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:
Sep. 01, 1992
Filed:
Oct. 09, 1990
Shang-yi Chiang, Walnut Creek, CA (US);
Wen-Ling M Huang, Milpitas, CA (US);
Clifford I Drowley, Moutain View, CA (US);
Paul V Voorde, Moutain View, CA (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
This invention pertains to a self-aligned, trench-isolated emitter structure and the method for forming same. The emitter structure comprises a portion of a bipolar transistor which exhibits improved function due to the emitter structure. A single layer of conductive material forms both the emitter and base contacts in the transistor structure, which structure has particularly shallow emitter and base junctions (about 0.15 micrometer or less). The self-aligned emitter contact, isolated from the base contact by a dielectric filled trench, permits overall size reduction of the device, whereby junction area and accompanying leakage across junctions is reduced. In addition, when the structure of the bipolar transistor is such that the trench isolates the emitter area from both the base contact and the extrinsic base, it is possible to provide improved base conductivity without generating peripheral transistor effects. The bipolar transistor can be either N-P-N type or P-N-P type depending on the materials of fabrication, although high speed devices are typically of the N-P-N type.