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:
May. 20, 2003
Filed:
Mar. 01, 2000
Applicant:
Inventors:
Hidekatsu Onose, Hitachi, JP;
Tsutomu Yatsuo, Hitachi, JP;
Toshiyuki Ohno, Hitachi, JP;
Saburou Oikawa, Hitachi, JP;
Assignee:
Hitachi, Ltd., Tokyo, JP;
Primary Examiner:
Int. Cl.
CPC ...
H01L 2/940 ;
U.S. Cl.
CPC ...
H01L 2/940 ;
Abstract
To reduce the field intensity on the termination surface, almost not affecting the on-characteristic, a drift layer is made of two layers, an n-layer and n layer, and a termination region is formed on the surface of the above n layer. An impurity concentration ratio between the n layer and the n-layer is less than 1:2, and the thickness of the n layer is less than that of a source n layer. Reliability can be secured even in a high temperature operation.