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. 27, 1986
Filed:
Oct. 18, 1983
Syoichi Washizuka, Yokohama, JP;
Sadao Matsumura, Tokyo, JP;
Tokyo Shibaura Denki Kabushiki Kaisha, Kawasaki, JP;
Abstract
A method for controlling the shape of a single crystal. The weight of a single crystal pulled by the Czochralski method is detected, to obtain a weight signal W. The weight signal W is differentiated over time, to obtain a differential signal dW/dt. Using the differential signal dW/dt, (A.multidot.dW/dt+B).theta. is computed, to obtain an operation signal f. A and B are parameters which are determined by predetermined manufacturing conditions of the Czochralski method, and .theta. is a preset growing angle of the single crystal. The operation signal f is integrated over time, to obtain an integral signal F. The integral signal F and the differential signal dW/dt are compared to obtain a deviation signal. The heating power supplied to the crucible is controlled by use of the deviation signal, to keep the growing angle of the single crystal constant.