JPS5826658B2 - Vapor phase growth equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vapor phase growth apparatus, and particularly to a vapor phase growth apparatus capable of carrying out a vapor phase growth reaction even under low reaction temperature conditions.

As is well known, a vapor phase growth apparatus is one of the processing apparatuses for processing wafers, etc. used when manufacturing ICs, LSIs, etc., and it flows a reaction gas through a reaction tube under normal pressure or reduced pressure conditions. This is a device that grows a thin film on the surface of a wafer, etc. placed inside a tube.

During such treatments, the reaction tube is heated by a heating device such as a resistance heating furnace.

This heating is usually carried out at a temperature in the high range of 400 to 1,000°C, although it varies depending on the type of reaction gas used.

Therefore, even if an attempt is made to vapor-phase grow a thin film on the surface of a semiconductor substrate using a metal with a low melting point that is eutectic with a silicon substrate, such as aluminum or gold, as a wiring material, it may not be technically possible to do so. be.

Such problems would of course be solved if the vapor phase growth reaction could be carried out at a low temperature, but this is extremely difficult to do with a vapor phase growth apparatus using a conventionally commonly used resistance heating furnace.

An object of the present invention is to provide a vapor phase growth apparatus that can carry out vapor phase growth reactions at lower temperatures.

In line with these objectives, the present invention replaces the conventional heating method using a resistance heating furnace with a heating method using an infrared lamp, and also uses ultraviolet irradiation in combination with this to excite the reaction gas and lower the reaction temperature. is planned.

That is, the vapor phase growth apparatus according to the present invention is characterized in that infrared lamps and ultraviolet lamps are alternately arranged along the outer periphery of a reaction tube for carrying out a vapor phase growth reaction, and the whole is covered with a reflecting plate. It is said that

The present invention will be described below with reference to the drawings.

FIG. 1 is a longitudinal sectional view showing an example of a vapor growth apparatus according to the present invention, and FIG. 2 is a sectional view taken along the line X-X in FIG. 1, particularly illustrating the arrangement of infrared lamps and ultraviolet lamps. This is a diagram for

In these figures, 1 is a reaction tube, which is made of a material that is transparent to infrared and ultraviolet radiation, for example quartz.

The reaction tube 1 has a reaction gas inlet 1a and an outlet 1b at both ends thereof.

A vacuum pump (not shown) such as a rotary pump is connected to the discharge port 1b, and sucks the reaction gas while causing it to flow into the reaction tube.

In the reaction tube 1, infrared lamps 2 and ultraviolet lamps 3 are arranged alternately along its outer periphery.

The reason why the lamps 2 and 3 are arranged alternately is to uniformly irradiate the processing substrate 4 placed in the reaction tube and the reaction gas in the reaction tube with infrared rays and ultraviolet rays.

The amount of infrared rays irradiated can be controlled by adjusting the amount of power applied to the lamp, or by turning on the power switch to control the number of lamps to be turned on.
This is done by controlling with N and OFF.

Further, the amount of ultraviolet irradiation is also controlled in the same way.

In order to improve the irradiation efficiency of infrared rays, the lamp group of both lamps 2.3 is surrounded by a reflector plate 5.

The reflecting plate 5 is made, for example, by depositing gold, silver, or aluminum on a metal plate.

In order to introduce a cooling medium such as air or nitrogen gas into the spatial region defined by the reflection plate 5 and the reaction tube 1, the reflection plate 5 is provided with a cooling gas inlet 5a.

The purpose of cooling this space is to prevent the sealing parts of the lamps 2 and 3 from being damaged.

Since the vapor phase growth apparatus according to the present invention has the above configuration, the reaction gas introduced into the reaction tube is irradiated with ultraviolet rays.

As a result, the component reactants are excited and the chemical reaction can proceed even at low reaction temperatures.

Next, an example in which vapor phase growth was actually performed using the apparatus of the present invention will be described.

In this example, a thin film of polycrystalline silicon was grown in a vapor phase on the surface of a silicon wafer using SiH4 as a reactive gas.

As a result, in the absence of ultraviolet irradiation, the wafer had to be heated to a temperature of about 700° C. or higher in order to cause the growth reaction to occur smoothly.

On the other hand, when three 400W mercury vapor lamps are turned on to perform a growth reaction while irradiating ultraviolet rays, three IKW infrared lamps are used, but the input power is low and the wafer is only heated to about 100℃. The reaction proceeded smoothly just by doing this.

[Brief explanation of the drawing]

FIG. 1 is an explanatory longitudinal cross-sectional view showing an example of a vapor phase growth apparatus according to the present invention, and FIG. 2 is a cross-sectional view taken along the line X-X in FIG.
In particular, it is a diagram for explaining the arrangement of infrared lamps and ultraviolet lamps. Explanation of symbols: 1...Reaction tube, 2...Infrared lamp, 3...Ultraviolet lamp, 5...
··a reflector.

Claims (1)

[Claims] 1 Along the outer periphery of the reaction tube for performing the vapor phase growth reaction,
A vapor phase growth device with a structure in which infrared lamps and ultraviolet lamps are arranged alternately, and the entire structure is covered with a reflector.