JPH11282176A - Composition for removing photoresist - Google Patents

Abstract

PROBLEM TO BE SOLVED: To remove a resist-modified material and a side wall protecting coat at a low temp. in a short time without corroding an electrically conductive film of Al or the like by using a compsn. for removing a photoresist consisting of an aprotic polar solvent, water, an amino-alcohol and an anticorrosive essentially contg. EDTA or its salt. SOLUTION: The compsn. for removing a photoresist consists of an aprotic polar solvent, water, an amino-alcohol and an anticorrosive essentially contg. EDTA or its salt, preferably ammonium salt. The aprotic polar solvent is not particularly limited but a water-soluble solvent is preferably used because it is excellent in affinity for the photoresist and facilitates the treatment of waste liquor from a washing step after the removal of a side wall protecting coat. In particular, a solvent that readily dissolves a positive type photoresist and is a good solvent for inorg. salts is preferably used. It is preferable that the amino-alcohol readily dissolves the positive type photoresist.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composition for removing a photoresist, and more particularly, to a liquid crystal panel element and an LSI.
The present invention relates to a photoresist stripping composition that is used in the manufacture of semiconductor devices such as a semiconductor device and does not corrode a conductive metal film.

[0002]

2. Description of the Related Art In the manufacture of semiconductor elements such as liquid crystal panel elements and LSIs, a conductive metal film is formed on a substrate, an insulating film such as an SiO ₂ film is formed, and then a mask is formed using a photoresist. After forming a fine circuit by etching an insulating film in a non-mask portion, an unnecessary photoresist layer is removed with a stripping solution.

[0003] Conventionally, such a photoresist is stripped.
Heretofore, various suitable organic or inorganic chemicals have been found and used. For example, in practical use,
Japanese Patent Application Laid-Open No. 81950 proposes a release agent composed of dimethyl sulfoxide (hereinafter, referred to as DMSO) and amino alcohols as an organic release agent. Also, in JP-A-4-350660, 1,3-dimethyl-2-
A release agent comprising imidazolysin and DMSO has been proposed, and a release agent comprising an organic ammonium carboxylate, a fluorine compound and DMSO has been proposed in JP-A-7-271056.

In recent years, with the increase in the density of integrated circuits, photoresists for forming high-precision fine patterns have been used. As for the etching method, a dry etching method using a halogen-based gas is used instead of a conventional chemical etching method using an organic solvent or the like. further,
In addition to the dry etching method, processes such as ashing and ion implantation are performed.

[0005] By such processes as dry etching, ashing, and ion implantation, the photoresist film is transformed from an organic film to a film having inorganic properties. In addition, a deposited film composed of a halogen gas and aluminum wiring or a sidewall protective film, which is a reaction product, adheres to the side surface of the fine pattern by dry etching. Detergents such as these photoresists and deposits such as side wall protective films cannot always be sufficiently stripped with a normal stripping solution composed of DMSO and amino alcohols.
Processing at a high temperature such as ℃ is required. In addition, when amino alcohols are used, there is a problem in that aluminum rinse is corroded by a trace amount of amino alcohols when rinsing with water after the peeling treatment. When a fluorine compound is used, there is a problem that the silicon oxide portion is corroded depending on the processing conditions.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and to reduce the denatured resist and the sidewall protective film formed at the time of etching without corroding a conductive film such as aluminum or copper at all. To provide a photoresist stripping composition that can be stripped in a short period of time.

[0007]

The photoresist stripping composition of the present invention, which achieves the above objects, comprises an aprotic polar solvent, water, amino alcohol, and ethylenediaminetetraacetic acid (EDTA) or a salt thereof. It is characterized by being composed of an essential anticorrosive agent, and preferably, these proportions are 5 to 90% by weight of the aprotic polar solvent, 1 to 70% by weight of water and 1 to 70% by weight of amino alcohol. ~ 90
% By weight, and 0.01 to 40% by weight of an anticorrosive containing ethylenediaminetetraacetic acid or a salt thereof as an essential component.

