JPS58145605A - Synthesis of inp - Google Patents

Abstract

PURPOSE:To produce high purity polycrystalline InP in a large amount at a low cost, by heating synthesized InPO4 at a specific temperature range in a gydrogen gas stream. CONSTITUTION:A polycrystalline InP is synthesized by placing a previously synthesized powdery InPO4 in a reaction tube, and contacting with continuously supplied hydrogen gas stream at 500-800 deg.C to effect the reduction of the powder. Since the reaction is carried out under nearly normal pressure at a relatively low temperature, the apparatus can be simplified and the cost can be reduced. The contamination from the reaction system is little, and a high purity polycrystalline InP can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical field to which the invention pertains] This invention relates to a method for producing indium phosphide polycrystals.

[Technical background of the invention and its problems]

Indium phosphide is used as a material for light-emitting diodes, semiconductor lasers, light-receiving elements, etc., and inexpensive, high-quality single crystals are desired. Manufacture a single crystal of indium phosphide (Secondly, indium phosphide polycrystal prepared in advance is melted in a high-pressure container, and rotated and pulled using a seed crystal.

Therefore, in order to produce inexpensive and high-quality indium phosphide single crystals, inexpensive and high-purity indium phosphide polycrystals are required.

By the way, as a method for manufacturing indium phosphide polycrystals, conventionally, In, ? A so-called direct method is known in which P is reacted with P while controlling its vapor pressure.

This method will be explained using FIG. Install a two-temperature zone furnace in a pressure-resistant container (9) with a pressure of 50 atmospheres or more. Immediately place the quartz reaction tube (08) in the above furnace (copper tube in 1). and P(15) are stored separately, and In(14) and Pal5) are independently (double heating controlled) by a two-temperature imperial furnace.
(14) is heated to a temperature close to the melting point of InP (1050° C.) using a carbon boat (16) with high frequency, and PQ5J is resistance heated and evaporated. Indium phosphide (np) is generated by reacting with In (the P vapor that has reached the first stage is n04). The vapor pressure of P is precisely controlled at high enough (~30 atm) that InP is produced rapidly. Pressure-resistant container (6 in 111)
Second, fill the quartz reaction tube (1B) with high-pressure inert gas that is balanced with the pressure inside the quartz reaction tube (1B) to prevent rupture or damage to the quartz reaction tube (marked 1).In addition, the pressure vessel (11) should be sufficiently cooled with water. As described above, in this method, the reaction operation and equipment are extremely complicated, the mass productivity is poor, and the manufacturing cost is high.Furthermore, the starting materials In and P are 99. Even if one with a high purity of 9999% or more is used, the synthesized InP polycrystal tends to have a low purity of 99.999% or less due to unavoidable contamination from the reaction system. OBJECTIVE: The present invention was made in the spring of 2013 to solve this problem, and aims to provide a method for producing nP that is economical and suitable for production by eliminating the above-mentioned drawbacks.

[Summary of the invention]

That is, the present invention combines pre-synthesized indium phosphate (NPO4) into a continuously supplied hydrogen gas stream.
This is a method of synthesizing polynP polycrystals by heating at 50 to 800°C.

In this invention, 550~8
This is based on the discovery that by heating at 00°C, nPO4 is reduced to InP on the spot, and that nP powder can be efficiently produced. Simply heat nPO4 at 550 to 800℃ in an atmosphere of hydrogen gas.
Even when heated, no nP was produced, and nPO4 was seen to change into lumps, as if sintered.

In order to proceed with the reduction, it was necessary to continuously supply hydrogen gas. The reduction reaction of nPO4 with hydrogen 12 is reversible, and it is considered necessary to remove H20, a reaction product other than InP, from the system in order to proceed with the reduction. Since hydrogen gas participates in the interface reaction C2 and at the same time serves as a carrier for H2, sufficient hydrogen must be continuously supplied to ensure sufficient contact with the InPO4 powder and to flow quickly. The hydrogen gas flow rate depends on the size of the reduction furnace, ■nPO4 charge award, ■nPO4
Depends on the method of charging the boat, etc.
When reducing 50 st of nPO4 in a reaction tube with an inner diameter of 30 mm, more than 30 t/hr was required. When the hydrogen gas flow rate was reduced, only the surface layer of the charged InPO4 powder was reduced with C.

The heating temperature of PO4 is particularly important to maintain the reduction yield. At temperatures below 550 °C, the reaction slowed down and no substantial PO was produced. At temperatures above 30°F, phosphorus evaporates from the phosphorus that has been formed on the spot, and there is a tendency for not only phosphorus but also phosphorus to precipitate from the gas phase in the low-temperature area, causing damage to various parts of boats, etc. The yield of InP produced in the vessel C1 decreases.Thus, it was concluded that 550 to 800°C is appropriate.

〔Effect of the invention〕

According to the present invention, since the reaction can be carried out near normal pressure and at a relatively low temperature, the apparatus can be simplified, the process can be simplified, and costs can be reduced.In addition, there is less contamination from the reaction system. It has advantages such as the ability to obtain highly pure polynP polycrystals, and its industrial effects are outstanding. [Embodiments of the Invention] The present invention will be explained below with reference to Examples. Fig. 2 shows an example of the apparatus used in the present invention ζ2.
21) Inner I''' - The reaction tube is attached to the old tube. Attach a heat-resistant stopper (to) to one end of this inner - to the old tube, and pass through the stopper g!8) to supply the main hydrogen gas. An introduction pipe and a hydrogen gas sub-induction pipe @51 extending to the center of the reaction 1iH221 are provided. A quartz tube was used to provide a hydrogen gas shower flow to promote the catalytic reaction between InPO4 powder til+ placed in a boat (@) and hydrogen.

Hydrogen gas was transferred from the main inlet pipe and the auxiliary inlet pipe to the reactor, which was filled with PO4 powder in a boat.
A mixed flow forms just above the surface and reacts with the nPO4K71. The remaining hydrogen gas that does not take part in the reaction becomes a carrier for H40, a reaction product other than nP produced by the reaction, and is exhausted to the outside (exhaust) through the outlet.

Using the above-mentioned apparatus in which the inner diameter of the reaction tube (transformer) was 30 M and the length was 1000 m, a 50-st process of reducing PO4 was carried out at a hydrogen gas flow of 150 z/hr and a temperature of 620°C. The hydrogen gas flow rate was set at a ratio of 1 shower flow to 4 main flow.

After about 8 hours of processing time, 31st nP powder was obtained. Since the theoretical yield of InP is 34.75, the yield is approximately 90%. Analysis by the X-ray powder method showed that the reflection peak of the nP was sufficiently sharp (I), indicating excellent crystallinity. Furthermore, in analysis of residual impurities in spark mass, etc., no evidence of impurity contamination due to reduction treatment was found.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an apparatus for explaining a conventional method, and FIG. 2 is a sectional view showing an example of an apparatus for implementing the present invention. 11...Pressure vessel 12...2nd degree Teirō 13
...Quartz reaction tube 14...In15...P
16...Carbon boat 17...Water-cooled tube 21...Reduction furnace 22...Alumina reaction tube 23...Heat-resistant plug 24...Main introduction pipe for hydrogen gas) 25...Hydrogen gas Sub-introduction pipe 26...Boat 27
... Engineering nPO4ZkS ... Outlet (7317) Agent Patent attorney Kensuke Chika (and 1 other person) No. 1
Figure 2-1!

Claims (1)

[Claims] Indium phosphide β is produced by heating pre-synthesized indium phosphate (XnPO4) to 550-800°C in a continuously supplied hydrogen gas stream to produce indium phosphide (Xnp). Synthesis method 0