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:
Jun. 11, 1996
Filed:
Feb. 01, 1995
Masana Harada, Itami, JP;
Katsuhiro Tsukamoto, Itami, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
There is disclosed a semiconductor device including a plurality of P well regions (4) and a P well region (41) insulated from each other by a plurality of trench isolating layers (10) formed regularly in predetermined spaced relation with each other and having the same depth. The outermost P well region (41) isolatedly formed externally of an outermost trench isolating layer (10A) is made as deep as the trench isolating layers (10) and, accordingly, is made deeper than the P well regions (4) except the outermost P well region (41). This provides for the alleviation of the electric field concentration generated in the bottom edge of the outermost isolating layer of trench structure, thereby achieving the semiconductor device having an improved device breakdown voltage and a method of fabricating the same.