JPS6261317A - Vapor growth method - Google Patents

Abstract

PURPOSE:To obtain the crystal of a uniform thickness by a method wherein a plurality of gas feeding holes are provided in such a manner that the cross-sectional area of the holes are formed large in the center part and they are formed small on the outer circumferential part. CONSTITUTION:The raw gas introduced from an introducing pipe 6 is discharged from a nozzle 6a having a large cross-section in the center part and a small cross-section on the outer circumferential part. As a result, the trouble of insufficient crystal growth on the circumferential part of a substrate generated in the past when a large quantity of gas is flowed can be removed, and the thickness of crystal can be made almost uniform on each position of the substrate. Also, the nozzle part 6a has a hollow structure, and the formation of a reaction product on the nozzle part 6a can be prevented by the radiant heat of a heating device 5 by flowing the cooling medium such as water and the like in the vacant space provided in the nozzle 6a.

Description

[Detailed description of the invention] [Technical field of invention] The present invention relates to a semiconductor vapor phase growth apparatus.

[Technical background of the invention and its problems]

A conventional vapor phase growth apparatus has a structure as shown in FIG. 4, in which organometallic gases such as trimethylgallium and trimethylaluminum are alternately supplied from a gas supply port 6 at the top, and the apparatus is rotated. Although a method is used in which the entire crystal is grown on a gallium arsenide substrate 2 mounted on a graphite support 3, the thickness of the crystal is not restricted in the radial direction of the substrate for the following reasons.

In other words, in the reactor according to the prior art, since there is only one supply port in the center, when the gas flow rate is slow, the flow rate near the outer periphery of the substrate is relatively high, so that the substrate Many crystals grow outside [61 parts]. It is also known that when the flow rate is high, the inertial force of the raw material gas causes a large amount of growth on the substrate at 3° C. on the extension line of the supply port, resulting in a curve like the curve I3 in FIG. 5.

However, in semiconductor manufacturing, such non-uniformity significantly reduces yield, and therefore a growth apparatus that can uniformly grow crystals over a large area is desired.

[Purpose of the invention]

This invention improves the drawbacks of the conventional device mentioned above.
The overall purpose is to provide a complete device capable of obtaining uniform crystalline gold.

[Summary of the invention]

A complete overview of the invention follows. In the vapor phase growth apparatus according to the present invention, a plurality of gas supply ports are provided, and the cross-sectional area of the supply ports is large at the center and small at the outer periphery. In order to prevent the growth of crystals, this part is made into a single layer through which a cooling medium can flow.

〔Effect of the invention〕

According to the present invention, crystals with uniform thickness can be obtained, and unnecessary crystal growth in areas other than the substrate inside the reaction tank can be minimized.

[Embodiments of the invention]

Embodiments of the invention are fully described below. FIG. 1 is a sectional view of an embodiment of the invention. The raw material gas introduced from the introduction pipe 6 in the figure is discharged from a nozzle 6a having a large section at the center and a small section at the outer periphery.

As a result, the lack of crystal growth around the substrate, which has conventionally been a problem when a large flow rate is used, is resolved, and the thickness of the crystal can be made almost constant at each position on the substrate.

The secondary nozzle part 6a has a gold hollow structure, and by flowing a cooling medium such as water into this space, the 6
It is possible to prevent reaction products from forming in the nozzle portion of a.

[Other embodiments of the invention]

Note that the present invention is not limited to the above-mentioned embodiment, and for example, as shown in FIG.
A configuration in which there is more in the central part and less in one peripheral part is also conceivable. Further, the cross-sectional shape of the raw material gas supply nozzle is not limited to a circle, and other shapes such as a rectangular shape or an ellipse are also possible. Furthermore, the supply nozzle is not limited to the open-hole type, and may be one inserted into all the reaction vessels of a plurality of pipes.

The cooling method of the main nozzle part is not limited to the above embodiment, and other shapes may be adopted as long as the entire supply nozzle part can be effectively cooled.For example, as shown in Fig. 3, the cooling method is completely independent. It may also be provided.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an embodiment of the invention.
The figure is a sectional view showing another embodiment of the present invention. FIG. 4 is a cross-sectional view of a conventional vapor phase growth apparatus, and FIG. 5 is a conceptual diagram showing the state of crystal growth due to differences in gas flow values. 1... Reaction tank 2... Gallium arsenide substrate 3... Graphite support stand 4... Graphite support stand rotation mechanism 5... High frequency coil e... Raw material gas introduction pipes 6a, 6b, 5c... Raw material Gas supply nozzle 7...Gas discharge pipe 8...Cooling water distribution pipe 8a...Cooling water passage 9...Cooling water piping Fig. 1 Fig. 2 Fig. 3

Claims (3)

[Claims] (1) A vapor phase growth apparatus for a method of obtaining crystals by reacting gaseous organic metals, characterized in that a plurality of nozzles for introducing gas into a reaction tank are provided. (2) The vapor phase growth apparatus according to claim 1, wherein the supply nozzle opening area per unit area is large in the center and small in the peripheral area. (3) Claim 1, characterized in that the supply nozzle part has a hollow structure and is cooled by flowing a cooling medium therein.
Vapor phase growth apparatus described in Section 1.