| 摘要 |
PURPOSE:To produce a uniform single crystal without rippling a melt in a boat by turning on and off a plurality of heaters, in order, arranged in the longitudinal direction of a heating furnace set around a reaction tube to zone-melt semiconductor materials in the boat placed in the tube. CONSTITUTION:While evacuating reaction tube 21a a current is supplied to heaters 24 arranged in the inner part of heating furnace 23 to melt semiconductor materials such as In and Sb in boat 22. This melt is treated at below a predetermined temp. for a predetermined time to scatter Sb, and the inside of tube 21 is replaced with a reducing gas such as H2 gas. Heaters 24 are turned off, and independent heaters 25a -25j arranged in the outer part of furnace 23 are turned on and off through counters in order. As a result, without applying vibration boat 2 is zone-heated in a static state to prevent impurities in liquid phase from being taken in solid phase, and a preliminary process is performed to effectively purify polycrystalline InSb with good reproducibility. By similar operation a zone refining process is performed to grow uniform crystalline ingot 26. |
