JP2001324821A - Method for removing silicon-containing two-layer resist - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for removing a silicon-containing two-layer resist comprising a first resist layer containing an organic high molecular compound and a photosensitive silicon-containing second resist layer for reworking after the patterning of the second resist layer while suppressing the occurrence of defects on a wafer in removal in a process for producing a device using the two-layer resist on a substrate. SOLUTION: When the top of a substrate is coated with a first resist layer containing an organic high molecular compound and a photosensitive second resist layer containing silicon atoms in this order, the second resist layer is exposed and developed to form a pattern and then the first and second resist layers are removed, the second resist layer is removed by a wet method with a solution based on N-methylpyrrolidone and then the first resist layer is subjected to ashing treatment with oxygen or an oxygen-containing gaseous mixture.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a first resist layer containing an organic polymer compound and a sensitivity to radiation such as ultraviolet rays, far ultraviolet rays, X-rays, electron beams, molecular beams, gamma rays and synchrotron radiation. More specifically, the present invention relates to a method of removing a so-called silicon-containing two-layer resist comprising a second resist layer containing silicon atoms, and more particularly, to a method of manufacturing a circuit board or the like in a semiconductor manufacturing process of an IC or the like. The present invention relates to a silicon-containing two-layer resist stripping method suitably used in a process such as rework of a processing silicon-containing two-layer resist. The method for stripping a silicon-containing two-layer resist of the present invention is particularly applicable to a method for removing a silicon-containing two-layer resist comprising the first resist layer and the second resist layer coated on a substrate such as a semiconductor wafer, glass, ceramic, or metal. Used for peeling. Typical application fields include a semiconductor manufacturing process such as an IC, a circuit board manufacturing such as a liquid crystal and a thermal head, and other photofabrication processes.

[0002]

2. Description of the Related Art With the increase in integration of LSIs, the resolution limit of conventional single-layer resists is becoming clearer. A method for forming a shape ratio pattern has been proposed. That is, a thick film of an organic polymer is formed on the first layer, a thin resist material layer is formed on the second layer thereon, and then the second resist material is irradiated with high energy rays and developed. The organic polymer of the first layer is subjected to oxygen plasma etching (O
_An attempt is made to obtain a pattern having a high rectangular shape by anisotropic etching using _2- RIE (Rin, Solid State Technology, Vol. 24, p. 73 (19).
81). This method is generally called a two-layer resist method,
Since the resist layer is a thin film, it is expected to exhibit lithography performance exceeding that of a normal single-layer resist.

In this case, the second resist layer is made of O ₂ -RIE
Because of their high resistance, silicon-containing polymers are usually used, and many silicon-containing photosensitive compositions using these polymers have been proposed.

A typical example of a silicon-containing photosensitive composition is a silicon-containing photosensitive composition obtained by mixing an alkali-soluble ladder-type polysiloxane containing a silicon atom in the main chain thereof with a resist composition comprising a novolak resin and naphthoquinonediazide. Photosensitive compositions (eg, Patent 264624)
No. 1 etc.) Also, a chemically amplified silicon-containing photosensitive composition using an acid-decomposable group-containing vinyl polymer having a silicon atom in the side chain and a photoacid generator (for example, Japanese Patent Publication No. 7-99)
435, EP 494383, U.S. Pat.
5856071) and a chemically amplified silicon-containing photosensitive composition using an acid-decomposable group-containing siloxane polymer having a silicon atom in the main chain (see, for example, JP-A-6-184311,
Nos. 8-160620, 10-324748, and Patent 2897786).

In the manufacture of devices such as semiconductors, a resist is applied to a substrate to be used, and then a pattern is formed by exposure and development. In a normal case, however, the target pattern size is actually changed after the pattern is formed. There is a step of inspecting whether or not it is formed. In the case where the dimension is out of the permissible range, the resist layer is generally stripped / removed and the pattern is formed again from the resist coating (rework).

