JPS62291023A - Rotary branch valve - Google Patents

Abstract

PURPOSE:To enable a growth layer to be formed particularly having steep and excellent layer impurity concentration in thin film lamination growth of a compound semiconductor or the like, by making such a composition that reactant gases are made to branch by rotating a branching rod. CONSTITUTION:When lamination growth of a thin film is performed on a substrate by introducing reactant gases into a reactor chamber in which the substrate is mounted, as branch valve, in which introduction tubes for the reactive gases containing constituents for thin film semiconductor formation are made to branch in two or more directions, is composed so that the said reactant gases are made to branch by rotating as branch rod 15. The said branch rod 15, for example, is shaped in a cylinder, and being provided with a hole which is shaped rectilinearly or in a L character that links the center of the one end with the side plane, with the other end directly connected with a rotary drive motor 13. Such a branching valve enables the reactant gases to branch not only in two or three directions but also in more ones by means of rotation of the branch rod 15. Gases can be quickly exchanged with all lines symmetrized.

Description

[Detailed Description of the Invention] 3. Detailed Description of the Invention 2 B/ Industrial Application Field The present invention provides a good growth layer in which the interlayer impurity concentration is particularly steep in the layered growth of thin films such as compound semiconductors. The present invention relates to a rotary branch valve that can perform

BACKGROUND OF THE INVENTION Recently, research and development of beterojunction devices using compound semiconductors has been actively conducted. Conventional liquid phase epitaxy (LPE, Li
Instead of the quick phase epitaxy (quid phase epitaxy) method, molecular beam epitaxy (
M B E Molecular Beam Epit
axy) method and vapor phase growth (V P E Vapor Ph
Ase Epitaxy) method is the mainstream. Among these vapor phase growth methods, MOVPEMetal Organic Vapor Growth using an organometallic compound
The por phase epitaxy method is attracting attention as a method with particularly high mass productivity. This MOVPE
The device has a normally open one-way air differential valve.
The reactant gas has been branched by a combination of the equation and the normally close method, but recently a 3-bay branch valve (Nupro Company) shown in FIG. 4 has come into use. This figure is a schematic diagram showing only the main parts of the branch valve. 1.2 is an inlet; for example, 1 is used as an inlet for reaction gas and hydrogen for gear gas, and 2 is used as an inlet for only hydrogen. 3 and 4 are outputs 1], 6 is a bellows, 6 is a stem tip, 7 is a spring, and 8 is an air inlet. When the air is not injected from the air population 8, the stem tip 6 is closed by the spring 7.
is at the bottom. For example, an organometallic compound is introduced through the inlet 1 and flows to the outlet 4. At this time, only hydrogen is introduced into the inlet 2 and is allowed to flow toward the outlet 3. Next, when air is introduced into the air outlet 8, the stem tip 6 rises upward, and the organometallic compound introduced from the inlet 1 does not flow toward the outlet 4, but flows only to the outlet 3.

Problems to be Solved by the Invention However, with this method, the stem tip 6 is located upward, and when the organometallic compound introduced from the inlet 1 flows toward the outlet 3, it flows without stagnation, but the stem tip 6 is located downward. There is a bellows 5 in the middle of the flow when it flows towards exit 4, and there is a problem of stagnation in the gap between the bellows 5 and exit 3.
There was a problem that the symmetry was poor and the gas flow was different at outlet 4 and outlet 4. Further, it is not possible to branch into three or more directions with only two directions.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention has, for example, a cylindrical shape, an L-shaped or linear hole connecting the center of one end and the side surface, and a hole at the other end. A rotary type that can branch to a desired position by inserting and rotating a branching frame, which is directly connected to a rotary drive motor, into a body having several holes according to the positions of the holes on the side surface. It is a branch valve.

For production The effect of this technical means is as follows.

Place the branch frame into a body that has several holes at the same height as the holes drilled on the side of the branch frame, and insert one side of the branch frame according to the positions of the holes on the side of the branch frame and the holes provided in the body. For example, an organometallic compound is introduced from the end and flows from the body into the line. If you want to send 6 vanes to another line, quickly rotate the branch frame to the desired hole position. All lines have good symmetry and gas switching can be done quickly. Also, 3 on the body
By providing holes in different directions, it is possible to branch in multiple directions.

