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:
Jun. 10, 2014
Filed:
Aug. 04, 2011
Reiner Pech, Neuoetting, DE;
Erich Dornberger, Burghausen, DE;
Reiner Pech, Neuoetting, DE;
Erich Dornberger, Burghausen, DE;
Wacker Chemie AG, Munich, DE;
Abstract
Polycrystalline silicon of the invention contains: (a) polycrystalline silicon fragments, wherein at least 90% of the fragments have a size from 10 to 40 mm, (b) <15 ppmw of silicon dust particles having particle sizes <400 μm; (c) <14 ppmw of silicon dust particles having particle sizes <50 μm; (d) <10 ppmw of silicon dust particles having particle sizes <10 μm; (e) <3 ppmw of silicon dust particles having particle sizes <1 μm; and (f) surface metal impurities in an amount ≦0.1 ppbw and ≧100 ppbw. A polycrystalline silicon production method of the invention includes fracturing polycrystalline silicon deposited on thin rods in a Siemens reactor into fragments; classifying the fragments by size; and treating the fragments with compressed air or dry ice to remove silicon dust from the fragments without wet chemical cleaning.