JPH0530352Y2 - - Google Patents

Description

[Detailed explanation of the invention] [Summary] Metal Organic Chemical Vapor Deposition
(hereinafter abbreviated as MOCVD method) The structure of the open door of the sample outlet of the reaction tube used in the device,
The opening of the manifold is placed in an open door that is placed opposite to a jig called a manifold, which surrounds the reaction tube and is cylindrical and open at the point where the reaction tube is inserted, via an O-ring. A vapor phase growth apparatus in which a ring-shaped protrusion that is inserted into the O-ring is provided, and this protrusion prevents reaction products after growth from adhering to the O-ring.

[Industrial Application Field] This invention relates to a gas phase device using the MOCVD method.
In particular, the present invention relates to the structure of an open door provided opposite to a manifold installed at a sample insertion port of a reaction tube used in a vapor phase growth apparatus.

When manufacturing compound semiconductor substrates such as gallium arsenide (GaAs), hydrogen gas carrying trimethylgallium, which is an organic compound of gallium (Ga), and arsine (AsH ₃ ), which is a hydrogen compound of arsenic, are used.
By introducing the gas into the reaction tube in which the GaAs substrate is installed and heating the substrate, a gas phase chemical reaction occurs between the substrate and the reaction gas introduced into the reaction tube, and the arsenic gas is decomposed from the arsine gas. The components of GaAs and the components of gallium decomposed from trimethyl gallium are deposited on the substrate to form GaAs on the GaAs substrate.
MOCVD methods for forming epitaxial layers are well known.

The sample outlet of the reaction tube used in such MOCVD method is required to be hermetically sealed so that the reaction gas introduced into the reaction tube does not leak to the outside.

[Conventional technology]

FIG. 2 is an explanatory diagram showing the main parts of a conventional MOCVD apparatus. As shown in the figure, one end A is in an open state, and the other end B is connected to the open end A of a reaction tube 1 made of quartz glass squeezed into a tubular shape. A manifold 2 made of stainless steel is attached to the manifold 2, which is cylindrical and has an open position where the reaction tube 1 is inserted.

This manifold 2 is provided with a discharge pipe 3 through which the reaction gas is discharged to the outside after the reaction is completed, and on the side opposite to the side that contacts the open end A of the reaction tube 1, the inside of this reaction tube 1 is kept airtight. A groove 5 is provided into which an O-ring 4 for maintaining the temperature is inserted, and the above-mentioned O-ring 4 is installed within the groove 5.

Furthermore, a disc-shaped open door 6 made of stainless steel is installed to face the open end A of the reaction tube 1, and this open door 6 presses the reaction tube 1 through the O-ring 4 using air pressure or the like. It is set up like this.

Further, a support rod 7 is inserted into the center of the open door 6 using a magnetic shield to prevent the reaction gas inside the reaction tube 1 from leaking to the outside, and its tip is made of carbon and supports the GaAs substrate 8. An installation stand 9 for installation is provided.

Further, a high frequency induction coil 10 for heating the substrate 8 is installed around the reaction tube 1.

GaAs substrate 8 is grown using such a vapor phase growth apparatus.
The case where a GaAs epitaxial layer is grown in a vapor phase will be described.

First, with the open door 6 open, insert the support rod 7 into the open door and place it on the installation stand 9 at the tip of the support rod.
With the GaAs substrate 8 installed, the open door 6 is pressed against the open end A of the reaction tube 1 using air pressure.

In this state, hydrogen gas is introduced into the reaction tube 1 from the gas introduction tube 11 of the reaction tube 1, and after the inside of the reaction tube 1 is sufficiently replaced with hydrogen gas, hydrogen gas carrying trimethyl gallium is introduced from the gas introduction tube 11. and arsine gas, and by passing a high frequency current through the high frequency induction coil 10, the temperature of the substrate is raised to 650 to 750°C.
to rise to. After a predetermined period of time in this state,
After stopping the introduction of the reaction gas into the reaction tube 1 and stopping the energization of the high-frequency coil 10, when the apparatus has cooled down, the open door 6 is opened to take out the GaAs substrate 8 on which GaAs has epitaxially grown. There is.

