JPS61231174A - Manifold for vapor growth - Google Patents

Abstract

PURPOSE:To prevent quality deterioration of product to be deposited due to mixing of gas, by using a specified manifold in accordance with kinds of gas, at depositing compd. semiconductor and polycrystal, etc. on semiconductor substrate by CVD method. CONSTITUTION:On GaAs substrate, AsH3, TMG, TMA as growing gas, H2Se, DEZn, etc., as doping gas are supplied, to form GaAs-AlGaAs multilayer structure by CVD method. In this case, a supplying line 3 and an exhausting line 2 of reaction gas in the manifold A of CVD apparatus are provided parallelly in a single block 1 to conduct a prescribed quantity of carrier gas in supplying and exhausting directions, supplying and exhausting valve seats 7 and 8 are provided between both lines 2, 3, therethrough, the manifold A in which valve rod side and another side are connected to exhausting line and supplying line respectively is used. Stagnation of gas between valve seat and supplying line is decreased to prevent mixing with another gas and manifold is miniaturized, to prevent deterioration in quality of deposited product due to mixing of gas.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to a chemical vapor deposition method used in the CVD method, particularly in the production of semiconductors, to deposit compound semiconductors, insulating films, and polycrystals on semiconductor substrates by chemical reactions. This relates to phase gas switching valves.

(Prior Art) As a semiconductor vapor phase growth film, for example, in an AItGaAs semiconductor laser, AsI(l) is used as a growth gas on a GaAs substrate, and Hz S e % D E Z n is used as a TMGSTMA doping gas. , GaAs
-A! A multilayer structure of GaAs is formed.

However, the supply and exhaust of each of the above gases to the reactor involves an MFC that controls the flow rate of each gas and a valve that sends the gas to the reactor line.
Two valves for sending the gas to the exhaust line were connected to each other by a connecting pipe.

However, in the Qa-As crystal, 1022/cflI3 crystals of Ga and As exist alternately on the top, bottom, left and right.

However, in a semiconductor laser, the impurity Se is doped to make the n-type, and Zn is doped to make the p-type, and the doping density at this time is about 111 IQ pieces/1.
Therefore, 1 out of 10,000 pieces of Ga-As will be replaced with 5e-1PZn. Therefore, Se emits one electron and becomes n-type, and Zn loses one electron and becomes p-type, but n
A 0.1 μm p-type A I G is placed at the junction between the type and p-type.
There is an extremely thin film of a As (Z n), and since the growth rate of this AlGaAs is about 1 μm per hour, about 6 minutes are required for the film to grow.

However, before this p-type AlGaAs (Zn), n
Type AJGaAs (Se) is used, and if it remains in the supply line leading from the switching valve to the reactor and there is so-called stagnation, this will cause the 0 to 1 pmp mentioned above.
Type Aj! It enters GaAs and combines with Se and Zn, killing the p-type. For example, even if this stagnation line has a small amount of law, the amount of electrons is large enough to easily kill Zn. If this growth time is long, the effect will be less to some extent, but if it is only 6 minutes, a small amount of S will be removed from the stagnation line.
e flows into the supply line and the number is 1011 pieces/a11
3. That is, as mentioned above, the disadvantage of killing Zn occurs.

(Problems to be Solved by the Invention) In the conventional example described above, in which two switching valves that switch between a supply pipe and an exhaust pipe for one type of growth gas are connected by a connecting pipe, On10ff operation and the above MF
The most serious problem is that, as mentioned above, two valves are used for each type of growth gas, and these are connected to connecting pipes, supply pipes,
The main problem is that the supply line leading to the reactor is longer than the valve due to mechanical constraints connected to the exhaust pipe, which increases the amount of gas phase gas remaining in this long line.

(Means for Solving the Problems) In order to solve the above problems, the present invention uses, for example, electromagnetism or air to quickly perform one opening or closing operation for one gas phase gas. A plurality of manifolds corresponding to the type of gas phase gas, a supply line leading to the reactor, an exhaust line, etc. are configured in a single block, and the manifold has valve seats on both sides of the valve body and a valve seat in the middle. This problem can be solved by at least shortening the supply line by opening a gas phase gas supply port in the front and reducing the size of both lines and the manifold by making them block-shaped.

