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:
Aug. 29, 1989
Filed:
Jun. 17, 1987
Tsutomu Matsushita, Yokohama, JP;
Teruyoshi Mihara, Yokosuka, JP;
Nissan Motor Company Limited, Yokohama, JP;
Abstract
Vertical MOS and another component such as CMOS are made in a single semiconductor substrate having a highly doped underlying layer and a lightly doped epitaxial surface layer of a first conductivity type. The vertical MOS includes a channel region of a second conductivity type, formed in the surface layer, and a source region of the first conductivity type, formed in the channel region. The channel region is made deep and joined with the highly doped underlying layer to form a first Zener diode for regulating a drain-source voltage. A drain electrode is formed on the bottom surface of the substrate and connected to a power supply, and a topside source electrode is connected to a load. The vertical MOS is surrounded, and separated from the CMOS, by a grounded guard ring region of the second conductivity type, formed in the surface layer. The guard ring region is also made deep and joined with the underlying layer.