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:
Apr. 27, 1999
Filed:
Jul. 15, 1997
Hitachi, Ltd., Tokyo, JP;
Abstract
A high voltage semiconductor device is provided with a p layer which forms a main pn-junction, a plurality of p layers which surround the p layer in a ring form, a ring-like n+ layer which further surrounds those p layers, forward field plates extending in the peripheral direction and reverse field plates extending in the inside direction, the field plates being in contact at a low resistance with the p and n+ layers and reaching the surface of an n- layer through an insulating film, the area of the field plates being not less than one half of the n- surface. This arrangement is particularly effective in stabilizing the blocking voltage of a high voltage semiconductor device which is used in a severe environment, and is very effective in improving the reliability of a high voltage control unit.