[Problem that the invention attempts to solve]

However, at the stage of opening the open door 6 and taking out the substrate 8, reaction products such as GaAs attached to the surface of the open door 6 on the side of the reaction tube 1 and the inner wall of the manifold 2 are peeled off and attached to the O-ring 4. A problem arises.

If the reaction product adheres to the O-ring 4 in this way, the open door 6 cannot be airtightly sealed against the reaction tube 1, causing problems such as toxic gas inside the reaction tube 1 being discharged to the outside. There are many. Therefore, the reaction product adhering to the O-ring 4 has been removed by wiping it off using a clean cloth, but such removal work is complicated.

The present invention eliminates the above-mentioned problems and
An object of the present invention is to provide a vapor phase growth apparatus having an open door that prevents reaction products from adhering to the vapor phase growth apparatus.

[Means for solving problems]

The vapor phase growth apparatus of the present invention has a gas introduction tube into which a reaction gas is introduced at one end, and is provided at an open end of a reaction tube with the other end open, and has an opening corresponding to the inner diameter of the reaction tube. a manifold having a groove at the end into which an O-ring is inserted, and a flat open door disposed opposite to the manifold with the O-ring inserted in the groove, A ring-shaped protrusion is provided on a plane exposed inside the reaction tube along the inner surface of the opening of the manifold.

[Effect]

The vapor phase growth apparatus of the present invention has a flat open door 6 installed facing the manifold 2, which is inserted into the opening 22 of the manifold 2 on the flat surface 21 facing the manifold 2. For example, a ring-shaped protrusion 23 made of stainless steel is provided.

In this way, reaction products adhering to the manifold side surface 21 of the opening/closing door 6 or the inner wall of the manifold 2 are prevented from adhering to the O-ring 4, and when the opening door 6 is attached to the manifold 2, the reaction tube 1 Make sure the inside is kept airtight.

〔Example〕

An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is an explanatory diagram of the vapor phase growth apparatus of the present invention. Here, in FIG. 1, parts equivalent to those in FIG. 2 described above are given the same reference numerals.

As shown in the figure, the vapor phase growth apparatus of the present invention differs from conventional apparatuses in that the manifold 2 of the open door 6
The opening door 6 is provided with a ring-shaped protrusion 23 made of, for example, stainless steel and inserted into the opening 22 of the manifold 2 on the side 21 facing the opening door 6.

In this manner, when the open door 6 is opened to remove the grown substrate 8, the reaction products adhering to the surface 21 of the open door 6 facing the manifold 2 do not move in the direction of the O-ring 4 because they are blocked by the protrusion 23, thereby preventing the reaction products from adhering to the O-ring 4.

Therefore, when the open door 6 is fastened to the manifold 2 via the O-ring 4, the reaction tube is kept in an airtight state because the O-ring is kept clean.

Note that this ring-shaped protrusion 23 is not limited to stainless steel, and may be made of a metal that can withstand temperatures of about 400° C. and is chemically resistant to attack.

[Effect of idea]

As described above, according to the vapor phase growth apparatus of the present invention, reaction products attached to the manifold or the open door do not move toward the O-ring, and the O-ring is kept in a clean state. Therefore, the manifold and the open door can be connected without leakage, which has the effect of preventing accidents such as leakage of toxic gas inside the reaction tube to the outside.

[Brief explanation of drawings]

Figure 1 is an explanatory diagram of the vapor phase growth apparatus of the present invention, Figure 2
The figure is an explanatory diagram of a conventional vapor phase growth apparatus. In the figure, 1 is a reaction tube, 2 is a manifold,
4 is an O-ring, 5 is a groove, 6 is an open door, 11 is a gas introduction pipe, 21 is a surface of the open door, 22 is an opening, 23
indicates a protrusion.

Claims (1)

[Claims for Utility Model Registration] It has a gas introduction pipe 11 at one end into which a reaction gas is introduced, and the other end is provided at the open end of the reaction tube 1 and corresponds to the inner diameter of the reaction tube 1. Opening 2
2, and a manifold 2 having a groove 5 at the end into which an O-ring 4 is inserted; and a flat open door 6 disposed opposite to the manifold 2 with the O-ring 4 inserted into the groove 5. a ring-shaped protrusion 23 provided on the flat surface 21 of the open door 6 exposed inside the reaction tube 1 along the inner surface of the opening 22 of the manifold 2;
A vapor phase growth apparatus characterized by having: