced into the composition for forming an organic film is directly below the silicon-containing resist intermediate film that is soluble in ammonia superwater and directly above the organic resist underlayer film that is sparingly soluble in ammonia superwater. It is preferably for forming.

The composition for forming an organic film of the present invention is an organic film formed between an organic resist underlayer film and a silicon-containing resist intermediate film formed directly under a photoresist in a three-layer resist method formed on a substrate (hereinafter referred to as an organic film). , Also referred to as the present organic film) (hereinafter, also referred to as the present composition), and is a composition for forming an organic film capable of forming a substantially four-layer resist. An organic resist underlayer film is formed on the substrate, this organic film is formed between the organic resist underlayer film and the silicon-containing resist interlayer film, then a silicon-containing resist interlayer film is formed, and then an upper layer resist is formed. A pattern is formed with the upper layer resist, this pattern is transferred to the silicon-containing resist intermediate film by dry etching, and the transferred pattern is used as a mask to dry-etch the main organic film and the organic resist lower layer film at once to transfer the pattern. Can be done. Here, if the silicon-containing resist interlayer film is soluble in ammonia superwater and the organic resist underlayer film is sparingly soluble in ammonia superwater, it remains on the pattern transferred as described above. The silicon component can be removed together with the present organic film by ammonia superwater, whereby an organic resist underlayer film pattern without a silicon content residue can be obtained. When this organic resist underlayer film pattern is applied as an ion implantation shielding mask, accurate ion implantation is possible even in a three-dimensional transistor having a large step, and three-dimensional transistor processing is possible with a high yield.

At this time, it is preferable that the silicon-containing resist interlayer film contains either or both of boron and phosphorus.

When the pattern is transferred to the organic film and the organic resist underlayer film at once by dry etching using the patterned silicon-containing resist interlayer film as a mask, the structure of the silicon-containing resist interlayer film pattern changes due to the action of gas and plasma during dry etching. It may occur and the solubility in ammonia overwater may decrease. However, since the silicon-containing resist interlayer film contains either or both of boron and phosphorus, the silicon-containing resist interlayer film and / / which are soluble in ammonia excess water even after dry etching, regardless of the gas and conditions of dry etching. Alternatively, it can be a silicon residue.

At this time, it is preferable that the composition for forming an organic film further contains either or both of a thermoacid generator and a cross-linking agent.

If the composition for forming an organic film of the present invention contains either or both of a thermoacid generator and a cross-linking agent, the organic film having a uniform composition is formed on the underlayer film of the organic resist. Not only that, it is possible to suppress the occurrence of intermixing when forming a silicon-containing resist intermediate film on the organic film.

At this time, the organic film-forming composition was spin-coated on the substrate and then heated to mix at 65 ° C. with 29% ammonia water / 35% hydrogen peroxide solution / water = 1/1/8. It is preferable that an organic film having a dissolution rate of 5 nm / min or more is provided by treatment with the solution of.

If it is a composition for forming an organic film that gives an organic film having such performance, the organic film and the silicon residue on the organic film can be sufficiently removed by ammonia superwater without damaging the substrate for manufacturing a semiconductor device. Can be removed.

Further, it is preferable that the composition for forming an organic film gives an organic film having a film thickness of 10 nm or more and less than 100 nm.

In the case of an organic film forming composition that gives an organic film having such a film thickness, even if the silicon-containing resist intermediate film is used as a dry etching mask and the pattern is transferred to the main organic film and the organic resist lower layer film at once, the upper layer resist can be used. It becomes possible to transfer the pattern while maintaining the accuracy of the formed pattern.

Such an organic film forming composition can be used with a stripping solution that does not damage the semiconductor device substrate or the organic resist underlayer film required in the patterning process, for example, SC1 generally used in the semiconductor manufacturing process. A composition for forming an organic film capable of forming an organic film that can be easily wet-removed together with a silicon residue modified by dry etching using so-called ammonia superwater. Further, by applying the composition for forming an organic film of the present invention between the organic resist underlayer film and the silicon-containing resist intermediate film, ion implantation in which silicon content does not remain on the pattern when forming a shielding mask for ion implantation is formed. It becomes possible to form a mask. As a result, it becomes possible to prevent a decrease in yield in the manufacturing process of the three-dimensional transistor, and it becomes possible to economically manufacture a higher-performance semiconductor device.

As described above, dry using a stripping solution that does not damage the semiconductor device substrate or the organic resist underlayer film required in the patterning process, for example, ammonia superwater called SC1 generally used in the semiconductor manufacturing process. There has been a demand for an organic film forming composition capable of forming an organic film that can be easily wet-removed together with a silicon residue modified by etching.

As a result of diligent studies on the above problems, the present inventors include a polymer compound having at least one of the repeating units represented by the following general formulas (1) to (4) and an organic solvent. The above problem can be solved if the composition for forming an organic film in which the total of one or more selected from propylene glycol esters, ketones, and lactones accounts for more than 30 wt% of the total organic solvent in the organic solvent. Find out and complete the present invention.

（式中、Ｒ_１は炭素数１〜１９の炭化水素基、ハロゲン原子、アルコキシ基、カルボキシ基、スルホ基、メトキシカルボニル基、ヒドロキシフェニル基、又はアミノ基であり、Ｒ_２は水素原子又はＡＬである。ＡＬは加熱又は酸の作用により酸性の官能基を生じる基である。Ｒ_３は水素原子、フラニル基、又は塩素原子もしくはニトロ基を有していてもよい炭素数１〜１６の炭化水素基である。ｋ_１、ｋ_２、及びｋ_３は１〜２であり、ｌは１〜３であり、ｍは０〜３であり、ｎは０又は１である。） That is, the present invention is a composition for forming an organic film, and the composition for forming an organic film is a polymer having any one or more of the repeating units represented by the following general formulas (1) to (4). A composition for forming an organic film containing a compound and an organic solvent, in which the total of one or more selected from propylene glycol esters, ketones, and lactones accounts for more than 30 wt% of the total organic solvent. ..

(In the formula, R ₁ is a hydrocarbon group having 1 to 19 carbon atoms, a halogen atom, an alkoxy group, a carboxy group, a sulfo group, a methoxycarbonyl group, a hydroxyphenyl group, or an amino group, and R ₂ is a hydrogen atom or AL. AL is a group that produces an acidic functional group by heating or the action of an acid. R ₃ is a hydrocarbon having 1 to 16 carbon atoms which may have a hydrogen atom, a phenylyl group, or a chlorine atom or a nitro group. Hydrogen groups. K _{1 , k 2} , and k ₃ are 1-2, l is 1-3, m is 0-3, and n is 0 or 1.)

Hereinafter, embodiments of the present invention will be described, but the present invention is not limited thereto.

[Composition for forming an organic film]
The composition for forming an organic film of the present invention contains a polymer compound and an organic solvent. Hereinafter, each component will be described in more detail.

