Claims
- 1. In a method for forming a single crystal of GaAs which comprises crystallizing a melt of GaAs under controlled conditions in a quartz boat wherein said crystal is grown within said boat and in which at least a surface of the boat in contact with the melt has been sufficiently roughened to reduce wetting by the melt, the improvement which comprises: providing a quartz boat with at least a roughened surface is to contact the melt, tridymitizing said surface by heating the boat at a temperature of from about 830.degree. C. to 1450.degree. C. for from about 1 to 10 hours, to further reduce wetting by the melt and to thereby increase the yield of said single GaAs crystal, and thereafter growing said single GaAs crystal employing said boat.
- 2. A method according to claim 1, wherein said boat is heated to a temperature of from 830.degree. C. to 1200.degree. C. for tridymitizing.
- 3. The method of claim 1 wherein the roughened surface is roughened by contact with Al.sub.2 O.sub.3.
- 4. The method of claim 1 wherein the roughened surface is roughened by contact with SiC.
- 5. The method of claim 1 wherein said tridymitizing is effected by heating said boat at a temperature of from about 900.degree. C. to 1200.degree. C. for from 2 to 10 hours.
- 6. In a method for growing a single crystal of GaAs utilizing the boat growth method wherein said crystal is grown within said boat, the improvement which comprises
- (a) preparing a quartz boat by:
- (i) contacting the inner surface of said boat with an inorganic powder under conditions whereby said surface is roughened to reduce wetting;
- (ii) cleaning said inner roughened surface with acid;
- (iii) washing and drying said inner roughened surface; and
- (iv) tridymitizing said surface by heating said boat at a temperature of from about 830.degree. C. to 1450.degree. C. for from about 1 to 10 hours, and then cooling to further reduce wetting by the melt and to thereby increase the yield of said single GaAs crystal and
- (b) growing said single GaAs crystal in said quartz boat.
- 7. The method of claim 6 wherein said inorganic powder is Al.sub.2 O.sub.3.
- 8. The method of claim 6 wherein said inorganic powder is SiC.
- 9. The method of claim 6 wherein said tridymitizing is effected by heating said boat at a temperature of from about 900.degree. C. to 1200.degree. C. for from about 2 to 10 hours.
Priority Claims (1)
Number |
Date |
Country |
Kind |
58-198929 |
Oct 1983 |
JPX |
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Parent Case Info
This application is a continuation of application Ser No. 857,404, filed Apr. 21, 1986, now abandoned, which is a continuation of U.S. Ser. No. 663,437 filed Oct. 22, 1984, now abandoned.
US Referenced Citations (2)
Number |
Name |
Date |
Kind |
3927697 |
Baumler et al. |
Dec 1975 |
|
4268483 |
Davey et al. |
May 1981 |
|
Foreign Referenced Citations (1)
Number |
Date |
Country |
658110 |
Jul 1965 |
BEX |
Non-Patent Literature Citations (1)
Entry |
Kingery et al, "Introduction to Ceramics", 1976, pp. 70-71. |
Continuations (2)
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Number |
Date |
Country |
Parent |
857404 |
Apr 1986 |
|
Parent |
663437 |
Oct 1984 |
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