TWI653284B - Composition for forming organic film - Google Patents

Abstract

The problem to be solved by the present invention is to provide a composition for forming an organic film that can form an organic film that can be easily removed by wet removal with a silicon component residue that has been modified by dry etching using a stripping solution. The stripping solution does not cause damage to the semiconductor device substrate and the organic resist underlayer film required in the patterning step. The stripping solution is, for example, a hydrogen peroxide-containing ammonia solution called SC1 commonly used in semiconductor manufacturing processes. . The solution to the present invention is a composition for forming an organic film. The composition for forming an organic film includes a polymer compound and an organic solvent, and the polymer compound has a repeating unit represented by the following general formulae (1) to (4). Any one or more of them, and in this organic solvent, the total amount of one or more selected from propylene glycol esters, ketones, and lactones accounts for more than 30% by weight of all organic solvents.

Description

Composition for forming organic film

The present invention relates to a multilayer resist film material, and more particularly to a composition for forming an organic film. The material (composition) is used when a circuit pattern is formed on a substrate for manufacturing a semiconductor device.

Conventionally, the high performance of the processing capability of semiconductor devices has been accompanied by the miniaturization of the pattern size by shortening the wavelength of light sources in lithography technology. However, in recent years, the speed of shortening the wavelength of the ArF light source and the like has been slowed down. Therefore, conventionally, an attempt has been made to replace the miniaturization to improve the processing performance of semiconductor devices. As one of the methods, a semiconductor device having a high processing capacity has been proposed, which is configured by densely disposing three-dimensional transistors, and the three-dimensional transistors can operate at a higher speed than a planar transistor. A substrate (hereinafter referred to as a substrate) for manufacturing such a semiconductor device is formed into a three-dimensional structure through a more complicated level difference process than a conventional substrate. Therefore, if patterning is performed by a patterning method implemented by a single-layer photoresist that has been previously applied when forming a conventional planar transistor, a photoresist film is formed for the level difference formed during substrate processing. It will follow and a level difference will generate | occur | produce on the surface of a photoresist film, and as a result, a flat resist film cannot be obtained. When the photoresist is exposed to form a pattern, the focus cannot be accurately aligned with the photoresist. As a result, the yield of substrate processing is reduced. New materials and methods are being sought to prevent this problem.

As one method to solve such a problem, there is a multilayer resist method. This method uses an underlayer film with a high planarization performance to flatten a substrate with a step difference, and then forms a photoresist film on the flat film to increase the focus tolerance during exposure, thereby preventing the substrate from being processed. Yield decreases. Further, in this method, if a lower layer film is selected and its etching selectivity is different for the upper layer photoresist film and the substrate, the pattern of the upper layer film of the resist can be used as a dry etching mask after the pattern is formed on the upper layer of the resist film. Cover, and use dry etching to transfer the pattern to the intermediate film, and further use the lower film as a dry etching mask, and use dry etching to transfer the pattern to the substrate to be processed.

The multilayer resist method is generally a three-layer resist method, and the three-layer resist method can be performed using a general resist composition used in the single-layer resist method. For example, an organic resist underlayer film is formed on a substrate to be processed, and a silicon resist-containing underlayer film (silicon-containing resist underlayer film) is formed thereon as an intermediate film (hereinafter, referred to as a silicon resist-containing intermediate film) A photoresist film is formed thereon as a resist upper layer film. The organic resist lower layer film has high flatness and sufficient dry etching resistance for substrate processing. For dry etching using a fluorine-based gas plasma, since the organic resist upper layer film can obtain a better etching selection ratio than the silicon-containing resist intermediate film, the resist pattern uses a fluorine-based gas electrode The dry etching performed by the slurry can be transferred to the silicon resist-containing intermediate film. In addition, for dry etching using an oxygen-based gas plasma, since the silicon-based resist interlayer film can achieve a better etching selection ratio than the organic resist underlayer film, the pattern of the silicon resist-containing interlayer film is borrowed. Dry etching using an oxygen-based gas plasma can be transferred to the organic resist underlayer film. According to this method, even if it is difficult to form a resist upper-layer film-forming composition having a pattern having a sufficient film thickness for directly processing a substrate to be processed, or dry etching resistance for processing a substrate, The composition for forming an insufficient resist upper layer film, as long as the pattern can be transferred only to a silicon-containing film, can still obtain a pattern of an organic resist lower layer film, which has sufficient dry etching resistance for processing. Such a pattern transfer by dry etching does not cause the problem of pattern collapse. The reason for the pattern collapse is friction caused by the developer during the development of the resist, etc., so it can be obtained even with a high aspect ratio. An organic film pattern having a thickness capable of fully exerting the function of a dry etching mask. Moreover, by using the pattern of the organic resist underlayer film thus formed as a dry etching mask, the pattern can be transferred to a substrate having a three-dimensional transistor structure having a complicated level difference. Various kinds of films such as the film described in Patent Document 1 are known as the organic resist underlayer film described above.

When the pattern is transferred to the organic resist underlayer film by dry etching in order to stabilize the processing size, the three-layer resist method must generally leave a silicon resist-containing intermediate film with a thickness of several nm in the organic resist underlayer film pattern. on. When the pattern of the organic resist underlayer film is being used as a mask to transfer the pattern to the substrate, this residual silicon component will be etched and removed by the dry etching gas used to process the substrate, so it will not be removed after the substrate is processed. It remains on the organic resist underlayer film pattern. Therefore, even if the organic resist underlayer film pattern remaining after substrate processing is dry-etched (ashed) or wet-removed, the silicon component does not remain on the substrate as a residue.

As described above, the multilayer resist method is widely used for substrate processing because it can be applied as a substrate processing method even on a substrate having a large level difference. Therefore, it is expected to use this feature to utilize an ion implantation mask which is a part of the three-dimensional transistor formation step, that is, an ion implantation step. However, since the organic resist underlayer film pattern for ion implantation formed by the three-layer resist method is not used as a mask for substrate processing, the silicon composition is actually as described above. It remains on the organic resist underlayer film pattern. Therefore, if such an organic resist underlayer film pattern is used as a mask for ion implantation, the silicon component remaining on the organic resist underlayer film pattern will be modified by the implanted ions and will end at the implantation step. In the subsequent cleaning step, the pattern of the underlying film of the organic resist cannot be removed at the same time, and those who cannot be removed will remain on the substrate as foreign matter, resulting in a decrease in the yield of ion implantation. To prevent this problem, the silicon component remaining on the organic resist underlayer film pattern before ion implantation must be selectively washed and removed without affecting the organic resist underlayer film pattern. However, this silicon component has been modified due to the dry etching gas used when the pattern is transferred to the organic resist underlayer film. If an aqueous ammonia solution containing hydrogen peroxide (hereinafter, also referred to as ammonia hydrogen peroxide water) is used, it cannot be washed. For net removal, the aqueous hydrogen peroxide-containing ammonia solution is generally used as a cleaning solution that does not damage the substrate in the semiconductor manufacturing process. In order to completely clean and remove the modified silicon component, a hydrofluoric acid-based cleaning solution is required. However, if this cleaning solution is used, it will also damage the surface of the semiconductor substrate and reduce the yield in this processing step. . Therefore, a method and a material suitable for the method are being sought. After the pattern is transferred to the organic resist underlayer film by dry etching, the method can remain in the organic material without causing damage to the substrate. Removal of the silicon component on the resist underlayer film pattern. [Prior Art Literature] (Patent Literature)

Patent Document 1: Japanese Patent Application Publication No. 2016-094612 (US Patent Application Publication No. 2013/0337649 (A1))