（式中、Ｒ_１は炭素数１〜１９の炭化水素基、ハロゲン原子、アルコキシ基、カルボキシ基、スルホ基、メトキシカルボニル基、ヒドロキシフェニル基、又はアミノ基であり、Ｒ_２は水素原子又はＡＬである。ＡＬは加熱又は酸の作用により酸性の官能基を生じる基である。Ｒ_３は水素原子、フラニル基、又は塩素原子もしくはニトロ基を有していてもよい炭素数１〜１６の炭化水素基である。ｋ_１、ｋ_２、及びｋ_３は１〜２であり、ｌは１〜３であり、ｍは０〜３であり、ｎは０又は１である。） <Polymer compound>
The polymer compound in the composition for forming an organic film of the present invention has one or more of the repeating units represented by the following general formulas (1) to (4).

(In the formula, R ₁ is a hydrocarbon group having 1 to 19 carbon atoms, a halogen atom, an alkoxy group, a carboxy group, a sulfo group, a methoxycarbonyl group, a hydroxyphenyl group, or an amino group, and R ₂ is a hydrogen atom or AL. AL is a group that produces an acidic functional group by heating or the action of an acid. R ₃ is a hydrocarbon having 1 to 16 carbon atoms which may have a hydrogen atom, a phenylyl group, or a chlorine atom or a nitro group. Hydrogen groups. K _{1 , k 2} , and k ₃ are 1-2, l is 1-3, m is 0-3, and n is 0 or 1.)

Here, as the repeating unit represented by the general formula (1), those having the following structure can be exemplified.

Examples of the repeating unit represented by the general formula (2) include those having the following structure.

Examples of the repeating unit represented by the general formula (3) include those having the following structure.

Examples of the repeating unit represented by the general formula (4) include those having the following structure.

Among these, as the preferable repeating unit, those represented by the above general formula (2) or (3) can be exemplified. In a composition for forming an organic film containing a polymer compound having such a repeating unit, an organic film having excellent wet removal property due to ammonia superwater is formed by effectively locating a highly polar carboxy group. can.

Here, as the monomer for obtaining n = 0 as the repeating unit represented by the above general formulas (1) to (4), phenol, o-cresol, m-cresol, p-cresol, 2, 3 -Dimethylphenol, 2,5-dimethylphenol, 3,4-dimethylphenol, 3,5-dimethylphenol, 2,4-dimethylphenol, 2,6-dimethylphenol, 2,3,5-trimethylphenol, 3, 4,5-trimethylphenol, 2-t-butylphenol, 3-t-butylphenol, 4-t-butylphenol, resorcinol, 2-methylresorcinol, 4-methylresorcinol, 5-methylresorcinol, catechol, 4-t-butylcatechol , 2-methoxyphenol, 3-methoxyphenol, 2-propylphenol, 3-propylphenol, 4-propylphenol, 2-isopropylphenol, 3-isopropylphenol, 4-isopropylphenol, 2-methoxy-5-methylphenol, 2-t-Butyl-5-methylphenol, 4-phenylphenol, tritylphenol, pyrogallol, timol, hydroxyphenylglycidyl ether, 4-fluorophenol, 3,4-difluorophenol, 4-trifluoromethylphenol, 4-chloro Examples thereof include phenol, 4-hydroxybenzene sulfonic acid, 4-vinyl phenol, 1- (4-hydroxyphenyl) naphthalene and the like.

Examples of the monomer for obtaining n = 1 include 1-naphthol, 2-naphthol, 2-methyl-1-naphthol, 4-methoxy-1-naphthol, 7-methoxy-2-naphthol, 1,2-dihydroxyl. Naphthalene, 1,3-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 1,4-dihydroxynaphthalene, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 1,7-dihydroxynaphthalene. , 2,7-Dihydroxynaphthalene, 1,8-dihydroxynaphthalene, 5-amino-1-naphthol, 2-methoxycarbonyl-1-naphthol, 6- (4-hydroxyphenyl) -2-naphthol, 6- (cyclohexyl) -2-naphthol, 1,1'-bi-2,2'-naphthol, 6,6'-bi-2,2'-naphthol, 9,9-bis (6-hydroxy-2-naphthyl) fluorene, 6 -Hyhydroxy-2-vinylnaphthalene, 1-hydroxymethylnaphthalene, 2-hydroxymethylnaphthalene, 8-hydroxynaphthalene-1-sulfonic acid, 2-hydroxynaphthalene-7-sulfonic acid, 2,3-dihydroxynaphthalene-7-sulfon Acids, 1,7-dihydroxynaphthalene-3-sulfonic acid and the like can be mentioned.

Each of these may be used alone, or two or more types may be combined in order to control the n value, k value, and etching resistance.

Examples of the condensing agent for the condensation reaction with these monomers include the following aldehyde compounds. For example, formaldehyde, trioxane, paraformaldehyde, acetaldehyde, propylaldehyde, butylaldehyde, cyclopentanecarboxyaldehyde, cyclopentenecarboxyaldehyde, cyclohexanecarboxyaldehyde, cyclohexenecarboxyaldehyde, norbornancarboxyaldehyde, norbornenecarboxyaldehyde, adamantancarbaldehyde, benzaldehyde, phenylacetaldehyde. , Α-phenylpropylaldehyde, β-phenylpropylaldehyde, 2-hydroxybenzaldehyde, 3-hydroxybenzaldehyde, 4-hydroxybenzaldehyde, 2,3-dihydroxybenzaldehyde, 2,4-dihydroxybenzaldehyde, 3,4-dihydroxybenzaldehyde, 2 -Chlorobenzaldehyde, 3-chlorobenzaldehyde, 4-chlorobenzaldehyde, 2-nitrobenzaldehyde, 3-nitrobenzaldehyde, 4-nitrobenzaldehyde, 2-methylbenzaldehyde, 3-methylbenzaldehyde, 4-methylbenzaldehyde, 2-ethylbenzaldehyde, 3 -Ethylbenzaldehyde, 4-ethylbenzaldehyde, 2-methoxybenzaldehyde, 3-methoxybenzaldehyde, 4-methoxybenzaldehyde, anthracenecarbaldehyde, pyrenecarbaldehyde, furfural and the like can be mentioned.

In addition, compounds that can be represented by the following formulas can be exemplified.

The ratio of the monomer to the aldehyde compound which is a condensing agent is preferably 0.01 to 5 mol, more preferably 0.05 to 2 mol, based on 1 mol of the total molar amount of the monomer.

The ratio of the repeating units represented by the general formulas (1) to (4) to all the repeating units is preferably 10% or more, more preferably 30% or more, assuming that the whole is 100%.

