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:
Aug. 10, 1999
Filed:
Nov. 21, 1997
Toshirou Kotooka, Kanagawa, JP;
Toshimichi Kubota, Kanagawa, JP;
Makoto Kamogawa, Kanagawa, JP;
Yoshiyuki Shimanuki, Kanagawa, JP;
Komatsu Electronic Metals Co., Ltd., Kanagawa, JP;
Abstract
An cylindrical after-heater surrounding a single crystal being lifted and a cylindrical heat-retaining cylinder installed between the after-heater and the single crystal are provided above a reversed frustrated heat-shielding sleeve disposed near the melted liquid. The heat history of the single crystal can be controlled by adjusting the output of the after-heater and the location of the heat-retaining cylinder. By such an arrangement, rapid respond to the change of the heat environment in a furnace can be made and control of the temperature gradient of the single crystal can be achieved. The single crystal, throughout the whole length, is maintained in the range of from 1000.degree. C. to 1200.degree. C. for more than one hour during lifting operation.