[Problems to be Solved by the Invention] The present invention has been developed in view of the problems described above, and an object thereof is to provide an organic film forming composition capable of forming an organic film that can be easily related to a conventional solution using a peeling liquid The silicon component residues modified by dry etching are wet-removed together. The stripping solution does not cause damage to the semiconductor device substrate and the organic resist underlayer film required in the patterning step. The stripping solution is generally used in semiconductor processes, for example. It is called SC1 (Standard Cleaner 1) aqueous ammonia solution containing hydrogen peroxide. [Technical means to solve the problem]

In order to solve the above-mentioned problems, the present invention provides a composition for forming an organic film. The composition for forming an organic film includes a polymer compound and an organic solvent. The polymer compound has the following general formulae (1) to ( 4) Any one or more of the repeating units represented, and in this organic solvent, the total amount of one or more selected from propylene glycol esters, ketones and lactones accounts for more than 30 wt. Of all organic solvents % In the formulae (1) to (4), R ₁ is a hydrocarbon group, a halogen atom, an alkoxy group, a carboxyl group, a sulfo group, a methoxycarbonyl group, a hydroxyphenyl group, or an amine group, and R ₂ is a hydrogen atom. Or AL; AL is a functional group that generates acidity due to heating or acid; R ₃ is a hydrogen atom, a furyl group, or a hydrocarbon group having 1 to 16 carbon atoms that may have a chlorine atom or a nitro group; k ₁ , k ₂ and k ₃ is 1 ~ 2, l is 1 ~ 3, m is 0 ~ 3, n is 0 or 1.

With such a composition for forming an organic film, it is possible to form an organic film that can be easily wet-removed together with a silicon component residue that has been modified by dry etching using a peeling liquid, and the peeling liquid does not The semiconductor device substrate and the organic resist underlayer film required in the patterning step are damaged. The stripping solution is, for example, a hydrogen peroxide-containing ammonia aqueous solution called SC1 commonly used in semiconductor manufacturing processes. Moreover, if it is such a composition for organic film formation, it can apply as a material for ion implantation masks when forming a three-dimensional transistor.

At this time, it is preferable that the aforementioned composition for forming an organic film is used to form an organic film which is introduced directly below the intermediate film containing a silicon resist and directly above the lower layer of the organic resist. The resist intermediate film is soluble in ammonia hydrogen peroxide water, and the organic resist underlayer film is hardly soluble in ammonia hydrogen peroxide water.

The composition for forming an organic film of the present invention is a composition (hereinafter, also referred to as the present composition), which can form an organic film (hereinafter, also referred to as the present organic compound) in a three-layer resist method formed on a substrate. Film) to form a substantially four-layer resist. The organic film is formed between the organic resist underlayer film and the silicon-containing resist intermediate film formed directly under the photoresist. An organic resist underlayer film is formed on the substrate, and the organic film is formed between the organic resist underlayer film and the silicon resist-containing intermediate film, and then the silicon resist-containing intermediate film is formed. After further forming the upper resist, the upper resist is After the agent is used to form a pattern, and the pattern is transferred to the silicon resist-containing intermediate film by dry etching, the transferred pattern is used as a mask to dry-etch the organic film and the organic resist underlayer film in one go. Pattern transfer. Here, if the silicon resist-containing intermediate film is soluble in ammonia hydrogen peroxide water and the organic resist underlayer film is hardly soluble in ammonia hydrogen peroxide water, the ammonia hydrogen peroxide water can be used to transfer the residual The silicon component on the pattern is removed together with the organic film, so that an organic resist underlayer film pattern without a silicon component residue can be obtained. If the organic resist underlayer film pattern is applied as an ion implantation mask, the ion implantation can be performed correctly even in a three-dimensional transistor with a large level difference, and three-dimensional transistor processing can be performed with a high yield.

In addition, at this time, it is preferable that the silicon-containing resist-containing intermediate film includes any one or both of boron and phosphorus.

If the patterned silicon-resist-containing intermediate film is used as a mask, and dry etching is used to transfer the pattern to the organic film and the organic resist underlayer film in one breath, the pattern of the silicon-resist-containing intermediate film may sometimes be caused by dry etching. The structure change occurs due to the action of gas in the plasma or plasma, so that the solubility to ammonia hydrogen peroxide water is reduced. However, since the silicon-containing resist intermediate film contains either one or both of boron and phosphorus, regardless of the dry etching gas and conditions, it can be made soluble in ammonia hydrogen peroxide water after dry etching. Silicone-containing resist interlayer and / or silicon component residue.

In this case, it is preferable that the composition for forming an organic film further contains any one or both of a thermal acid generator and a crosslinking agent.

If the composition for forming an organic film of the present invention contains any one or both of a thermal acid generator and a cross-linking agent, the organic film having a uniform thickness and a uniform composition can be formed not only on the organic resist underlayer film, In addition, it is possible to suppress intermixing when a silicon resist-containing intermediate film is formed on the organic film.

In addition, at this time, it is preferred that the organic film forming composition is spin-coated on a substrate and then heated to obtain an organic film. The organic film can be obtained by using 29% ammonia water / 35% hydrogen peroxide. A 65 ° C solution mixed with a ratio of water / water = 1/1/8 has a dissolution rate of 5 nm / min or more when processed.

If it is a composition for forming an organic film that can obtain an organic film having such properties, it is possible to combine the organic film and the organic film with ammonia hydrogen peroxide water without causing damage to the substrate for semiconductor device manufacturing. The silicon component residue on the membrane is sufficiently removed.

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

If it is a composition for forming an organic film that can obtain an organic film having such a thickness, even if a silicon resist-containing intermediate film is used as a dry etching mask, the pattern is transferred to the organic film and the organic resist in one breath. The lower layer film can transfer the pattern while maintaining the accuracy of the pattern formed by the upper layer resist. [efficacy]

With such a composition for forming an organic film, it is possible to form an organic film that can be easily wet-removed together with a silicon component residue that has been modified by dry etching using a peeling liquid, and the peeling liquid does not The semiconductor device substrate and the organic resist underlayer film required in the patterning step are damaged. The stripping solution is, for example, ammonia hydrogen peroxide water called SC1 generally used in semiconductor manufacturing processes. In addition, by applying the composition for forming an organic film of the present invention between an organic resist underlayer film and a silicon resist-containing intermediate film, an ion implantation mask can be formed when an ion implantation mask is formed. No silicon component remains on the pattern. Thereby, it is possible to prevent a decrease in the yield in the manufacturing process of the three-dimensional transistor, and it is possible to manufacture a higher-performance semiconductor device at a reduced cost.

As described above, a composition for forming an organic film that can form an organic film that can be easily removed by wet removal with a silicon component residue that has been modified by dry etching has been sought. The stripping liquid does not cause damage to the semiconductor device substrate and the organic resist underlayer film required in the patterning step. The stripping liquid is, for example, ammonia hydrogen peroxide water called SC1, which is generally used in semiconductor manufacturing processes.

As a result of repeated studies on the problems to be solved by the present inventors, the inventors have found that if the composition for forming an organic film can solve the problems to be solved, the present invention is completed. The composition for forming an organic film includes A polymer compound and an organic solvent, the polymer compound having any one or more of the repeating units represented by the following general formulae (1) to (4), and in the organic solvent, propylene glycol esters, ketones, and The total amount of one or more selected lactones accounts for more than 30% by weight of the total organic solvents.

