JPH06103668B2 - Vapor phase growth equipment - Google Patents

Description

The present invention relates to a semiconductor manufacturing apparatus, and more particularly to a vapor phase growth apparatus.

[Conventional technology]

FIG. 3A is a sectional view showing a conventional example of a vapor phase growth apparatus. In FIG. 3 (a), a quartz bell jar 2 and a stainless bell jar 3 are airtightly mounted on a base plate 1 via an O-ring 4 and fixed by a stopper 17. A reaction gas introduction nozzle 11 for introducing a reaction gas 10 through the base plate 1 is provided at a central position in the bell jar. Further, a disk-shaped SiC coat susceptor 6 on which a semiconductor substrate to be processed (hereinafter simply referred to as a wafer) 5 is mounted is attached to the outer periphery of the nozzle 11, and a lower side of the SiC coat susceptor 6 is provided for shielding reaction gas. The spiral high frequency heating coil 7 is attached via a coil cover 18. In the vapor phase growth apparatus having the above structure,
The wafer 5 placed on the SiC coat susceptor 6 is heated by high-frequency induction, and at the same time, the SiC coat susceptor 6 is rotated by the motor 9 via the rotation shaft 16 so that each wafer 5
Heat evenly. Meanwhile, during this heating, the reaction gas 10
A uniform film is grown on the surface of the wafer 5 by jetting from 11 in the direction of arrow 11a. The gas ejected from the nozzle outlet 11a is discharged from the reaction gas outlet 12 to the outside of the bell jar.

On the other hand, the coil purge gas 15 is introduced from the coil purge inlet 13 into the coil cover 18, and the coil purge gas outlet
It is discharged from the bell jar together with the reaction process gas from 14.

[Problems to be Solved by the Invention]

In the above-described conventional vapor phase growth apparatus, as the cover 18 of the coil 7, as shown in FIG. 3 (b), a hollow body that covers the upper side and the lateral side of the coil 7 is provided. The nozzle 18 and the opening 18 'through which the rotary shaft 16 of the susceptor 6 penetrates were provided. This coil cover
Reference numeral 18 denotes a partition between the heating chamber side and the reaction furnace side. The opening 18 'of the cover 18 is, as shown in FIG.
A gap through which gas can flow is formed between 18 'and the rotating shaft 16, and the coil cover 18 is passed through this gap during the reaction.
When the residual gas of chloride such as HCl, SiCl ₄ , SiH ₂ Cl ₂ , which is a reaction gas, flows into the inside through the gap, and when the surface of the high frequency induction heating coil 7 is condensed due to the influence of the cooling liquid, the surface of the surface is removed. Corrosion, and vice versa, inside the reactor and coil cover 18
Since the inside is at the same pressure, the coil purge gas 15a is sucked into the reaction furnace side from the inside of the coil cover 18 at the flow rate of the reaction gas, and the metal such as copper contained in the coil purge gas 15 forms the SiC coat layer of the susceptor 6. There is a problem in that the phenomenon of erosion and sublimation of SiC occurs to induce SiC peeling, which shortens the life of the susceptor 6 and adversely affects the product due to inclusion of impurities.

An object of the present invention is to provide a vapor phase growth apparatus that solves the above problems.

[Differences from the Prior Art of the Invention]

In the conventional vapor phase growth apparatus described above, due to the shape of the coil cover, a flow occurs between the gas in the reaction furnace and the heating chamber, but in the vapor phase growth apparatus of the present invention,
The difference lies in that the gas on the reaction furnace side and the gas on the heating chamber side are completely separated, and the mixing of the reaction gas and the coil purge gas is prevented.

[Means for Solving the Problems]

In order to achieve the above object, a vapor phase growth apparatus according to the present invention is a vapor phase growth apparatus including a coil cover, a susceptor, a high frequency induction heating coil, a nozzle, and a purge gas supply / discharge mechanism. Has a hollow shaft-cylindrical part, and a heating chamber is formed in the bell-jar by being isolated from the reaction chamber in the bell-jar, and the susceptor is a rotary shaft that penetrates the hollow-shaft-cylindrical part of the coil cover. Mounted on a shaft and supporting a semiconductor substrate to be processed; a high frequency induction heating coil is housed in a heating chamber of the coil cover and heats the susceptor; It is installed above the susceptor and sprays the reaction gas toward the susceptor side.

The purge gas supply / discharge mechanism has a pair of a coil purge gas inlet and a coil purge gas outlet opened in the heating chamber inside the coil cover, and the coil purge gas is fed from the coil purge gas inlet into the heating chamber. By exhausting the purge gas from the discharge port, the high frequency induction heating coil in the heating chamber is purged.

〔Example〕

 Next, an embodiment of the present invention will be described with reference to the drawings.

1 (a) is a sectional view showing a first embodiment of the present invention, and FIG. 1 (b) is a perspective view showing the shape of a coil cover used in the first embodiment of the present invention.

