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:
Aug. 03, 1993
Filed:
Jul. 01, 1992
Robert G Brink, St. Louis, MI (US);
Norman H Deitering, Chesaning, MI (US);
Michael H Greene, Midland, MI (US);
Kimmai T Nguyen, Midland, MI (US);
Hemlock Semiconductor Corporation, Hemlock, MI (US);
Abstract
The present invention relates to a method for the purification of tetrachlorosilane used for the manufacture of electronic grade silicon and, more particularly, to a method for removing trace impurities of phosphorus. The method involves contacting liquid tetrachlorosilane with activated charcoal. The process is effective in reducing the phosphorus levels in the tetrachlorosilane to the parts per trillion range. The process can be run as a continuous or batch process with easy separation of the activated charcoal. containing the phosphorus contaminate from the tetrachlorosilane.