The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 26, 1993
Filed:
May. 29, 1991
Kawasaki Steel Corporation, Kobe, JP;
Abstract
Disclosed herein are a method and apparatus for purifying silicon, which are suitable for economical and mass production of high-purity silicon for solar cells from regular-grade silicon containing boron and carbon in large quantities. The method comprises directing a plasma jet stream of an inert gas toward the surface of molten silicon held in a container lined with silica or a silica-based refractory. For improved purification, the inert gas as the plasma gas is mixed with 0.1-10 vol % steam and/or less than 1 g of silica powder per liter of the inert gas at normal state. Alternatively, the container may have a bottom opening and is provided with an electrode having a cooling means underneath the bottom of the container, with the electrode and the cathode of the plasma torch connected to a power source for plasma generation, so that the plasma jet and electron beam are directed toward the surface of molten silicon.