JPS61168589A - Crucible for producing compound semiconductor - Google Patents

Abstract

PURPOSE:A crucible for producing a compound semiconductor, stable to a sealing agent B2O3, suppressing occurrence of twins during single crystal growth, having low deterioration in crucible, obtained by coating the surface of a PBN (pyrolytic boron nitride) crucible with amorphous BN (boron nitride) by plasma CVD method. CONSTITUTION:The surface of a PBN crucible is coated with BN by the use of NH3 and BCl3 as raw materials by plasma CVD method. PBN and BN have the same composition, the former is produced by CVD method, and the latter by plasma CVD method, so formation temperatures are different (CVD method; 2,000 deg.C, and plasma CVD method; <=1,000 deg.C), and formed crystal structures are different. Namely, PBN has a hexagonal system, is formed in a laminated way, so it is slightly released. On the other hand, BN film is amorphous, and one film, so it is stable. The thickness of BN coating is generally 5-50mum, especially preferably about 10mum. Consequently, the PBN crucible coated with BN will not cause fusion with a liquid sealing agent, has neither release during growing nor problem of occurrence of twin crystal caused by the release.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to GaAs, GaP, and nP
凰-V group compound semiconductors such as
The present invention relates to an apparatus for producing Group VI compound semiconductors or single crystals, particularly a crucible for production.

[Conventional technology]

For m-v group compound semiconductors and n-vi group compound semiconductors,
In many cases, one of the constituent elements has a high dissociation pressure, such as Ca in A8.0aTe in GaAs.

Therefore, B and O3 are used as liquid sealants in their synthesis and single crystal growth to prevent volatilization of high dissociation pressure elements. In addition, a PB1 crucible is generally used as a crucible at that time. This is made by coating carbon with nm (boron nitride) using the CVD method and removing it from the carbon, which has the advantage of not contaminating the raw material melt.

[Problem that the invention seeks to solve]

However, the conventionally commonly used PBN crucible has a B! 03 and nto
Another problem is that when the s is taken out, it peels off, causing rapid deterioration and a short lifespan. In addition, delamination occurs during single crystal growth, and its fragments float on the surface of the raw material melt, resulting in the serious problem of generation of twin crystals in the single crystal being grown.

The object of the present invention is to provide a new crucible for producing compound semiconductors that is more stable, does not cause B, OS, and does not peel off during synthesis or crystal growth, in place of the PllB crucible that has such drawbacks. Our goal is to provide the following.

[Means for solving problems]

That is, the present invention applies plasma CV to the surface of the PBN crucible.
This is a crucible for manufacturing compound semiconductors coated with amorphous BN by method D.

The crucible of the present invention will be explained in detail below with reference to the drawings.

FIG. 1 is a diagram showing an embodiment of the present invention, in which 1 is a PBN coated with fiBN by plasma CVD method.
It is a crucible (hereinafter referred to as BN Coco-PBN crucible).

The other parts are the same as the normal LICO method single crystal production equipment, 2 is the raw material melt, 3 is the liquid sealant I3zom %
4 is a heater, 5 is an f-'r7 bar, 6 is a seed, and 7 is a single crystal being grown.

In the apparatus of the present invention, the PBN crucible is coated with BH by plasma CVD using NHs and BCls as raw materials.

Although PBN and BN have the same composition, the production methods for the former are CVD and the latter are plasma CVP, so the production temperatures are different6 (CVN method: 2000°C; plus-r OV D method: 100G). ℃ or below), the resulting crystal structure is different. That is, FBI has a hexagonal crystal structure, but since it is formed in a layered manner, it is easily peeled off, but 9BN, which is coated by plasma CVD, is amorphous and forms a single film, so it is stable. The thickness of the BN coating is generally 10 μm in e-ct) μm.
Preferably before and after.

Therefore, the BN-coated FBI crucible does not cause any sticking with the liquid sealant, and there is no problem of delamination during growth or generation of twins due to this.

A specific method for synthesizing a compound semiconductor and a method for manufacturing a single crystal are as follows, for example.

■Synthesis method: Put the raw material crystal of the compound semiconductor to be synthesized into BN Coco-FBN pot 1, add liquid sealant B, 0. 3 and heat and melt with heater 4. The inside of the chamber 5 is pressurized to 10 to 50 atmospheres with an inert gas such as nitrogen or argon to prevent volatilization of high dissociation pressure elements. Thereafter, by gradually cooling it, a polycrystalline compound semiconductor can be synthesized.

■Single crystal production method: Compound semiconductor polycrystalline raw material 2 and liquid encapsulant B, 0. 5 into BN Coco-PB) crucible 1 and heat and melt with heater 4.

The chamber 5 is filled with an inert gas such as nitrogen or argon.
Pressure is applied to 0 to 50 atmospheres to prevent volatilization of high dissociation pressure elements. A single crystal 7 is grown from the seed 6 according to the usual IIZC single crystal growth method.

In both cases of ■ and ■, the BM coat 'PBli crucible is B,
It is stable against OS, does not cause twinning of the single crystal due to fragments exfoliated during single crystal growth, and B! When taking out the Os, the surface does not peel off. Therefore, there is little deterioration of the crucible and it can be used for a long period of time.

〔Example〕

An engineered nP single crystal was produced using the apparatus of the present invention.

A single crystal was grown using a PBN crucible containing B and Os as liquid sealants. The inside of the chamber was pressurized to 0 atmospheres with nitrogen gas to prevent evaporation of P. Normal LICO
Although a single crystal was grown by this method, there was no peeling of FBH during the growth, and a twin-free single crystal could be grown.

Furthermore, when B, os was taken out from the crucible after cooling, there was no sticking to the crucible (the FBI was able to easily take out B, os without peeling it off).

This BN-coated FBI crucible has a long repeated use life, about twice as long as a conventional PBl crucible without 1M coating.

〔Effect of the invention〕

As explained above, by using the FBI crucible coated with amorphous BM by the plasma CVD method of the present invention for compound semiconductor synthesis and single crystal production, liquid sealant B,
Since it is stable against O, it is possible to suppress the generation of twins during single crystal growth. In addition, since the crucible is less likely to deteriorate, it has the advantage of being able to be rounded over a long period of time and being economically advantageous.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of one embodiment of the crucible of the present invention.

Claims (1)

[Claims] Amorphous B was deposited on the surface of the PBN crucible using the plasma CVD method.
A crucible for manufacturing compound semiconductors coated with N.