Patent ID: 6503322
Filing Date: 2003-01-07
Classification: C30B,Y10T

Abstract:
An electrical resistance heater for use in a crystal puller used for growing monocrystalline silicon ingots according to the Czochralski method, the crystal puller having a housing, a crucible in the housing for containing molten silicon and a pulling mechanism for pulling a growing ingot upward from the molten silicon, the heater comprising a heating element sized and shaped for placement in the housing of the crystal puller generally above the crucible in spaced relationship with the outer surface of the growing ingot for radiating heat to the ingot as it is pulled upward in the housing relative to the molten silicon, the heating element having an upper end and a lower end, the lower end of the heating element being disposed substantially closer to the molten silicon than the upper end when the heating element is placed in the housing, said heating element being constructed such that the heating power output generated by the heating element gradually increases from the lower end to the upper end of the heating element; said heating element including first and second vertically oriented heating segments arranged in a generally side-by-side relationship and being electrically connected together, said segments each having an upper end and a lower end, the second segment having a length substantially greater than the first segment and being arranged relative to the first segment so that when the heating element is placed in the housing the lower end of the second segment is disposed closer to the molten silicon in the crucible than the lower end of the first segment.