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. 21, 2007
Filed:
Dec. 08, 2003
Masahiro Sakurada, Fukushima, JP;
Izumi Fusegawa, Fukushima, JP;
Satoshi Soeta, Fukui, JP;
Makoto Iida, Gunma, JP;
Masahiro Sakurada, Fukushima, JP;
Izumi Fusegawa, Fukushima, JP;
Satoshi Soeta, Fukui, JP;
Makoto Iida, Gunma, JP;
Shin-Etsu Handotai Co., Ltd., Tokyo, JP;
Abstract
The present invention discloses a graphite heater for producing a single crystal used when producing a single crystal by the Czochralski method which comprises at least a terminal part to which electric current is supplied and a cylindrical heat generating part by resistance heating and are provided so as to surround a crucible for containing a raw material melt wherein the heat generating part has heat generating slit parts formed by being provided with upper slits extending downward from the upper end and lower slits extending upwards from the lower end by turns, and a length of at least one slit of the upper slits differs from others and/or a length of at least one slit of the lower slits differs from others so that a heat generating distribution of the heat generating part may be changed. Thereby, there can be provided a graphite heater for producing a single crystal which makes it possible to produce a silicon single crystal with high productivity when the silicon single crystal is pulled in a predetermined defect-free region or a predetermined defect region.