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:
Feb. 27, 2018
Filed:
Oct. 31, 2014
Sumco Corporation, Tokyo, JP;
SUMCO CORPORATION, Tokyo, JP;
Abstract
There is provided a silicon single crystal producing method in producing a silicon single crystal by the Czochralski method using a pulling apparatus including a heat shield, wherein an oxygen concentration in the crystal is controlled through the adjustment of a flow velocity of inert gas introduced into the apparatus at the gap portion between an exterior surface of the single crystal and a lower-end opening edge of the heat shield, in accordance with a gap-to-crystal-diameter ratio ('the area of the gap portion'/'the area of a cross-sectional of the single crystal'). By this producing method, it is possible to appropriately control the oxygen concentration in the pulled single crystal.