When the polycondensation reaction is carried out using the above-mentioned raw materials, it can be carried out at room temperature or, if necessary, under cooling or heating, usually using an acid or a base as a catalyst in a solvent-free or solvent-free manner. Thereby, a polymer compound (polymer) can be obtained. As the solvent used, alcohols such as methanol, ethanol, isopropyl alcohol, butanol, ethylene glycol, propylene glycol, diethylene glycol, glycerol, methyl cellosolve, ethyl cellosolve, butyl cellosolve, propylene glycol monomethyl ether, diethyl ether, dibutyl ether, diethylene glycol diethyl Ethers, diethylene glycol dimethyl ether, ethers such as tetrahydrofuran and 1,4-dioxane, chlorine-based solvents such as methylene chloride, chloroform, dichloroethane and trichloroethylene, hydrocarbons such as hexane, heptane, benzene, toluene, xylene and cumene, acetonitrile. Nitriles such as acetone, ethyl methyl ketone, ketones such as isobutyl methyl ketone, esters such as ethyl acetate, n-butyl acetate, propylene glycol methyl ether acetate, lactones such as γ-butyrolactone, dimethyl sulfoxide, N, Aprotonic polar solvents such as N-dimethylformamide and hexamethylphosphoric triamide can be exemplified, and these can be used alone or in combination of two or more. These solvents can be used in the range of 0 to 2,000 parts by mass with respect to 100 parts by mass of the reaction raw material.

Acid catalysts include inorganic acids such as hydrochloric acid, hydrobromic acid, sulfuric acid, nitrate, phosphoric acid, and heteropolyacid, oxalic acid, trifluoroacetic acid, methanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, and trifluoromethanesulfone. Organic acids such as acids, aluminum trichloride, aluminum ethoxydo, aluminum isopropoxide, boron trifluoride, boron trichloride, boron tribromide, tin tetrachloride, tin tetrabromide, dibutyl tin dichloride, dibutyl tin dimethoxydo , Dibutyltin oxide, titanium tetrachloride, titanium tetrabromide, titanium (IV) methoxydo, titanium (IV) ethoxydo, titanium (IV) isopropoxide, titanium oxide (IV) and other Lewis acids can be used. Base catalysts include inorganic bases such as sodium hydroxide, potassium hydroxide, barium hydroxide, sodium carbonate, sodium hydrogencarbonate, potassium carbonate, lithium hydride, sodium hydride, potassium hydride, calcium hydride, and methyllithium. , N-butyllithium, methylmagnesium chloride, alkylmetals such as ethylmagnesium bromide, alkoxides such as sodium methoxydo, sodium ethoxydo, potassium t-butoxide, triethylamine, diisopropylethylamine, N, N-dimethylaniline, pyridine , 4-Dimethylaminopyridine and other organic bases can be used. The amount used is preferably in the range of 0.001 to 100% by weight, more preferably 0.005 to 50% by weight, based on the raw material. The reaction temperature is preferably from −50 ° C. to about the boiling point of the solvent, and more preferably from room temperature to 100 ° C.

Examples of the polycondensation reaction method include a method in which the monomer, the condensing agent, and the catalyst are charged all at once, and a method in which the monomer and the condensing agent are dropped in the presence of the catalyst.

Further, after the completion of the polycondensation reaction, in order to remove the unreacted raw materials, the catalyst, etc. existing in the system, the temperature of the reaction kettle is raised to 130 to 230 ° C., and the volatile matter is removed at about 1 to 50 mmHg. Alternatively, a method of fractionating the polymer by adding an appropriate solvent or water, a method of dissolving the polymer in a good solvent and then reprecipitating in a poor solvent, or the like can be used depending on the properties of the obtained reaction product.

The polystyrene-equivalent molecular weight of the polymer thus obtained is preferably a weight average molecular weight (Mw) of 500 to 500,000, and particularly preferably 1,000 to 100,000. The degree of molecular weight dispersion is preferably in the range of 1.2 to 20. By cutting the monomer component, oligomer component, or low molecular weight substance with a molecular weight (Mw) of 1,000 or less, the volatile components in the bake can be suppressed, and the contaminated or accumulated volatile components around the bake cup fall onto the wafer. It is possible to prevent surface defects due to this.

<Organic solvent>
The composition for forming an organic film of the present invention contains an organic solvent. Specific examples of the organic solvent include ketones such as cyclopentanone, cyclohexanone and methyl-2-amyl ketone, 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol and 1-ethoxy-. Alcohols such as 2-propanol, propylene glycol monomethyl ether, ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, ethers such as propylene glycol dimethyl ether and diethylene glycol dimethyl ether, propylene glycol monomethyl ether acetate, propylene glycol mono Esters such as ethyl ether acetate, ethyl lactate, ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, tert-butyl acetate, tert-butyl propionate, propylene glycol mono tert-butyl ether acetate, etc. , Gamma-butylollactone and the like, and one or more of these can be mixed and used, but the present invention is not limited thereto.

Here, in the organic solvent, one or more selected from propylene glycol ester, ketone, and lactone (for example, among the above-exemplified organic solvents, propylene glycol monomethyl ether acetate, cyclopentanone, cyclohexanone, methyl-2-amyl ketone, γ). -The total of one or more selected from butyrolactone) must account for more than 30 wt% of the total organic solvent. If the organic solvent does not satisfy this condition, a homogeneous organic film cannot be formed directly above the organic resist underlayer film.

Further, an acid generator or a cross-linking agent for further promoting the cross-linking reaction can be added to the composition for forming an organic film of the present invention. As the acid generator, there are those that generate acid by thermal decomposition (thermal acid generator) and those that generate acid by light irradiation, but any of them can be added.

Acid generators include onium salts, diazomethane derivatives, glyoxime derivatives, bissulfon derivatives, sulfonic acid esters of N-hydroxyimide compounds, β-ketosulfonic acid derivatives, disulfone derivatives, nitrobenzylsulfonate derivatives, sulfonates, sulfonic acid ester derivatives. And so on. Specifically, those described in paragraphs (0081) to (0111) of JP-A-2008-65303 (US Patent Application Publication No. 2008/0038662 (A1)) can be mentioned.

Examples of the cross-linking agent include a melamine compound, a guanamine compound, a glycoluril compound or a urea compound, an epoxy compound, a thioepoxy compound, an isocyanate compound, and an azide substituted with at least one group selected from a methylol group, an alkoxymethyl group, and an acyloxymethyl group. Examples thereof include compounds, compounds containing a double bond such as an alkenyl ether group, and the like. Specific examples thereof include those described in paragraphs (0074) to (0080) of JP-A-2008-65303 (US Patent Application Publication No. 2008/0038662 (A1)).

Further, a surfactant can be added to the composition for forming an organic film of the present invention in order to improve the coatability in spin coating. Surfactants include polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, polyoxyethylene polyoxypropylene block copolymers, sorbitan fatty acid esters, nonionic surfactants of polyoxyethylene sorbitan fatty acid esters, and fluorine. Examples thereof include based surfactants, partially fluorinated oxetane ring-opening polymer-based surfactants, and the like. Specific examples thereof include those described in paragraphs (0142) to (0147) of Japanese Patent Application Laid-Open No. 2009-269953 (US Patent Application Publication No. 2009/0274978 (A1)).

