JPH08190205A - Photoresist removing agent composition and removing method - Google Patents

Abstract

PURPOSE: To easily remove residue of a photoresist at a low temp. in a short time without corroding a circuit material at all and to enable superfine working by incorporating specified alkanolamines and specified glycol monoalkyl ether. CONSTITUTION: This photoresist removing agent compsn. consists of 5-50wt.% alkanolamines, alkoxyalkylamines or alkoxyalkanolamines represented by the formula R<1> R<2> -NCm H2m OR<3> [where each of R<1> and R<2> is H, 1-4C alkyl or hydroxyethyl, R<3> is H, 1-4C alkyl, hydroxyethyl, methoxyethyl or ethoxyethyl and (m) is an integer of 2-4], 1-30wt.% glycol monoalkyl ether represented by the formula R<4> -(Cp H2p O)q -R<4> [where R<4> is H or 1-4C alkyl, (p) is an integer of 2-3 and (q) is an integer of 1-3], 0.5-15wt.% saccharides or sugaralcohols and the balance water.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stripping composition for stripping a photoresist layer in a semiconductor integrated circuit manufacturing process and a photoresist stripping method.

[0002]

2. Description of the Related Art In a semiconductor integrated circuit, a photoresist is coated on an inorganic substrate, a pattern is formed by exposure and development, and then the photoresist pattern is used as a mask to etch the inorganic substrate in a non-masked area to form a fine pattern. It is manufactured by a method of peeling the photoresist film from the inorganic substrate after forming a circuit, or a method of forming a fine circuit in the same manner and then ashing to peel the remaining resist residue from the inorganic substrate.

Conventionally, an acidic stripping agent and an alkaline stripping agent have been generally used as photoresist stripping solutions for these methods. As the acidic stripping agent, for example, a stripping agent composed of aryl sulfonic acids such as benzene sulfonic acid, toluene sulfonic acid, xylene sulfonic acid, phenols and a chlorine-based organic solvent (US Pat. No. 3,582,401)
No.), naphthalene and other aromatic hydrocarbons, phenols, and aryl sulfonic acids (Japanese Patent Laid-Open No. 62-35357). These acidic stripping agents have a weak stripping force and have a strong corrosive action on aluminum, copper, etc., which are often used as wiring materials for fine wiring processing, and are therefore not preferable for fine processing with severe dimensional accuracy in recent years. Further, since these acidic stripping solutions have low solubility in water, it is necessary to rinse with an organic solvent such as alcohol after stripping the photoresist, and then wash with water, which has a problem that the process becomes complicated. There is.

On the other hand, the alkaline stripping solution is a stripping agent consisting of an ethylene oxide adduct of an alkanolamine or polyalkylenepolyamine, a sulfone compound and a glycol monoalkyl ether (JP-A-62-49355).
No.), a release agent comprising dimethyl sulfoxide as a main component and a diethylene glycol monoalkyl ether and a nitrogen-containing organic hydroxy compound (JP-A-64-42653).
No.) and the like. However, the above-mentioned alkaline release agent exhibits alkalinity due to the dissociation of amine due to moisture absorbed during use, and exhibits alkalinity when washed with water without using an organic solvent such as alcohol after peeling. Further, the alkaline release agent has a strong corrosive effect on aluminum, copper, etc., which are often used as wiring materials for fine wiring processing, and is not preferable for processing ultrafine wiring, which has a severe dimensional accuracy in recent years. Further, the alkaline stripping agent requires rinsing with an organic solvent such as alcohol after stripping the photoresist, and has a problem that the process is complicated as in the case of the acidic stripping solution.

Further, in recent years, with the ultra-miniaturization in the wiring process, the etching conditions of the wiring material have become stricter, and the photoresist used tends to deteriorate, and the acid stripping solution or alkaline stripping solution described above has a releasability. Is weak,
There is a problem that the photoresist remains on the inorganic substrate. Therefore, to prevent the above problems,
There is a demand for a peeling agent that can easily peel off a resist film, a resist layer, a resist residue, and the like, and at the time does not corrode wiring materials.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the stripping agent in the prior art, and to apply a photoresist film coated on an inorganic substrate or a photo-resist coated on an inorganic substrate. The photoresist layer remaining after dry etching of the resist film or the photoresist residue remaining after ashing after dry etching can be easily peeled off at a low temperature in a short time, and the wiring material is not corroded at all. A photoresist stripper composition that can be microfabricated and that does not require the use of an organic solvent such as alcohol as a rinse liquid, can be rinsed only with water, and can produce highly accurate circuit wiring. Is to provide.

[0007]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found that alkanolamines, alkoxyalkylamines or alkoxyalkanolamines and glycol monoalkyl ethers, Furthermore, a stripping composition comprising an aqueous solution containing sugars or sugar alcohols can easily strip a photoresist in a manufacturing process of a semiconductor integrated circuit at a low temperature in a short time, and further, the stripping composition does not corrode wiring materials at all. The inventors have found that they have extremely excellent characteristics with non-corrosiveness and workability, and arrived at the present invention.