In this case, it is important to completely remove and remove the resist layer on the substrate in order to prevent the occurrence of defects in the exposure and development steps. In a normal single-layer resist stripping method, most of organic compounds on a substrate are removed by dry processing (ashing) using oxygen gas,
Further, by performing a rinsing process, the resist layer can be almost completely removed, and is widely used. Examples of the wet treatment include a method of stripping using a mixed solution of sulfuric acid / hydrogen peroxide solution and a method of stripping using a dilute hydrofluoric acid aqueous solution.

However, in a two-layer resist using a silicon-containing resist, it is extremely difficult to completely remove the second resist layer containing silicon atoms in the form of silicon oxide when the ashing process is performed. Becomes In addition, even in the above-mentioned conventionally known wet processing, it is extremely difficult to completely dissolve and remove the layer containing silicon, and there is a problem that the type of substrate used is greatly restricted. That is, satisfactory results cannot be obtained even when a conventional method for removing a single-layer resist is applied to a silicon-containing two-layer resist.
This has been a major problem in putting a silicon-containing two-layer resist into practical use.

[0008]

An object of the present invention is to provide a first resist layer containing an organic polymer compound coated on a substrate and a second resist layer containing photosensitive silicon coated thereon. In a device manufacturing process using a silicon-containing two-layer resist, a method for removing the two-layer resist for rework or the like after patterning the second resist layer is provided. More specifically, it is an object of the present invention to provide a method for removing the above-mentioned two-layer resist while significantly reducing the occurrence of defects on the wafer at the time of removing the resist.

[0009]

Means for Solving the Problems The inventors of the present invention have made intensive studies while paying attention to the above viewpoints, and as a result, have completed the present invention. That is, the object of the present invention can be achieved by the following method. (1) A first resist layer containing an organic polymer compound is applied on a substrate, a photosensitive second resist layer containing silicon atoms is applied thereon, and the second resist layer is exposed and developed. In the method of removing the first resist layer and the second resist layer after pattern formation, N-
A wet-peeling process for the second resist layer using a solution comprising methylpyrrolidone, and an ashing process for the first resist layer using oxygen or a mixed gas containing oxygen. How to remove resist.

(2) In the method of removing the second resist layer, the method comprises the steps of: using N-methylpyrrolidone as a main component, a lactate ester, a propylene glycol derivative, a propionate ester derivative, a cyclic carbonate, a lactone derivative, and
The method for stripping a silicon-containing two-layer resist according to the above (1), wherein a mixed solution further containing at least one selected from ketone derivatives is used.

(3) The silicon-containing two layers according to (1) or (2), wherein the solution used in the wet stripping treatment of the second resist layer contains 50 to 98% by volume of N-methylpyrrolidone. How to remove resist. (4) The method for stripping a silicon-containing two-layer resist according to any one of (1) to (3), wherein the wet stripping treatment of the second resist layer is performed at 45 to 120 ° C.

(5) The solution according to any of (1) to (4), wherein the solution used in the wet stripping treatment of the second resist layer further contains 0.1 to 30% by weight of a nitrogen-containing organic compound. Method of stripping silicon-containing two-layer resist.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below, but the present invention is not limited to these embodiments. The peeling method of the present invention is applied to a silicon-containing two-layer resist comprising a first resist layer containing an organic polymer compound coated on a substrate and a silicon-containing photosensitive second resist layer coated thereon. Is done.

First, the first resist layer used in the present invention will be described. As the organic polymer compound of the first resist layer, a known organic polymer compound is used. However, a sufficient anti-reflection property with respect to an exposure wavelength, an edge rinse suitability, a high dry etching resistance in a substrate processing step, a second resist layer It is possible to select from various polymer compounds in consideration of sufficient adhesion to the second resist layer, appropriate optical characteristics to the second resist layer, non-intermixing property with the second resist layer, and the like. In general, novolak resins, phenolic resins, condensation polymer compounds such as cresol resins,
Vinyl polymers having an aromatic ring such as a phenyl group on the side chain or a condensed aromatic ring such as a naphthyl group or an anthryl group (for example, polyvinylphenol, polyvinylnaphthalene,
(A (meth) acrylate having a phenyl group, a naphthyl group, an anthryl group, etc. in the side chain). Further, various known photoresists can also be suitably used. For example, FH series and FHi series manufactured by Fuji Film Ohlin Co., Ltd. or P
Each series of the FI series can be mentioned.

