Patent ID: 6176924
Filing Date: 2001-01-23
Classification: C30B

Abstract:
A method for controlling the growth of a crystal in a crystal growth furnace comprising the steps of:providing a furnace with a substantially transparent inner tube having a cavity therethrough and a plurality of separate heating elements wound thereabout, each said heating element defining a heat zone, said inner tube having coupled thereto a temperature thermocouple associated with each said heat zone, said inner tube insulated by a substantially transparent outer tube;inserting an ampoule filled with a crystal growth material into said cavity;energizing each said heating element to obtain a predetermined temperature gradient in the furnace thereby melting the crystal growth material into a liquid;monitoring the temperature of each said heat zone via said temperature thermocouples; andadjusting voltage input to a said heating element to a new setting based upon the monitored temperatures of all the other heat zones so that said temperature gradient around said ampoule allows growth of crystal material from said liquid.