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:
Oct. 01, 2002
Filed:
Jun. 19, 2000
Applicant:
Inventors:
Makoto Kojima, Tochigi-Prefecture, JP;
Yasuhiro Ishii, Tochigi, JP;
Assignee:
MEMC Electronic Materials, Inc., St. Peters, MO (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C30B 1/514 ;
U.S. Cl.
CPC ...
C30B 1/514 ;
Abstract
A Czochralski method of producing a single crystal silicon ingot having a uniform thermal history. In the process, the power supplied to the side heater is maintained substantially constant throughout the growth of the main body and end-cone of the ingot, while power supplied to a bottom heater is gradually increased during the growth of the second half of the main body and the end-cone. The present process enables an ingot to be obtained which yields wafers having fewer light point defects in excess of about 0.2 microns, while having improved gate oxide integrity.