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. 11, 1999
Filed:
Feb. 03, 1997
Naoki Nagai, Annaka, JP;
Isamu Harada, Annaka, JP;
Chihiro Tashiro, Annaka, JP;
Michiaki Oda, Annaka, JP;
Shin-Etsu Handotai Co., Ltd., Tokyo, JP;
Abstract
In a pulling apparatus operated according to the multi-pulling method or CCZ method, granular silicon material is first fed to a feed pipe from a feeder so as to form stagnation of the granular silicon material in the feed pipe. The feeding of the granular silicon material from the feeder to the feed pipe is repeatedly commenced and stopped so as to maintain the stagnation of the granular silicon material. The feed rate of the granular silicon material from the feeder to the feed pipe is increased with time until the feed of the silicon material is completed. This prevents abrasion of a coating or lining provided on the inner surface of the feeder and also prevents damage of the feeder. In a pulling apparatus operated according to the Czochralski method, after causing granular silicon material to stagnate in the feed pipe, the crucible is lowered or the feed pipe is raised, while the stagnation of the granular silicon material is maintained, so as to form an unmolten layer of the granular silicon material on the molten or solidified surface of the silicon melt. The unmolten layer is then melted, and the granular silicon material is fed onto the unmolten layer through the feed pipe while the stagnation of the granular silicon material in the feed pipe is maintained. Accordingly, silicon material can be recharged without damaging the crucible, so that productivity and manufacturing yield of silicon monocrystals can be improved.