The formation of the first resist layer made of such an organic polymer is performed by dissolving these in an appropriate solvent and applying the resulting solution by a spin coating method, a spray method or the like. It is preferable that the obtained first resist layer is further subjected to a heat treatment and / or an exposure treatment to progress a crosslinking reaction, in order to prevent intermixing with the second resist layer. When performing heat treatment,
The heating temperature varies depending on the type of organic polymer used, additives, and the like, but is generally set at about 100 ° C to 270 ° C.
When performing the exposure processing, various light sources such as ultraviolet rays and far ultraviolet rays are used as the exposure light source.

The thickness of the first resist layer can be set to a desired value. However, considering the oxygen plasma resistance of the second resist layer, the aspect ratio of the pattern after dry etching, etc. It is generally used with a thickness of about 1.5 μm.

Next, the second resist layer used in the present invention will be described. As the silicon-containing photosensitive composition used in the second resist layer, known ones can be used. As a typical example of a suitable silicon-containing photosensitive composition, a resist composition comprising a novolak resin and naphthoquinonediazide can be used. A silicon-containing photosensitive composition for ultraviolet exposure, which is obtained by polymer blending an alkali-soluble ladder-type polysiloxane containing a silicon atom in the main chain and having a silanol structure in the molecule (for example, Japanese Patent No. 2646241); Examples of the silicon-containing photosensitive composition for exposure include an acetal structure, a tertiary ester structure, and t-type.
Alkali-soluble ladder-type polysiloxane containing a silicon atom in the main chain and having a silanol structure in the molecule in a chemically amplified resist composition comprising a polymer containing an acid-decomposable group such as a butyloxycarbonyl structure and a photoacid generator. UV-exposed silicon-containing photosensitive composition obtained by polymer blending of (for example, Japanese Patent Application Nos. 11-20224 and 11-315).
No. 91, Japanese Patent Application No. 11-65102, Japanese Patent Application No. 11-202179), having a silicon atom in the side chain and an acetal structure in the side chain,
Tertiary ester structure, t-butyloxycarbonyl structure,
Alternatively, a chemically amplified silicon-containing photosensitive composition for deep ultraviolet exposure comprising a vinyl polymer having an acid-decomposable group such as a β-silylethyl ester structure and a photoacid generator (for example, Japanese Patent Publication No. 7-99435) , European Patent No. 494383, U.S. Patent Nos.
No. 1) and a chemically amplified silicon-containing photosensitivity using a siloxane polymer containing a silicon atom in the main chain and containing an acid-decomposable group such as an acetal structure, a tertiary ester structure, and a t-butyloxycarbonyl structure. Composition (for example,
JP-A-6-184431, JP-A-8-160620, JP-A-10-324748, Japanese Patent No. 2897786, Japanese Patent Application No. 11-202179) and the like.
The second resist layer is formed by coating the first resist layer formed on the substrate to be processed.
The coating method may be the same as the method described in the description of the coating of the first resist layer. Although the thickness of the second resist layer can be used at a desired thickness, lithography performance, oxygen plasma resistance of the second resist layer,
It is generally used in a thickness of about 0.03 to 0.5 μm in consideration of coating properties and the like.

Next, a method of removing the silicon-containing two-layer resist of the present invention will be described. After forming the first resist layer and the second resist layer on the substrate, the second resist layer is exposed to light using a predetermined exposure light source, and then patterned by development. The patterned substrate is generally inspected in a subsequent pattern dimension inspection step, and if it deviates from a desired dimension, it is turned to a rework step, and the first resist layer and the second resist layer are peeled off. In this case, it is necessary that the second resist layer of the substrate to be reworked is first completely removed. This is because if a small amount of the silicon-containing polymer in the second resist layer remains, it becomes silicon oxide due to the subsequent ashing treatment using oxygen gas and adheres to the substrate, causing defects. . The second resist layer can be easily removed by the wet processing of the present invention.

