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:
May. 14, 1996
Filed:
Nov. 17, 1994
Xiao-Ming Li, Ottawa, CA;
T Victor Herak, Kanata, CA;
Northern Telecom Limited, Montreal, CA;
Abstract
A self-aligned single polysilicon bipolar transistor structure and a method of formation thereof are provided. The transistor has an emitter structure characterised by T shape defined by inwardly extending sidewall spacers formed by oxidation of amorphous or polycrystalline silicon, rather than the conventional oxide deposition and anisotropic etch back. Advantageously the method compatible with bipolar CMOS processing and provides a single polysilicon self-aligned bipolar transistor with a reduced number of processing steps. Further the formation of inwardly extending sidewalls defining the emitter width reduces the emitter base junction width significantly from the minimum dimension which is defined by photolithography, while a large area emitter contact is also provided.