Further, a basic compound for improving storage stability can be added to the composition for forming an organic film of the present invention. The basic compound acts as a quencher for the acid to prevent the acid generated in a smaller amount than the acid generator from advancing the cross-linking reaction. Examples of such basic compounds include primary, secondary and tertiary aliphatic amines, mixed amines, aromatic amines, heterocyclic amines, nitrogen-containing compounds having a carboxy group, and sulfonyl groups. Examples thereof include a nitrogen-containing compound having a hydroxyl group, a nitrogen-containing compound having a hydroxyl group, a nitrogen-containing compound having a hydroxyphenyl group, an alcoholic nitrogen-containing compound, an amide derivative, and an imide derivative. Specifically, those described in paragraphs (0112) to (0119) of JP-A-2008-65303 (US Patent Application Publication No. 2008/0038662 (A1)) can be mentioned.

The composition for forming an organic film of the present invention as described above is introduced directly below the silicon-containing resist interlayer film that is soluble in ammonia superwater and directly above the organic resist underlayer film that is sparingly soluble in ammonia superwater. It can be suitably used for forming an organic film.

Further, the composition for forming an organic film of the present invention preferably gives an organic film having a film thickness of 10 nm or more and less than 100 nm, and more preferably 20 nm or more and 80 nm or less. If the film thickness of the organic film is 10 nm or more, the effect of removing silicon by wet treatment can be sufficiently obtained, and if it is less than 100 nm, side etching during dry etching can be suppressed, which makes it suitable for processing. There is no risk of malfunction.

[Organic film]
An organic film can be formed by the composition for forming an organic film of the present invention. Examples of the method for forming an organic film using the composition for forming an organic film of the present invention include a method of coating the above-mentioned composition for forming an organic film of the present invention on a substrate to be processed by a spin coating method or the like. After spin coating, the solvent is evaporated and baking is performed to promote the cross-linking reaction in order to prevent mixing with the resist upper layer film and the resist intermediate layer film. Baking is carried out within the range of 100 ° C. or higher and 400 ° C. or lower, and is carried out within the range of 10 to 600 seconds, preferably 10 to 300 seconds. The bake temperature is more preferably 150 ° C. or higher and 350 ° C. or lower.

As described above, the organic film formed by the composition for forming an organic film of the present invention can be suitably introduced directly below the silicon-containing resist intermediate film and directly above the organic resist underlayer film.

As such a silicon-containing resist interlayer film, one that is soluble in ammonia hydrogen peroxide and can be dissolved or peeled off by ammonia hydrogen peroxide is preferable. For example, Japanese Patent Application Laid-Open No. 2010-085912 (US Patent Application Publication No. 2010/088687 (A1)), Japanese Patent Application Laid-Open No. 2010-085893 (US Patent Application Publication No. 2010/0086872 (A1)), Japanese Patent Application Laid-Open No. 2015-028145 (US Patent Application Publication No. 2015/0004791 (A1)), International Publication No. 2010/068336 (US Patent Application Publication No. 2011/02333489 (A1)), JP-A. The silicon content described in Japanese Patent Application Publication No. 2016/074772 (US Patent Application Publication No. 2016/0996977 (A1)) and Japanese Patent Application Laid-Open No. 2016-074774 (US Patent Application Publication No. 2016/0996978 (A1)). It is preferable to use the resist underlayer film as the silicon-containing resist intermediate film in the present invention. Among these, those containing either or both of boron and phosphorus are particularly preferable because they are excellent in wet removal property with aqueous ammonia.

Further, as the organic resist underlayer film applicable in the present invention, one that is resistant to ammonia hydrogen peroxide (that is, one that is sparingly soluble in ammonia hydrogen peroxide) is preferable. For example, Japanese Patent Application Laid-Open No. 2004-205685 (US Patent No. 7,427,464 (B2)), Japanese Patent Application Laid-Open No. 2010-122656 (US Patent Application Publication No. 2010/090944 (A1)) and the United States. Japanese Patent Application Publication No. 2013/01/84404 (A1)), Japanese Patent Application Laid-Open No. 2012-214720 (US Patent Application Publication No. 2012/0252218 (A1)), Japanese Patent Application Laid-Open No. 2016-094612 (US Patent Application) The organic resist underlayer film disclosed in Japanese Patent Application Laid-Open No. 2013/0337649 (A1)) can be used.

The organic resist underlayer film is formed by coating an organic resist underlayer film composition on a substrate to be processed by a spin coating method or the like. Good embedding characteristics can be obtained by using a spin coating method or the like. After spin coating, the solvent is evaporated and baking is performed to promote the cross-linking reaction in order to prevent mixing with the resist upper layer film and the resist intermediate film. Baking is carried out within the range of 100 ° C. or higher and 600 ° C. or lower, and is carried out within the range of 10 to 600 seconds, preferably 10 to 300 seconds. The bake temperature is more preferably 200 ° C. or higher and 500 ° C. or lower. Considering the influence on device damage and wafer deformation, the upper limit of the heating temperature in the lithographic wafer process is preferably 600 ° C. or lower, more preferably 500 ° C. or lower.

In the method of forming an organic resist underlayer film as described above, the organic resist underlayer film composition on a substrate to be processed, was coated by spin coating or the like, the composition air, N _2, Ar, and He, etc. An organic resist underlayer film can be formed by firing and curing in an atmosphere. By firing this organic resist underlayer film composition in an atmosphere containing oxygen, a cured film resistant to ammonia hydrogen peroxide can be obtained.

By forming the organic resist underlayer film in this way, a flat cured film can be obtained regardless of the unevenness of the substrate to be processed due to its excellent embedding / flattening property. Therefore, a structure having a height of 30 nm or more. Alternatively, it is extremely useful when forming a flat cured film on a substrate having a step.

The thickness of the organic resist underlayer film for manufacturing and flattening the semiconductor device is appropriately selected, but is preferably 5 to 500 nm, particularly preferably 10 to 400 nm.

When the composition for forming an organic film of the present invention is applied to the formation of an organic film to be introduced directly under a silicon-containing resist intermediate film and directly above an organic resist underlayer film to form a shielding mask for ion implantation, the above-mentioned organic film is formed. In order to wet-remove the membrane and the silicon-containing resist interlayer film, a stripping solution containing hydrogen peroxide is preferable. At this time, in order to promote the peeling, it is more preferable to add an acid or an alkali to the stripping liquid to adjust the pH. Examples of such pH adjusters (acids or alkalis) include inorganic acids such as hydrochloric acid and sulfuric acid, organic acids such as acetic acid, oxalic acid, tartaric acid, citric acid and lactic acid, ammonia, ethanolamine and tetramethylammonium hydroxide. Examples thereof include an alkali containing nitrogen, an organic acid compound containing nitrogen such as EDTA (ethylenediamine tetraacetic acid), and the like. Ammonia is particularly preferable. That is, ammonia peroxide is preferable as the stripping solution.

