| 摘要 |
PURPOSE:To obtain a high-purity GaAs single crystal free from contamination with Si, by a specific two-step growth process comprising the growth of polycrystalline GaAs by pouring Ga into a quartz boat and the growth of a single crystal by remelting the polycrystalline GaAs. CONSTITUTION:The present process comprises the following two steps (a) and (b). (a) Ga contained in a refractory vessel nonreactive with Ga is poured into a quartz boat preheated at a temperature exceeding the temperature to equalize the free energy to form Ga2O3 to the free energy to form fused quartz and below the softening point of fused quartz and a polycrystalline GaAs is synthesized from the Ga and As in a reaction tube. (b) The top side and the tail side of the obtained polycrystalline GaAs are cut off and the remaining polycrystalline GaAs is remelted to effect the growth of a GaAs single crystal. The above process for growing GaAs single crystal is effective in lowering the concentration of impurity elements existing in the original Ga and As as well as in preventing the contamination of the single crystal with contaminants from a quartz boat for crystal growth.
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