In other words, the present invention is a composition for forming an organic film. The composition for forming an organic film includes a polymer compound and an organic solvent. The polymer compound has one of the repeating units represented by the following general formulae (1) to (4). Any one or more of them, and in the organic solvent, the total amount of one or more selected from propylene glycol esters, ketones and lactones accounts for more than 30% by weight of all organic solvents; In the formulae (1) to (4), R ₁ is a hydrocarbon group, a halogen atom, an alkoxy group, a carboxyl group, a sulfo group, a methoxycarbonyl group, a hydroxyphenyl group, or an amine group, and R ₂ is a hydrogen atom. Or AL; AL is a functional group that generates acidity due to heating or acid; R ₃ is a hydrogen atom, a furyl group, or a hydrocarbon group having 1 to 16 carbon atoms that may have a chlorine atom or a nitro group; k ₁ , k ₂ and k ₃ is 1 ~ 2, l is 1 ~ 3, m is 0 ~ 3, n is 0 or 1.

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

[Composition for forming organic film] The composition for forming an organic film of the present invention includes a polymer compound and an organic solvent. Hereinafter, each component is demonstrated in detail.

<Polymer Compound> The polymer compound in the composition for forming an organic film of the present invention has any one or more of the repeating units represented by the following general formulae (1) to (4). In the formulae (1) to (4), R ₁ is a hydrocarbon group, a halogen atom, an alkoxy group, a carboxyl group, a sulfo group, a methoxycarbonyl group, a hydroxyphenyl group, or an amine group, and R ₂ is a hydrogen atom. Or AL; AL is a functional group that generates acidity due to heating or acid; R ₃ is a hydrogen atom, a furyl group, or a hydrocarbon group having 1 to 16 carbon atoms that may have a chlorine atom or a nitro group; k ₁ , k ₂ and k ₃ is 1 ~ 2, l is 1 ~ 3, m is 0 ~ 3, n is 0 or 1.

Here, examples of the repeating unit represented by the general formula (1) include a repeating unit having the following structure.

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

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

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

Among these, as a preferable repeating unit, the repeating unit represented by the said General formula (2) or (3) is illustrated. If it is a composition for forming an organic film that includes a polymer compound having such a repeating unit, an organic film can be formed because a highly polar carboxyl group is located at an effective position, which is carried out by aqueous hydrogen peroxide. Excellent wet removal.

Here, as a monomer for obtaining a repeating unit of n = 0 in the repeating units represented by the above general formulae (1) to (4), for example, phenol, o-cresol, m-cresol, p-cresol Phenol, 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-tertiarybutylphenol, 3-tertiarybutylphenol, 4-tertiarybutyl Phenol, resorcinol, 2-methylresorcinol, 4-methylresorcinol, 5-methylresorcinol, catechol, 4-tert-butylcatechol, 2- Methoxyphenol, 3-methoxyphenol, 2-propylphenol, 3-propylphenol, 4-propylphenol, 2-isopropylphenol, 3-isopropylphenol, 4-isopropylphenol , 2-methoxy-5-methylphenol, 2-tert-butyl-5-methylphenol, 4-phenylphenol, tritylphenol, pyrogol, thymol ( thymol), hydroxyphenyl glycidyl ether, 4-fluorophenol, 3,4-difluorophenol, 4-trifluoromethylphenol, 4-chlorophenol, 4-hydroxybenzenesulfonic acid, 4-vinylphenol, 1- (4-hydroxyphenyl) naphthalene, etc.

As a monomer for obtaining a repeating unit of n = 1 in the repeating units represented by the above-mentioned general formulae (1) to (4), for example, 1-naphthol, 2-naphthol, 2-methyl- 1-naphthol, 4-methoxy-1-naphthol, 7-methoxy-2-naphthol, 1,2-dihydroxynaphthalene, 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) Hydrazone, 6-hydroxy-2-vinylnaphthalene, 1-hydroxymethylnaphthalene, 2-hydroxymethylnaphthalene, 8-hydroxynaphthalene-1-sulfonic acid, 2-hydroxynaphthalene-7-sulfonic acid, 2,3- Dihydroxynaphthalene-7-sulfonic acid, 1,7-dihydroxynaphthalene-3-sulfonic acid, and the like.

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

Examples of the condensing agent for causing a condensation reaction of these monomers include the following aldehyde compounds. For example: formaldehyde, trioxane, polyformaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, cyclopentane formaldehyde, cyclopentene formaldehyde, cyclohexane formaldehyde, cyclohexene formaldehyde, norbornane formaldehyde, Norbornene formaldehyde, adamantane formaldehyde, benzaldehyde, phenylacetaldehyde, α-phenylpropanal, β-phenylpropanal, 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, anthracenaldehyde, pyrene formaldehyde, furfural and the like.

Other examples include compounds which can be represented by the following formula.

Relative to the total amount of moles of the monomer (1 mol), the ratio of the monomer to the condensing agent, that is, the aldehyde compound, is preferably 0.01 to 5 moles, and more preferably 0.05 to 2 moles.

When the entire content is 100%, the proportion of the repeating units represented by the general formulae (1) to (4) in the total repeating units is preferably 10% or more, and more preferably 30% or more.

When using the raw materials as described above for the polycondensation reaction, it is generally possible to use an acid or a base as a catalyst in a solvent-free or solvent-based manner, and to perform the reaction at room temperature or under cooling or heating as needed. This makes it possible to obtain a polymer compound (polymer). Examples of the solvent to be used include methanol, ethanol, isopropanol, butanol, ethylene glycol, propylene glycol, diethylene glycol, glycerol, methylcellulose, ethylcellulose, and butylcellulose. Alcohols such as threon, propylene glycol monomethyl ether (PGME); diethyl ether, dibutyl ether, diethylene glycol diethyl ether, diethylene glycol dimethyl ether, tetrahydrofuran (THF), 1,4-dioxane Ethers such as alkane; chlorine solvents such as dichloromethane, chloroform, dichloroethane, trichloroethane; hydrocarbons such as hexane, heptane, benzene, toluene, xylene, cumene; nitriles such as acetonitrile; Ketones such as acetone, ethyl methyl ketone, isobutyl methyl ketone; esters such as ethyl acetate, n-butyl acetate, propylene glycol methyl ether acetate; lactones such as γ-butyrolactone; dimethylene Aprotic, polar solvents such as osmium, N, N-dimethylformamide, and hexamethylphosphonium amine 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.

As the acid catalyst, inorganic acids such as hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid, and heteropoly acid; oxalic acid, trifluoroacetic acid, methanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, Organic acids such as trifluoromethanesulfonic acid; aluminum chloride, aluminum ethoxide, aluminum isopropoxide, boron trifluoride, boron trichloride, boron tribromide, tin tetrachloride, tin tetrabromide, dichloride Tin butyl, dimethoxydibutyltin, dibutyltin oxide, titanium tetrachloride, titanium tetrabromide, titanium (IV) methoxide, titanium (IV) ethoxide, titanium (IV) isopropoxide, titanium oxide (IV) Wait for Lewis acids. Alkali catalysts can be used: sodium hydroxide, potassium hydroxide, barium hydroxide, sodium carbonate, sodium bicarbonate, potassium carbonate, lithium hydride, sodium hydride, potassium hydride, calcium hydride and other inorganic bases; methyl lithium, n-butyl Alkyl metal such as lithium lithium, methyl magnesium chloride, ethyl magnesium bromide; alkoxides such as sodium methoxide, sodium ethoxide, potassium tert-butoxide; triethylamine, diisopropylethylamine, N , N-dimethylaniline, pyridine, 4-dimethylaminopyridine and other organic bases. The use amount of the raw material is preferably in the range of 0.001 to 100% by weight, and more preferably in the range of 0.005 to 50% by weight. The reaction temperature is preferably from -50 ° C to the boiling point of the solvent, and more preferably from room temperature to 100 ° C.

