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:
Mar. 09, 1999
Filed:
Jun. 26, 1997
Masahiko Urano, Takasaki, JP;
Yasushi Nakamura, Tomioka, JP;
Seiichiro Otsuka, Tomioka, JP;
Eiichi Iino, Annaka, JP;
Shin-Etsu Handotai Co., Ltd., Tokyo, JP;
Abstract
A method and an apparatus for pulling a single crystal are disclosed. A first neck portion, a convex portion, and a second neck portion are formed in this order under a seed crystal held by a seed chuck, and subsequent to the second neck portion, a single crystal having a diameter-expanding portion and a straight cylindrical portion is formed. Lifting holders are brought around and in proximity to the second neck portion when the second neck portion rises to a predetermined position during the pulling by the seed chuck. The single crystal and the lifting holders are moved relative to each other in the vertical direction to thereby bring the convex portion into contact with the lifting holders in a resting manner, so that part of a load borne by the seed chuck is shifted to the lifting holders. Subsequently, the pulling operation is performed by the lifting holders. Accordingly, a single crystal having a larger weight can be pulled safely while maintaining high quality.