JPS58223317A - Method and device for growing of compound semiconductor crystal - Google Patents

Abstract

PURPOSE:To prevent the formation of an intermediate reaction product, and to form a crystal of excellent crystallinity and surface state by setting up a parting plate inhibiting mixing until at least two kinds of raw material compounds reach a growth layer. CONSTITUTION:Triethyl indium (TEI) and triethyl gallium (TEG) diluted by hydrogen are introduced gas-supply pipe 8 and arsine AsH2 phosphine PH3 diluted similarly by hydrogen form a gas supply pipe 9, and these substances are injected in the opposite direction partitioned by the parting plate 13 for example, from a jet 15 formed to a nozzle 14 constituted by a material such as quartz. Consequently, TEI or TEG and AsH2 or PH3 do no mix directly because they are isolated by the parting plate 13. Accordingly, the intermediate reaction product is not formed, and the crystal of excellent crystallinity and surface state can be formed extending over a range of a wide composition.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for vapor phase growth of compound semiconductor crystals and an apparatus therefor.

AtGaAs on a substrate such as GaAe or InP
.

AtGa, AsP, InGaAs or InGa
Epitaxial growth of AsP and the like has recently become increasingly important for the realization of new functional devices such as semiconductor lasers, photodetectors, and superlattices.

One such vapor phase epitaxial technology for compound semiconductors
As one example, the MOCVD method, which utilizes a thermal decomposition reaction between an organometallic compound and arsine or phosphine, has been developed. However, this conventional method had the following drawbacks. Below, for ease of understanding, zn
The case of growing Tno aA sp on a P substrate will be explained. The growth is performed by diluting with hydrogen and growing Tno aA sp on an InP substrate heated to about 600°C to 700°C.
2H5) 3, hereinafter abbreviated as TEI], triethylgallium (G a (C2H5)3, hereinafter abbreviated as TEG), arsine (AsH3), phosphine (・PH
3) is introduced to cause a thermal decomposition reaction.

This will be explained in detail with reference to FIG. 1 of the attached drawings. 1st
The figure is a schematic diagram of a conventional compound semiconductor crystal growth apparatus.

In FIG. 1, numeral 1 is a reaction vessel, 2 is a susceptor, and 5 is a susceptor.
is a susceptor holder, 4 is a work coil, 5 is a cooling water inlet, 6 is a cooling water outlet, 7 is a board, 8 and 9 are air supply pipes,
10 means an exhaust pipe. In FIG. 1, during epitaxial growth, an InP substrate Z is heated by a work coil 4 that performs high-frequency induction heating in a susceptor 2-I.
Above, TEI and TEG are introduced from the air supply pipe 8 into the reaction chamber, and AsH3 and PH3i are diluted with hydrogen and introduced from the air supply pipe 9, respectively. In order to make the composition and film thickness of the epitaxially grown layer uniform, these gases need to be sufficiently mixed before reaching the substrate, but on the other hand, TEI and A SH3 or PH3 react and form intermediate reaction products. is generated, the composition cannot be controlled sufficiently, and the crystallinity and surface condition deteriorate.

The present invention is characterized by achieving good epitaxial crystal growth without the above-mentioned mixing noise of raw material gases, and its first purpose is to suppress the generation of intermediate reaction products unlike the prior art. The second object is to provide a method and apparatus that can increase the number of wafers that can be processed at one time (and reduce epitaxial growth costs).

That is, to summarize the present invention, the invention of the first method of the present invention is that during epitaxial growth of a compound semiconductor consisting of a compound of at least two or more elements, two or more raw material compound gases containing the elements are fully reacted. The present invention relates to a compound semiconductor crystal growth method in which a single crystal is grown using a compound semiconductor crystal growth method, which is characterized in that mixing of at least two types of raw material compounds in a trench reaching a growth layer is suppressed.

1. The second device invention of the present invention is that, when epitaxially growing a compound semiconductor made of a compound of at least two or more elements, two or more raw material compound gases containing the elements are reacted to grow a single crystal as a whole. The present invention relates to a compound semiconductor crystal growth apparatus in which a partition plate is provided for completely suppressing mixing of at least two types of raw material compounds before reaching the growth layer.

According to the present invention, a plurality of raw material compound gases used for growth are partitioned to prevent at least two kinds of raw material compound gases from mixing at the point where the compound gases reach the growth substrate, and as described below. It has the following effects.

The first effect is that by mixing, it is possible to prevent the mixing of raw material compounds that would produce intermediate reaction products and adversely affect epitaxial single crystal growth, thus making it easier to produce single crystals with good crystallinity and surface condition. It is possible to grow, and furthermore, the composition and impurity concentration can be controlled over a wide range.

The second effect is that many substrates can be arranged on the susceptor, making mass production possible and significantly reducing manufacturing costs.

The fifth effect is that contamination of impurities from the outside world is suppressed, and epitaxial crystals of good quality can be obtained.

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the present invention is not limited to these.