Examples of the method for the polycondensation reaction include a method of feeding a monomer, a condensing agent, and a catalyst in a batch; and a method of gradually dropping the monomer and the condensing agent in the presence of the catalyst.

In addition, after the completion of the polycondensation reaction, in order to remove unreacted raw materials, catalysts, and the like existing in the system, the following methods can be used according to the properties of the obtained reaction products: the temperature of the reaction kettle is raised to 130 to 230 ° C. Method of removing volatile components by about 1 to 50 mmHg; adding a suitable solvent or water to fractionate the polymer; and dissolving the polymer in a good solvent and reprecipitating it in a poor solvent Wait.

As the molecular weight in terms of polystyrene of the polymer obtained in the above manner, a weight average molecular weight (Mw) is preferably 500 to 500,000, and a weight average molecular weight (Mw) is particularly preferably 1,000 to 100,000. The degree of molecular weight dispersion is preferably within a range of 1.2 to 20. Separating the monomer component, oligomer component, or low molecular weight body with a molecular weight (Mw) of 1,000 or less can suppress the volatile components in baking and prevent surface defects caused by: Contaminated or accumulated volatile components fall on the wafer.

<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-pentyl ketone; 3-methoxybutanol and 3-methyl-3-methoxybutane Alcohol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, propylene glycol monomethyl ether, ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl Alcohols such as ethers; ethers such as propylene glycol dimethyl ether, diethylene glycol dimethyl ether; propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, ethyl lactate, ethyl pyruvate, Butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, tertiary butyl acetate, tertiary butyl propionate, propylene glycol mono (tertiary butyl) ether acetate, etc. Esters; γ-butyrolactone, etc. These can be used singly or in combination of two or more, but are not limited to these.

Here, it must be one or more selected from propylene glycol esters, ketones, and lactones in an organic solvent (for example, propylene glycol monomethyl ether acetate and cyclopentane from the organic solvents illustrated above). The total amount of ketones, cyclohexanone, methyl-2-pentyl ketone, and γ-butyrolactone) is more than 30% by weight of all organic solvents. When the organic solvent does not satisfy this condition, a homogeneous organic film cannot be formed directly above the organic resist underlayer film.

In addition, the organic film-forming composition of the present invention may contain an acid generator and a crosslinking agent to further promote the crosslinking reaction. Examples of the acid generator include an acid generator (thermal acid generator) which generates an acid due to thermal decomposition, and an acid generator which generates an acid by irradiation with light, and any of these can be added.

Examples of the acid generator include onium salts, diazomethane derivatives, glyoxaldioxime derivatives, bisfluorene derivatives, sulfonate esters of N-hydroxyamidoimine compounds, and β-ketosulfonic acid derivatives. Compounds, difluorene derivatives, nitrobenzyl sulfonate derivatives, sulfonates, sulfonate derivatives, and the like. Specifically, the acid generator described in paragraphs (0081) to (0111) of Japanese Patent Application Laid-Open No. 2008-65303 (US Patent Application Publication No. 2008/0038662 (A1)) can be cited.

Examples of the cross-linking agent include a melamine compound, a guanamine compound, and a glycoluril compound substituted with at least one group selected from methylol, alkoxymethyl, and methyloxymethyl. Or urea compounds, epoxy compounds, episulfide compounds, isocyanate compounds, azide compounds, compounds containing double bonds such as alkenyl ether groups, and the like. Specifically, for example, the cross-linking agents described in paragraphs (0074) to (0080) of Japanese Patent Application Laid-Open No. 2008-65303 (US Patent Application Publication No. 2008/0038662 (A1)) can be cited.

Moreover, a surfactant can also be added to the composition for organic film formation of this invention in order to improve the coating property at the time of spin coating. Examples of the surfactant include polyoxyethyl ethers, polyoxyethyl alkylallyl ethers, polyoxyethylene polyoxypropylene block copolymers, and sorbose. Non-ionic surfactants of fatty acid esters of alcohol anhydrides, polyoxyethylene sorbitan fatty acid esters; fluorine-based surfactants; partially fluorinated oxetane ring-opening polymer-based surfactants, etc. . Specifically, for example, the surfactants described in paragraphs (0142) to (0147) of Japanese Patent Application Laid-Open No. 2009-269953 (US Patent Application Publication No. 2009/0274978 (A1)) can be cited.

Furthermore, 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 can act as a quencher on the acid to prevent the trace amount of acid generated by the acid generator from causing the crosslinking reaction to proceed. Examples of such basic compounds include primary, secondary, and tertiary aliphatic amines, mixed amines, aromatic amines, heterocyclic amines, nitrogen-containing compounds having a carboxyl group, and sulfonyl groups. A nitrogen-containing compound, a nitrogen-containing compound having a hydroxyl group, a nitrogen-containing compound having a hydroxyphenyl group, an alcoholic nitrogen-containing compound, an amidine derivative, an amidine derivative, and the like. Specifically, for example, the basic compounds described in paragraphs (0112) to (0119) of Japanese Patent Application Laid-Open No. 2008-65303 (US Patent Application Publication No. 2008/0038662 (A1)) can be cited.

The composition for forming an organic film of the present invention as described above can be preferably used to form an organic film which is introduced directly under the silicon resist-containing intermediate film and directly above the organic resist underlayer film. The silicon resist-containing intermediate film is soluble in ammonia hydrogen peroxide water, and the organic resist underlayer film is difficult to dissolve in ammonia hydrogen peroxide water.

In addition, the composition for forming an organic film of the present invention is preferably capable of obtaining an organic film having a film thickness of 10 nm or more and less than 100 nm, and more preferably a film thickness of the organic film of 20 nm or more and Below 80 nm. If the thickness of the organic film is 10 nm or more, a sufficient silicon component removal effect can be obtained by wet processing, and if the thickness of the organic film is less than 100 nm, dry etching processing can be suppressed. Side etch at the time, there will be no doubt about the occurrence of adverse conditions during processing.

[Organic Film] 有机 An organic film can be formed from the composition for forming an organic film of the present invention. As a method of forming an organic film using the composition for forming an organic film of the present invention, for example, a method of applying the composition for forming an organic film of the present invention to a substrate to be processed by a spin coating method or the like. After spin coating, baking is performed in order to evaporate the solvent to prevent the resist upper film and the resist intermediate film from being mixed and to promote the crosslinking reaction. The baking is performed in a range of 100 ° C to 400 ° C, and is performed in a range of 10 to 600 seconds, preferably 10 to 300 seconds. The baking temperature is more preferably 150 ° C to 350 ° C.

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

As such a silicon-containing resist-containing intermediate film, it is preferred that it is soluble in ammonia hydrogen peroxide water and can be dissolved or peeled by using ammonia hydrogen peroxide water. As the silicon-containing resist-containing intermediate film in the present invention, for example, a silicon-containing resist-containing underlayer film described in the following is preferably used: Japanese Patent Application Laid-Open No. 2010-085912 (U.S. Patent Application Publication No. 2010/0086870 (A1) )), Japanese Patent Application Publication No. 2010-085893 (US Patent Application Publication No. 2010/0086872 (A1)), Japanese Patent Application Publication No. 2015-028145 (US Patent Application Publication No. 2015/0004791 (A1 )), International Publication No. 2010/068336 (US Patent Application Publication No. 2011/0233489 (A1)), Japanese Patent Application Publication No. 2016-074772 (US Patent Application Publication No. 2016/0096977 (A1 )), Japanese Patent Application Publication No. 2016-074774 (US Patent Application Publication No. 2016/0096978 (A1)). Among these, the silicon-containing resist-containing intermediate film containing either one or both of boron and phosphorus is particularly preferable because it has excellent wet-removability using ammonia hydrogen peroxide water.

