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.

Date of Patent:
May. 02, 2000

Filed:

Mar. 31, 1998
Applicant:
Inventors:

Masahiro Ogawa, Hyogo, JP;

Toshiyuki Yamamoto, Osaka, JP;

Yoshiyuki Kashiwara, Osaka, JP;

Tokuji Maeda, Saga, JP;

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C30B / ;
U.S. Cl.
CPC ...
117 14 ; 117 15 ; 117 20 ; 117201 ; 117202 ;
Abstract

In the pulling of a single crystal, hitherto, it is difficult to reduce the OSF density while the deformation rate is held down within the tolerance, so that it is difficult to improve the quality and productivity. In the present invention, a deviation from a true circle in each part of a single crystal S.sub.n-1 which was pulled in the preceding batch is found and the pulling speed pattern f.sub.pn-1 (L.sub.1) in the preceding batch is updated (f.sub.pn (L.sub.1)) before a single crystal S.sub.n is pulled, in order to pull the single crystal as fast as possible so that the OSF density is small while the deviation is within the tolerance.


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