JPS59207816A - Production of inp crystal - Google Patents

Abstract

PURPOSE:To synthesize InP polycrystals of high purity efficiently in the vapor phase, by reducing In oxide vapor with a thermally dissociated phosphine gas. CONSTITUTION:Molten In 1 is placed on a boat in an apparatus, and In2O3 is placed thereon. Resistance heating elements 7 and 10 are respectively set at a polycrystal deposition temperature and geeration temperature of In2O3, and a graphite heating element 9 is set at the reaction temperature. A carrier gas, e.g. Ar, is passed from a carrier gas inlet pipe 3 and a preheated and thermally dissociated phosphine gas is passed from a phosphine inlet pipe 4. Fine particulate polycrystals of InP are stuck and deposited on a crucible 6 and a protrusion 5 for producing eddy currents by the above-mentioned operation. According to the method, impurities contained in the molten InP are left in the boat, and purification is carried out even in reduction of In2O3. Thus, the impurities do not take part in the synthetic reaction, and fine particulate polycrystals of Inp of high purity are obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing InP crystals necessary for manufacturing high-performance electronic devices and optical devices.

Conventionally, various boat methods such as the horizontal 7° Ridgeman method, gradual cooling method, and pressure balance method have been used as methods for producing polycrystals of compound semiconductors. FIG. 1 shows an outline of an ILI-V group semiconductor synthesis apparatus using the horizontal Norifugeman method as an example. In the figure, 11 is quartz 7-north, 12 is quartz boat,
13 represents a group V element, and 4 represents a group II element. To operate this, the closed tube constructed of the above 11°, 12, 13, and 14 is placed in an electric furnace that provides the temperature distribution shown in the upper part of the figure, and the closed tube is moved in the direction of the arrow in the figure. The group V vapor generated in region A diffuses into the molten group III element in the quartz boat 12 and synthesizes a compound. At the same time, the compound melt synthesized by the movement of the closed tube is cooled and solidified. However, these methods have a drawback in that the containers used to support the Group I elements are exposed to high temperatures, and therefore impurity contamination from these containers cannot be prevented.

Furthermore, since the method uses a melting method, impurities contained in group (I) elements used as raw materials remain in the produced polycrystals, and the purity of the crystals cannot be increased.

An object of the present invention is to solve the above-mentioned drawbacks of conventional compound semiconductor polycrystal manufacturing methods and to provide a method capable of manufacturing high purity 1nP polycrystals.

The present invention will be explained in detail below.

The present invention is characterized in that, in the production of InP, InP is synthesized in a vapor phase by reducing InP oxide vapor with thermally dissociated phosphine gas.

Next, examples of the present invention will be described.

FIG. 2 is a schematic diagram of an example of an InP polycrystal manufacturing apparatus according to the manufacturing method of the present invention. 1 is molten indium, 2 is I
n 201.3 is a carrier gas introduction tube, 4 is a phosphine gas introduction tube, 5 is a protrusion, 6 is a crucible, 7゜10 is a resistance heating element, 8 is a high frequency coil, 9 is a graphite heating element, 1
5 shows a quartz reaction open tube. The protrusion 5 is provided to generate a vortex flow, and is fixedly held on the crucible 6 by a quartz jig. To operate this, heat generating elements 7 and 9 in FIG.
, 10 are respectively polycrystalline deposition temperature (750°C), reaction temperature (950°C), and indium oxide gas generation temperature (80°C).
0° C.) and flow the carrier gas through the carrier gas introduction pipe 3. In this example, Ar was used. Next, preheat (900°C) through the phosphine gas introduction pipe 4.
Flow the phosphine gas. By such an operation, fine particle-like polycrystals of InP are attached and deposited on the vortex generation projection 5 and the crucible 6. As is clear from FIG. 2, according to the method of the present invention, a gas phase reaction is used to produce InP, impurities contained in the molten In are left in the boat, and the reduction of indium oxide is Since purification was sometimes performed and impurities were not involved in the InP synthesis reaction, high purity InP fine particle polycrystals could be produced. The growth rate here was 5 g/hour.

Table 1 shows a comparison between a crystal according to the prior art and a crystal according to the method of the present invention for InP.

Table 1 Comparison of crystal purity As is clear from the above, it was confirmed that the method of the present invention is effective in improving crystal purity.

In Figure 2, a crucible used for single crystal production is installed as the crucible 6, and after producing polycrystals according to the above procedure, it is loaded into a single crystal production apparatus, and the polycrystals are produced using a liquid capsule pulling method, etc. If crystal production is carried out, not only will a new terminal for single crystal production become unnecessary, but also the operations up to single crystal production can be simplified.

As explained in detail above, in the InP semiconductor polycrystal manufacturing method according to the present invention, polycrystals are synthesized from vapors of group II and group II elements, and the polycrystals are directly deposited inside a crucible for manufacturing single crystals. Since it can be grown, high-purity compound semiconductor polycrystals can be immediately manufactured in a form that can be used for single-crystal manufacturing, so there is an advantage that high-purity polycrystals can be manufactured at low cost and with a simplified process.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view showing the principle of an apparatus in a conventional horizontal Bridgman method, and FIG. 2 is a schematic cross-sectional view of a manufacturing apparatus showing an embodiment of the method of the present invention. 11...Quartz ampoule, 12...Quartz boat, 13
...■ group element, 14...■ group element, l... molten indium, 2... indium sesquioxide (In20
a), 3...Carrier gas introduction tube, 4...Phosphine gas introduction tube, 5...Protrusion, 6...Routa,
7... Resistance heating element, 8... High frequency coil, 9
...graphite heating element, lO...resistance heating element,
]5...Quartz reaction open tube. Patent applicant: Nippon Telegraph and Telephone Public Corporation Representative: Tsune Hakusui and one other person

Claims (1)

[Claims] A method for producing an InP crystal, comprising producing polycrystals of InP by reducing and reacting indium oxide gas with dissociated phosphine nonosu.