In addition, as the organic resist underlayer film that can be used in the present invention, it is preferred that it is resistant to ammonia hydrogen peroxide water (that is, hardly soluble in ammonia hydrogen peroxide water). The organic resist underlayer film disclosed in, for example, Japanese Patent Application Laid-Open No. 2004-205685 (U.S. Patent No. 7,427,464 (B2)), Japanese Patent Application Laid-Open No. 2010-122656 (US Patent Application Publication No. Specification 2010/0099044 (A1) and U.S. Patent Application Publication No. 2013/0184404 (A1)), Japanese Patent Application Publication No. 2012-214720 (U.S. Patent Application Publication No. 2012/0252218 (A1)), Japanese Patent Application Laid-Open No. 2016-094612 (US Patent Application Publication No. 2013/0337649 (A1)).

The organic resist underlayer film is formed by applying the organic resist underlayer film composition to a substrate to be processed by a spin coating method or the like. By using a spin coating method or the like, good landfill characteristics can be obtained. After spin coating, in order to evaporate the solvent to prevent the resist upper film and the resist intermediate film from mixing and to promote the cross-linking reaction, baking is performed in a range of 100 ° C to 600 ° C, and It is performed within the range of 10 to 600 seconds, preferably 10 to 300 seconds. The baking temperature is more preferably 200 ° C to 500 ° C. When the influence on the element damage and wafer deformation is taken into consideration, the upper limit of the heating temperature in the wafer process of the lithography method is preferably 600 ° C. or lower, and more preferably 500 ° C. or lower.

In the method for forming an organic resist underlayer film as described above, the organic resist underlayer film can be formed by applying the organic resist underlayer film composition to a substrate to be processed by a spin coating method or the like. The composition is calcined in the environment of air, N ₂ , Ar, He, etc. to harden it. By calcining the organic resist underlayer film composition in an environment containing oxygen, a hardened film having resistance to ammonia hydrogen peroxide water can be obtained.

By forming the organic resist underlayer film in the manner described above, because of its excellent landfill / planarization characteristics, a flat hardened film can be obtained regardless of the unevenness of the substrate to be processed, so it should be a structure with a height of 30 nm or more Or it is extremely useful when forming a flat cured film on a substrate with a step.

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

When the composition for forming an organic film of the present invention is used to form an organic film and form a mask for ion implantation, in order to wet-remove the organic film and the silicon-containing resist-containing intermediate film, it is preferable to include peroxide. For the stripping solution of hydrogen, the organic film is introduced directly under the silicon-containing resist intermediate film and directly above the organic resist lower layer film. In this case, in order to promote peeling, it is more preferable to adjust the pH by adding an acid or an alkali to the peeling solution. Examples of such pH adjusters (acids or bases) 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; Base; organic compounds containing nitrogen, such as EDTA (ethylenediaminetetraacetic acid), and the like. Particularly preferred is ammonia. In other words, as the peeling liquid, ammonia hydrogen peroxide water is preferred.

When ammonia hydrogen peroxide water 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, and preferably 0.05 to 100 parts by mass of deionized water. 15 parts by mass, more preferably 0.1 to 10 parts by mass, and hydrogen peroxide is 0.01 to 20 parts by mass, preferably 0.05 to 15 parts by mass, and more preferably 0.1 to 10 parts by mass.

Wet removal may be performed by the following method: preparing a stripping solution at 0 ° C to 80 ° C, preferably 5 ° C to 70 ° C, and immersing a silicon wafer having a substrate to be processed to be processed in the stripping liquid. . In addition, when necessary, the silicon resist-containing intermediate film and the organic film for forming the organic film of the present invention can be easily formed in accordance with a conventional method such as spraying the peeling liquid on the surface or applying the peeling liquid while rotating the wafer. The organic film formed by the composition is removed.

In particular, the composition for forming an organic film of the present invention is preferably: an organic film can be obtained by spin-coating on a substrate and then heating, and the organic film can be obtained by using 29% ammonia water / 35% hydrogen peroxide. A 65 ° C solution mixed with a ratio of water / water = 1/1/8 has a dissolution rate of 5 nm / min or more when processed.

In addition, after the ammonia hydrogen peroxide water treatment, it is preferable to quantify the silicon remaining on the surface of the organic resist underlayer film to confirm the degree of removal of the silicon component. The analysis can be performed by a method described in, for example, Japanese Patent Application Laid-Open No. 2016-177262 (US Patent Application Publication No. 2016/0276152 (A1)).

As described above, if the composition for forming an organic film according to the present invention can form an organic film, the organic film can be easily removed by wet removal together with the silicon component residue that has been modified by dry etching. The stripping solution does not damage the semiconductor device substrate and the organic resist underlayer film required in the patterning step. The stripping solution is, for example, ammonia hydrogen peroxide water called SC1 commonly used in semiconductor manufacturing processes. In addition, by applying the composition for forming an organic film of the present invention between an organic resist underlayer film and a silicon resist-containing intermediate film, an ion implantation mask can be formed when an ion implantation mask is formed. No silicon component remains on the pattern. Thereby, it is possible to prevent a decrease in the yield in the manufacturing process of the three-dimensional transistor, and it is possible to manufacture a higher-performance semiconductor device at a reduced cost. [Example]

Hereinafter, the present invention will be specifically described with reference to Synthesis Examples, Examples, and Comparative Examples, but the present invention is not limited by the description of these examples. In addition, in the following examples,% means mass%, and molecular weight measurement was performed by the gel permeation chromatography (GPC). In the GPC measurement, detection is performed with a refractive index detector (RI), and the eluent solvent is tetrahydrofuran, and the molecular weight in terms of polystyrene is calculated.

[Synthesis of Polymer Compound] [Synthesis Example (A1)] Measure 40.00 g (0.36 mol) of resorcinol, 10.00 g of a 20% by mass PGME solution of p-toluenesulfonic acid monohydrate, and 2-methoxy- 72.00 g of 1-propanol to a 500-mL three-necked flask, and heat to 80 ° C while stirring. To this was added 23.59 g of 37% formalin (0.29 mol of formaldehyde) and stirred for 11 hours. 160 g of ultrapure water and 200 g of ethyl acetate were added to the reaction solution and transferred to a separating funnel, and then washed with 150 g of ultrapure water 10 times 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. After the n-hexane layer becomes the upper layer and the high-concentration polymer solution becomes the lower layer, the upper layer is removed. After repeating the same operation twice, the obtained polymer solution was concentrated, and further dried under reduced pressure at 80 ° C. for 13 hours to obtain a polymer compound A1. The weight average molecular weight (Mw) and the dispersion (Mw / Mn) were determined by GPC, and Mw = 800 and Mw / Mn = 1.3. This polymer compound A1 has a repeating unit represented by the general formula (4).

