| 摘要 |
PURPOSE:To stably obtain a wafer which is uniform in various characteristics with good reproducibility by subjecting a compd. semiconductor single crystal to a heat treatment in the state of an ingot, then subjecting the wafer cut out of the heat-treated ingot further to a heat treatment. CONSTITUTION:The compd. semiconductor single crystal having an as-grown shape or circular cylindrical shape formed by grinding is subjected to the heat treatment and thereafter, the single crystal is sliced to a thin sheet. Such thin sheet is subjected to the heat treatment. The above-mentioned heat treatment is preferably executed by heat-treating the compd. semiconductor single crystal sized >=50mmphi diameter and >=10mm thickness in the state of the ingot at the temp. of 0.6-0.9 times the m.p. of the crystal in an inert gas or gaseous nitrogen, then heat-treating the wafer cut out of the heat-treated ingot to <=1mm thickness at the temp. of 0.6-0.9 times the m.p. of the crystal in the inert gas or gaseous nitrogen. The above-mentioned heat treatments for the wafer are preferably executed repeatedly plural times (adequately up to 3 times).
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