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:
Mar. 28, 2006
Filed:
Aug. 30, 2002
Gunther Lippert, Frankfurt an der Oder, DE;
Hans-jörg Osten, Muellrose, DE;
Bernd Heinemann, Frankfurt/Oder, DE;
Gunther Lippert, Frankfurt an der Oder, DE;
Hans-Jörg Osten, Muellrose, DE;
Bernd Heinemann, Frankfurt/Oder, DE;
Abstract
A silicon-germanium hetero bipolar transistor comprising a silicon collector layer, a boron-doped silicon-germanium base layer, a silicon emitter layer and an emitter contact area. The transistor is fabricated using an epitaxy process on a surface of pure silicon. An electrically inert material is incorporated into the epitaxial layers in order to link the defects in the semiconductor structure and to reduce the outdiffusion of the dopant. Thus, a transistor for high-frequency applications can be fabricated in two ways: to increase the dopant dose of the base region or to reduce the thickness of the base layer. In particular, the concentration profile of germanium in the base layer has a general shape of a triangle or trapezoid.