JPH0691060B2 - Substrate processing method - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a method for treating a substrate. More specifically, the present invention is excellent in rinsing effect of the substrate after removing the resist pattern after the etching treatment with the stripping solution in the manufacturing process of the semiconductor element, and in environmental aspects such as toxicity to human body and wastewater treatment. The present invention relates to a method of rinsing a substrate with a specific solvent which has extremely few problems and is also excellent in fire safety.

BACKGROUND OF THE INVENTION In the manufacture of semiconductor devices such as ICs and LSIs, a thin film such as an oxide film is usually first formed on a substrate such as a silicon wafer, and then a photoresist is evenly applied on the surface to form a photosensitive layer. , A step of forming a resist pattern by performing exposure and development, then using this resist pattern as a mask to selectively etch the oxide film in the lower layer, and then completely removing the resist pattern on the substrate. Has been.

Conventionally, for removing the photoresist pattern, a method of removing using an inorganic acid or an inorganic base and a method of dissolving and peeling off using an organic solvent are known, but a method of removing using an inorganic acid or an inorganic base is known. Since the method described above is dangerous in terms of work, a method using an organic solvent is generally used.

However, in this method, in order to dissolve and peel the photoresist pattern with an organic solvent, when the substrate is washed immediately after peeling and removing, the photoresist dissolved in the peeling liquid remaining on the substrate is deposited, Redeposit on the substrate. Therefore, the substrate cannot be immediately washed with water after the photoresist pattern is peeled off and removed, and a rinse treatment of the substrate is indispensable.

This rinsing treatment is performed to completely wash away the stripping solution remaining on the substrate and prevent the photoresist dissolved in the stripping solution from reattaching to the substrate.

As the rinse liquid used for such a rinse treatment,
Conventionally, trichlorethylene, methanol, acetone, etc. are known. However, these rinse solutions are effective for cleaning the stripping solution on the substrate, but in the case of trichlorethylene, the toxicity to human body and environmental problems due to waste solution have been greatly closed up in recent years, and low flammability of methanol, acetone, etc. In the case of the point solvent, there are various problems such as disaster prevention and storage problems, a high volatilization rate, and an adverse effect on the working environment.

Problems to be Solved by the Invention The object of the present invention is to solve the problem of such a rinse treatment in the manufacturing process of a semiconductor element, in the rinse treatment of the substrate after removing the resist pattern with a stripping solution, excellent in the rinse effect, Another object of the present invention is to provide a method for treating a substrate using a rinse liquid which has extremely few environmental problems such as toxicity to human bodies and wastewater treatment, and which is also excellent in fire safety.

Means for Solving the Problems The inventors of the present invention have conducted in-depth research to achieve the above object, and as a result, by using a solvent composed of an aromatic hydrocarbon compound as a rinse liquid, the object can be achieved. Based on this finding, the present invention has been completed.

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 by a stripping solution, and then the substrate is rinsed with a solvent containing an aromatic hydrocarbon. The present invention provides a method for treating a substrate.

In the method of the present invention, the aromatic hydrocarbon used as the rinse liquid is not particularly limited as long as it is a compound having an aromatic ring, but naphthalene compounds and alkylbenzene compounds are preferable. Specific examples of the aromatic hydrocarbon compound include naphthalene, methylnaphthalene, dimethylnaphthalene, ethylnaphthalene, butylnaphthalene, propylnaphthalene, tetrahydronaphthalene, decahydronaphthalene and other naphthalene compounds, toluene, xylene, trimethylbenzene, tetramethyl. Benzene, ethylbenzene, diethylbenzene, methylethylbenzene, dimethylethylbenzene, triethylbenzene, butylbenzene, pentylbenzene, hexylbenzene, heptylbenzene, octylbenzene, nonylbenzene, decylbenzene, undecylbenzene, dodecylbenzene, tridecylbenzene, tetradecylbenzene , Pentadecylbenzene, hexadecylbenzene,
Heptadecylbenzene, isopropylmethylbenzene,
An alkylbenzene compound such as butyltoluene may be mentioned. The alkyl group in the alkylbenzene compound may be linear or branched.
The aromatic hydrocarbon compounds may be used alone or in combination of two or more, but they are required to be liquid.

In consideration of fire safety and storability, the rinse liquid used in the present invention contains at least one selected from the above naphthalene compounds and alkylbenzene compounds having an alkyl group having 4 or more carbon atoms as a main component. Is preferred. From the viewpoint of rinsing effect, a mixture of the naphthalene-based compound and the alkylbenzene-based compound is preferable, and the mixing ratio of the content of the alkylbenzene-based compound is 10 to 70% by weight, and particularly 40 to 60% by weight.
Those in the range of (4) have an excellent rinsing effect and are preferable.