When ammonia superwater is used as the stripping solution, the ratio of ammonia, hydrogen peroxide, and deionized water for dilution is 0.01 to 20 parts by mass, preferably 0, with respect to 100 parts by mass of deionized water. 05 to 15 parts by mass, more preferably 0.1 to 10 parts by mass, hydrogen hydrogen is 0.01 to 20 parts by mass, preferably 0.05 to 15 parts by mass, more preferably 0.1 to 10 parts by mass. It is a department.

For wet removal, it is only necessary to prepare a stripping solution at 0 ° C. to 80 ° C., preferably 5 ° C. to 70 ° C., and immerse the silicon wafer on which the substrate to be processed is formed. Further, if necessary, the silicon-containing resist interlayer film and the composition for forming an organic film of the present invention can be easily applied by a conventional procedure such as spraying a release liquid on the surface or applying the release liquid while rotating the wafer. It is possible to remove the formed organic film.

In particular, the composition for forming an organic film of the present invention was spin-coated on a substrate and then heated to mix at 65 ° C. with 29% aqueous ammonia / 35% aqueous hydrogen peroxide / water = 1/1/8. It is preferable that an organic film having a dissolution rate of 5 nm / min or more is provided by treatment with the solution of.

After the treatment with ammonia peroxide, it is preferable to quantify the silicon remaining on the surface of the organic resist underlayer film and confirm the degree of removal of the silicon content. For example, the analysis can be performed by the method described in JP-A-2016-177262 (US Patent Application Publication No. 2016/0276152 (A1)).

As described above, the composition for forming an organic film of the present invention is generally used in a stripping solution that does not damage the semiconductor device substrate or the organic resist underlayer film required in the patterning process, for example, in a semiconductor manufacturing process. A composition for forming an organic film capable of forming an organic film that can be easily wet-removed together with a silicon residue modified by dry etching using an aqueous ammonia called SC1. Further, by applying the composition for forming an organic film of the present invention between the organic resist underlayer film and the silicon-containing resist intermediate film, ion implantation in which silicon content does not remain on the pattern when forming a shielding mask for ion implantation is formed. It becomes possible to form a mask. As a result, it becomes possible to prevent a decrease in yield in the manufacturing process of the three-dimensional transistor, and it becomes possible to economically manufacture a higher-performance semiconductor device.

Hereinafter, the present invention will be specifically described with reference to Synthesis Examples, Examples, and Comparative Examples, but the present invention is not limited to these descriptions. In the following example,% represents mass%, and the molecular weight measurement was performed by GPC. In the GPC measurement, the detection was performed by RI, the elution solvent was tetrahydrofuran, and the molecular weight in terms of polystyrene was determined.

[Synthesis of polymer compounds]
[Synthesis example (A1)]
Take 40.00 g (0.36 mol) of resorcinol, 10.00 g of a 20 mass% PGME solution of p-toluenesulfonic acid monohydrate, and 72.00 g of 2-methoxy-1-propanol in a 500 ml three-necked flask and stir. While heating to 80 ° C. 23.59 g of 37% formalin (0.29 mol of formaldehyde) was added thereto, and the mixture was stirred for 11 hours. 160 g of ultrapure water and 200 g of ethyl acetate were added to the reaction solution, transferred to a liquid separation funnel, and washed 10 times with 150 g of ultrapure water to remove the acid catalyst and metal impurities. The obtained organic layer was concentrated under reduced pressure to 76 g, ethyl acetate was added to make a 150 g solution, and 217 g of n-hexane was added. The n-hexane layer became the upper layer and the high-concentration polymer solution became the lower layer, and the upper layer was removed. The same operation was repeated twice, the obtained polymer solution was concentrated, and the mixture was further dried under reduced pressure at 80 ° C. for 13 hours to obtain the polymer compound A1. When the weight average molecular weight (Mw) and the dispersity (Mw / Mn) were determined by GPC, they were Mw = 800 and Mw / Mn = 1.3. This polymer compound A1 has a repeating unit represented by the general formula (4).

[Synthesis example (A2)]
In a 1,000 ml three-necked flask, 80.1 g (0.50 mol) of 1,5-dihydroxynaphthalene, 26.4 g (0.24 mol) of a 37% formalin solution, and 250 g of 2-methoxy-1-propanol were placed in a nitrogen atmosphere. After making a uniform solution at a liquid temperature of 80 ° C., 18 g of a 20% 2-methoxy-1-propanol solution of paratoluenesulfonic acid was slowly added, and the mixture was stirred at a liquid temperature of 110 ° C. for 12 hours. After cooling to room temperature, 500 g of methyl isobutyl ketone was added, the organic layer was washed 5 times with 200 g of pure water, and the organic layer was dried under reduced pressure. 300 mL of THF was added to the residue and the polymer was reprecipitated with 2,000 mL of hexane. The precipitated polymer was separated by filtration and dried under reduced pressure to obtain a polymer compound A2. When the weight average molecular weight (Mw) and the dispersity (Mw / Mn) were determined by GPC, they were Mw = 3,000 and Mw / Mn = 2.7. This polymer compound A2 has a repeating unit represented by the general formula (4).

[Synthesis example (A3)]
80.1 g (0.50 mol) of 1,5-dihydroxynaphthalene, 100.1 g (0.40 mol) of 3,4-di-t-butoxybenzaldehyde, and 2-methoxy-1-propanol in a 2,000 ml three-necked flask. After 600 g was prepared as a uniform solution at a liquid temperature of 80 ° C. under a nitrogen atmosphere, 6.4 g of a 25% sodium hydroxide aqueous solution was slowly added, and the mixture was stirred at a liquid temperature of 110 ° C. for 24 hours. After cooling to room temperature, 1,500 g of ethyl acetate was added, and the organic layer was washed with 300 g of a 3% aqueous nitric acid solution, further washed with 300 g of pure water 5 times, and dried under reduced pressure. 400 mL of THF was added to the residue and the polymer was reprecipitated with 3,000 mL of hexane. The precipitated polymer was separated by filtration and dried under reduced pressure to obtain a polymer compound A3. When the weight average molecular weight (Mw) and the dispersity (Mw / Mn) were determined by GPC, they were Mw = 2,900 and Mw / Mn = 2.9. This polymer compound A3 has a repeating unit represented by the general formula (1).

[Synthesis example (A4)]
To a 1,000 mL flask, add 80 g (0.50 mol) of 1,5-dihydroxynaphthalene, 36.6 g (0.30 mol) of 4-hydroxybenzaldehyde, and 145 g of methyl cellosolve, and p-toluenesulfonic acid with stirring at 70 ° C. 20 g of a 20 mass% methylcellosolve solution was added. The temperature was raised to 85 ° C., the mixture was stirred for 6 hours, cooled to room temperature, and diluted with 800 mL of ethyl acetate. The mixture was transferred to a separating funnel and washed repeatedly with 200 mL of deionized water to remove the reaction catalyst and metal impurities. After concentrating the obtained solution under reduced pressure, 600 mL of ethyl acetate was added to the residue, and the polymer was precipitated with 2,400 mL of hexane. The precipitated polymer was filtered off, recovered, and dried under reduced pressure to obtain a polymer compound A4. When the weight average molecular weight (Mw) and the dispersity (Mw / Mn) were determined by GPC, they were Mw = 3,800 and Mw / Mn = 2.4. This polymer compound A4 has a repeating unit represented by the general formula (1).

