JPH04177721A - Vapor growth device - Google Patents

Abstract

PURPOSE:To make it possible to make uniform the film thickness of a crystal thin film, which is grown on a substrate, over the whole surface of the substrate by a method wherein a horn installed over the substrate for diffusing raw gases is formed into a double structure. CONSTITUTION:Gases, whose components are both identical, are introduced through a raw gas introducing port A5 and a raw gas introducing port B6 and the flow rates of the gases can be respectively controlled individually by flow rate control systems, which are not shown in the diagram, at the ports A5 and B6. In the case the film thickness of a crystal thin film grown on a substrate 3 is uneven, such as in the case the center of the substrate 3 is thick and the outer peripheral part of the substrate 3 is thin, the raw gases are respectively introduced through the ports A5 and B6 in such a way that the flow rate of the gas which is fed through a horn B8 is relatively higher than the flow rate of the gas which is fed through a horn A7. Thereby, the film thickness of the crystal thin film which is grown on the substrate 3 can be made even.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vapor phase growth apparatus, and particularly to a vapor phase growth apparatus for growing a crystal thin film of compound semiconductor or the like on a substrate.

[Conventional technology]

FIG. 2 is a sectional view showing a conventional vapor phase growth apparatus.

The vapor phase growth apparatus shown in FIG.
A conical horn 10 centered around the center of the reaction tube 1 installed above and a source gas inlet 9 for introducing waste only into the horn 10 are connected.

A carrier gas such as hydrogen is introduced through the carrier gas introduction 1''4 located at the upper part of the reaction tube 1, and group M metal raw materials such as indium and phosphorus and group V hydrides such as arsine and phosphine are introduced through the raw material gas inlet 9. Introducing the raw material mixed gas,
A thin film of a compound semiconductor is grown on the substrate 3' by supplying it to a substrate 3' placed on a substrate 2' and heating the substrate 3 by a heating system (not shown). The raw material gas introduced from the raw material 1 gas introduction 19 is diffused by the horn 10 with a velocity distribution as shown by the dotted line in the figure so that it is supplied to the substrate 3'2 as uniformly as possible. usually,
Growth is performed by rotating the susceptor 2 so that the raw material is more uniformly supplied to the substrate 3''.

[Problem to be solved by the invention]

The conventional vapor phase growth apparatus described above has one gas inlet port 9
When the introduced raw material gas passes through the horn 10, it has a velocity distribution as shown by the dotted line in the figure. As a result, the crystal thin film grown on the substrate 3 becomes thinner at the outer periphery than at the center, impairing film thickness uniformity, and reducing the yield of the vapor phase growth process. There was a drawback.

[Means to solve the problem]

The vapor phase growth apparatus of the present invention includes a conical horn A with the center of the reaction tube as an axis installed on a susceptor placed on a susceptor housed in a vertical reaction tube; A source gas inlet A for introducing gas only into the horn A, a conical horn B having a solid opening concentrically with the horn A on the outside of the horn A, and a conical horn B for introducing gas only into the horn B. It is configured to include a raw material gas introduction port B to be introduced.

[Example] Next, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a sectional view showing an embodiment of the present invention.

The vapor phase growth apparatus shown in FIG. 1 includes a substrate 3+ placed on a susceptor 2-1- housed in a vertical reaction tube 1.

A horn A7 with a circular rust shape centered around the center of the reaction tube 1 installed in the horn, a source gas inlet A5 that introduces gas only into the horn huff, and a concentric opening in the horn huff on the vertical side of the horn A7. It is composed of a horn B8 having a conical shape and a source gas inlet B6 that introduces waste only into the horn B8.

A gear carrier gas such as hydrogen is introduced from the carrier gas inlet 4 located in the second part of the reaction tube 1, and the raw ore gas is introduced through the carrier gas inlet 4.
5 and raw ore gas introduction D B 6 introduces a mixture of Group I metal raw materials such as indium and phosphorus and Group V hydride raw materials such as arsine and phosphine, and then introduces a mixture of raw materials of group I metals such as indium and phosphorus and raw materials of group V hydrides such as arsine and phosphine. A compound semiconductor thin film is grown on the substrate 3 by heating the substrate 3 with a heating system (not shown). Raw material gas inlet A5 and source A3
The raw material gas introduced through the t-gas inlet B6 is transferred to the substrate 3.
''-The horn A7 and the horn B8 diffuse the light with a velocity distribution as shown by the dotted line in the figure so that the light is supplied as uniformly as possible. Normally, growth is performed by rotating the susceptor 2 so that the raw material is more uniformly supplied to the substrate 3''.

Gases having the same composition are introduced from both the raw material gas inlet A5 and the raw material gas inlet B6, and the gas flow rate can be independently controlled by a flow rate control system (not shown). can. Substrate 3”
Second, if the thickness of the grown crystal thin film is non-uniform, for example, if the center of the substrate 3 is thick and the outer circumference is thin, the gas flow rate supplied from horn B8 is relatively higher than the gas flow rate supplied from horn A7. In order to increase the amount of raw material gas inlet A5
The raw material gas is introduced from each of the raw material gas inlet B6 and the raw material gas inlet B6.

[Effects of the invention]

The vapor phase growth apparatus of the present invention has a double horn installed on the substrate to diffuse the raw material gas.
It is unique because it is possible to supply ore gas independently to the center and outer periphery of the substrate.

This has the effect of uniformly supplying raw gas to the substrate, and making the thickness of the crystal thin film grown on the substrate uniform over the entire surface of the substrate.This means that the yield in the vapor phase growth process can be made the same. , it has the effect of being able to do something.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the present invention, and FIG. 2 is a sectional view showing a conventional vapor phase growth apparatus. 1... Reaction tube, 2... Susceptor, 3... Substrate, 4
... Carrier gas inlet, 5... Raw material gas inlet A, 6... Raw material gas inlet B17... Horn A,
8... Pawn B19... Raw material gas inlet, 10...
·Horn.

Claims (1)

[Claims] In a vapor phase growth apparatus in which a substrate is placed on a susceptor housed in a vertical reaction tube and a crystal thin film is grown on the substrate, the center of the reaction tube placed on the substrate in the reaction tube is the axis. A horn A having a conical shape, a source gas inlet A that introduces gas only into the horn A, and a horn B having a conical shape having an opening concentric with the horn A on the outside of the horn A. and a source gas inlet B for introducing gas only into the horn B.