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. 13, 2019
Filed:
May. 27, 2015
Shin-etsu Chemical Co., Ltd., Tokyo, JP;
Shin-Etsu Chemical Co., Ltd., Tokyo, JP;
Abstract
A polycrystalline silicon rod is synthesized by the Siemens method (S). After the polycrystalline silicon rod is covered from above with a plastic bag whose inner surface has been washed, and housed in the plastic bag in a reactor (S), the polycrystalline silicon rod is removed out of the reactor (S), and heat-sealed and stored in an enclosed state (S). According to the present invention, steps conventionally considered as essential, such as washing, etching, and water washing, are not always necessary, and therefore the concentrations of fluorine ions, nitrate ions, and nitrogen dioxide ions remaining on the surface can each be less than 0.2 ppbw. In addition, by covering with the plastic bag, the metal contamination levels decrease significantly. Moreover, when the handling according to the present invention is performed, surface contamination hardly proceeds even if the polycrystalline silicon rod is stored for a long period.