FIG. 2 is a schematic diagram showing an embodiment of the compound semiconductor crystal growth apparatus of the present invention. In FIG. 2, symbols 2 to 4 and 7 to 10 have the same meaning as in FIG. 1, 11 is a Pelger of an epitaxial growth apparatus, 12 is a work coil cover,
5 is a partition plate, 14 is a nozzle, 15 is a blowhole, and 7 is an InP substrate. In FIG. 2, the susceptor 2
is made of carbon, S]C-coated carbon, or has a quartz plate placed thereon. Dilute with hydrogen 11 nI,
TKG is supplied with AsH3 similarly diluted with hydrogen from the air supply pipe 8.
, PH3 are introduced from the air supply pipe 9, and they are connected to the partition plate 15.
The liquid is ejected from a blowhole 15 provided in a nozzle 14 made of quartz, for example, in opposite directions partitioned by quartz.

The susceptor 2 on which the substrate 7 is placed is rotated at an appropriate speed.

TEI and TEG injected from the fumarole 15 undergo a thermal decomposition reaction on the heated substrate 7 (indium and gallium are adsorbed to the substrate), but since the susceptor is rotating, AsH3 and PH3 0 adsorbed indium and gallium or those and A brought into the gas atmosphere of
The combination of sH3 or PH3 with arsenic or phosphorus diffuses on the surface and reaches the kink (~
, crystal growth progresses.

In such a crystal growth method of the present invention, TEI or T
Since EG and AsH3 or PH3 are separated by the partition plate 15, they do not mix directly. Therefore, intermediate reaction products are not generated, and crystals with good crystallinity and surface condition can be grown over a wide range of composition. can do.

Substrate heated to 1600 °C, H2 flow rate 15 cm3/min to TRI bubbler at 24 °C, H2 flow rate 5 cm3/min to TEG bubbler at -2 °C, diluted with hydrogen 1
When the flow rate of 0% AsH3 was 150 cm for 37 minutes and the flow rate of 10% PH3 diluted with hydrogen was 10 crn3/min, a process of about 2 μm that was lattice matched to the InP substrate in 1 hour was obtained.
It was possible to obtain 6P0.4i of GaO, 28 so. The surface of the obtained InGaAsP had a good mirror surface, and there were no problems with crystallinity. The crystal composition could be easily changed by adjusting the gas flow rate. In addition, regarding this eviaxial growth, susceptor 2
The In which is adsorbed during one rotation of approximately 50 revolutions per minute
It is important that the amount of , Ga, etc. does not become too large, and the thickness of the growth layer during one revolution must be approximately equal to or less than the lattice constant.

According to this method, it is possible to mount a plurality of substrates 7 on the susceptor 2, and it is clear that this method is suitable for mass production.

Figure 6 (a) shows the nozzle 14 and partition plate 1 in Figure 2.
50 is a partially enlarged view, and FIG. 3(b) is a cross-sectional view taken along line A-A' in FIG. 6(a). Figure 5 (C) is Figure 5 (B)
It is a BB' sectional view of. In FIG. 5, reference numeral 8.
9. 15 to 15 have the same meaning as in Fig. 2, 16 is a partition wall, 1
7 means slit. In FIG. 6, nozzle 14
The pipes 8.9 are connected to the air supply pipes 8.9, respectively, and are provided with blowholes 15 for gas injection.
This is a bulkhead that completely separates tubes 8 and 9. The partition plate 15 is fitted into a slit 17 provided in the nozzle 14.

FIG. 4 is a schematic cross-sectional view of one embodiment of the partition plate in the device of the present invention, in which a recess 18 is provided to ensure stability when fitted into the nozzle 14.

FIG. 5 is a schematic cross-sectional view of another embodiment of the partition plate in the device of the present invention, in which projections 19 are provided to provide the same effect as in FIG. 4.

FIG. 6 is a schematic cross-sectional view of another embodiment of the partition plate in the apparatus of the present invention, in which a gas containing TEI, TEGi,
AsH31PH3'ff: In order to more thoroughly separate the contained gas, an upper lid is provided to cover the upper part of the gas. In FIG. 6, numeral 15 is a partition plate, 20 is an upper cover plate,
21 means a side wall plate. FIG. 6(A) shows a bottom view thereof, and FIG. 6(B) shows a sectional view taken along line c-c' in FIG. 6(A). The partition plate 15 and the upper cover plate 20 are integrated. Figure 6 (c)
Furthermore, a cylindrical side wall plate 21 is provided on the side surface to ensure gas separation. Furthermore, according to this structure, it is possible to suppress the mixing of impurity gas from the outside.

FIG. 7 shows the separation of the gas 'ff:,! in the partition plate according to the present invention. This is a cross-sectional view of a partition plate in which a gas supply pipe 22 and an injection port 25 for inert gas such as argon or nitrogen or hydrogen are provided at the bottom of the partition plate in order to further ensure this.

