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. 09, 1988
Filed:
Jan. 23, 1987
Petrus M Moors, Nijmegen, NL;
U.S. Philips Corporation, New York, NY (US);
Abstract
A method is set forth of manufacturing a bipolar transistor with emitter ballast resistors. According to the invention, a base window and a strip-shaped opening are formed beside each other on a collector region. The strip-shaped opening is first covered by a masking layer and then doping of the base is provided. After removal of the masking layer, oxide layers of the same thickness are formed in the base window and in the strip-shaped opening. After formation of emitter fingers, base contact windows are formed within the base zone, and resistance windows are formed within the strip-shaped opening, whereupon simultaneously base contact zones and mutually separated emitter ballast resistors are formed in these windows.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile