JP2002162755A - Method for manufacturing semiconductor device - Google Patents

Abstract

(57) [Problem] To provide a method of manufacturing a semiconductor element capable of manufacturing a high-precision circuit wiring by a safe method without corroding a metal film such as an aluminum-based conductive film at all. SOLUTION: When the photoresist formed on the substrate is stripped, the photoresist is stripped with a basic stripping solution, and then washed with a rinsing solution containing water containing carbon dioxide gas.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for cleaning a photoresist after removing a photoresist using a basic stripping solution in a process of manufacturing a semiconductor device for forming an electrode or a wiring on a substrate.

[0002]

2. Description of the Related Art In a semiconductor device, after a conductive film as a wiring material is formed on a substrate by a method such as sputtering or CVD, a photoresist is applied onto the conductive film, and a pattern is formed by a photolithographic process based on exposure and phenomenon. Forming
Then, using the photoresist pattern as a mask, dry etching of an unmasked region using a reactive gas to form fine wiring, and then removing the photoresist film from the conductive film, or in a similar manner, After a fine wiring is formed, ashing is performed to remove the remaining resist from the conductive film. Conventionally, as a photoresist stripping agent of these methods, a basic stripping agent has a high resist stripping property, and in recent years, has been widely used for fine wiring processing. Conventionally, the following techniques are generally used as the basic release agent. 1) Aqueous release agent containing quaternary ammonium hydroxide as a main component (JP-A-60-147736, JP-A-62-28)
No. 1332, JP-A-64-2325, JP-A-4-48633, etc.) 2) Release agents containing alkanolamine as a main component (JP-A-62-49355, JP-A-64-426)
No. 53, JP-A-64-88548, JP-A-6-88548
-222573, JP-A-7-28254,
3) Release agents containing alkanolamine as a main component and a reducing agent as an auxiliary (JP-A-4-289866, JP-A-6-2661)
No. 19, etc.) JP-A-60-147736, JP-A-62-281332, JP-A-64-2325 in the above 1)
The aqueous release agent containing a quaternary ammonium hydroxide as a main component described in Japanese Patent Application Laid-Open Publication No. H10-15064 has a large corrosion effect on aluminum or the like as a wiring material. In addition, many pit-like or crater-like corrosion phenomena occur on the surface of aluminum or the like, and the aluminum wiring itself is corroded. In Japanese Patent Application Laid-Open No. 4-48633, a quaternary ammonium hydroxide is used as a main ingredient and sugars or sugar alcohols are added to suppress corrosion of aluminum and the like, but pure water or ultrapure water is rinsed. When the liquid is used, the occurrence of a pit-like or crater-like corrosion phenomenon cannot be avoided. The technology of 2) above
It is common to use alcohol such as methanol or propanol as the rinse liquid, and then rinse with pure water or ultrapure water.Rinsing with alcohol is not sufficient and the next pure water or ultrapure water is rinsed. In the case of water rinsing, corrosion of aluminum or the like occurs, and a pit-like or crater-like corrosion phenomenon occurs. The technique 2) does not use alcohol as a rinsing liquid,
When rinsing is performed using pure water or ultrapure water as a rinsing liquid directly after using a alkanolamine-based stripper, the corrosion phenomena of aluminum etc. significantly progress, and pit-like or crater-like corrosion phenomena also occur. Many occur. The technique 3) uses alkanolamine as a main agent and a reducing substance such as hydroxylamine as an auxiliary agent. In this case as well, an organic solvent such as alcohol is used as a rinsing liquid, and then pure water or ultrapure water is used. Is generally used as a rinsing liquid. Further, when rinsing is performed directly using pure water or ultrapure water as a rinsing liquid without using an organic solvent such as alcohol, a corrosion phenomenon similar to the technique 2) occurs in any case. In addition to the above, JP-A-6-184595 discloses that
After using the basic release agent, in place of alcohol, rinsing with a hydroxycarboxylic acid-based solvent, an alkoxycarboxylic acid-based solvent, an amide-based solvent, a lactone-based solvent, a sulfur compound solvent, etc. A technique of rinsing using water or ultrapure water as a rinsing liquid has been disclosed. In this case, too, the above technical example 2),
A problem similar to 3) occurs, and the corrosion phenomenon of aluminum or the like is not improved at all. As described above, in the ultra-fine processing technology in which the dimensional accuracy of the wiring process in recent years is severe, when a basic release agent is used, dangerous substances such as flammable alcohol must be used in large quantities as a rinsing liquid. Furthermore, no solution has been found for crater or pit-like corrosion and the corrosion of the aluminum wiring itself generated when pure water or ultrapure water is used. There is a demand for a stripping method that includes a rinsing liquid that does not show any phenomenon.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the problems of the above-mentioned prior art stripping method using a basic stripping agent, and to solve the above problems by using an aluminum-based conductive film formed on a semiconductor wafer. The resist film applied to the, or a photoresist layer remaining after dry etching the resist film applied on the aluminum-based conductive film, or remaining photoresist residue after ashing after dry etching, etc., with a basic stripping agent After peeling, it is washed with pure water containing carbon dioxide gas or rinse water that is ultrapure water, and then dried, so that it does not corrode metal films such as aluminum-based conductive films at all, and has high precision by a safe method. It is an object of the present invention to provide a peeling method including a rinsing liquid that can manufacture the circuit wiring of the present invention.

