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:
May. 19, 1998
Filed:
Aug. 28, 1995
Mohsen Banan, St. Louis, MO (US);
Richard L Hansen, Cleveland, OH (US);
MEMC Electronic Materials, Inc., St. Peters, MO (US);
Abstract
A process for removing metallic contaminants from the surface of chunk or granular polycrystalline silicon is disclosed. The metallic contaminants are exposed to a gas-phase halogen etchant which reacts with the metallic contaminants to form metal halides. The gas-phase halogen etchant is preferably a halogen plasma. The metal halides are volatilized into an atmosphere adjacent to the surface of the polycrystalline silicon, and purged therefrom. The cleaned polycrystalline silicon is used to prepare a mass of molten silicon for use in producing a single crystal silicon ingot by the Czochralski method.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile