JPS6237374A - Vapor growth device - Google Patents

Abstract

PURPOSE:To grow a film having high quality without forming a gas stagnating part in a reaction tube of a vapor growth device by inserting a reactive gas supply pipe into the reaction tube in such a manner as to create a space between the same and the inside wall of the reaction tube and providing plural carrier gas supply pipes to the periphery in the upper part of the reaction tube. CONSTITUTION:A susceptor 4 carrying a substrate is placed in the vapor reaction tube 1 and the reactive gas supply pipe 2'' is inserted therein so as to reach the inside of the tapered part 1a of the reaction tube 1. The reactive gas for film formation and growth is supplied from the reactive gas supply pipes 2, 2' connecting to the supply pipe 2'' into the reaction tube 1 and the film is formed on the substrate surface on the susceptor 4 by the vapor growth. Burble swirls where the reactive gas stagnates are formed in the space 5 between the inside wall in the tapered part 1a of the reaction tube 1 and the reactive gas supply pipe 2''; therefore, the carrier gas such as H2 is supplied from the carrier gas supply pipes 6 provided at equal intervals in the peripheral direction to the upper part of the reaction tube 1 to prevent the formation of the burble swirls so that the film having excellent quality is grown on the substrate.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a vapor phase growth apparatus that utilizes chemical reactions such as MOCVD (organometallic compound method), and in particular, to a vapor phase growth apparatus that uses chemical reactions such as MOCVD (organometallic compound method), and in particular, to The present invention relates to a vapor phase growth apparatus.

[Conventional technology]

In the vapor phase growth method that utilizes chemical reactions, the method of introducing the reaction gas into the reaction tube is as shown in Figure 3.
A reaction gas supply pipe 2.2' and an atmospheric gas supply pipe 3 are provided in a reaction tube 1 having a non-tapered circular or rectangular cross section through the end wall of the tube, and from these tubes. A method of introducing a reaction gas into the vicinity of the susceptor 4 in a reaction tube in which a substrate etc. are set, and a method of supplying the reaction gas to the inlet portion sandwiched by the taper of the reaction tube 1 with a taper 1a as shown in FIG. A method of connecting tube 2 and introducing the tube from the inlet of tube 1, or as shown in FIG.
．． A method is known in which a reactant gas supply pipe 2 is extended and inserted from the end of the susceptor 4 to a point close to the susceptor 4, and the reactant gas is introduced through the pipe 2.

[Problem that the invention seeks to solve]

However, among these conventional methods, Figs.
In the method shown in the figure, a so-called separation vortex A is generated in the space between the reaction tube 1 and the reaction gas supply tube 2 inserted therein, which is separated from the gas flow and stays for a long time. There are drawbacks that prevent rapid replacement.

Furthermore, in the above three methods, including the method shown in FIG. Both methods have the disadvantage of contaminating the inside of the pipe, and therefore, it is impossible to grow a high-quality film over a long period of time, making it impossible to further increase the operating rate of the device.

This invention was proposed with the aim of eliminating the above-mentioned problems.

[Means for solving problems]

In order to eliminate the above-mentioned drawbacks, the present invention provides a reaction gas supply pipe 2 which is inserted into the reaction tube from one end side of the reaction tube 1 whose one end is made thinner by applying a taper 1a, as shown in FIG. The tube is inserted in such a manner that a space 5 is created between the tube and the inner wall of the reaction tube around the entire circumference of the tube, and a supply tube 6 for a carrier gas inert to the growth reaction is communicated with the space at one end of the reaction tube. It is something that

[For production]

In this way, when the reaction gas is introduced into the reaction tube 1 through the gas supply tube 2 and the carrier gas is introduced through the gas supply tube 6 at the same time, the carrier gas flow prevents separation vortices in the outer circumferential space of the reaction gas supply tube 2. Therefore, the steepness of the gas composition within the reaction tube can be exchanged.

