NOVELTY - Forming a silicon ingot (36) using a low-grade silicon (34) feedstock involves forming molten silicon within a crucible device from low-grade silicon feedstock; solidification of molten silicon to form silicon ingot, forming solidified quantity of silicon and molten quantity of silicon; removing a portion of molten silicon from the crucible device while retaining within the solidified silicon; and controlling solidification of solidified silicon to form silicon ingot possessing a higher grade of silicon than low-grade silicon feedstock.    USE - For forming a silicon ingot (claimed); for fabrication of semiconductor materials such as silicon; for integrated circuit and solar cell industries require a refined, purified, silicon feedstock as a starting material.    ADVANTAGE - The method provides higher purity semiconductor ingot; is capable of producing a higher quality silicon ingot using a low-grade silicon feedstock to achieve a general cost reduction; has ability to reduce the metallic and non-metallic impurities present in a semiconductor ingot which is useful in solar cell fabrication; and avoids high-concentration regions of non-metals, in top regions of ingots made from upgraded metallurgical-silicon feedstock materials.    DETAILED DESCRIPTION - Forming a silicon ingot (36) using a low-grade silicon (34) feedstock involves forming molten silicon within a crucible device from low-grade silicon feedstock; solidification of molten silicon to form silicon ingot, forming solidified quantity of silicon and molten quantity of silicon; removing a portion of molten silicon from the crucible device while retaining within the solidified silicon; and controlling solidification of solidified silicon to form silicon ingot possessing a higher grade of silicon than low-grade silicon feedstock. The method further involves extending the duration of solidification of solidified silicon for reducing material stresses arising from the crystallization of silicon ingot; pre-conditioning molten silicon for extracting impurities deriving from low-grade silicon; removing portion of molten quantity of silicon by flowing molten silicon via a pathway associated with crucible device, the pathway comprises a felt device for absorbing at least a portion of molten silicon; controlling further involves holding silicon ingot at an elevated temperature following removing step for removing the stress-related structural defects in silicon ingot, thus enhancing silicon ingot quality. An INDEPENDENT CLAIM is included for a system comprising a crucible device; temperature control units; a removal mechanism; and temperature control mechanism.    DESCRIPTION OF DRAWING(S) - The figure shows solar cell formation process.    Low grade silicon (34)    Ingot (36)    Wafer (38)    Wafer treatment (40)    Solar cell process (42)