JPH01257191A - Vapor phase crystal growth equipment - Google Patents

Abstract

PURPOSE:To efficiently form a high-purity thin film crystal by placing plural susceptors on a discoid rotary holder provided in a spare chamber, and successively moving the evacuated susceptors into a growth chamber to grow a crystal. CONSTITUTION:Plural substrates 6 are loaded in the susceptors 5 on the discoid holder 4 in the spare chamber 2, and then the spare chamber 2 and the growth chamber 1 are evacuated to remove remaining moisture and oxygen. The holder 4 is rotated, the susceptor 5 to be sent to the growth chamber 1 is placed under a transfer rod 10, the susceptor 5 is lifted by the rod 10 into an attached chamber 11 of the spare chamber 2, the holder 4 is rotated to position an opening 8 under the susceptor 5, a gate valve 3 is opened, then the susceptor 5 is lowered and loaded on a supporting shaft 9 in the growth chamber 1, the rod 10 is lifted up into the spare chamber 2, and the valve 3 is closed. The substrate 6 is then heated by a high-frequency coil 12, and a raw gas 11 is supplied from the upper part to grow a crystal.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an apparatus for growing semiconductor thin film crystals on a substrate in vapor phase, and in particular, an apparatus suitable for carrying out metal-organic vapor phase epitaxy. Regarding.

(Prior Art) Conventionally, AfGaAs-based semiconductor thin film crystals are grown by metal organic vapor phase epitaxy (OMVPE).

In this type of crystal growth, there is a problem that if moisture or oxygen in the air enters the growth chamber, the characteristics of the crystal deteriorate. An apparatus is used in which the substrate is removed and then transferred to a growth chamber for vapor phase crystal growth.

FIG. 2 is a conceptual diagram of a conventional vapor phase crystal growth apparatus. A preliminary chamber 2 is provided above the vertical growth chamber 1 via a gate valve 3, and the preliminary chamber 2 is connected to a vacuum evacuation system so that the growth chamber 1 can also be evacuated separately.

The susceptor 5 loaded with the substrate 6 is stored in the preliminary chamber 2, and after being vacuum-exhausted to remove residual moisture and oxygen, the gate valve 3 is opened, and the susceptor 5 is transferred to the support shaft 9 of the growth chamber 1 using the transfer rod 10. Mount. After the transfer rod 10 is pulled up to the preliminary chamber 2, the gate valve 3 is closed, the substrate 6 is kept at a predetermined temperature by the high frequency filter 12, and the raw material gas 11 is introduced to grow a thin film crystal on the substrate 6. When the film has grown to a predetermined thickness, the supply of raw material gas is stopped, the residual gas in the growth chamber 1 is exhausted or purged with an inert gas, and then the gate valve 3 is opened again and the susceptor 5 is transferred using the transfer rod 10. Take it to preliminary room 2. Then, after closing the gate valve 3,
Open the lid, take out the substrate on which the thin film crystal is to be grown, load a new substrate onto the susceptor, and then repeat the operating procedures such as evacuation of the preliminary chamber, movement of the susceptor to the growth chamber, and crystal growth. Thin film crystals are sequentially grown on multiple substrates.

(Problems to be Solved by the Invention) In this way, in the conventional apparatus, one susceptor is used to sequentially perform operations from vacuum evacuation in the preliminary chamber to crystal growth in the growth chamber. When performing vacuum evacuation, the growth chamber must be rested, which greatly limits the productivity of the entire apparatus.

SUMMARY OF THE INVENTION The present invention aims to solve the above-mentioned problems and provide a vapor phase crystal growth apparatus capable of exchanging substrates and evacuating the preliminary chamber during crystal growth.

(Means for Solving the Problems) The present invention provides a vapor phase crystal growth apparatus in which a preliminary chamber is connected to the upper part of a vertical growth chamber via a gate valve, and both are provided with exhaust means, in which a substrate is loaded. A disc-shaped support base on which the susceptor is placed in an annular manner is provided in the preliminary chamber, an opening for passing the susceptor is provided in at least one of the locations where the susceptor is placed on the support base, and a rotating means is attached to the support base, The vapor phase crystal growth apparatus is characterized in that it is provided with means for moving the susceptor into the growth chamber through the opening and the gate valve.

(Operation) FIG. 3 is an explanatory diagram showing a procedure for growing crystals on a substrate using the apparatus of the present invention. After loading a substrate into each of the many susceptors in the preliminary chamber and removing residual moisture and oxygen by evacuating the preliminary chamber, one of the susceptors is moved to the growth chamber, mounted on a support shaft, and the substrate is loaded. Crystal growth is performed on the substrate by heating and introducing raw material gas. After the crystal growth is completed, the residual gas in the growth chamber is exhausted or purged, and then the susceptor is collected on the support stand in the preliminary chamber, a new susceptor is moved from the support stand to the growth chamber, and crystal growth is performed again. After moving the last susceptor on the support stand to the growth chamber, the preliminary chamber is opened to the atmosphere, the substrate after crystal growth is taken out, a new substrate is loaded onto the susceptor, and the preliminary chamber is evacuated. and prepare for susceptor replacement. In this way, the growth chamber can be operated continuously, except when replacing the susceptor, and the throughput can be significantly improved.

On the other hand, in the conventional device, as shown in Figure 2, 1
In order to perform all operations using one susceptor, it is necessary to exchange the substrate and evacuate the preliminary chamber every - degree of crystal growth, and during that time, no crystal growth can be performed in the growth chamber.