[Synthesis Example (A2)] (1) In a 1,000 mL three-necked flask, in a nitrogen atmosphere and at a liquid temperature of 80 ° C., 80.1 g (0.50 mol) of 1,5-dihydroxynaphthalene and 26.4 g of 37% formalin ( 0.24 mole) and 250 g of 2-methoxy-1-propanol into a homogeneous solution, then slowly add 18 g of 20% p-toluenesulfonic acid 2-methoxy-1-propanol solution, and Stir at 110 ° C for 12 hours. After cooling to room temperature, 500 g of methyl isobutyl ketone was added, and the organic layer was washed 5 times with 200 g of pure water, and then the organic layer was dried and solidified under reduced pressure. 300 mL of THF was added to the residue, and the polymer was reprecipitated with 2,000 mL of hexane. The deposited polymer was separated by filtration and dried under reduced pressure to obtain a polymer compound A2. The weight average molecular weight (Mw) and the dispersion (Mw / Mn) were determined by GPC, and 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)] (1) In a 2,000 mL three-necked flask, in a nitrogen atmosphere and at a liquid temperature of 80 ° C., 80.1 g (0.50 mol) of 1,5-dihydroxynaphthalene and 3,4-bis (tri) Grade butoxy) benzaldehyde 100.1 g (0.40 mole) and 600 g of 2-methoxy-1-propanol into a homogeneous solution, then slowly add 6.4 g of 25% sodium hydroxide aqueous solution, and the liquid temperature is 110 Stir at 24 ° 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% nitric acid aqueous solution. After the organic layer was further washed with 300 g of pure water five times, the organic layer was reduced. Press dry and solidify. 400 mL of THF was added to the residue, and the polymer was reprecipitated with 3,000 mL of hexane. The deposited polymer was separated by filtration and dried under reduced pressure to obtain a polymer compound A3. The weight average molecular weight (Mw) and the dispersion (Mw / Mn) were determined by GPC, and 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)] In a 1,000 mL flask, 80 g of 1,5-dihydroxynaphthalene (0.5 mol), 36.6 g of 4-hydroxybenzaldehyde (0.30 mol), and methylcellulose 145 were added. g, and 20 g of a 20% by mass methylcellulose solution of p-toluenesulfonic acid was added while stirring at 70 ° C. After raising the temperature to 85 ° C. and stirring for 6 hours, it was cooled to room temperature and diluted with 800 mL of ethyl acetate. Transfer to a separatory funnel and repeat washing with 200 mL of deionized water to remove the reaction catalyst and metal impurities. After the resulting solution was concentrated under reduced pressure, 600 mL of ethyl acetate was added to the residue, and the polymer was reprecipitated with 2,400 mL of hexane. The precipitated polymer was separated by filtration and recovered, and then dried under reduced pressure to obtain a polymer compound A4. The weight average molecular weight (Mw) and the dispersion (Mw / Mn) were determined by GPC, and 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)] In a 2,000 mL three-necked flask, in a nitrogen atmosphere and at a liquid temperature of 80 ° C., 80.1 g (0.50 mol) of 2,7-dihydroxynaphthalene and trimethylparaben After 100.1 g (0.40 mole) of grade butyl ester and 600 g of 2-methoxy-1-propanol became a homogeneous solution, 6.4 g of a 25% aqueous sodium hydroxide solution was slowly added, and the mixture was stirred at 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% nitric acid aqueous solution. The organic layer was further washed with 300 g of pure water five times, and then dried and solidified under reduced pressure. . 400 mL of THF was added to the residue, and the polymer was reprecipitated with 3,000 mL of hexane. The deposited polymer was separated by filtration and dried under reduced pressure to obtain a polymer compound A5. The weight average molecular weight (Mw) and the dispersion (Mw / Mn) were determined by GPC, and 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)] In a 2,000 mL three-necked flask, in a nitrogen atmosphere and at a liquid temperature of 80 ° C., 94.4 g (0.50 mol) of 6-hydroxy-2-naphthoic acid and p-toluenylbenzoic acid were prepared. After 100.1 g (0.40 mole) of tertiary butyl ester and 600 g of 2-methoxy-1-propanol became a homogeneous solution, 6.4 g of a 25% sodium hydroxide aqueous solution was slowly added, and the mixture was stirred at 110 ° C for 24 hours. hour. 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% nitric acid aqueous solution. The organic layer was further washed with 300 g of pure water five times, and then dried and solidified under reduced pressure. . 400 mL of THF was added to the residue, and the polymer was reprecipitated with 3,000 mL of hexane. The deposited polymer was separated by filtration and dried under reduced pressure to obtain a polymer compound A6. The weight average molecular weight (Mw) and the dispersion (Mw / Mn) were determined by GPC. 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)] In a 2,000 mL three-necked flask, in a nitrogen atmosphere and at a liquid temperature of 80 ° C., 80.1 g (0.50 mol) of 1,5-dihydroxynaphthalene and 60.1 of p-methylbenzoic acid were prepared. g (0.40 mol) and 600 g of 2-methoxy-1-propanol became a homogeneous solution, and then 6.4 g of a 25% aqueous sodium hydroxide solution was slowly added, followed by stirring 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% nitric acid aqueous solution. The organic layer was further washed with 300 g of pure water five times, and then dried and solidified under reduced pressure. . 400 mL of THF was added to the residue, and the polymer was reprecipitated with 3,000 mL of hexane. The deposited polymer was separated by filtration and dried under reduced pressure to obtain a polymer compound A7. The weight average molecular weight (Mw) and the dispersion (Mw / Mn) were determined by GPC, and 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)] In a 200 mL three-necked flask, 9.4 g (0.05 mol) of 6-hydroxy-2-naphthoic acid and p-toluenylbenzoic acid were placed in a nitrogen atmosphere at a liquid temperature of 80 ° C. After 5.3 g (0.05 mol) and 60 g of 2-methoxy-1-propanol became a homogeneous solution, 0.6 g of a 25% sodium hydroxide aqueous solution was slowly added, and 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% nitric acid aqueous solution. The organic layer was further washed with 30 g of pure water five times, and then dried and solidified under reduced pressure. . 40 mL of THF was added to the residue, and the polymer was reprecipitated with 300 mL of hexane. The deposited polymer was separated by filtration and dried under reduced pressure to obtain a polymer compound A8. The weight average molecular weight (Mw) and the dispersion (Mw / Mn) were determined by GPC, and 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)] In a 2,000 mL three-necked flask, in a nitrogen atmosphere and at a liquid temperature of 80 ° C, o-cresol 54.1 g (0.50 mol) and 3,4-bis (tertiary butoxycarbonyl) After 140.2 g (0.40 mole) of methoxy) benzaldehyde and 600 g of 2-methoxy-1-propanol became a homogeneous solution, 6.4 g of a 25% sodium hydroxide aqueous solution was slowly added, and the liquid temperature was 110 ° C. Stir 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% nitric acid aqueous solution. The organic layer was further washed with 300 g of pure water five times, and then dried and solidified under reduced pressure. . 400 mL of THF was added to the residue, and the polymer was reprecipitated with 3,000 mL of hexane. The deposited polymer was separated by filtration and dried under reduced pressure to obtain a polymer compound A9. The weight average molecular weight (Mw) and the dispersion (Mw / Mn) were determined by GPC, and 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)] (1) In a 2,000 mL three-necked flask, in a nitrogen atmosphere and at a liquid temperature of 80 ° C., 80.1 g (0.50 mol) of 1,6-dihydroxynaphthalene and 4-tert-butoxycarbonyl were prepared. After 94.5 g (0.40 mol) of methoxybenzaldehyde and 600 g of 2-methoxy-1-propanol became a homogeneous solution, 6.4 g of a 25% sodium hydroxide aqueous solution was slowly added, and stirred at a liquid temperature of 110 ° C. 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% nitric acid aqueous solution. The organic layer was further washed with 300 g of pure water five times, and then dried and solidified under reduced pressure. . 400 mL of THF was added to the residue, and the polymer was reprecipitated with 3,000 mL of hexane. The deposited polymer was separated by filtration and dried under reduced pressure to obtain a polymer compound A10. The weight average molecular weight (Mw) and the dispersion (Mw / Mn) were determined by GPC, and 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] The polymer compounds A1 to A10 described above, the cross-linking agents XL1 to 3 as additives, the thermal acid generator AG1, and 0.1% by mass were included as surfactants at the ratios shown in Table 1. FC-4430 (manufactured by Sumitomo 3M Co., Ltd.) was mixed with an organic solvent, and filtered through a 0.1 μm fluororesin filter to prepare a composition for forming an organic film (Sol. 1 to 19). In addition, Sol. 1-10, 17-19 is a composition for organic film formation of this invention, and Sol. 11-16 is a composition for organic film formation for comparison. In addition, the ratio of the total amount of one or more selected from propylene glycol esters, ketones, and lactones in the prepared organic film-forming composition to the total organic solvents is shown in Table 1.