In FIG. 1 (a), the base plate 1 is covered with a quartz bell jar 2 and a stainless bell jar 3, and an O-ring 4 is formed on the joint surface between the bell jar 3 and the base plate 1.
The SiC coat susceptor 6 is supported by a rotary shaft 16 directly connected to the motor 9, and a high frequency induction heating coil 7 is provided below the rotary shaft 16.
Is installed and the nozzle 11 is opened upward through the rotary shaft 16 as in the conventional device shown in FIG. The same components as those in FIG. 3 are denoted by the same reference numerals and the description thereof will be omitted. In the present invention, as shown in FIG. 1 (b), a coil cover 8 which is composed of an inner and outer double cylinder and whose upper surface between the inner and outer cylinders is closed is installed on the base plate 1 so that the reaction chamber in the bell jar 2 is removed. The heating chamber is formed in the coil cover 8 by being isolated. The inner cylinder of the cover 8 is used as a shaft cylinder, and the rotary shaft 16 is penetrated through the opening 8 ', and the coil purge gas introduction port 13 and the coil purge gas discharge port 14 provided on the base plate 1 are coiled as shown in FIG. 3 (a). The cover 8 is opened in the heating chamber. In the present invention, the coil purge gas exhaust port
14 is a pipe line separate from the reaction gas discharge port 12 and independent.
As a result, the gas does not leak from the opening 8'and the coil purge gas 15 that has entered the coil cover 8 through the coil purge gas inlet 13 is not mixed with the reaction gas 10 but is discharged alone through the discharge port 14, 10 is a reaction gas outlet
Emitted from 12 alone.

Next, a second embodiment of the present invention is shown in FIG. In the figure, in this embodiment, a recess is provided in a part of the base plate 1, and the rising portion thereof is the coil cover 8 in the previous embodiment.
It is the outer cylinder part.

Therefore, according to the present embodiment, the upper surface of the recess of the base plate 1 and the shaft cylinder portion of the rotating shaft are covered with the coil cover 8, and the coil 7 is housed in this isolated closed space. The reaction gas fed into the reaction furnace and the purge gas fed into the heating chamber are not mixed with each other. Therefore, the internal pressure P ₁ in the reactor and the internal pressure P _{2 in the} heating chamber become independent,
The reaction gas and the inert gas can be fed in and discharged by applying a differential pressure freely.

〔The invention's effect〕

As described above, according to the present invention, the heating chamber is provided separately from the reaction chamber, the high frequency induction heating coil is housed in the heating chamber, and the gas for purging the coil is supplied to and discharged from the heating chamber. The high frequency induction heating coil can be purged with a purge gas independently of the treatment in step 1, and the coil purge gas for purging the high frequency induction heating coil is not sucked into the reaction chamber and the coil purge gas does not contact the susceptor. It is possible to prevent the coating layer of the susceptor from being eroded by the metal contained in the purge gas.

Further, there is an effect that the reaction gas in the reaction chamber does not flow into the heating chamber and the surface of the high frequency induction heating coil can be prevented from being corroded by the reaction gas.

[Brief description of drawings]

FIG. 1 (a) is a sectional view showing a first embodiment of the present invention, FIG. 1 (b) is a perspective view of the coil cover of FIG. 1 (a), and FIG. 2 is a second embodiment. FIG. 3A is a sectional view showing a conventional example, and FIG. 3B is a perspective view of a coil cover. 1 ... Base plate, 2 ... Quartz bell jar 3 ... Stainless steel bell jar 4 ... O-ring 5 ... Wafer, 6 ... Susceptor 7 ... High frequency induction heating coil 8 ... Coil cover, 8 '... Opening 10 ... Reactive gas, 11 ... Nozzle 12 … Reaction gas outlet 13… Coil purge gas inlet 14… Coil purge gas outlet 15… Coil purge gas, 16… Rotating shaft

Claims (1)

[Claims] 1. A vapor phase growth apparatus having a coil cover, a susceptor, a high frequency induction heating coil, a nozzle, and a purge gas supply / discharge mechanism, wherein the coil cover has a hollow shaft cylinder portion, A heating chamber is formed in the bell jar so as to be separated from the reaction chamber in the bell jar. The susceptor is attached to a rotary shaft that penetrates the hollow shaft cylinder portion of the coil cover and supports a semiconductor substrate to be processed. The high frequency induction heating coil is housed in the heating chamber of the coil cover and heats the susceptor, and the nozzle is provided at a position above the susceptor through the rotation shaft to supply the reaction gas. It is sprayed toward the susceptor side. The purge gas supply / discharge mechanism has a pair of a coil purge gas inlet and a coil purge gas outlet opened in the heating chamber inside the coil cover, and the coil purge gas is fed from the coil purge gas inlet into the heating chamber. A vapor phase growth apparatus characterized in that a high frequency induction heating coil in a heating chamber is purged with a purge gas by exhausting the purge gas from an outlet.