[0008] The present invention includes the following preferred embodiments. a. The aprotic polar solvent is dimethyl sulfoxide, N-methyl-2-pyrrolidone, γ-butyrolactone or propylene carbonate. b. The water is rectified water or ion-exchanged water. c. When the amino alcohol is ethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, 2-aminoethoxyethanol, 2-aminoethoxyethanol or 2-aminoethoxyethanol;
(2-aminoethylamino) ethanol, N-methylethanolamine, or 2-diethylaminoethanol. d. The anticorrosive may further comprise, in addition to ethylenediaminetetraacetic acid or a salt thereof, hydroxylamine, N, N
-Dimethylhydroxylamine, N, N-diethylhydroxylamine, tetramethylammonium hydroxide, tetramethylammonium hydroxide pentahydrate, citric acid, ammonium citrate, ammonium hydrogen citrate, pyrocatechol, pyrogallol, methylcatechol -Pt butyl catechol, hydroquinone momethyl ether, protocatechuic acid, or phloroglucinol.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The aprotic polar solvent used in the present invention is not particularly limited, but has an excellent affinity with a photoresist, and a waste water in a washing step after removing a side wall protective film. For ease of processing, it is preferably water-soluble, and particularly preferably a positive solvent which easily dissolves a positive photoresist and is a good solvent for inorganic salts.

As the aprotic polar solvent in the present invention, for example, dimethyl sulfoxide (DMSO),
N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone (NMP),
N, N-dimethylsulfonamide, γ-butyrolactone,
Glycols such as propylene carbonate, 1,3-dimethyl-2-imidazolidinone, N-aceto-ε-caprolactam, and triethylene glycol; 3-methoxy-
Examples include glycol ethers such as 3-methyl-1-butanol, glycol acetates such as 3-methoxy-3-methyl-butyl acetate, and propylene glycol-1-monomethyl acetate. For this reason, dimethyl sulfoxide, N-methyl-2-pyrrolidone, γ-butyrolactone, and propylene carbonate are particularly preferably used. In the practice of the present invention, one kind of these aprotic polar solvents may be used, but two or more kinds may be used in combination.

The water used in the present invention is preferably purified water such as rectified water or ion-exchanged water.

Also, the amino alcohol used in the present invention
It is preferable that the compound readily dissolves a positive photoresist, and specifically, ethanolamine (MEA), diethanolamine, triethanolamine, monoisopropanolamine, 2-aminoethoxyethanol, 2-aminoethoxyethanol,
-(2-aminoethylamino) ethanol, N-methylethanolamine, 2-diethylaminoethanol, t
-Butyldiethanolaminoisopropanolamine,
2-amino-propanol, 3-amino-1-propanol, isobutanolamine, and 2-amino (2-
Ethoxy) propanol and the like, and in the present invention, versatile ethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, 2-aminoethoxyethanol, 2- (2- Ethanolamine is particularly preferably used from the viewpoint of aminoethylamino) ethanol and N-methyl alcohol. In the practice of the present invention, one type of these amino alcohols may be used, but two or more types may be used in combination.

The photoresist stripping composition of the present invention contains an anticorrosive in addition to the above components. As the anticorrosive, an anticorrosive containing ethylenediaminetetraacetic acid (EDTA) or a salt thereof as an essential component is preferably used. EDTA has no ionic contamination or sublimability, and is particularly preferable. Examples of EDTA salts include ammonium salts and alkali metal salts such as sodium and potassium. Among them, ammonium salts are preferable because they have no ionic contamination and sublimability.

