Patent ID: 6299682
Filing Date: 2001-10-09
Classification: C30B,Y10S

Abstract:
A method for producing a silicon ingot having a directional solidification structure, the method comprising:placing a silicon raw material into a crucible of a melting device constructed by mounting a chill plate on an underfloor heater, mounting the crucible on the chill plate, providing an overhead heater over the crucible, and surrounding a circumference of the crucible with a heat insulator;heat-melting the silicon raw material by flowing electric current through the underfloor heater and the overhead heater without feeding a refrigerant to the chill plate, followed by halting or decreasing the electric current through the underfloor heater after the silicon raw material has been completely melted, the molten silicon being chilled from a bottom of the crucible by chilling the chill plate by feeding the refrigerant; andintermittently or continuously lowering a temperature of the overhead heater by intermittently or continuously decreasing the electric current through the overhead heater along with halting the electric current or decreasing the electric power through the underfloor heater.