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. 11, 2000
Filed:
May. 11, 1998
Kenneth Vaccaro, Acton, MA (US);
Helen M Dauplaise, Brockton, MA (US);
Andrew Davis, Boston, MA (US);
Joseph P Lorenzo, Stow, MA (US);
Abstract
A novel indium phosphide (InP) based heterojunction bipolar transistor (HBT) is described. A II-VI compound, cadmium sulfide (CdS), is used as the emitter to improve the emitter injection efficiency and reduce recombination losses. The cadmium sulfide emitter is applied following the epitaxial growth of III-V compound collector and base regions. The large valence band discontinuity (.quadrature.E=0.75 eV) between CdS and InP allows InP to be used for both the base and collector material. Prior to cadmium sulfide deposition, the exposed surfaces of the epitaxial layers can be passivated with sulfur, further reducing the recombination losses.