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:
Jul. 14, 1992
Filed:
Nov. 16, 1990
Applicant:
Inventors:
Assignee:
Shin-Etsu Handotai Co., Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C30B / ;
U.S. Cl.
CPC ...
156601 ; 156605 ; 156606 ; 1566171 ; 1566181 ; 1566204 ; 422249 ;
Abstract
A method for controlling a specific resistance of a single crystal in a Czochralski-method type single crystal pulling apparatus having a hermetical chamber in which the single crystal is pulled up from a polycrystal melt and an inert gas supply and exhaust system by means of which an inert gas is supplied to the hermetical chamber and exhausted therefrom; the method being characterized in that the pneumatic pressure in the hermetical chamber and the supply rate of the inert gas are controlled in accordance with a prepared control pattern with respect to the passage of pulling time.