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. 13, 2009
Filed:
Aug. 15, 2006
Applicant:
Simon Green, Cardiff, GB;
Inventor:
Simon Green, Cardiff, GB;
Assignee:
International Rectifier Corporation, El Segundo, CA (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L 27/108 (2006.01); H01L 29/76 (2006.01);
U.S. Cl.
CPC ...
Abstract
The size of BVdistribution is controlled by the active manipulation of the distribution of silicon parameters across a wafer to offset opposing effects inherent in the wafer fabrication process. Thus, the resistivity of the silicon wafer is increased toward the edge of the wafer. This offsets the drop-off of BVacross the wafer caused in wafer fabrication by deeper trenches at the edge of the wafer. This causes a flatter BVprofile across the wafer and significantly reduced BV distribution over the wafer.