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:
Oct. 21, 1986
Filed:
Sep. 30, 1985
Naoki Yokoyama, Atsugi, JP;
Toshio Ohshima, Atsugi, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
When the collector, base and emitter layers of a heterojunction bipolar transistor or a tunneling hot electron transistor are vertically stacked, the thickness of the base layer is preferably small so as to increase the current gain or switching speed. A thin base layer, however, has a disadvantage in that a space of the base layer between the actual base region and the base electrode makes the base resistance too large, decreasing current gain or switching speed, or is fully depleted due to interface states, making the transistor inoperable. This disadvantage is eliminated by forming a base contact region by doping in a region in alignment with the edge of an electrode so as to remove said space, that is, the base contact region is in contact with the actual base region.