[Table 1]

Hereinafter, the thermal acid generator AG1 and the crosslinking agents XL1 to XL3 are shown.

In addition, 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

[Evaluation of Solvent Resistance: Examples 1-1 to 13 and Comparative Examples 1-1 to 6] (1) Because a silicon resist-containing intermediate film is spin-coated on a positive organic film formed from the composition for forming an organic film of the present invention, Above, therefore, in order to investigate whether the formed organic film is an organic film that does not cause intermixing, the resistance to an organic solvent is evaluated. The organic film forming composition (Sol. 1 to 19) was coated on a silicon substrate, and calcined at 285 ° C. for 60 seconds to form an organic film, and then the film thickness T1 was measured. After PGMEA / PGME = 30/70 (mass ratio) was spin-coated on the obtained organic film, a heat treatment was performed at 100 ° C for 30 seconds, and then the film thickness T2 was measured. Based on the measurement results of these film thicknesses, the amount of film thickness reduction shown by T1-T2 is calculated. The results are shown in Table 2.

[Table 2]

As can be seen from Examples 1-1 to 13 in Table 2, the organic films formed from Sol. 1 to 10 and 17 to 19 have sufficient resistance to organic solvents. Therefore, even if a silicon resist-containing intermediate film is spin-coated directly above these organic films, a laminated film can be formed without being mixed with each other.

[Evaluation of the film-forming property on the organic resist underlayer film: Examples 2-1 to 13 and Comparative Examples 2-1 to 6] The organic resist formed by the organic film-forming composition of the present invention is laminated on the organic resist Therefore, the film formation property on the organic resist underlayer film was confirmed. A spin-coated carbon film ODL-102 manufactured by Shin-Etsu Chemical Co., Ltd. was coated on a silicon wafer as an organic resist underlayer film to form an organic resist underlayer film having a thickness of 200 nm. An organic film-forming composition (Sol. 1 to 19) was applied thereon, and calcined at 285 ° C for 60 seconds to form an organic film. Then, the film-forming state of the organic film was confirmed. The results are shown in Table 3.

[table 3]

As shown in Examples 2-1 to 13 of Table 3, Sol. 1 to 10 and 17 to 19 can form a film on an organic resist underlayer film by spin coating without a film formation defect. On the other hand, as shown in Comparative Examples 2-1 to 6, Sol. 11-16 containing 70% by weight or more of an alcohol-based organic solvent, uneven coating occurred on the organic resist underlayer film and the film could not be laminated. .

[Wet Removability of Organic Film with Ammonia Hydrogen Peroxide Water: Examples 3-1 to 10] The above-mentioned organic film forming composition (Sol. 1 to 10) was coated on a silicon substrate, respectively, After firing at 285 ° C for 60 seconds to form an organic film so as to have a thickness of 25 nm, the film thickness T1 was measured. This film was immersed in ammonia hydrogen peroxide water mixed at a ratio of 29% ammonia water / 35% hydrogen peroxide water / water = 1/1/8 and kept at 65 ° C for 5 minutes, and washed with pure water Then, after heating and drying at 100 ° C for 60 seconds, the film thickness T3 was measured. The film removal rate at this time was determined. These results are shown in Table 4.

[Table 4]

As shown in Table 4, it can be seen that the organic films formed from Sol. 1 to 10 can be removed at a rate of 5 nm / min or more with ammonia hydrogen peroxide water.

[Residue evaluation after ashing of the organic resist underlayer film: Examples 4-1 to 13 and Comparative Example 4-1] A spin-coated carbon film made by Shin-Etsu Chemical Industry Co., Ltd. was formed on a silicon wafer with a thickness of 200 nm. ODL-102 is used as an organic resist underlayer film. The organic film-forming composition (Sol. 1-10, 17-19) of the present invention was coated thereon and 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.

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

Then, an ArF liquid immersion exposure device (NSR-S610C manufactured by Nikon Corporation, NA1.30, σ0.98 / 0.65, 35-degree dipole polarized illumination, and 6% half-tone phase shift mask) was used for these crystals. After exposure to a circle and baking at 100 ° C (PEB) for 60 seconds, developing with a 2.38% tetramethylammonium hydroxide (TMAH) aqueous solution for 30 seconds, a positive line and pitch pattern of 160 nm 1: 1 was obtained. For the wafer obtained in the above manner, the cross-sectional shape of the pattern was observed using an electron microscope (S-4800) manufactured by Hitachi, Ltd., and the electron microscope (CG4000) manufactured by Hitachi High-Technologies Corporation was used to observe the pattern. collapse.

Using an etching apparatus made by Tokyo Electron, Telius, dry etching was performed on these wafers having obtained a photoresist pattern under the processing conditions shown in Tables 8 and 9, and the silicon resist-containing intermediate film and the organic resist were separately etched. The lower film is processed. The obtained wafer was observed for the cross-sectional shape of the pattern using an electron microscope (S-9380) manufactured by Hitachi, Ltd.

Then, in order to wet-remove the silicon resist-containing intermediate film remaining after processing the organic resist underlayer film, a ratio of 29% ammonia water / 35% hydrogen peroxide water / water = 1/1/8 was used. The above-mentioned wafer was processed by mixing and maintaining hydrogen peroxide water at 65 ° C for 5 minutes. After the treatment, it was washed with pure water and dried at 100 ° C for 60 seconds. In addition, in order to confirm whether the silicon component can be removed by ammonia hydrogen peroxide water treatment, K-ALPHA manufactured by Thermo Fisher Scientific Co., Ltd. was used to perform X-ray photoelectron spectroscopy (XPS) analysis on the surface of the lower layer of the organic resist, The silicon on the organic resist underlayer film was quantified.

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

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

[Table 5] <TABLE border = "1" borderColor = "# 000000" width = "85%"><TBODY><tr><td> No. </ td><td> Polymer (mass parts) </ td><td> Additive (mass parts) </ td><td> Solvent (mass parts) </ td></tr><tr><td> SiARC-1 </ td><td> SiARC Polymer 1 (4.0) SiARC polymer 2 (0.2) </ td><td> TPSNO <sub> 3 </ sub> (0.02) maleic acid (0.04) D-sorbitol (0.5) </ td><td> PGEE (310) water (65) </ td></tr></TBODY></TABLE> TPSNO ₃ : triphenylphosphonium nitrate

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

The composition of the ArF resist solution (PR-1) for positive development is shown in Table 6 below. [TABLE 6]         <TABLE border = "1" borderColor = "# 000000" width = "85%"> <TBODY> <tr> <td> No. </ td> <td> Polymer (parts by mass) </ td> <td > Acid generator (parts by mass) </ td> <td> Alkali (parts by mass) </ td> <td> Solvent (parts by mass) </ td> </ tr> <tr> <td> PR-1 < / td> <td> ArF resist polymer 1 (100) </ td> <td> PAG1 (7.0) </ td> <td> Quencher (1.0) </ td> <td> PGMEA (2,500) </ td> </ tr> </ TBODY> </ TABLE>

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

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

The base shown in Table 6: The structural formula of Quencher is shown below.

