PROCESS FOR GROWING SINGLE CRYSTAL OF COMPOUND HAVING HIGH DISSOCIATION PRESSURE

摘要

PURPOSE:To make a compsn. of Ga and As controllable during the growth of a single crystal of a compd. having high dissociation pressure by dipping a bottom end of a diaphragm cylinder at a fixed position on the surface of a melt of a compd. having high dissociation pressure and covering the inside or outside of the diaphragm cylinder with B2O3. CONSTITUTION:A vessel 3 for sealing tightly the gas dissociable from a compd. having high dissociation pressure is enclosed by a heater 2 and provided in a metallic vessel 1. A pulling shaft 10 for a single crystal attached with a seed crystal 8 and a crucible 5 supported by a crucible supporting shaft 11 are provided in the metallic vessel 1. A diaphragm cylinder 6 is floated on the GaAs melt 12 contained in the crucible 5, and foron oxide for covering the diaphragm cylinder is contained in the inside of the diaphragm cylinder 6 covering a part of the surface of the melt. Since the diaphragm cylinder 6 on the melt 12 is floated on the melt, the diaphragm cylinder moves downward in accordance with the surface of the melt even if the amt. of the melt is decreased in accompany with pulling of the single crystal. Accordingly, there is no fear for causing clogging of the surface of the melt by the foron oxide. Thus, the compsn. of the melt 12 is controllable by controlling the pressure of gaseous As in the sealed vessel.