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:
Nov. 20, 1990
Filed:
Dec. 18, 1989
Farzin H Azad, Clifton Park, NY (US);
General Electric Company, Schenectady, NY (US);
Abstract
A method and apparatus for crystal growth control in a Czochralski crystal pulling process are provided wherein a plurality of thermocouples and individually controllable heating elements are embedded in an upper control section of a raised platform in a crucible containing a melt from which the crystal is pulled. The upper control section is disposed in the melt at a height below the bulk level of the melt in the crucible and underneath the crystal being pulled so as to retain the thermocouples in a position to monitor the temperature distribution of the melt below a solidification front of the crystal, and to retain the individually controllable heating elements in a position whereby the heating elements may be selectively controlled to attain a predetermined temperature distribution in the melt in a region underneath the solidification front.