In addition to EDTA and its salts, other anticorrosives can be used in combination. Other anticorrosives include hydroxylamine, N, N-dimethylhydroxylamine, N, N-diethylhydroxylamine, tetramethylammonium hydroxide, teramethylammonium hydroxide pentahydrate, citric acid, ammonium citrate, citric acid Ammonium hydrogen oxy, pyrocatechol, pyrogallol, Pt butyl catechol, methyl catechol
, Hydroquinone monomethyl ether, protocatechuic acid, and phloroglucinol, but in the present invention, hydroxylamine, N, N-diethylhydroxylamine, teramethylammonium hydroxide, ammonium hydrogen citrate, pyrocatechol, Hydroquinone monomethyl ether, protocatechuic acid, and phloroglucinol are preferably used. By using these anticorrosives, it is possible to improve the anticorrosion of the conductive film and to improve the peelability of the side wall protective film.

In the practice of the present invention, a photoresist stripping composition comprising the above-mentioned aprotic polar solvent, water, amino alcohol, and an anticorrosive of a specific component essentially comprising EDTA or a salt thereof, Other components can be appropriately blended and used as long as the effect of (1) is not hindered. For example, anionic surfactants such as alkyl benzene sulfate, nonionic surfactants such as polyoxyethylene ether of alkyl phenol, for example, in order to lower the surface tension or prevent the resist from re-adhering to the device. Agents, surfactants such as amphoteric surfactants such as dodecyldiaminoethylglycine hydrochloride, and cationic surfactants such as alkyldimethylbenzene ammonium chloride can be added.

The composition ratio of the aprotic polar solvent among the components of the photoresist stripping composition is preferably 5 to 90% by weight, more preferably 40 to 90% by weight.
% By weight. When the amount of the aprotic polar solvent is small, the photoresist strippability is low. On the contrary, when the amount is too large, the sidewall protective film tends to be not sufficiently removed.

The composition ratio of water in the photoresist stripping composition is preferably 1 to 70% by weight.
And more preferably 2 to 50% by weight. If the amount of water is small, the side wall protective film cannot be sufficiently removed. Conversely, if the amount of water is too large, the photoresist removability tends to be low, and the aluminum wiring and the copper wiring tend to be corroded.

Further, among the components of the photoresist stripping composition, the composition ratio of amino alcohol is preferably 1 to 90% by weight, more preferably 3 to 80% by weight. If the amount of amino alcohol is small, the side wall protective film cannot be sufficiently removed, and depending on the type of the anticorrosive, the solution stability tends to be poor. Conversely, if the amount is too large, the side wall protective film is extremely removed. The resulting work width is narrow and shows a tendency to corrode aluminum wiring.

Further, among the components of the above-mentioned photoresist stripping composition, the composition ratio of the anticorrosive which essentially comprises ethylenediaminetetraacetic acid or a salt thereof is preferably 0.01%.
-40% by weight, more preferably 0.05-30% by weight. When the amount of the anticorrosive is small, the aluminum wiring tends to corrode easily. On the other hand, when the amount of the anticorrosive is too large, the resist residue and the side wall protective film tend not to be sufficiently removed.

Photoresists to which the stripping composition of the present invention is preferably used include a positive resist, a negative resist, and a positive / negative resist, and particularly a positive resist comprising a novolak phenol resin and a naphthoquinonediazide. Effectively used for mold photoresist.

The dry etching gas used in the present invention may be any of halogen gas such as chlorine, hydrogen bromide, and boron trichloride, and may further include carbon tetrafluoride, boron trifluoride, hydrogen chloride, It can also be used in systems containing gases such as carbon chloride and silicon tetrachloride.

Using the photoresist stripping composition (stripping solution) of the present invention, the conditions for removing the resist residue remaining after ashing and the side wall protective film do not require high temperature stripping at 80 ° C. or higher. Processing at low temperatures is possible. That is, by using the stripping solution of the present invention, 80
Although stripping treatment is possible even at a temperature of not less than ° C, the composition of the stripping solution tends to fluctuate. In the present invention, for example, about 40 to 7
8 ° C, more preferably about 50-70 ° C.
The resist can be removed at a relatively low temperature of less than 0 ° C.