The carrier gas also acts as a screening gas when nonvolatile decomposition products generated by thermal decomposition near the susceptor 4 reach the inner wall of the reaction tube.

In order to suppress the adhesion of non-volatile decomposition products to the inner wall of the reaction tube,
There is also less dirt in the reaction tube.

〔Example〕

FIG. 2 attached hereto shows an example of an apparatus for introducing a plurality of types of reaction gases into a reaction tube.

Reference numeral 1 in the figure is a cylindrical reaction tube with a tapered end 1a, and a gas introduction section 7 is provided at the tapered end of the tube. This gas introduction section 7 includes a reaction gas supply tube 2 inserted into the axial center of the reaction tube 1, a reaction gas supply tube 2' having a gas passage concentrically surrounding the outer circumference of the tube 2 at its tip, and this tube 2'. A reactant gas supply pipe 2'' extending the gas passage at the tip of the pipe to near the susceptor 4, a carrier gas supply pipe 6.6 connected to the peripheral wall of a flanged sleeve 8 surrounding the rear outer periphery of this pipe 2'', and such members. The carrier gas (for example, H2) flows toward the susceptor 4 through the annular space 5 created between the tube 2'' and the reaction tube 1. It looks like this.

The tube 2″ is connected to a reactant gas supplied from the tube 2 (for example, (CH
3) 3Ga or (CH3) 3AI2. ) and the reaction gas (e.g. AsH3) supplied from the tube 2'' and guide it to the vicinity of the susceptor 4. However, in order to improve the mixing of the reaction gas, it is necessary to close the end of the tube 2 as shown in the figure. It is preferable to close the section and make a small hole 2a in the outer circumferential surface near the hole 2a, through which the gas passing through the tube 2 is blown radially into the gas supplied from the tube 2'.

Although at least one carrier gas supply pipe 6 is sufficient, the number of carrier gas supply pipes 6 may be increased and connected to the sleeve 8 at equal intervals in the circumferential direction in order to generate a carrier gas flow evenly around the pipe 2''. It is preferable to leave it there.

〔effect〕

As described above, according to the present invention, the carrier gas is directed toward the susceptor side into the space between the reaction gas supply pipe facing into the reaction tube from the tapered end of the reaction tube and the inner wall of the reaction tube. Because of the flow configuration, the carrier gas flow prevents the separation vortices that tend to occur around the reaction gas supply pipe, and as a result, the gas composition within the reaction pipe is rapidly exchanged, resulting in the formation of thin films such as semiconductor multilayer thin films. The effect is that rapid interface formation occurs during growth.

In addition, the carrier gas also helps to suppress the adhesion of non-volatile decomposed products generated by thermal decomposition of the reaction gas to the inner walls of the reaction tubes, thereby preventing fouling of the inner walls of the reaction tubes, thereby extending the cleaning cycle of the reaction tubes. It becomes possible to do so.

Therefore, a stable growth reaction over a long period of time can be expected.
The operating rate of the equipment will increase.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the basic configuration of the device of the present invention, and FIG.
The figure is a sectional view showing the main part of one embodiment, and each of FIGS. 3 to 5 is a diagram showing a conventional vapor phase growth apparatus. 1...Reaction tube, 1a...Taper, 2.2', 2''.
...Reaction gas supply pipe, 4... Susceptor, 5... Space continuous in the circumferential direction, 6... Carrier gas supply pipe, 7.
...Gas introduction part, 8...Sleeve with flange, 9.
・0 ring

Claims (2)

[Claims] (1) Insert the reaction gas supply pipe into the inside of the reaction tube from one end side of the reaction tube whose one end is tapered so that there is a space between it and the inner wall of the reaction tube around the entire circumference of the tube. A vapor phase growth apparatus further comprising: a supply pipe for a carrier gas inert to the growth reaction being communicated with the space at one end side of the reaction tube. (2) The vapor phase growth apparatus according to claim (1), wherein a plurality of carrier gas supply pipes are provided at equal intervals in the circumferential direction.