JPH0345954Y2 - - Google Patents

Description

[Detailed description of the invention] [Technical field to which the invention pertains] The present invention relates to an apparatus for vapor phase growth of a semiconductor material on a semiconductor substrate or an insulator substrate (hereinafter referred to as a wafer).

[Prior art]

An example of a conventional vertical vapor phase growth apparatus will be described with reference to FIG. A reaction chamber 13 is formed by a base plate 11 and a quartz bell gear 12 placed thereon.
A plurality of wafers 16 are placed on the upper surface of the susceptor 15 supported by the susceptor 4 . The susceptor 15 is rotatably driven by an electric motor 17 via a gear mechanism 18, a drive shaft 19, and a susceptor support 14, and a work coil 20 is provided on its lower surface. Further, a metal bell gear 21 is arranged around the outer periphery of the quartz bell gear 12 to cover it.

By supplying power to the work coil 20, the susceptor 15 is heated to a predetermined temperature by supplying power to the work coil 20, and the wafer 16 is heated to a predetermined temperature by receiving the heat.Semiconductor crystals are formed on the upper surface of the wafer 16 by ejecting a reaction gas mixed with the carrier gas from the nozzle 22. is growing.

At this time, since the quartz bell gear 12 is heated, a hole 23 is provided at the top of the metal bell gear 21.
3, a suitable gas such as nitrogen gas is allowed to flow into the quartz bell gear 12 to cool the quartz bell gear 12 and prevent reaction gas from adhering to its inner surface.

In such an apparatus, the vapor growth surface of the wafer 16 is the upper surface, which is opposite to the heated lower surface, so the temperature decreases due to heat radiation and contact with the reaction gas, causing a temperature difference between the front and back surfaces of the wafer 16, which may cause crystal defects. A slip occurs. As a preventive measure, the inner surface of the metal bell gear 21 should be made of a metal with high reflection efficiency, such as gold.
It has been proposed to coat silver, aluminum, or other materials by vapor deposition or the like. However, in reality, the diameter of the wafer 16 tends to increase, and the reaction chamber 13 also increases accordingly, making it economically and technically difficult to form a metal coating layer with high reflection efficiency on the metal bell gear 21. It was difficult and almost never achieved. Also, a method has been proposed in which the outer wall of the quartz bell gear 12 is coated with a metal having high reflection efficiency by vapor deposition or the like, but like the metal bell gear 21, this method is not very practical.

[Purpose of invention]

The present invention was developed from this point of view, and its purpose is to form a reflective surface with a simple structure without coating both metal and quartz bell gears with metals with high reflection efficiency, and to make the reflective surface easy to maintain. ,
An object of the present invention is to provide an apparatus that can effectively utilize the reflection of radiant light, thereby uniformly heating a wafer and performing high-quality vapor phase growth with few slip defects.

[Key points of the idea]

The vapor phase growth apparatus of the present invention is characterized in that a reflecting plate formed separately from the metal bell gear and the quartz bell gear is attached between the metal bell gear and the quartz bell gear.

[Example of idea]

FIG. 1, which shows an embodiment of the present invention, will be described below. Between the upper spherical part of the quartz bell gear 12 and the metal bell gear 21, a reflecting plate 31 whose inside is coated with a metal having high reflection efficiency is attached to the mounting member 3.
2, it is attached to the metal bell gear 21 by a spring or bayonet, etc., so that it can be easily attached and detached. The reflector plate 31 is larger than the outer diameter of the susceptor 15 and smaller than the inner diameter of the metal bell gear 21, and its radius of curvature is at the center C1 of the upper surface of the susceptor 15.
The distance between the center C2 and the center C2 of the lower surface of the reflecting plate 31 is approximately equal to or longer than the distance between the center C2 and the center C2 of the lower surface of the reflecting plate 31, and it may be a flat plate.

Although the reflector is coated with a metal with high reflection efficiency, it still absorbs some heat, so in order to cool both the reflector 31 and the quartz bellgear 12, it is necessary to pass through the hole 33 of the reflector 31 from the hole 23 of the metal bellgear 21. Nitrogen gas is passed between the reflector plate 31 and the quartz bell gear 12. Particularly when the growth temperature is 1000° C. or higher, it is preferable to perform water cooling by providing a water cooling jacket on the reflecting plate 31 or attaching a cooling pipe to its upper surface. By arranging the reflective plate 31 above the spherical part of the quartz bell gear 12 in this way, the heat rays emitted from the susceptor 15 etc. can be transferred to the reflective plate 31.
It is reflected by the wafer 16 and heats the front side of the wafer 16.

Therefore, a decrease in temperature of the surface of the wafer 16 due to heat dissipation from the surface or contact with the reaction gas is prevented.
The temperature difference between the front and back sides of the wafer 16 is reduced, and the occurrence of slips is suppressed. In addition, since the reflector plate 31 can be manufactured by being separated from either the quartz bell gear 12 or the metal bell gear 21, it is easy to manufacture.Moreover, it can be easily maintained by removing it from the metal bell gear 21, and it can be used as a spare during repair. Reflector plate 3
1, it is possible to continue operation.

[Effect of idea]

As explained above, the vapor phase growth apparatus of the present invention has the following features:
A separately formed reflective plate is attached to the metal bell gear, and this reflective plate is provided between the quartz bell gear and the metal bell gear, so a reflective surface can be provided at a relatively low cost and its maintenance is easy. Moreover, since the heat capacity of the reflector is relatively small, cooling is easy and the reflective surface can be protected more reliably, and the heat rays emitted from the susceptor etc. can be more effectively reflected to heat the wafer surface, making it possible to prevent slips. It has many advantages, such as suppressing heat generation and effectively utilizing thermal energy, thereby saving energy.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an embodiment of the present invention, and FIG. 2 is a sectional view of a conventional example. 12... Quartz bell gear, 15... Susceptor, 1
6...Wafer, 21...Metal bell gear, 31...
a reflector.

Claims (1)

[Claims for Utility Model Registration] 1. In a vapor phase growth apparatus having a quartz bell gear that covers a susceptor and a metal bell gear that covers the quartz bell gear, a reflecting plate for the susceptor is attached to the upper inner surface of the metal bell gear, and the metal bell gear and the metal bell gear A vapor phase growth apparatus characterized in that the reflecting plate is positioned between the upper part of the quartz bell gear. 2. The vapor phase growth apparatus according to claim 1, which is a utility model registration, characterized in that a metal film with high reflection efficiency is provided on the lower surface of the reflection plate. 3 Set the radius of curvature of the reflector to the center C1 of the top surface of the susceptor.
2. The vapor phase growth apparatus according to claim 1, wherein the distance is approximately equal to or greater than the distance between C2 and the center C2 of the lower surface of the reflector.