The solution used for stripping the second resist layer in the present invention is a solution containing N-methylpyrrolidone as a main component, preferably 50 to 100% by volume.
Is a solution containing N-methylpyrrolidone. In addition, the use of the above-mentioned mixed solution improves the solubility of the polymer of the silicon-containing resist layer to be dissolved, and lowers the solution viscosity, resulting in a further improvement in the peelability of the silicon-containing resist layer. . Lactate ester, propylene glycol derivative, propionate derivative,
It is further preferable to use a mixed solution using at least one selected from propylene carbonate, γ-butyrolactone, and heptanone.

Examples of the lactic acid ester include methyl lactate, ethyl lactate, propyl lactate, and isopropyl lactate, with ethyl lactate being particularly preferred. Examples of the propylene glycol derivative include propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol dimethyl ether, propylene glycol monoethyl ether, propylene glycol monoethyl ether acetate, and the like.
Propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate are particularly preferred.

Examples of propionate derivatives include methyl propionate, ethyl propionate, propyl propionate, methoxymethyl propionate, ethoxymethyl propionate, ethoxyethyl propionate, 1-hydroxymethyl propionate and the like. And methoxymethyl propionate and ethoxyethyl propionate are particularly preferred. Examples of the cyclic carbonate include propylene carbonate, ethylene carbonate, butylene carbonate and the like, and propylene carbonate and ethylene carbonate are particularly preferred. As an example of the lactone derivative, γ-butyrolactone is particularly preferred. Examples of ketone derivatives include 2-heptanone, 3-heptanone, cyclohexanone, 2-nonanone, and the like, with 2-heptanone being particularly preferred.

In the present invention, when a mixed solution is used for stripping the second resist layer, the content of N-methylpyrrolidone, which is an essential component, is preferably 50 to 98% by volume, more preferably 60 to 95% by volume. %, Particularly preferably 70 to 95% by volume. In addition, other solvents other than those described above may be appropriately mixed and used. In this case, the amount of the other solvent is preferably 20% by volume or less, more preferably 10% by volume or less.

In the present invention, it is preferable to further add a nitrogen-containing organic compound to the stripping solution for the second resist layer. The nitrogen-containing organic compound is considered to effectively remove the acid remaining in the silicon-containing resist layer after pattern formation, and is effective in preventing generation of defects. As the nitrogen-containing organic compound, compounds represented by the following general formulas (A1) and (A2), and compounds having the structures of (B) to (E) are preferable.

[0024]

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In the formula (A1), R ₁ , R ₂ and R
₃ is the same or different and is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an aminoalkyl group having 1 to 6 carbon atoms,
Or a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, wherein R ₂ and R ₃
May combine with each other to form a ring. In the formula (A2), R _{4 to} R ₇ are the same or different and are the same as those defined for R _{1 to} R ₃ . R ₈ is an alkylene group having 1 to 6 carbon atoms. n represents an integer of 1 to 6.

[0026]

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(Wherein R ₉ , R ₁₀ , R ₁₁ and R ₁₂ are
Same or different, and represents an alkyl group having 1 to 6 carbon atoms)

In the general formula (A1), preferably, R
₁ , at least one of R ₂ and R ₃ has 1 to 6 carbon atoms
And more preferably a hydroxyalkyl group having 2 to 4 carbon atoms such as hydroxyethyl group and hydroxypropyl. In the general formula (A2), n is preferably 1 to 4, R ₈ is an alkylene group having 1 to 6 carbon atoms, more preferably n is 1 to 3, and R ₈ is an ethylene group, a propylene group, or the like. Is an alkylene group having 2 to 4 carbon atoms. More specifically, monoethanolamine, diethanolamine, triethanolamine, diglycolamine, diethylenetriamine, and triethylenetetramine are preferred. Further, a nitrogen-containing cyclic compound or a nitrogen-containing organic compound having two or more nitrogen atoms having different chemical environments in one molecule can also be mentioned as preferable nitrogen-containing organic compounds. As the nitrogen-containing cyclic compound,
More preferably, it has a polycyclic structure. As the nitrogen-containing polycyclic compound, an aliphatic cyclic amine is preferable, and specific examples include a compound represented by the following general formula (VI).

