Purification of Silicon by Electric Induction Melting and Directional Partial Cooling of the Melt

摘要

The present invention is apparatus for, and method of, purification of silicon by electric induction heating and melting of silicon in a crucible or susceptor vessel, with subsequent directional partial cooling of the silicon melt to an initial amorphous-to-crystalline (solidification) temperature to produce a directionally solidified purified quantity of silicon and a separate quantity of high impurity silicon. The quantity of high impurity silicon is removed from the vessel and the purified quantity of silicon at solidification temperature is remelted in the vessel for removal from the vessel or further processing.

主权项

1. A method of producing a molten quantity of silicon in a vessel and directionally purifying the molten quantity of silicon by a partial cooling of the molten quantity of silicon, the method comprising:
supplying a silicon charge to the vessel; inductively heating and melting at least a portion of the silicon charge by supplying an alternating current to a plurality of induction coils arranged vertically around the exterior of the vessel to form a molten quantity of silicon in the vessel; sequentially removing the alternating current from each one of the plurality of induction coils while sequentially supplying a cooling medium to each one of a plurality of high temperature ceramic composite cooling jackets interposed exclusively between the exterior of the vessel and the one of the plurality of induction coils that the alternating current is sequentially removed from to vertically form a directionally purified quantity of silicon cooled to an initial amorphous-to-crystalline phase transition temperature and a high impurity quantity of silicon; and removing the high impurity quantity of silicon from the vessel.