That is, the present invention has the general formula R ¹ R ² -NC _m
H _2m OR ³ (R ¹ and R ² are a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or a hydroxyethyl group, R ³ is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a hydroxyethyl group,
Methoxyethyl group or ethoxyethyl group, m is 2-4
5 to 50% by weight of an alkanolamine, an alkoxyalkylamine or an alkoxyalkanolamine represented by the general formula R ⁴ — (C _p H _2p O) _q −
R ⁴ (R ⁴ is hydrogen or an alkyl group having 1 to 4 carbon atoms, p
Is an integer of 2 to 3, q is an integer of 1 to 3) 1 to 30% by weight of a glycol monoalkyl ether, 0.5 to 15% by weight of sugars or sugar alcohols, and the balance is water. It is a photoresist stripping agent composition characterized by the above.

In the present invention, the general formula R ¹ R ² --NC _m
Examples of the alkanolamines, alkoxyalkylamines or alkoxyalkanolamines represented by H _2m OR ³ include ethanolamine, N-methylethanolamine, N, N-dimethylethanolamine, N-ethylethanolamine and N. , N-diethylethanolamine, propanolamine, N-methylpropanolamine, N, N-dimethylpropanolamine, N-ethylpropanolamine, N, N-diethylpropanolamine, 2-methoxyethylamine, 2-
Ethoxyethylamine, 3-methoxypropylamine,
3-ethoxypropylamine, 2- (2-aminoethoxy) ethanol, 2- (2-aminoethoxy) propanol, 2-amino-1-propanol, 1-amino-2
-Propanol and the like. Among the above-mentioned alkanolamines, alkoxyalkylamines and alkoxyalkanolamines, ethanolamine, N-methylethanolamine, 2- (2-aminoethoxy) ethanol and the like are preferably used. The concentration range of these alkanolamines, alkoxyalkylamines, and alkoxyalkanolamines is 5 to 50% by weight, preferably 10 to 40% by weight in the total solution. When the concentration of alkanolamines, alkoxyalkylamines, alkoxyalkylamines or alkoxyalkanolamines is lower than the range, the photoresist peeling rate is slow, and when it is higher than the range, the wiring material Cannot prevent corrosion.

[0010] Formula ^{_{R 4 - (C p H 2p}} O) q -R
^The glycol alkyl ether represented by ⁴ , for example, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether,
Diethylene glycol monobutyl ether, diethylene glycol dimethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, dipropylene glycol monomethyl ether,
Examples include dipropylene glycol monomethyl ether and dipropylene glycol dimethyl ether. The concentration range of these glycol alkyl ethers is 1 to 30% by weight, preferably 5 to 30% by weight, based on the total solution. When the glycol alkyl ether is lower than the concentration range, the wiring material is corroded, and when the glycol alkyl ether is higher than the concentration range, the peeling rate of the photoresist decreases.

The saccharides or sugar alcohols used in the present invention include saccharides such as monosaccharides and polysaccharides, specifically, glycerin aldehydes having 3 to 6 carbon atoms, threose, arabinose, xylose, ribose, ribulose, Examples thereof include xylulose, glucose, mannose, galactose, tagatose, allose, altrose, gulose, idose, talose, sorbose, psicose and fructose. Examples of sugar alcohols include threitol, erythritol, adonitol, arabitol, xylitol, talitol, sorbitol, mannitol, iditol, dulcitol and the like.
Of these, glucose, mannose, galactose, sorbitol, mannitol, xylitol and the like are preferable from the viewpoint of solubility or degradability. 0.1 to 15% by weight of these sugars or sugar alcohols in the total solution,
It is preferably used in a concentration range of 1 to 10% by weight, and when the sugar or sugar alcohol is lower than the concentration range, corrosion of the wiring material cannot be sufficiently prevented. On the other hand, even if the concentration is higher than the range, there is no particular advantage and it is not economically advantageous.

The inorganic substrate used in the present invention includes
Semiconductor wiring materials such as silicon, polysilicon, silicon oxide film, aluminum, aluminum alloy, titanium, titanium-tungsten, titanium nitride and tungsten, or compound semiconductors such as gallium-arsenic, gallium-phosphorus and indium-phosphorus, and glass for LCD. A substrate or the like is used. The photoresist stripping agent of the present invention is a photoresist film coated on an inorganic substrate, or a photoresist layer remaining after dry etching a photoresist film coated on an inorganic substrate, or remains after ashing after dry etching. The photoresist residue or the like is used when peeling off the photoresist film on the inorganic substrate, and when peeling these, heating or ultrasonic waves can be appropriately used together if necessary. The treatment method with the release agent according to the present invention is generally an infiltration method, but other methods such as a spray method may be used. As the rinse after the treatment of the stripping agent according to the present invention, it is not necessary to use an organic solvent such as alcohol, and it is sufficient to rinse with water.