(Example) Next, an example of the present invention shown in the drawings will be described in detail.

Reference numeral 1 designates a block, on which are formed an exhaust line 2 that communicates with the inside of a reactor for vapor phase gas growth (not shown) and a gas phase gas supply line 3, both of which lines 2.3. For example, an electromagnetic device 4.4a...
- has a valve body 6.6a... via a valve rod 5.5a... which performs quick valve opening and closing, and this valve body 6.6a...
Supply valve seat 7.7a... and exhaust valve seat 8 at both operating ends of ・
．． 8a... is formed, and both valve seats 7.7a.
The opening manifolds A, Aa, . . . are constituted by an inlet port 9.9a, which is connected to a gas phase gas cylinder (not shown), between .

(Function) Carrier gas flows through the exhaust line 2 and the supply line 3, respectively. To explain one example using the schematic diagram in FIG. 3, 2127111n Ht is constantly flowing as a carrier gas in the direction of the arrow in the exhaust line 2 and the supply line 3.
200cc of DEZn from inlet 9 of manifold A
/win, same (H, Se 100c from 9a of Aa
c/win, same (AsH from 9b of Ab, 500
cc/win is always running.

In the illustrated state, however, the valve element 6a of the manifold Aa (see FIG. 1) opens the supply valve seat 7a and closes the exhaust valve seat 8a, so that the gas phase gas Hzse flowing from the inlet 9a flows through the supply line 3. It reaches the reactor carried by the carrier gas H8 flowing inside. At this time, manifold A is valve body 6--
- is carried to the supply valve seat H2 and exhausted.

The flow of HzSe to the supply line 3 is caused by the valve seat 7a and the valve body 6.
When valves for other gaseous gases are opened to the supply line side by contact with a, the valve body 6a of manifold Aa is positioned like the valve body 6 of manifold A, so the remaining amount of gaseous gas The stagnation area is only an extremely small space indicated by S in the diagram of manifold A in Figure 1.
It is suitable for use in VD equipment, and is even more effective by using Teflon material for the sealing part.

However, as mentioned above, since the stagnation part S of the gas phase gas is extremely small, the supply flow of the gas phase gas by switching the valve body is
Both are carried out along with the flow of the carrier gas, allowing for favorable vapor phase growth without being mixed in when other vapor phase gases are supplied.Moreover, since they are constructed in a single block, they are not only compact, but also easy to handle. It has advantages.

[Brief explanation of drawings]

The drawings show an example of the implementation of the present invention; FIG. 1 is a partially cutaway front view, FIG. 2 is a side view, and FIG. 3 is a schematic diagram of each line. Code, A % A a s A b... is the manifold, S is the stagnation part of gas phase gas, 1 is the block, 2 is the exhaust line, 3 is the supply line, 6.6a... is the valve body, 7
．． 7a... is a supply valve seat, 8.8a... is an exhaust valve seat,
9.9a.°... is the gas phase gas inlet. Figure 2 Party Figure 3

Claims (1)

[Claims] In a manifold in a gas-phase chemical reaction device, a supply line for a reaction gas connected to a reaction vessel and an exhaust line for releasing gas when not supplied are configured in parallel in a single block, and are arranged in the supply direction and the exhaust direction. A predetermined amount of carrier gas is allowed to flow, and between the above two lines, valve seats are formed on both operating sides of the valve body, and through each valve seat, the valve rod side is connected to the exhaust line, and the other side is connected to the exhaust line. The gas phase between the valve seat and the supply line is connected to the supply line, and consists of an integral block using a manifold that can only open and close, and is connected to the gas phase by opening the gas phase gas line between the two valve seats. A manifold for vapor phase growth characterized by minimizing the amount of gas stagnation to avoid mixing with other gases and being miniaturized.