[0029]

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In the formula (VI), Y and W each independently represent a linear, branched or cyclic alkylene group which may contain a hetero atom and may be substituted. Here, examples of the hetero atom include a nitrogen atom, a sulfur atom, and an oxygen atom. The alkylene group preferably has 2 to 10 carbon atoms, and more preferably has 2 to 5 carbon atoms. Examples of the substituent of the alkylene group include an alkyl group having 1 to 6 carbon atoms, an aryl group, an alkenyl group, a halogen atom, and a halogen-substituted alkyl group. Further, specific examples of the compound represented by the general formula (VI) include the following compounds.

[0031]

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Of the above, 1,8-diazabicyclo [5.4.0] undec-7-ene and 1,5-diazabicyclo [4.3.0] non-5-ene are preferred.

The nitrogen-containing organic compound having two or more nitrogen atoms having different chemical environments in one molecule is particularly preferably a compound containing both a substituted or unsubstituted amino group and a ring structure containing a nitrogen atom. Or a compound having an alkylamino group.

Specific examples include substituted or unsubstituted guanidine, substituted or unsubstituted aminopyridine, substituted or unsubstituted aminoalkylpyridine, substituted or unsubstituted aminopyrrolidine, substituted or unsubstituted indazole, substituted or unsubstituted Substituted pyrazole, substituted or unsubstituted pyrazine, substituted or unsubstituted pyrimidine, substituted or unsubstituted purine, substituted or unsubstituted imidazoline, substituted or unsubstituted pyrazoline,
Examples thereof include substituted or unsubstituted piperazine, substituted or unsubstituted aminomorpholine, and substituted or unsubstituted aminoalkylmorpholine. Preferred substituents are an amino group, an aminoalkyl group, an alkylamino group,
An aminoaryl group, an arylamino group, an alkyl group, an alkoxy group, an acyl group, an acyloxy group, an aryl group, an aryloxy group, a nitro group, a hydroxyl group, and a cyano group.

Preferred compounds are guanidine, 1,
1-dimethylguanidine, 1,1,3,3-tetramethylguanidine, 2-aminopyridine, 3-aminopyridine, 4-aminopyridine, 2-dimethylaminopyridine, 4-dimethylaminopyridine, 2-diethylaminopyridine, 2- (aminomethyl) pyridine, 2-amino-3-methylpyridine, 2-amino-4-methylpyridine, 2-amino-5-methylpyridine, 2-amino-6
-Methylpyridine, 3-aminoethylpyridine, 4-aminoethylpyridine, 3-aminopyrrolidine, piperazine, N- (2-aminoethyl) piperazine, N- (2-
Aminoethyl) piperidine, 4-amino-2,2,6,
6-tetramethylpiperidine, 4-piperidinopiperidine, 2-iminopiperidine, 1- (2-aminoethyl)
Pyrrolidine, pyrazole, 3-amino-5-methylpyrazole, 5-amino-3-methyl-1-p-tolylpyrazole, pyrazine, 2- (aminomethyl) -5-methylpyrazine, pyrimidine, 2,4-diaminopyrimidine ,
4,6-dihydroxypyrimidine, 2-pyrazoline, 3
-Pyrazoline, N-aminomorpholine, N- (2-aminoethyl) morpholine, trimethylimidazole,
Triphenylimidazole, methyldiphenylimidazole and the like.

The nitrogen-containing organic compound used in the present invention is
They can be used alone or in combination of two or more. The amount of the nitrogen-containing basic compound used is generally 0.1 to 30% by weight, based on the total amount of the solution and the nitrogen-containing organic compound.
Preferably, it is 0.5 to 15% by weight.

