APPARATUS FOR PRODUCTION OF CRYSTAL

摘要

PURPOSE:To control temperature distribution in a crystal growing zone in high accuracy and to produce an oxide crystal having high quality, by placing an assistant heater together with a main heater in a crucible. CONSTITUTION:A main heater 17 made of high-purity graphite, etc., is placed at outer circumference of a crucible 11. An assistant heater 18 having a protection cover 19 is placed in the crucible 11 in a manner coaxially encircling a pulled-up crystal 13. The assistant heater 18 eliminates the influence of heat reflected or scattered by the crucible 11 and enables the direct heating of the pulled-up crystal and the accurate control of temperature distribution in the crystal and molten liquid just below the crystal.