JPS5839373B2 - Exhaust treatment method for semiconductor manufacturing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel exhaust treatment method for semiconductor manufacturing equipment, particularly for low pressure vapor phase growth equipment.

Conventionally, the vapor phase growth method has been an important and indispensable method for semiconductor manufacturing.In order to improve the physical properties of the vapor phase grown layer and to easily control impurities and film thickness, low pressure vapor phase growth has been used. The law has come into regular use.

Furthermore, monosilane (SiH4), phosphine (PH3), and the like are used as source gases in such a reduced pressure vapor phase growth method, and these are known as natural gases that combust spontaneously in the presence of oxygen.

For this reason, if these gases are used and discharged directly into the air from the booster pump or rotary pump exhaust system of a reduced pressure vapor deposition device, there is a risk of combustion, so argon (Ar) is usually used. The main component is an inert gas such as, and SiH4 gas or PH3 gas is diluted with 1 to about 1 to 2%.

However, when such a diluted source gas is used, a large amount of exhaust is required, which not only increases the size of the booster pump or rotary pump exhaust system, but also limits the degree of pressure reduction.

In addition, the degree of depressurization can range from the current several Torr, for example, to I T
If it is set to about 1 below orr, there will be less variation and it will be suitable for large-scale processing.

Therefore, it is preferable to use a small amount of S i H4 gas or PH gas without using a source gas diluted with an inert gas, and such a method is currently being considered.

The present invention has been made in consideration of such problems, and has the following features:
The purpose of using 00 natural gases is to introduce oxygen or an inert gas containing oxygen into the discharged natural gas and cause it to react, and the reaction gas is taken in by a water ring pump to produce the reaction gas. This paper proposes an exhaust gas treatment method characterized by separating components into water ring pump exhaust gas and waste water.

Hereinafter, examples will be specifically described with reference to the drawings.

For example, if 100% SiH and gas are used to form a silicon vapor phase growth layer, excess SiH and gas will be sucked in and exhausted from the reduced pressure vapor growth apparatus by the exhaust system. Ru.

In Fig. 1, 1 is an inflow pipe for S i H gas discharged from such a reduced pressure vapor phase growth apparatus, and 2 is a booster/gas inflow pipe.
Although an exhaust system device consisting of a pump or a rotary pump is shown, the S i H gas sucked in and exhausted from the exhaust system device 2 is generally fed into a reaction tube section 3 made of stainless steel.
Meanwhile, a larger amount of oxygen than the S i H4 gas or an inert gas containing oxygen is similarly introduced into the reaction tube section 3 by the blower 4 .

Then, SiH4 gas and oxygen react and burn in the reaction tube section 3, producing silicon oxide (SiO2) and water (H2O).
and generate.

If sufficient combustion is not achieved, some hydrogen (H2) gas may be mixed in.

The products and gas produced in this way are sucked by the water ring pump 5, and the solid SiO2 is contained in the waste water from the water ring pump 5 and discharged from the drain port 6, and excess oxygen and nitrogen are removed. The active gas or sufficiently diluted H2 gas is cooled by water and exhausted from the exhaust lower.

Treatment in this way is safe, and if an exhaust treatment device configured as shown in Figure 1 is attached, 100% S
i H, it becomes possible to use the gas in a reduced pressure vapor phase growth apparatus without diluting the gas.

Although the above is an example of SiH and gas, other natural gases can be treated easily and without worry in the same way.

Also, when using dichlorosilane (SiH2cA'2) gas, hydrochloric acid (Hcl) gas is generated, so
In the past, the oil in the pump of the exhaust system deteriorated and it was difficult to deal with it, but with the exhaust treatment system of the present invention, HCl is removed faster than in the pump of the exhaust system because it is sucked by a water ring pump. Since the gas is exhausted and the life of the oil is extended, the present invention is considered to be effective when applied not only to self-combustible gases but also to the treatment of water-soluble hydrogen halides.

As described above, the present invention can be applied to the reduced pressure vapor phase growth apparatus without diluting the pyrophoric gas, so a large number of semiconductor wafers to be vapor phase grown can be processed at one time, and the exhaust system can be made smaller. It is an excellent thing that can be transformed into

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of the principle of the exhaust treatment apparatus of the present invention, and numeral 4 represents a blower for introducing gas, and 15 represents a water ring pump.

Claims (1)

[Claims] 1. Oxygen or an inert gas containing oxygen is introduced into natural gas discharged from semiconductor manufacturing equipment to cause a reaction, the reaction gas is taken in by a water ring pump, and the reaction gas components are combined with the exhaust gas of the water ring pump. A semiconductor manufacturing equipment exhaust treatment method characterized by separating and treating wastewater.