In the peeling treatment of the present invention, a method of dipping a wafer in a solution or a method of spraying a solution is preferable, but a method of dipping in a solution is particularly preferable. The immersion time is preferably from 10 seconds to 60 minutes, more preferably from 20 seconds to 30 minutes. If the time is shorter than 10 seconds, the peeling of the second resist layer may be insufficient, and if the time is longer than 60 minutes, it is not preferable from the viewpoint of manufacturing suitability. Further, the wet treatment of the present invention is more preferably performed under a heated condition in order to efficiently remove the second resist layer. The heating temperature is preferably from 45 to 120 ° C, particularly preferably from 50 to 110 ° C.

In the peeling method of the present invention, the second
Subsequent to the stripping of the resist layer, the first resist layer is stripped by dry stripping. As the dry peeling treatment, an ashing treatment using an existing asher is preferable. As an ashing gas used for the treatment, it is preferable to use oxygen gas, and to mix fluorine-substituted hydrocarbon gas (tetrafluoromethane, trifluoromethane, hexafluoroethane, tetrafluoroethane, etc.), nitrogen gas, argon gas, etc. May be used. When a mixed gas is used, the proportion of oxygen gas in the mixed gas is preferably 50 to 99% by volume, and more preferably 70 to 97% by volume. If the proportion of oxygen gas is less than 50% by volume, ashing efficiency is undesirably reduced. The ashing processing time is preferably from 5 seconds to 20 minutes, more preferably from 10 seconds to 10 minutes. If the time is shorter than 5 seconds, the first resist layer may be insufficiently peeled off. The processing temperature is not particularly limited, but for the purpose of improving the ashing efficiency, the temperature of the substrate is preferably −30 to 200 ° C., and 0 to 150 ° C.
C is more preferred.

By performing a rinsing process after the above-mentioned dry stripping process, the silicon-containing two-layer resist is completely stripped. As the rinsing liquid, water and an organic solvent (alcohols such as ethanol, propanol and glycol, ketones such as acetone and methyl ethyl ketone) can be used. The rinsing time is preferably 5 seconds to 10 minutes, more preferably 10 seconds to 5 minutes. If it is shorter than 5 seconds, the rinsing effect may be insufficient, and if it is longer than 10 minutes, it is not preferable from the viewpoint of production suitability. Rinse temperature is 10 ~
70 ° C is preferred, and 20 to 50 ° C is more preferred.

[0040]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to examples, but, of course, the present invention is not limited to these examples.

Example 1 A silicon wafer was coated with FHi-028D resist (i-line resist manufactured by FUJIFILM Aurin Co., Ltd.) using a coater CDS-650 manufactured by Canon Inc.
After baking for 2 seconds, a uniform film having a thickness of 0.65 μm was obtained. This was further heated at 200 ° C. for 3 minutes to form a first 0.50 μm thick film.
A resist layer was obtained. On this, Japanese Patent Application No. 11-338300
The second resist layer described in Example 1 of Example 1 was applied. That is, 0.9 g of the following resin (1) and 0.1 g of triphenylsulfonium-2,4,6-triisopropylsulfonate.
05g, 1,8-diazabicyclo [5.4.0] -7-
Undecene (0.006 g) was dissolved in methoxypropyl acetate (9 g), and the resulting solution was finely filtered through a 0.1 μm-diameter membrane filter to obtain a resist composition. This resist composition is applied in the same manner on the first resist layer and heated at 110 ° C. for 90 seconds to form a film having a thickness of 0.2
A 0 μm second resist layer was obtained. Resin (1):

[0042]

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The wafer obtained in this manner was made of Ar
An F excimer laser stepper 9300 was loaded with a line / space pattern mask and exposed. Thereafter, the film was heated in a clean room at 90 ° C. for 90 seconds, developed with a tetrahydroammonium hydroxide developer (2.38% by weight) for 60 seconds, rinsed with distilled water and dried to obtain a pattern.