[Synthesis example (A5)]
Nitrogen 2,7-dihydroxynaphthalene 80.1 g (0.50 mol), terephthalaldehyde acid = t-butyl 100.1 g (0.40 mol), and 2-methoxy-1-propanol 600 g in a 2,000 ml three-necked flask. After making a uniform solution at a liquid temperature of 80 ° C. under an atmosphere, 6.4 g of a 25% sodium hydroxide aqueous solution was slowly added, and the mixture was stirred at a liquid temperature of 110 ° C. for 24 hours. After cooling to room temperature, 1,500 g of ethyl acetate was added, and the organic layer was washed with 300 g of a 3% aqueous nitric acid solution, further washed with 300 g of pure water 5 times, and dried under reduced pressure. 400 mL of THF was added to the residue and the polymer was reprecipitated with 3,000 mL of hexane. The precipitated polymer was separated by filtration and dried under reduced pressure to obtain a polymer compound A5. When the weight average molecular weight (Mw) and the dispersity (Mw / Mn) were determined by GPC, they were Mw = 2,900 and Mw / Mn = 2.9. This polymer compound A5 has a repeating unit represented by the general formula (2).

[Synthesis example (A6)]
94.4 g (0.50 mol) of 6-hydroxy-2-naphthoic acid, 100.1 g (0.40 mol) of terephthalaldehyde acid = t-butyl, and 600 g of 2-methoxy-1-propanol in a 2,000 ml three-necked flask. Was made into a uniform solution at a liquid temperature of 80 ° C. under a nitrogen atmosphere, 6.4 g of a 25% aqueous sodium hydroxide solution was slowly added, and the mixture was stirred at a liquid temperature of 110 ° C. for 24 hours. After cooling to room temperature, 1,500 g of ethyl acetate was added, and the organic layer was washed with 300 g of a 3% aqueous nitric acid solution, further washed with 300 g of pure water 5 times, and dried under reduced pressure. 400 mL of THF was added to the residue and the polymer was reprecipitated with 3,000 mL of hexane. The precipitated polymer was separated by filtration and dried under reduced pressure to obtain a polymer compound A6. When the weight average molecular weight (Mw) and the dispersity (Mw / Mn) were determined by GPC, they were Mw = 3,500 and Mw / Mn = 2.8. This polymer compound A6 has a repeating unit represented by the general formula (2).

[Synthesis example (A7)]
Liquid 1,5-dihydroxynaphthalene 80.1 g (0.50 mol), terephthalaldehyde acid 60.1 g (0.40 mol), and 2-methoxy-1-propanol 600 g in a 2,000 ml three-necked flask under a nitrogen atmosphere. After making a uniform solution at a temperature of 80 ° C., 6.4 g of a 25% aqueous sodium hydroxide solution was slowly added, and the mixture was stirred at a liquid temperature of 110 ° C. for 24 hours. After cooling to room temperature, 1,500 g of ethyl acetate was added, and the organic layer was washed with 300 g of a 3% aqueous nitric acid solution, further washed with 300 g of pure water 5 times, and dried under reduced pressure. 400 mL of THF was added to the residue and the polymer was reprecipitated with 3,000 mL of hexane. The precipitated polymer was separated by filtration and dried under reduced pressure to obtain a polymer compound A7. When the weight average molecular weight (Mw) and the dispersity (Mw / Mn) were determined by GPC, they were Mw = 2,200 and Mw / Mn = 2.9. This polymer compound A7 has a repeating unit represented by the general formula (2).

[Synthesis example (A8)]
A solution containing 9.4 g (0.05 mol) of 6-hydroxy-2-naphthoic acid, 5.3 g (0.05 mol) of terephthalaldehyde acid, and 60 g of 2-methoxy-1-propanol in a 200 ml three-necked flask under a nitrogen atmosphere. After making a uniform solution at a temperature of 80 ° C., 0.6 g of a 25% aqueous sodium hydroxide solution was slowly added, and the mixture was stirred at a liquid temperature of 110 ° C. for 24 hours. After cooling to room temperature, 150 g of ethyl acetate was added, and the organic layer was washed with 30 g of a 3% aqueous nitric acid solution, further washed with 30 g of pure water 5 times, and dried under reduced pressure. 40 mL of THF was added to the residue and the polymer was reprecipitated with 300 mL of hexane. The precipitated polymer was separated by filtration and dried under reduced pressure to obtain a polymer compound A8. When the weight average molecular weight (Mw) and the dispersity (Mw / Mn) were determined by GPC, they were Mw = 2,000 and Mw / Mn = 2.6. This polymer compound A8 has a repeating unit represented by the general formula (2).

[Synthesis example (A9)]
54.1 g (0.50 mol) of o-cresol, 140.2 g (0.40 mol) of 3,4-bis (t-butoxycarbonylmethoxy) benzaldehyde, and 2-methoxy-1-propanol in a 2,000 ml three-necked flask. After 600 g was prepared as a uniform solution at a liquid temperature of 80 ° C. under a nitrogen atmosphere, 6.4 g of a 25% sodium hydroxide aqueous solution was slowly added, and the mixture was stirred at a liquid temperature of 110 ° C. for 24 hours. After cooling to room temperature, 1,500 g of ethyl acetate was added, and the organic layer was washed with 300 g of a 3% aqueous nitric acid solution, further washed with 300 g of pure water 5 times, and dried under reduced pressure. 400 mL of THF was added to the residue and the polymer was reprecipitated with 3,000 mL of hexane. The precipitated polymer was separated by filtration and dried under reduced pressure to obtain a polymer compound A9. When the weight average molecular weight (Mw) and the dispersity (Mw / Mn) were determined by GPC, they were Mw = 3,200 and Mw / Mn = 3.0. This polymer compound A9 has a repeating unit represented by the general formula (3).

[Synthesis example (A10)]
80.1 g (0.50 mol) of 1,6-dihydroxynaphthalene, 94.5 g (0.40 mol) of 4-t-butoxycarbonylmethoxybenzaldehyde, and 600 g of 2-methoxy-1-propanol were placed in a 2,000 ml three-necked flask. After making a uniform solution at a liquid temperature of 80 ° C. under a nitrogen atmosphere, 6.4 g of a 25% sodium hydroxide aqueous solution was slowly added, and the mixture was stirred at a liquid temperature of 110 ° C. for 24 hours. After cooling to room temperature, 1,500 g of ethyl acetate was added, and the organic layer was washed with 300 g of a 3% aqueous nitric acid solution, further washed with 300 g of pure water 5 times, and dried under reduced pressure. 400 mL of THF was added to the residue and the polymer was reprecipitated with 3,000 mL of hexane. The precipitated polymer was separated by filtration and dried under reduced pressure to obtain a polymer compound A10. When the weight average molecular weight (Mw) and the dispersity (Mw / Mn) were determined by GPC, they were Mw = 2,700 and Mw / Mn = 2.7. This polymer compound A10 has a repeating unit represented by the general formula (3).