(Example) Fig. 1 (a) is a conceptual diagram of a vapor phase crystal growth apparatus which is an embodiment of the present invention, and Fig. 1 (b) is a plan view of a susceptor support used in the apparatus. .

A preliminary chamber 2 is arranged above the vertical growth chamber 1 via a gate oil valve 3, and each is connected to an exhaust system. In the preliminary chamber 2, a disc-shaped rotation support base 4 on which the susceptor 5 is placed is provided,
The support stand 4 has a susceptor 5 arranged in an annular manner as shown in FIG.
can be placed thereon, and an opening 8 through which the susceptor 5 passes is provided in one of the places where the susceptor 5 is placed. The support base 4 is rotated by a rotation mechanism 7. Then, when the support base 4 is rotated to stop the opening 8 just above the growth chamber 1, the susceptor 5 can be lowered into the growth chamber 1 through the opening 8 and the gate nozzle 3. It is combined with the growth chamber 1. In addition, in order to raise and lower the susceptor 5, the preliminary chamber 2
A transfer rod IO is provided in the holder. The transfer rod 10 suspends the susceptor 5 in the auxiliary chamber 11 of the preliminary chamber 2, and allows the support base 4 to rotate.

The growth chamber 1 is provided with a support shaft 9 for holding the susceptor 5, which is lowered by the transfer port/rad 10, in the growth region, and a conduit for supplying the raw material gas 11 is arranged above the growth region. A high frequency filter 12 is provided to heat 6.

Although a pancake-shaped susceptor is shown in FIG. 1, a barrel-shaped susceptor or the like can also be used, and a large number of substrates can be loaded into one susceptor. Further, although the figure shows a support base on which seven susceptors are placed, the number can be changed as necessary.

Next, the operating procedure will be explained. First, seven substrates 6 are loaded into seven susceptors 5 on the support stand 4 in the preliminary chamber 2. This loading may be performed outside the preliminary chamber, and the susceptor 5 may be placed on the support stand 4 in the preliminary chamber. Then, the preliminary chamber 2 is evacuated to remove residual moisture and oxygen. At that time, growth room 1
It is also preferable to exhaust the air. Then, the support stand 4 is rotated, the susceptor 5 to be sent to the growth chamber 1 is placed under the transfer rod 10, and the susceptor 5 is carried into the attached chamber 11 of the preparatory chamber 2 by the transfer rod 10.
The support base 4 is rotated again to position the opening 8 under the susceptor 5, the gate valve 3 is opened, and the susceptor 5 is lowered and mounted on one of the support shafts 9 of the growth chamber 1. By pulling the transfer rod IO into the preliminary chamber 2 and closing the gate valve 3, preparations for crystal growth are completed. Thereafter, crystal growth is performed by heating the substrate 6 with the high-frequency coil 12 and supplying the raw material gas 11 from above, as in the conventional apparatus. When a crystal with a predetermined thickness is formed, the introduction of the source gas 11 is stopped, the residual gas in the growth chamber is exhausted, and if necessary, it is purged with an inert gas. Then, the gate valve 3 is opened, the susceptor 5 is recovered into the preliminary chamber 2 by reversing the previous procedure, and a new susceptor 5 is transferred from the support stand 4 of the preliminary chamber 2 onto the support shaft 9 of the growth chamber 1. Moving. These steps are repeated to sequentially form a crystal thin film on the substrate 6 on each susceptor 5. While the susceptor 5 loaded with the last substrate 6 is moved to the growth chamber 1 and crystal growth is performed, the preliminary chamber 2 is opened, the substrate 6 on which the crystal thin film has been formed is taken out, and a new substrate 6 is placed in the susceptor 5. After loading, the preliminary chamber is evacuated again to prepare for replacing the susceptor 5 to the growth chamber.

(Effects of the Invention) By adopting the above-described configuration, the present invention provides a disc-shaped rotating support base on which a plurality of susceptors are placed in the preliminary chamber, and sequentially moves the plurality of susceptors in a vacuum-exhausted state into the growth chamber. crystal growth can be performed continuously by moving to
During the final crystal growth, the substrate in the preparatory chamber can be replaced and vacuum evacuated to prepare for the next crystal growth, so impurities in the atmosphere are not brought into the growth chamber and high-purity thin film crystals can be efficiently grown. This greatly contributes to improving throughput.

[Brief explanation of the drawing]

FIG. 1 is a conceptual diagram of a vapor phase crystal growth apparatus which is an embodiment of the present invention, FIG. 1(a) is an overall view, and FIG. 1(b) is a plan view of a susceptor support. FIG. 2 is a conceptual diagram of a conventional device. FIG. 3 is an explanatory diagram showing the operating procedure by the apparatus of the present invention. Figure 3

Claims (1)

[Claims] In a vapor phase crystal growth apparatus in which a preliminary chamber is connected to the upper part of a vertical growth chamber via a gate valve, and both are provided with exhaust means, a disk-shaped support base on which a susceptor, on which a substrate is loaded, is placed in an annular manner, is used as described above. an opening through which the susceptor passes through at least one of the locations where the susceptor is placed on the support stand; a rotation means is attached to the support stand; the susceptor is moved into the growth chamber through the opening and the gate valve; A vapor phase crystal growth apparatus characterized by being provided with means.