| 摘要 |
PURPOSE:To reduce the evaporation of a starting material for a crystal by forming lower and higher temp. hot zones using a plurality of independently controllable heating elements and by moving a crucible between the two hot zones in a short time. CONSTITUTION:Starting materials are charged into a crucible 1, the internal pressure of a furnace is regulated, and heating elements 6, 8 are electrically conducted to raise the temps. Electric power for heating the 1st heating element 6 is regulated so as to heat the lower temp. hot zone 7 to about 600 deg.C, and electric power for heating the 2nd heating element 8 is regulated so as to heat the higher temp. hot zone 9 to a temp. above 820 deg.C which is the melting temp. of As. After confirming the stable internal state of the furnace, a crucible driving shaft 11 is rapidly pushed up to move the crucible 1 from the zone 7 to the zone 9. Since the zone 9 is kept at a temp. above the melting temp. of As, the internal temp. of the crucible rises quickly, unmelted As is melted in a short time, and the molten As reacts with Ga melted in the zone 7. By the reaction a GaAs crystal is synthesized. |
