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:
Apr. 03, 1990
Filed:
Oct. 16, 1989
Jenn-Hwa Huang, Gilbert, AZ (US);
Luke Mang, Phoenix, AZ (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
A heterojunction bipolar transistor having a planar surface topology, reduced lateral dimensions and a base electrode aligned to both the emitter and collector electrodes is fabricated by forming sub-collector, collector, base and one or more emitter layers on a substrate. An opening extending to the sub-collector layer is then formed and a first portion of the collector electrode is formed therein so that the sidewalls of the opening are not contacted by the first portion. Dielectric material is then formed between the sidewalls of the opening and the first portion of the collector electrode. A second portion of the collector electrode is then formed on the first portion of the collector electrode along with an emitter electrode so that the second portion of the collector electrode and the emitter electrode are substantially planar. After then exposing the base layer, the self-aligned base electrode is formed between the second portion of the collector electrode and the emitter electrode.