The composition of the liquid immersion protective film composition (TC-1) used in the pattern test by the positive development described above is shown in Table 7 below. [TABLE 7]         <TABLE border = "1" borderColor = "# 000000" width = "85%"> <TBODY> <tr> <td> </ td> <td> Polymer (mass parts) </ td> <td> Organic Solvent (parts by mass) </ td> </ tr> <tr> <td> TC-1 </ td> <td> Protective film polymer (100) </ td> <td> Diisoamyl ether (2700) 2-methyl-1-butanol (270) </ td> </ tr> </ TBODY> </ TABLE>

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

The dry etching processing conditions of the silicon resist-containing intermediate film are shown in Table 8 below. [TABLE 8]         <TABLE border = "1" borderColor = "# 000000" width = "85%"> <TBODY> <tr> <td> Chamber pressure </ td> <td> 10 Pa </ td> </ tr> < tr> <td> RF power </ td> <td> 200 W </ td> </ tr> <tr> <td> CF <sub> 4 </ sub> Air flow rate </ td> <td> 50 mL / min </ td> </ tr> <tr> <td> CHF <sub> 3 </ sub> Air flow rate </ td> <td> 50 mL / min </ td> </ tr> <tr> < td> N <sub> 2 </ sub> Air flow rate </ td> <td> 100 mL / min </ td> </ tr> <tr> <td> Time </ td> <td> 20 seconds </ td> td> </ tr> </ TBODY> </ TABLE>

The dry etching processing conditions of the organic resist underlayer film are shown in Table 9 below. [TABLE 9]         <TABLE border = "1" borderColor = "# 000000" width = "85%"> <TBODY> <tr> <td> Chamber pressure </ td> <td> 2.7 Pa </ td> </ tr> < tr> <td> RF power </ td> <td> 1000 W </ td> </ tr> <tr> <td> N <sub> 2 </ sub> Air flow rate </ td> <td> 500 mL / min </ td> </ tr> <tr> <td> H <sub> 2 </ sub> Air flow rate </ td> <td> 30 mL / min </ td> </ tr> <tr> < td> time </ td> <td> 60 seconds </ td> </ tr> </ TBODY> </ TABLE>

The ashing removal conditions of the organic resist underlayer film are shown in Table 10 below. [TABLE 10]         <TABLE border = "1" borderColor = "# 000000" width = "85%"> <TBODY> <tr> <td> Chamber pressure </ td> <td> 2.7 Pa </ td> </ tr> < tr> <td> RF power </ td> <td> 1000 W </ td> </ tr> <tr> <td> N <sub> 2 </ sub> Air flow rate </ td> <td> 500 mL / min </ td> </ tr> <tr> <td> H <sub> 2 </ sub> Air flow rate </ td> <td> 30 mL / min </ td> </ tr> <tr> < td> time </ td> <td> 180 seconds </ td> </ tr> </ TBODY> </ TABLE>

Observation results of the cross-sectional shape of the photoresist pattern and the collapse of the pattern obtained in the evaluation of the residue of the organic resist underlayer film after ashing, observation results of the cross-sectional shape of the pattern after dry etching, and Table 11 shows the residual amount of silicon on the surface of the organic resist underlayer film, and the presence or absence of residue after ashing the organic resist underlayer film pattern.

[TABLE 11]

As shown in Table 11, if an organic film formed by Sol. 1 to 10 that can be removed by ammonia hydrogen peroxide water is introduced, silicon does not remain on the organic resist underlayer film after the ammonia hydrogen peroxide water treatment. And no residue was generated after the ashing of the organic resist underlayer film pattern. In addition, as a result of confirming the influence of the film thickness of the organic films in Examples 4-11 to 13 and Comparative Example 4-1, as shown in Example 4-11, when the organic film is thin, ammonia hydrogen peroxide is used. After the water treatment, the silicon component residue was not observed on the surface of the organic resist underlayer film, and no residue was generated after the organic resist underlayer film pattern was ashed. In addition, as shown in Example 4-13, when the film is thick, there is side etching in the organic film portion during the dry etching process, but no residue is generated after the ashing of the organic resist underlayer film pattern. On the other hand, as shown in Comparative Example 4-1, the removal effect of the silicon component residue cannot be obtained when there is no organic film, and the residue is generated after ashing the pattern of the organic resist underlayer film.

From the above, it can be seen that if the composition for forming an organic film of the present invention can form an organic film, the organic film can be easily removed by wet with the silicon component residue that has been modified by dry etching. This peeling liquid does not cause damage to the semiconductor device substrate and the organic resist underlayer film required in the patterning step, and can be used as a material for ion implantation masks when forming a three-dimensional transistor. In particular, by introducing an organic film having a film thickness of 10 nm or more and less than 100 nm, it is possible to more reliably construct a processing process that does not cause residues. Thereby, it is possible to prevent a decrease in the yield in the manufacturing process of the three-dimensional transistor, and it is possible to manufacture a higher-performance semiconductor device at a reduced cost.

The present invention is not limited to the embodiments described above. The above-mentioned embodiment is merely an example, and as long as it has substantially the same configuration and produces the same effect as the technical idea described in the patent application scope of the present invention, it is included in the technical scope of the present invention no matter what.

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Claims (7)

A composition for forming an organic film, characterized in that the composition for forming an organic film includes a polymer compound and an organic solvent, and the polymer compound has a repeating unit represented by the following general formulae (1) to (4) Any one or more of the organic solvents, and in the organic solvent, the total amount of the one or more selected from propylene glycol esters, ketones, and lactones accounts for more than 30% by weight of the total organic solvents, and the composition for forming an organic film It is used to form an organic film. The organic film is introduced directly under the silicon-containing resist intermediate film and directly above the organic resist underlayer film. The silicon resist-containing intermediate film can be dissolved in ammonia hydrogen peroxide water. The organic resist underlayer film is difficult to dissolve in ammonia hydrogen peroxide water; In the formulae (1) to (4), R ₁ is a hydrocarbon group, a halogen atom, an alkoxy group, a carboxyl 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 functional group that generates acidity due to heating or acid; R ₃ is a hydrogen atom, a furyl group, or a hydrocarbon group having 1 to 16 carbon atoms that may have a chlorine atom or a nitro group; k ₁ , k ₂ and k ₃ is 1 ~ 2, l is 1 ~ 3, m is 0 ~ 3, n is 0 or 1. The composition for forming an organic film according to claim 1, wherein the silicon resist-containing intermediate film contains any one or both of boron and phosphorus. The composition for forming an organic film according to claim 1, wherein the composition for forming an organic film further comprises any one or both of a thermal acid generator and a crosslinking agent. The composition for forming an organic film according to claim 2, wherein the composition for forming an organic film further contains any one or both of a thermal acid generator and a crosslinking agent. The organic film forming composition according to any one of claims 1 to 4, wherein the organic film forming composition is spin-coated on a substrate and then heated to obtain an organic film. The organic film is The solution has a dissolution rate of 5 nm / min or more when processed by using a 65 ° C solution mixed with a ratio of 29% ammonia water / 35% hydrogen peroxide water / water = 1/1/8. The composition for forming an organic film according to any one of claims 1 to 4, wherein the composition for forming an organic film can obtain an organic film having a film thickness of 10 nm or more and less than 100 nm. The composition for forming an organic film according to claim 5, wherein the composition for forming an organic film can obtain an organic film, and the thickness of the organic film is 10 nm or more and less than 100 nm.