The photoresist stripping composition of the present invention comprises:
It can be effectively used for stripping a resist used for forming a fine circuit of a semiconductor element such as a liquid crystal panel element or an LSI and removing a side wall protective film.

[0024]

EXAMPLES (Examples 1 to 12, Comparative Examples 1 and 2) Approx.
Al—Si—Cu film and about 1 μm S
A positive photoresist THMR-iP3600 (manufactured by Tokyo Ohka Kogyo Co., Ltd.) is applied to a thickness of 2 μm on a Si substrate on which iO ₂ is sequentially deposited, and then exposed by a mask and developed to form a positive photoresist. It was formed on a mask.

Next, the SiO ₂ mask material in the non-mask region was removed by dry etching, and most of the photoresist was removed by ashing, and then the photoresist was removed at 70 ° C. 2
After the treatment for 0 minute, the substrate was rinsed with pure water, and the corrosion state of the resist residue, the side wall protective film, and the Al—Si—Cu film on the substrate was observed and evaluated by SEM (scanning electron microscope) photograph. The SEM photograph observation was determined as follows. Table 1 shows the results.

・ ・ ・: No resist residue and no sidewall protective film residue are observed.

No corrosion of Al-Si-Cu film No corrosion of SiO2 △: Resist residue and sidewall protective film residue are scarcely recognized.

The corrosion of the Al-Si-Cu film is slightly observed. X: The resist residue and the sidewall protective film residue cannot be removed at all.

Al-Si-Cu film corrosion SiO2 corrosion

[0030]

[Table 1]

[0031]

According to the photoresist stripping composition of the present invention, the resist residue and the sidewall protective film after dry etching and ashing, which have conventionally been difficult to strip, can be stripped well, and Al, which is easily corroded, Al-S
There is an effect that the substrate of i, Al-Si-Cu and Cu is hardly corroded.

According to the present invention, since EDTA or an ammonium salt is used in combination, the sidewall protective film can be more effectively peeled off without corroding a conductive film such as aluminum or copper.

Further, the temperature of the peeling treatment of the present invention can be made lower than the conventional temperature, and it is possible to improve the productivity and to maintain the high quality performance because it does not damage other necessary members such as corrosion. It has many industrial advantages.

Claims (6)

[Claims] 1. A photoresist stripping composition comprising an aprotic polar solvent, water, amino alcohol, and an anticorrosive which essentially comprises ethylenediaminetetraacetic acid or a salt thereof. 2. The aprotic polar solvent is 5 to 90% by weight, water is 1 to 70% by weight, and amino alcohol is 1 to 9% by weight.
A photoresist stripping composition comprising 0% by weight and 0.01 to 40% by weight of an anticorrosive containing ethylenediaminetetraacetic acid or a salt thereof. 3. The photoresist stripping composition according to claim 1, wherein the aprotic polar solvent is dimethyl sulfoxide, N-methyl-2-pyrrolidone, γ-butyrolactone or propylene carbonate. . 4. The photoresist stripping composition according to claim 1, wherein the water is rectified water or ion-exchanged water. 5. The method according to claim 1, wherein the amino alcohol is ethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, 2-aminoethoxyethanol, or 2- (2-aminoethylamino) ethanol. , N
The photoresist stripping composition according to any one of claims 1 to 4, wherein the composition is -methylethanolamine or 2-diethylaminoethanol. 6. The anticorrosive further comprises hydroxylamine, N, N-dimethylhydroxylamine, N, N-diethylhydroxylamine, tetramethylammonium hydroxide, tetramethylammonium hydroxide pentahydrate, citric acid, Ammonium citrate, ammonium hydrogen citrate, pyrocatechol, pyrogallol,
6. A composition comprising methyl catechol, Pt butyl catechol, hydroquinone monomethyl ether, protocatechuic acid, or phloroglucinol.
The composition for stripping a photoresist according to any one of the above.