The obtained wafer was immersed in an N-methylpyrrolidone (hereinafter abbreviated as NMP) solution heated to 60 ° C. for 1 minute, rinsed with pure water, and dried. In addition, plasma system reactive ion etching equipment DE
Ashing was performed for 60 seconds using S-245R. The gas used was oxygen, the pressure was 70 mTorr, and the applied power was 10
It was 0 mW / cm ² . Thereafter, the wafer was further rinsed with pure water and dried. The obtained wafer was observed with an optical microscope (using KLA-2112), and the number of defects on the wafer was determined as K
It was measured by LA2112 (manufactured by KLA Tencor Co., Ltd.) (Threshold: 12, Pixel Size = 0.39). The number of observed defects was as very small as 11 and was good.

Examples 2 to 15 Wafer treatment was performed in the same manner as in Example 1 except that the stripping solution shown in Table 1 was used instead of NMP in Example 1, and evaluation was performed in the same manner as in Example 1. did. The results are shown in Table 1.

Comparative Example 1 A wafer treatment was carried out in the same manner as in Example 1 except that a 0.5% by weight hydrofluoric acid aqueous solution was used in place of NMP in Example 1 and the immersion temperature was 30 ° C. The same was done. The results are shown in Table 1.

Comparative Examples 2-3 The wafer processing was performed in the same manner as in Example 1 except that the solutions shown in Table 1 were used instead of the NMP in Example 1, and the evaluation was performed in the same manner as in Example 1. . The results are shown in Table 1.

Comparative Example 4 A wafer treatment was performed in the same manner as in Example 1 except that the solution treatment was not performed, and the evaluation was performed in the same manner as in Example 1. The results are shown in Table 1.

[0049]

[Table 1]

The following are clear from the evaluation results of Examples 1 to 15 and Comparative Examples 1 to 4. That is, the method of stripping the silicon-containing two-layer resist in the embodiment in which the second resist layer is wet-stripped using N-methylpyrrolidone as a main solvent and the first resist layer is dry-stripped using a gas containing oxygen as a main component. Is good with very few defects after peeling. On the other hand, in the case of the comparative example using a solvent other than N-methylpyrrolidone, or when only the dry stripping treatment was performed using a gas containing oxygen as a main component without performing the wet treatment, there were many defects.

[0051]

According to the stripping method of the present invention, the occurrence of defects on the wafer during the stripping of the resist is remarkably reduced, and the silicon-containing photosensitive composition layer after patterning is removed.
A method for removing the layer resist can be provided.
Furthermore, the method is also excellent in manufacturing suitability. Therefore, the stripping method of the present invention is very suitably used for mass-production of semiconductor substrates using a silicon-containing two-layer resist.

Claims (5)

[Claims] 1. A first resist layer containing an organic polymer compound is applied on a substrate, a photosensitive second resist layer containing silicon atoms is applied thereon, and the second resist layer is exposed. In a method of stripping the first resist layer and the second resist layer after pattern formation by development, a wet stripping treatment of the second resist layer is performed using a solution containing N-methylpyrrolidone as a main component, Alternatively, an ashing process for the first resist layer is performed using a mixed gas containing oxygen, and the method for removing a silicon-containing two-layer resist is performed. 2. A method for stripping a second resist layer, the method comprising: mainly comprising N-methylpyrrolidone;
The silicon-containing two-layer resist according to claim 1, wherein a mixed solution further containing at least one selected from a propylene glycol derivative, a propionate derivative, a cyclic carbonate, a lactone derivative, and a ketone derivative is used. Peeling method. 3. The method for stripping a silicon-containing two-layer resist according to claim 1, wherein the solution used in the wet stripping treatment of the second resist layer contains 50 to 98% by volume of N-methylpyrrolidone. . 4. A wet stripping treatment of the second resist layer is performed for 45 to 12 times.
The method for stripping a silicon-containing two-layer resist according to claim 1, wherein the method is performed at 0 ° C. 5. 5. The silicon-containing composition according to claim 1, wherein the solution used in the wet stripping treatment of the second resist layer further contains 0.1 to 30% by weight of a nitrogen-containing organic compound. Method of stripping layer resist.