The rinsing liquid in the present invention is a liquid and can be used in any manner as long as it is composed of aromatic hydrocarbons, but commercially available as a mixed solvent of aromatic hydrocarbons. Preferably used. As such a mixed solvent, for example, an aromatic carbon containing 60% by weight or more of a mixture of naphthalene, methylnaphthalene, ethylnaphthalene and dimethylnaphthalene, and about 10% by weight of a mixture of tetramethylbenzene, undecylbenzene and dodecylbenzene. Solbetso 200 (manufactured by Exxon Chemical Co., Ltd.), which is a mixed solvent of hydrogen, Solbetso 100 (manufactured by Exxon Chemical Co., Ltd.), which is a mixed solvent of aromatic hydrocarbons containing trimethylbenzene and methylethylbenzene as main components, and Pegasol R
-100 (manufactured by Mobil Oil Co., Ltd.), Alken 56N (manufactured by Nippon Petrochemical Co., Ltd.), which is a mixed solvent composed of an alkylbenzene compound having 9 to 16 carbon atoms in the alkyl group containing undecylbenzene and dodecylbenzene of 75 mol% or more, Alkylbenzene, a mixed solvent of alkylbenzene compounds
Examples thereof include DAD A-40 (manufactured by Sumitomo Chemical Co., Ltd.).

These commercially available mixed solvents may be used alone or in admixture of two or more.
A mixture of 200 and alkene 56N is preferred.

The rinse liquid composed of aromatic hydrocarbon used in the present invention is effective for the rinse treatment after stripping, even if the resist pattern to be stripped is formed from any photoresist of negative type or positive type. As a rinse liquid when a negative photoresist is used, one containing at least 30% by weight or more of an alkylbenzene compound is preferable.

Next, one example of the method for treating a substrate of the present invention will be described. First, a photoresist is uniformly applied on a substrate made of a silicone wafer or the like on which a thin film such as an oxide film is formed, and dried to form a photosensitive layer, Then, after exposing the photosensitive layer to a desired pattern, a development process is performed and post-baking is performed to form a resist pattern. Next, using this resist pattern as a mask, the lower layer oxide film is selectively etched, and then the resist pattern on the substrate is completely removed by a stripping solution, and then a rinse solution containing the aromatic hydrocarbon is used. The substrate is rinsed to completely wash away the stripping solution.

Advantageous Effects of Invention The method for treating a substrate of the present invention has excellent rinsing effect as a rinsing liquid, and has less environmental problems such as toxicity to human bodies and wastewater treatment than the conventional rinsing liquid, and in addition, it has a great effect on fire fighting. It has high practical value because it uses one with excellent safety.

EXAMPLES Next, the present invention will be described in more detail with reference to Examples.

Example 1 OMR-83 (manufactured by Tokyo Ohka Kogyo Co., Ltd.) as a negative photoresist and OFPR-800 (manufactured by Tokyo Ohka Kogyo) as a positive photoresist were dried on two silicon wafers so that the dry film thickness was 1 μm. After coating with a spinner, it was exposed and developed, and then post-baked at 160 ° C. for 30 minutes to form a resist pattern film on the silicon wafer. Next, the stripping solution 502 kept at a liquid temperature of 120 ° C.
The silicon wafer was immersed in (Tokyo Ohka Kogyo Co., Ltd.), taken out after 5 minutes, further immersed in a dimethylnaphthalene solvent, and rinsed for 3 minutes.

By observing the surface of the silicon wafer treated in this way and judging whether the rinse effect was possible or not, both of the two silicon wafer surfaces were in a mirror surface state in which neither reattachment of resist nor residual stripper was observed. The rinsing effect was recognized.

Examples 2 to 18 Substrates were treated in the same manner as in Example 1 except that rinse liquids containing various aromatic hydrocarbons were used, and the rinse effects of the rinse liquids were observed. The results are shown in the table below.

Claims (3)

[Claims] 1. A desired photoresist pattern is provided on a substrate, an etching process is performed, the resist pattern is removed by a stripping solution, and then the substrate is rinsed with a solvent containing an aromatic hydrocarbon. A method for treating a characteristic substrate. 2. The method according to claim 1, wherein the aromatic hydrocarbon is at least one selected from naphthalene compounds and alkylbenzene compounds. 3. The method according to claim 2, wherein the naphthalene compound is naphthalene, methylnaphthalene, ethylnaphthalene and dimethylnaphthalene.