[Examples and Comparative Examples]
Tables show organic solvents containing the above polymer compounds A1 to A10, cross-linking agents XL1 to 3 as additives, thermal acid generator AG1, and FC-4430 (manufactured by Sumitomo 3M Co., Ltd.) as a surfactant in an amount of 0.1% by mass. Compositions for forming an organic film (Sol.1 to 22) were prepared by mixing at the ratio shown in 1 and filtering through a filter made of a fluororesin of 0.1 μm. In addition, Sol. 1 to 10, 15 to 16, 20 to 22 are the compositions for forming an organic film of the present invention, and Sol. 11 to 14 and 17 to 19 are compositions for forming an organic film for comparison. Table 1 also shows the amount of the total of one or more selected from propylene glycol ester, ketone, and lactone in the prepared composition for forming an organic film, which occupies the total organic solvent.

The thermal acid generator AG1 and the cross-linking agents XL1 to XL3 are shown below.

The organic solvent in Table 1 means the following.
PGMEA: Propylene Glycol Methyl Ether Acetate Cyho: Cyclohexanone PGEE: Propylene Glycol Ethyl Ether GBL: γ-Butyrolactone 4M2P: 4-Methyl-2-pentanol

[Solvent resistance evaluation: Examples 1-1 to 15, Comparative Examples 1-1 to 7]
Since the silicon-containing resist intermediate film is spin-coated directly above the organic film formed by the composition for forming an organic film of the present invention, it is investigated whether the formed organic film is an organic film in which intermixing does not occur. Therefore, the resistance to organic solvents was evaluated. The above organic film forming compositions (Sol. 1 to 22) were each applied onto a silicon substrate and fired at 285 ° C. for 60 seconds to form an organic film, and the film thickness T1 was measured. PGMEA / PGME = 30/70 (mass ratio) was spin-coated on the obtained organic film, and then heat-treated at 100 ° C. for 30 seconds to measure the film thickness T2. From these measurement results, the film thickness reduction indicated by T1-T2 was calculated. The results are shown in Table 2.

As shown in Examples 1-1 to 15 of Table 2, Sol. The organic film formed from 1 to 10, 15 to 16 and 20 to 22 has sufficient organic solvent resistance. Therefore, it was clarified that even if a silicon-containing resist intermediate film is spin-coated directly above these organic films, a laminated film can be formed without intermixing.

[Evaluation of film formation property on organic resist underlayer film: Examples 2-1 to 15, Comparative Examples 2-1 to 7]
Since the organic film formed by the composition for forming an organic film of the present invention is laminated on the organic resist underlayer film, the film forming property on the organic resist underlayer film was confirmed. A spin-on carbon film ODL-102 manufactured by Shin-Etsu Chemical Co., Ltd. was applied as an organic resist underlayer film on a silicon wafer to form an organic resist underlayer film having a film thickness of 200 nm. The composition for forming an organic film (Sol. 1 to 22) was applied onto this and fired at 285 ° C. for 60 seconds to form an organic film, and the film formation state of the organic film was confirmed. The results are shown in Table 3.

As shown in Examples 2-1 to 15 in Table 3, Sol. 1-10, 15-16, 20-22 could be formed on the organic resist underlayer film by spin coating without any film formation defect. On the other hand, as shown in Comparative Examples 2-1 to 7, Sol. In 11-14 and 17-19, repelling occurred on the organic resist underlayer film, and the film could not be laminated.

[Wet removal property of organic membrane by ammonia hydrogen peroxide: Examples 3-1 to 12]
The above composition for forming an organic film (Sol. 1-10, 15-16) is applied onto a silicon substrate, respectively, and fired at 285 ° C. for 60 seconds to form an organic film so as to have a film thickness of T1. Was measured. This film was mixed with 29% ammonia water / 35% hydrogen peroxide water / water = 1/1/8, immersed in ammonia superwater kept at 65 ° C. for 5 minutes, washed with pure water, and then washed at 100 ° C. for 60 seconds. It was dried by heating and the film thickness T3 was measured. In addition, the film removal rate at this time was determined. These results are shown in Table 4.

As shown in Table 4, Sol. It was found that the organic film formed from 1 to 10 and 15 to 16 can be removed with aqueous ammonia at a rate of 5 nm / min or more.

[Residual evaluation after ashing of organic resist underlayer film: Examples 4-1 to 15, Comparative Example 4-1]
A spin-on carbon film ODL-102 manufactured by Shin-Etsu Chemical Co., Ltd. was formed on a silicon wafer as an organic resist underlayer film with a film thickness of 200 nm. The composition for forming an organic film (Sol. 1-10, 15-16, 20-22) of the present invention was applied thereto, and the mixture was heated at 285 ° C. for 60 seconds to laminate the organic film. On the other hand, in Comparative Example 4-1 no organic film was introduced.

Next, the composition for forming a silicon-containing resist interlayer film (SiARC-1) shown in Table 5 below was applied and heated at 220 ° C. for 60 seconds to laminate a silicon-containing resist interlayer film having a film thickness of 35 nm. An ArF resist solution for positive development (PR-1) shown in Table 6 below was applied thereto and heated at 110 ° C. for 60 seconds to form a photoresist film having a film thickness of 100 nm. Further, the immersion protective film composition (TC-1) shown in Table 7 below was applied onto the photoresist film and heated at 90 ° C. for 60 seconds to form a protective film having a film thickness of 50 nm.

Subsequently, these wafers are exposed with an ArF immersion exposure apparatus (NSR-S610C, NA1.30, σ0.98 / 0.65, 35 degree dipole polarized illumination, 6% halftone phase shift mask manufactured by Nikon Corporation). Then, it was baked (PEB) at 100 ° C. for 60 seconds and developed with a 2.38% tetramethylammonium hydroxide (TMAH) aqueous solution for 30 seconds to obtain a positive line-and-space pattern of 160 nm 1: 1. For the wafer obtained in this way, the cross-sectional shape of the pattern was obtained with an electron microscope (S-4800) manufactured by Hitachi, Ltd., and the pattern collapsed with an electron microscope (CG4000) manufactured by Hitachi High-Technologies Corporation. Observed.

These wafers from which the photoresist pattern was obtained were dry-etched using the etching apparatus Telius manufactured by Tokyo Electron under the processing conditions shown in Tables 8 and 9, respectively, to form a silicon-containing resist interlayer film and an organic resist underlayer film, respectively. processed. Further, in the obtained wafer, the cross-sectional shape of the pattern was observed with an electron microscope (S-9380) manufactured by Hitachi, Ltd.