[0013]

EXAMPLES Next, the present invention will be described more specifically with reference to Examples and Comparative Examples. However, the present invention is not limited to these examples.

Examples 1 to 9 and Comparative Examples 1 to 4 FIG. 1 shows a cross section of a semiconductor device in which the aluminum wiring body 3 is formed by dry etching using the resist film 4 as a mask. In FIG. 1, a semiconductor device substrate 1 is covered with an oxide film 2, and a side wall protective film 5 is formed during dry etching. The semiconductor device of FIG. 1 was immersed in a release agent having the composition shown in Table 1 for a predetermined time, rinsed with ultrapure water, dried, and observed with an electron microscope (SEM). The peelability of the resist film 4 and the residue 5 and aluminum (A
l) The results of evaluation of the corrosiveness of the wiring body 3 are shown in Table 1.
Shown in The criteria for judgment by SEM observation are as follows. (Peelability) A: Completely removed. Δ: Some residual material was observed. X: Most of them remained. (Corrosion) A: No corrosion was observed at all. Δ: Some corrosion was observed. X: severe corrosion was observed

[0015]

[Table 1]

Examples 10 to 15 and Comparative Examples 5 to 8 FIG. 2 is a sectional view of the semiconductor device used in Example 1 in which resist ashing is performed using oxygen plasma and the resist film 4 of FIG. 1 is removed. Indicates. In FIG. 2, the residue (sidewall protective deposition film) 5 is not removed by oxygen-based plasma, and the upper side of the residue 5 is only deformed so as to open with respect to the center of the aluminum wiring body 3. The semiconductor device after the resist ashing shown in FIG. 2 was immersed in a release agent having the composition shown in Table 2 for a predetermined time, rinsed with ultrapure water, dried, and observed with an electron microscope (SEM). .
Peelability of residue 5 and aluminum (Al) wiring body 3
Table 2 shows the results of the evaluation of the corrosiveness of.

[0017]

[Table 2]

[0018]

EFFECTS OF THE INVENTION By using the photoresist stripper composition of the present invention, a photoresist film coated on an inorganic substrate or a photoresist remaining after dry etching a photoresist film coated on an inorganic substrate. Layers or photoresist residues remaining after ashing after dry etching can be easily peeled off at low temperature in a short time, at which time ultrafine processing is possible without corroding wiring materials. As a result, it is not necessary to use an organic solvent such as alcohol, and it is possible to rinse only with water, and it is possible to manufacture a highly accurate circuit wiring.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a cross section of a semiconductor device in which an aluminum wiring body 3 is formed by dry etching using a resist film 4 as a mask.

FIG. 2 is a cross-sectional view of the semiconductor device of FIG. 1 in which resist ashing is performed using oxygen plasma to remove the resist film 4.

[Explanation of symbols]

 1: Semiconductor device substrate 2: Oxide film 3: Aluminum wiring body 4: Resist film 5: Residue (sidewall protective deposition film)

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hidetoshi Ikeda Niigata City, Niigata City, Tayuhama, Niiwari 182, Niigata Research Center Mitsubishi Gas Chemical Co., Ltd. Niigata Research Center

Claims (5)

[Claims] 1. A general formula R ¹ R ² —NC _m H _2m OR ³ (R
¹ and R ² are a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or a hydroxyethyl group, R ³ is a hydrogen atom, having a carbon number of 1 to 1
5 to 50% by weight of alkanolamines, alkoxyalkylamines or alkoxyalkanolamines represented by 4 alkyl groups, hydroxyethyl groups, methoxyethyl groups or ethoxyethyl groups, m is an integer of 2 to 4, generally It is represented by the formula R ⁴ — (C _p H _2p O) _q —R ⁴ (R ⁴ is hydrogen or an alkyl group having 1 to 4 carbon atoms, p is an integer of 2 to 3, and q is an integer of 1 to 3). A photoresist stripper composition comprising 1 to 30% by weight of glycol monoalkyl ether, 0.5 to 15% by weight of sugar or sugar alcohol, and the balance being water. 2. A photoresist stripping method comprising stripping a photoresist using the stripping agent composition according to claim 1. 3. The photoresist stripping method according to claim 2, wherein the photoresist film coated on the inorganic substrate is stripped. 4. The photoresist stripping method according to claim 2, wherein a mask is formed on the inorganic substrate using a photoresist film, and the non-masked region is dry-etched to strip the masked photoresist layer. 5. A mask is formed on an inorganic substrate by using a photoresist film, a non-masked region is dry-etched, the masked photoresist layer is further ashed, and the remaining photoresist residue is peeled off. Item 3. The photoresist stripping method according to Item 2.