Example A specific embodiment according to the present invention is shown in FIG.

11 is an inlet for organometallic compounds, 12 is a female grommet screw, 13
14 is a motor, 14 is an outlet, 16 is a branch frame, 16 is a gasket, and 17 is a body. FIG. 2 shows the branch frame 16 and the motor section 13. In this example, the hole is L-shaped.

If three exits 14 are provided in the body 17, the branch frame 1
By quickly rotating 5, you can branch into three directions without stagnation.

An example of a MOVPE device manufactured using the branch valve of the present invention is shown in FIG. Epitaxial growth was performed and good results were obtained. In order to clarify the effect of this branch valve, an undope layer is used.

A good result was obtained in which the n-type layer and the p-type layer were formed continuously (the transition layer was extremely small).

A specific example of 6″′, - will be described below.For example, L12 of carrier gas)
26, TMA40°TM, which is a constituent element of compound semiconductor
G 39 , AsHs 38 using valve 27.
28.

Constituent gases via 29 to branch valve 30.

A carrier gas is introduced. Now, undoped-Ga
When epitaxially growing As on the substrate 23, constituent element gas TMG39. AsH33
The branch valve 30 is controlled so that the 8° carrier gas H226 is introduced.

Next, when epitaxially growing n+Alo, 3Gao, and 7As, TMG39, TMA40r
By quickly rotating the branch valve 3o, AsH338 is led to the introduction pipe 43 side, and through the valve 35, %Se36, TMG39, TMA40
, AsH338) is added to the town 26, mixed with various reaction gases, and supplied onto the substrate 23 to form n+AI, 3G
ao, 7As is epitaxially grown. Also, p+G
When growing aAs, TMG39. AsHs38.
Quickly turn the branch valve 3o to connect H226 to the inlet pipe 4.
DEZ 3 is TMG through the guiding valve 34 to the 1st side.
39, A sH338.

H226, mixed with various reaction gases, and supplied onto the substrate 23 to epitaxially grow p''GaAs.

In addition, the supply amounts of the various gases mentioned above are each TMA
= 3 cc/min (20″C), TMG
= 10Cc/mlyr (ooC).

AsH3=15cc/min, H2S e ml
E/min (H2 dilution 200ppm concentration), DE
Z = 6rx, 7m1n (0°C), H2 = 217-
The substrate temperature is 780°C2, the growth rate is 1μ for each layer
m/hr.

Using the branch valve 3o according to the invention, undoped
When the n-type layer and the p-type layer were successively grown, the transition region at the interface of each dopant was 208 or less, and very good results were obtained. Naturally, the memory effect of Se and Zn was completely absent.

Effects of the Invention The branching valve of the present invention can branch the reaction gas by rotating the branching frame, and can branch not only in two or three directions but also in more directions. Furthermore, this branch valve has good symmetry and almost no stagnation, so
When the ED layer, n-type layer, and p-type layer of GaAs are successively grown, a steep interface with an impurity transition region of 20 Å or less at each interface can be obtained with good reproducibility.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a branching device according to an embodiment of the present invention, FIG. 2 is a perspective view of a part of the present invention, and FIG. 3 is a M
A schematic diagram of an OVPE device, and FIG. 4 is a schematic diagram of a conventional branching device. 13...Motor, 15...Branch frame. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 1? Otome 0G 12 I3 Moog 2nd figure\-1〆

Claims (3)

[Claims] (1) When placing a substrate or introducing a reactive gas into the actor chamber to grow a thin film on the substrate,
1. A rotary branching valve, wherein the branching valve branches an inlet tube for a reactive gas containing constituent elements for forming a thin film semiconductor into at least two directions, and branches the reactive gas by rotating a branching rod. (2) The branch rod has a cylindrical shape, has an L-shaped or linear hole connecting the center of one end to the side, and has the other end directly connected to the rotational drive motor. A rotary branch valve according to claim (1). (3) The rotary branch valve according to claim 1, which is used in a metal organic vapor phase epitaxy device.