Next, in order to wet-remove the silicon-containing resist interlayer film remaining after the organic resist underlayer film processing, the wafer was mixed with 29% ammonia water / 35% hydrogen peroxide solution / water = 1/1/8 and 65 ° C. It was treated with ammonia peroxide kept in 1 for 5 minutes. After the treatment, it was washed with pure water and dried by heating at 100 ° C. for 60 seconds. In addition, in order to confirm whether the silicon content can be removed by the ammonia superwater treatment, the surface of the organic resist underlayer film is analyzed by XPS with K-ALPHA manufactured by Thermo Fisher Scientific Co., Ltd., and the silicon on the organic resist underlayer film is quantified. bottom.

The organic resist underlayer film pattern obtained in the above steps was treated with an etching apparatus Telius manufactured by Tokyo Electron under the treatment conditions shown in Table 10, and the remaining organic resist underlayer film was ashed and removed. The wafer after the ashing treatment was observed with an electron microscope (CG4000) manufactured by Hitachi High-Technologies Corporation, and the presence or absence of residue was confirmed. The results are shown in Table 11.

The composition of the above-mentioned composition for forming a silicon-containing resist interlayer film (SiARC-1) is shown in Table 5 below.

ＴＰＳＮＯ_３：硝酸トリフェニルスルホニウム

TPSNO ₃ : Triphenylsulfosphine nitrate

The molecular weight and structural formula of SiARC polymer 1 shown in Table 5 are shown below.
SiARC Polymer 1: Molecular Weight (Mw) = 2,800

The molecular weight and structural formula of SiARC polymer 2 shown in Table 5 are shown below.
SiARC Polymer 2: Molecular Weight (Mw) = 2,800

The composition of the above ArF resist solution for positive development (PR-1) is shown in Table 6 below.

The molecular weight, dispersity, and structural formula of ArF resist polymer 1 shown in Table 6 are shown below.
ArF resist polymer 1: Molecular weight (Mw) = 7,800
Dispersity (Mw / Mn) = 1.78

The structural formula of the acid generator shown in Table 6: PAG1 is shown below.

The structural formulas of the bases: Quencher shown in Table 6 are shown below.

The composition of the immersion protective film composition (TC-1) used in the patterning test by the above positive development is shown in Table 7 below.

The molecular weight, dispersity, and structural formula of the protective film polymer shown in Table 7 above are shown below.
Protective membrane polymer: Molecular weight (Mw) = 8,800
Dispersity (Mw / Mn) = 1.69

The dry etching processing conditions for the silicon-containing resist interlayer film are shown in Table 8 below.

The dry etching processing conditions for the organic resist underlayer film are shown in Table 9 below.

The ashing removal conditions for the organic resist underlayer film are shown in Table 10 below.

Observation results of the cross-sectional shape of the photoresist pattern and pattern collapse obtained in the residue evaluation after the above-mentioned organic resist underlayer film ashing, observation results of the pattern cross-sectional shape after dry etching, and organic resist after ammonia superwater treatment. The remaining amount of silicon on the surface of the underlayer film and the presence or absence of the residue after ashing the organic resist underlayer film pattern are shown in Table 11 below.

As shown in Table 11, Sol. When the organic film formed from 1 to 10 and 15 to 16 was introduced, silicon did not remain on the organic resist underlayer film after the ammonia superwater treatment, and no residue was generated after ashing the organic resist underlayer film pattern. Further, when the influence of the film thickness of the organic film was confirmed in Examples 4-13 to 15 and Comparative Example 4-1. As shown in Example 4-13, when the organic film was thin, the amount of ammonia was excessive. No silicon residue was found on the surface of the organic resist underlayer film after water treatment, and no residue was generated after ashing the organic resist underlayer film pattern. Further, as shown in Example 4-15, when the film was thick, the organic film portion was side-etched during the dry etching process, but no residue was generated after ashing the organic resist underlayer film pattern. .. On the other hand, as shown in Comparative Example 4-1, in the absence of the organic film, the effect of removing the silicon residue was not obtained, and the residue was generated after ashing the organic resist underlayer film pattern.

From the above, in the composition for forming an organic film of the present invention, a stripping solution that does not damage the semiconductor device substrate or the organic resist underlayer film required in the patterning process is used, together with the silicon residue modified by dry etching. It has been clarified that the composition for forming an organic film capable of forming an organic film that can be easily wet-removed can be applied as a material for an ion-embedded shielding mask at the time of forming a three-dimensional transistor. In particular, it has been clarified that by introducing an organic film with a film thickness of 10 nm or more and less than 100 nm, a processing process in which no residue is generated can be constructed more reliably. As a result, it becomes possible to prevent a decrease in yield in the manufacturing process of the three-dimensional transistor, and it becomes possible to economically manufacture a higher-performance semiconductor device.

The present invention is not limited to the above embodiment. The above-described embodiment is an example, and any object having substantially the same configuration as the technical idea described in the claims of the present invention and exhibiting the same effect and effect is the present invention. Is included in the technical scope of.

Claims (6)

A composition for forming an organic film
The composition for forming an organic film contains a polymer compound having at least one of the repeating units represented by the following general formulas (1) to (4) and an organic solvent, and the propylene glycol ester in the organic solvent. , ketones, and all SANYO least one total selected from a lactone account for an amount greater than 30 wt% of the total organic solvent, and,
To form an organic film to be introduced by the composition for forming an organic film directly below a silicon-containing resist intermediate film that is soluble in ammonia superwater and directly above an organic resist underlayer film that is sparingly soluble in ammonia superwater. the organic film-forming composition, characterized in der Rukoto ones.

(In the formula, R ₁ is a hydrocarbon group having 1 to 19 carbon atoms, a halogen atom, an alkoxy group, a carboxy group, a sulfo group, a methoxycarbonyl group, a hydroxyphenyl group, or an amino group, and R ₂ is a hydrogen atom or AL. AL is any of the groups represented by the following formula (G). _{R 3} has 1 to 16 carbon atoms which may have a hydrogen atom, a phenylyl group, or a chlorine atom or a nitro group. It is a hydrocarbon group. K _{1 , k 2} , and k ₃ are 1-2, l is 1-3, m is 0-3, and n is 0 or 1.)

(In the formula, * indicates the bond position.) The composition for forming an organic film according to claim 1 , wherein the silicon-containing resist interlayer film contains either or both of boron and phosphorus. The composition for forming an organic film according to claim 1 or 2, wherein the composition for forming an organic film further contains either or both of a thermoacid generator and a cross-linking agent. .. It is formed from the composition for forming an organic film according to any one of claims 1 to 3, and is 29% ammonia water / 35% hydrogen peroxide solution / water = 1/1/8. An organic membrane having a dissolution rate of 5 nm / min or more by treatment with a solution of 65 ° C. mixed in. The composition for forming an organic film according to any one of claims 1 to 3 , wherein the composition for forming an organic film gives an organic film having a film thickness of 10 nm or more and less than 100 nm. thing. The organic film according to claim 4, wherein the organic film is an organic film having a film thickness of 10 nm or more and less than 100 nm.