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. 05, 2000
Filed:
Jul. 30, 1999
Ming Fang, Plano, TX (US);
Jin Liu, Lewisville, TX (US);
Gilles E Thomas, Dallas, TX (US);
Viviane Marguerite Do-Bento-Vieira, Coppell, TX (US);
STMicroelectronics, Inc., Carrollton, TX (US);
Abstract
A vertical conduction NPN bipolar transistor with a tunneling barrier of silicon carbide in the emitter providing a high emitter injection efficiency and high, stable current gain. The emitter structure comprises a heavily doped polysilicon layer atop a silicon carbide layer that contacts a shallow, heavily doped emitter region at the surface of an epitaxial silicon layer, which is disposed on a monocrystallinie silicon substrate. The silicon carbide layer is about 100 to 200 angstroms thick and has a composition selected to provide an energy band gap in the 1.8 to 3.5 eV range. The thickness and composition of the silicon carbide can be varied within the preferred ranges to tune the transistor's electrical characteristics and simplify the fabrication process.