Summary: Photoemission studies on heterostructure bipolar transistors
*, Peter J. Zampardib
, Peter M. Asbeckc
Air Force Research Laboratory, AFRL/SNDD, Wright Patterson AFB, Dayton, OH 45433-7322, USA
Rockwell Science Center, 1049 Camino Dos Rios, Thousand Oaks, CA 91360, USA
University of California, San Diego, Department of ECE 0407, 9500 Gilman Dr, La Jolla, CA 92093, USA
We apply in-situ photoemission techniques to characterize the band proŽle in heterostructure bipolar transistors.
The measurements are performed on-wafer on fully fabricated InP based HBTs at room temperature. We
demonstrate that this technique is sensitive to detect and analyze barriers between emitter and base as well as
between base and collector. Furthermore, the photoresponse provides information on the doping characteristics of
the active layers. Published by Elsevier Science Ltd.
Heterostructure bipolar transistors (HBTs) are being
developed for applications where speed, power, e-
ciency, and low noise are of importance. These transis-