PRODUCTION OF SINGLE CRYSTAL AND EQUIPMENT FOR GROWING SINGLE CRYSTAL

摘要

PROBLEM TO BE SOLVED: To enhance the yield of the single crystal having a desired composition and to improve the extinction ratio in the production method in which the single crystal is grown by subjecting a vessel containing the raw material for the single crystal to heat-treatment to continuously form a molten zone for the production of the single crystal for an isolator element. SOLUTION: In this production, a raw material for a single crystal is charged into a crucible consisting of glassy carbon to produce a single crystal. This equipment has a heating furnace 40 in which a preheating section 40a and a molten zone formation section 40b are provided with a heater 35A and a heater 35B respectively and a single crystal formation section 40c consists of one or more attachable/detachable heat insulating material units e.g. 41A to 41D, wherein the crucible is preferably enclosed by a hermetic sealing member consisting of quartz.