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:
Jul. 27, 2004
Filed:
Apr. 03, 2002
Kyushik Hong, Thousand Oaks, CA (US);
Richard S. Burton, Newbury Park, CA (US);
Noureddine Matine, Aliso Viejo, CA (US);
Debora L. Green, Bethlehem, PA (US);
Charles F. Krumm, Newport Coast, CA (US);
Skyworks Solutions, Inc., Irvine, CA (US);
Abstract
According to one exemplary embodiment, a heterojunction bipolar transistor comprises an emitter. The heterojunction bipolar transistor further comprises a first emitter cap comprising a first high-doped layer, a low-doped layer, and a second high-doped layer, where the first high-doped layer is situated on the emitter, the low-doped layer is situated on the first high-doped layer, and the second high-doped layer is situated on the low-doped layer. The first high-doped layer, the low-doped layer, and the second high-doped layer form an emitter ballast resistor. According to this exemplary embodiment, the low-doped layer has a thickness and a dopant concentration level such that the resistance of the low-doped layer is substantially independent of the dopant concentration level, but corresponds to the thickness of the low-doped layer.