[0004]

The present inventors have conducted intensive studies to solve the above problems, and as a result, have found that a photoresist film on an aluminum-based conductive film, a photoresist layer after dry etching, or dry etching. After ashing is performed to remove the remaining photoresist residue and the like with a basic stripping agent, and then rinsed with a rinse solution that is carbon dioxide-containing pure water or ultrapure water, and dried, the aluminum-based conductive film or the like is removed. The present inventors have found a simple and extremely excellent peeling method without completely corroding the metal film and using a highly dangerous organic solvent such as alcohol, and have reached the present invention.

[0005] The concentration of carbon dioxide in pure water or ultrapure water used in the present invention is not specified, but the type of basic release agent used, the conditions at the time of release, the type of material used, etc. It should just be decided in consideration of. When using the rinsing liquid that is pure water or ultrapure water containing carbon dioxide according to the present invention, the use temperature is sufficient at room temperature, but heating or ultrasonic waves can be used as needed as needed. In addition, as a treatment method using a rinsing liquid that is pure water or ultrapure water containing carbon dioxide of the present invention, an immersion method is generally used, but other methods such as a spray method may be used.

The stripping solution used in the present invention is disclosed in JP-A-60-147736 and JP-A-6-147736 described in the prior art.
2-49355, JP-A-62-281332, JP-A-64-2325, JP-A-64-426
No. 53, JP-A-64-88548, JP-A-4
-48633, JP-A-6-266119,
Any of the basic release agents described in JP-A-7-64297 can be used, but is not limited to these release liquids, regardless of aqueous solution or non-aqueous solution. Applicable to all. In the rinsing liquid containing carbon dioxide gas in the present invention, in order to enhance the effects of the present invention, a surfactant, a chelating agent, or the like may be added as needed, without any problem.

[0007]

EXAMPLES Examples 1 to 3 and Comparative Examples 1 to 3 FIG. 1 is a sectional view of a substrate on which an aluminum wiring body (3) is formed by performing dry etching using a resist (4) as a mask. In FIG. 1, on a glass substrate (1),
A titanium nitride layer (2) which is a barrier metal is formed between the aluminum nitride layer and the aluminum layer. The glass substrate of FIG. 1 was immersed in a resist remover shown in Table 1 for a predetermined time, rinsed with an aqueous solution containing 0.15% by weight of carbon dioxide at 23 ° C. for 10 minutes, dried, and then analyzed with an electron microscope (SEM). Observations were made. Table 1 shows the results of evaluating the peelability of the resist film and the corrosion state of the surface of the aluminum wiring body.
The evaluation criteria based on SEM observation are as follows. (Peeled state) A: Completely removed. ：: Almost completely removed. Δ: Partial residual was observed. ×: Most of the residue remained. (Corrosion state) A: No corrosion was observed. ○: Almost no corrosion was observed. C: Crater-like or pit-like corrosion was observed. ×: Roughness was observed on the entire surface of the A1 mixed metal.
Retreat of the alloy was observed.

Examples 4 to 6 and Comparative Examples 4 to 6 FIG. 2 shows that an aluminum wiring (Al-Cu layer) was formed by performing dry etching using a resist film as a mask and further performing ashing using oxygen plasma. 1 shows a cross section of a semiconductor device. In FIG. 2, an SiO ₂ layer (5) is formed on a silicon wafer (9), and a titanium (6), an Al—Cu layer (7), and a titanium layer as barrier metals are further formed. Then, the resist residue (8) is deformed so as to open with respect to the center of the aluminum wiring body, and remains. After the semiconductor device after the ashing shown in FIG. 2 was immersed in a stripping agent having the composition shown in Table 2 for a predetermined time, ultrapure water containing carbon dioxide gas was used as a rinsing liquid to remove the resist residue and remove the aluminum wiring ( Al-Cu)
Table 2 shows the results of evaluation of the corrosiveness of the steel. The criterion by SEM observation is the same as that in the first embodiment.

[0009]

[Table 1]

[0010]

[Table 2]

[0011]

According to the method of the present invention, high-precision circuit wiring can be manufactured safely without corroding a metal film such as an aluminum-based conductive thin film at all.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a glass substrate on which an aluminum wiring body is formed by performing dry etching using a resist as a mask.

FIG. 2 performs dry etching using a resist film as a mask, and further performs ashing using oxygen plasma;
It is sectional drawing of the semiconductor device in which the aluminum wiring body (Al-Cu layer) was formed.

[Explanation of symbols]

1 glass substrate 2 titanium nitride 3 Aluminum 4 resist 5 SiO ₂ 6 Titanium 7 Al-Cu 8 resist residue 9 silicon wafer

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 21/306 H01L 21/30 572B 21/306 Z (72) Inventor Tetsuo Aoyama Tayuhama, Niigata City, Niigata No. 182 F-term in Niigata Research Laboratory, Mitsubishi Gas Chemical Co., Ltd. (reference)

Claims (3)

[Claims] 1. A method of manufacturing a semiconductor device, comprising: removing a photoresist formed on a substrate; removing the photoresist with a basic stripping solution; and washing the substrate with a rinsing solution containing water containing carbon dioxide gas. Method. 2. The method according to claim 1, wherein the basic stripping solution is a solution containing an amine. 3. The method according to claim 1, wherein the basic stripping solution is a solution containing a quaternary ammonium hydroxide.