FIG. 8 is a schematic diagram of another embodiment of the compound semiconductor crystal growth apparatus of the present invention. In Figure 8, 2.7.11.1
5 has the same meaning as in FIG. 2, and 24 means a housing. 8th
In the figure, as shown in the casing 24, the partition plate is stabilized as a structure that supports the partition plate. It is clear that in a partition plate having side wall plates on the side surfaces as shown in FIG. 6 or FIG. 7, a structure may be used to support the side wall plates. FIG. 2 is an example schematic diagram. A protrusion 25'ff is provided on a part of the inner surface of the Pelger 11: A protrusion 26 is provided on a part of the outer surface of the side wall plate 21 of the partition plate, and these engage with each other to insert the upper and lower parts of the Pelger into a predetermined position of the partition plate. and can be removed.

This greatly simplifies the work before and after crystal growth.
In the case of a partition plate having a gas injection port as shown in FIG. 7, gas can be easily introduced from the Pelger side.

The above explanation was about the case where the nozzle is divided into two parts and two systems of gas are flowed, but if the nozzle is divided into six parts, four parts, etc.
They are divided by many partition plates and TRI, TKG
XAsH3 and PH3 can be introduced into the device as separate systems.

If the number of reaction chambers partitioned by trench partition plates is greater than the number of gas systems, for example, by an integer multiple, then the gas atmosphere will be changed by the above multiple during one rotation of the susceptor, so the rotation speed of the susceptor should be Can be made smaller.

TEI and T were used for single crystal growth of nGaAEIP in this trench.
E.G.

Although we have explained the case of using PH3 and AsH3f, single crystal growth can be similarly achieved using indium compounds such as trimethylindium, gallium compounds such as trimethylgallium, arsenic compounds such as arsenic trichloride, and phosphorus compounds such as phosphorus trichloride. is clear.

In addition, by appropriately selecting the compound used, InP
, GaAs, InGaAs, InAsP,
Epitaxial growth of compound semiconductors such as GaAsP is possible, and by using aluminum compounds and antimony compounds, GaAtAθ, GaA7AsP
.

Epitaxial growth of Garb XGaAsSb etc. is also possible. Addition of impurities to completely control the conductivity type and conductivity of the epitaxially grown layer can also be easily carried out by introducing a compound of a desired element, such as a cadmium compound, into the reaction chamber in the same way as other gases.

The substrate for epitaxial growth has been described only in the case of nP, but it can also be applied to GaAe, Garb, etc., or other materials that lattice match the growth layer. be.

Furthermore, it is applicable not only to the epitaxial growth of III-V group compound semiconductors as described above, but also to the growth of TI-Vr group compound semiconductors.

Although the above explanation was given only for the case where the pressure in the reaction chamber is atmospheric pressure, it is possible to
It is also clear that growth under low pressure can be performed.

As explained in detail above, according to the present invention, (]) the generation of intermediate reaction products can be prevented, and therefore a good single crystal can be easily grown, and each control can be performed over a wide range. (2) The manufacturing cost can be significantly reduced, and (3) epitaxial crystals of good quality can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of a conventional compound semiconductor crystal growth apparatus, Fig. 2 is a schematic diagram showing an embodiment of the compound semiconductor crystal growth apparatus of the present invention, and Fig. 3G) is a nozzle in Fig. 2 of the present invention. and a partially enlarged view of the partition plate, FIG. 5(b) is a cross-sectional view taken along line A-A' in FIG. 6(a), and FIG. 5(c) is a cross-sectional view taken along line B-B' in FIG. 6(a). It is a diagram. Moreover, FIGS. 4 to 7 are schematic cross-sectional views showing one embodiment of the partition plate in the device of the present invention, and in FIG.
is a bottom view of the partition plate, (b) is a C-C' cross-sectional view of (a),
(C) is a cross-sectional view of (A) with a side wall plate attached, No. 8
9 and 9 are schematic diagrams of other embodiments of the device of the invention. 1: Reaction vessel, 2: Susceptor, 4: Work coil 17:
Substrate, 8 and 9: Air supply pipe, 10: Exhaust pipe, 13: Partition plate, 14: Nozzle, 15: Fumarole port, 20: Upper cover plate, 21:
Side wall plate, 22: Gas supply pipe, 26 two injection ports Patent applicant: Nippon Telegraph and Telephone Public Corporation agent Hirotoshi Nakamoto Akio Inoue / Figure 3 (a) Figure 2 t! Figure (c) Figure 7 Figure 8 Rate Figure 9

Claims (1)

[Claims] 1. During epitaxial growth of a compound semiconductor consisting of a compound of at least two or more elements,
A compound semiconductor crystal growth method in which a single crystal is grown by causing a total reaction of more than one species of raw material compound gases, which is characterized in that mixing of at least two kinds of raw material compounds is completely suppressed until they reach a growth layer. 2. When epitaxially growing a compound semiconductor consisting of a compound of at least two or more elements,
In a compound semiconductor crystal growth apparatus in which a single crystal is grown by a total reaction of more than one raw material compound gas, a partition plate is provided to suppress mixing of at least two kinds of raw material compounds before reaching the growth layer. Characteristic compound semiconductor crystal growth equipment.