JP2613755B2 - Substrate processing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for processing a substrate. More specifically, the present invention has an excellent rinsing effect on a substrate after removing a resist pattern after an etching process with a stripping solution in a semiconductor device manufacturing process, and is environmentally friendly to human bodies and wastewater treatment. The present invention relates to a method of rinsing a substrate with a specific solvent which has very few problems and is excellent in fire safety.

[0002]

2. Description of the Related Art In the manufacture of semiconductor devices such as ICs and LSIs, usually, a thin film such as an oxide film is first formed on a substrate such as a silicon wafer, and then a photoresist is uniformly applied on the surface to provide a photosensitive layer. After that, a step of forming a resist pattern by performing exposure and development treatments, subsequently selectively etching the oxide film in the lower layer using the resist pattern as a mask, and then completely removing the resist pattern on the substrate. Has been taken.

Conventionally, for removing a photoresist pattern,
Although a method of removing using an inorganic acid or an inorganic base and a method of dissolving and removing using an organic solvent are known,
Since the method of removing using an inorganic acid or an inorganic base involves danger in operation, a method using an organic solvent is generally used.

However, in this method, when the photoresist pattern is dissolved and removed by an organic solvent, the substrate is washed with water immediately after removal and removal, and the photoresist dissolved in the removal solution remaining on the substrate is deposited. Then, it adheres again on the substrate. Therefore, the substrate cannot be immediately washed with water after the photoresist pattern is peeled and removed, and rinsing of the substrate is indispensable. This rinsing treatment is performed to completely wash away the stripping solution remaining on the substrate and to prevent the photoresist dissolved in the stripping solution from re-adhering to the substrate.

As a rinsing liquid used for such a rinsing treatment, trichloroethylene, methanol, acetone, xylene and the like are conventionally known. However,
Although these rinsing solutions are effective for cleaning the stripping solution on the substrate, the use of trichlorethylene has been limited in recent years because of its harmfulness to the human body and environmental problems caused by waste liquids, and the use of methanol and acetone has been limited. ,
Xylene and the like have various problems such as a low flash point, problems in disaster prevention and storage, a high volatilization rate, and a bad influence on the working environment.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to solve such a problem of the rinsing process in the manufacturing process of a semiconductor device, and to provide an excellent rinsing effect in the rinsing process of a substrate after removing a resist pattern by a stripping solution. Another object of the present invention is to provide a method for treating a substrate using a rinsing liquid which is extremely free of environmental problems such as toxicity to human bodies and wastewater treatment, and is excellent in fire safety.

[0007]

Means for Solving the Problems The present inventors have made intensive studies to achieve the above object, and as a result, have obtained
It has been found that the object can be achieved by using a mixed solvent containing trimethylbenzene and methylethylbenzene as main components, and the present invention has been completed based on this finding.

That is, according to the present invention, a desired photoresist pattern is provided on a substrate, an etching process is performed, the resist pattern is removed with a stripping solution, and then the substrate is mixed with trimethylbenzene and methylethylbenzene as main components. An object of the present invention is to provide a method for treating a substrate, which comprises performing a rinsing treatment using a solvent.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The rinsing liquid used in the method of the present invention is a mixed solvent containing trimethylbenzene and methylethylbenzene as main components. Such a mixed solvent is particularly excellent in fire safety and storage stability. I have.

The rinsing liquid in the present invention may be prepared as long as it contains trimethylbenzene and methylethylbenzene as main components, but it is advantageous to use a commercially available mixed solvent for practical use. It is.

Examples of such commercially available mixed solvents include Solvesso 100 (manufactured by Exxon Chemical Co., Ltd.) and Pegasol R-100. These commercially available mixed solvents may be used alone or as a mixture of two or more.

The rinsing liquid used in the present invention is effective for rinsing after peeling, regardless of whether the resist pattern to be stripped is formed from a negative or positive photoresist. As the rinsing liquid in the case of using, a liquid containing at least 30% by weight or more of an alkylbenzene-based compound is preferable.

Next, an example of a method for processing a substrate according to the present invention will be described. First, a photoresist is uniformly coated on a substrate made of a silicon wafer or the like on which a thin film such as an oxide film is formed, dried, and dried. After exposure of the photosensitive layer to a desired pattern, development processing is performed, and post-baking is performed to form a resist pattern. Next, using the resist pattern as a mask, the lower layer oxide film is selectively etched, the resist pattern on the substrate is completely removed with a stripping solution, and then the substrate is rinsed with a rinsing solution containing the mixed solvent. Is rinsed, and the stripping solution is completely washed away.

[0014]

The method for treating a substrate according to the present invention is excellent in rinsing effect as a rinsing liquid, and has very few environmental problems such as toxicity to human body and wastewater treatment as compared with conventional rinsing solutions, It has high practical value because it uses a material with excellent safety.

[0015]

Next, the present invention will be described in more detail by way of examples.

REFERENCE EXAMPLE 1 kg of xylene and 1 kg of Solvesso 100 were placed in two 1-liter beakers, respectively, kept at 23 ° C. and left open. The leaving time (hr) at this time,
FIG. 1 is a graph showing the relationship with the amount (g) lost by evaporation. The solid line in the figure is for Solvesso 100, and the broken line is for xylene. Thus, the mixed solvent used in the method of the present invention has a significantly lower volatility than xylene,
It can be seen that it is excellent in fire safety and storage.

Example 1 On two silicon wafers, OMR-83 (manufactured by Tokyo Ohka Kogyo Co., Ltd.) as a negative photoresist and OFPR-800 (manufactured by Tokyo Oka Kogyo Co., Ltd.) as a positive photoresist were each dried to a thickness of 1 μm. After being applied by a spinner, exposure and development are performed, and then 160
Post-baking was performed at 30 ° C. for 30 minutes to form a resist pattern film on the silicon wafer. Next, the silicon wafer is immersed in a stripper 502 (manufactured by Tokyo Ohka Kogyo Co., Ltd.) maintained at a liquid temperature of 120 ° C., taken out 5 minutes later, and further immersed in Solvesso 100 solvent to perform a rinsing treatment for 3 minutes. Was.

Observing the surface of the silicon wafer treated in this manner and judging whether or not the rinsing effect was obtained, no re-adhesion of the resist and no remaining of the stripping liquid were observed on the surfaces of the two silicon wafers. It was a mirror surface, and a rinsing effect was observed.

Example 2 Example 1 was repeated except that an equal mixture of trimethylbenzene and methylethylbenzene was used instead of Solvesso 100.
The substrate was treated in the same manner as described above, and the rinsing effect of each rinsing liquid was observed. As a result, the same rinsing effect as in Example 1 was observed.

[Brief description of the drawings]

FIG. 1 is a graph showing the amount of evaporation over time of a mixed solvent and xylene used in the method of the present invention.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical indication location H01L 21/308 H01L 21/30 569E

Claims (1)

(57) [Claims] An etching process is performed by providing a desired photoresist pattern on a substrate, and after removing the resist pattern by a stripping solution, the substrate is removed by using a mixed solvent containing trimethylbenzene and methylethylbenzene as main components. A substrate processing method comprising performing a rinsing process.