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:
Jul. 14, 1992
Filed:
Jun. 11, 1991
Walter T Matzen, Richardson, TX (US);
Ronald B Foster, Garland, TX (US);
Honeywell Inc., Minneapolis, MN (US);
Abstract
A semiconductor device is provided for use as a bidirectional surge suppressor circuit. It incorporates doped regions of substrate and epitaxial layers which result in a dual Zener diode arrangement having the Zener diodes associated in an opposite polarity arrangement. The semiconductor device comprises a substrate with an epitaxial layer deposited on one of its surfaces. In an upper surface of the epitaxial layer, first and second regions of P type material are diffused with guard rings comprising P+ type material diffused around the first and second regions. The guard rings are heavily doped and extend much deeper than the relatively shallow junctions of P material. A channel stopper of N+ conductivity type material is diffused into the upper surface of the epitaxial layer to provide a channel stopper, or sinker, around both the first and second regions and their associated guard rings and, additionally, between the first and second regions. This structure provides several significant advantages including reduced current leakage reliability, uniform breakdown voltage, crack resistance and a smaller area needed to provide the required thermal capacity.