JPS573795A - Preparation of compound semiconductor crystal and apparatus therefor - Google Patents

Abstract

PURPOSE: To prepare a thin platy single crystal, e.g. a compound semiconductor, in an optional shape efficiently, by flowing a melt of a parent alloy containing a liquid sealing material through a slit tube provided at the bottom of a crucible, and forming a single crystal of the melt by the pulling down method.

CONSTITUTION: A seed crystal plate 3 is inserted in a slit tube 2 at the lower end of a crucible cell 1, and a small amount of a liquid sealing material powder 5, e.g. mixed powder of NaCl with KCl, is introduced into the cell 1. A parent alloy material 6 of Groups III, IV and V is then placed on the powder 5, and a liquid sealing material powder 7 is then added to the material 6 in the crucible cell 1. An electric current is passed through a resistance furnace 8 for heating the cell 1 to enclose the parent alloy material 6 in the liquefied sealing material 6' before the melting of the parent alloy material 6. An electric current is then passed through the lower auxiliary heater 9 to provide a temperature gradient at the tip of the slit tube 2. The molten sealing material 7' having the improved property to wet the cell 1 and the parent alloy material 6 flows through the gap between the seed crystal plate 3 and the inner wall of the slit tube 2, and the parent alloy melt flows into the slit tube 2 stably. A seed crystal supporting shaft 4 is then pulled down to give a thin platy single crystal having the same cross-sectional shape as that of the slit tube 2.

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