Patent ID: 7955433
Filing Date: 2011-06-07
Classification: H01L,Y02E,Y02P,Y10T

Abstract:
1. A method for forming a silicon ingot using a low-grade silicon feedstock, the silicon ingot comprising higher grade silicon than the low-grade silicon feedstock, comprising the steps of: forming within a crucible device a molten silicon from a low-grade silicon feedstock; performing a directional solidification of the molten silicon to form a silicon ingot within the crucible device, the directional solidification forming a generally solidified quantity of silicon and a generally molten quantity of silicon, the directional solidification increasing the height of the combined solidified and molten quantity of silicon; removing from the crucible device at least a portion of the generally molten quantity of silicon while retaining within the crucible device the generally solidified quantity of silicon, controlling said directional solidification of said generally solidified quantity of silicon to form a silicon ingot possessing a generally higher grade of silicon than said low-grade silicon feedstock.