Patent ID: 6554898
Filing Date: 2003-04-29
Classification: C30B,Y10T

Abstract:
A crystal puller for growing monocrystalline silicon ingots according to the Czochralski method, the crystal puller comprising:a housing; a crucible in the housing for containing molten silicon; a pulling mechanism for pulling a growing ingot upward from the molten silicon; a first electrical resistance heater comprising a first 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 first heating element having an upper end and a lower end, the lower end of the first heating element being disposed substantially closer to the molten silicon than the upper end when the first heating element is placed in the housing; and a second electrical resistance heater comprising a second heating element sized and shaped for placement in the housing of the crystal puller in generally longitudinally spaced relationship above the first electrical resistance heater and 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 first electrical resistance heater, the second heating element having an upper end and a lower end, the lower end of the second heating element being in closely spaced relationship with the upper end of the first heating element of the first electrical resistance heater, the crystal puller being substantially free of structure interposed between the lower end of the second heating element and the upper end of the first heating element.