Reliability of Gaas-based HBTs

Most of the applications of the Heterojunction Bipolar Transistors (HBTs) are in the field of telecommunications, where device reliability is a key issue. This work reports on a major HBT reliability issue: base dopant stability. In particualr, the most two widely employed base dopnats are addressed: Beryllium and Carbon. The instability phenomena typical of each doping impurity, and their effects on the HBT cahracteristics are briefly overviewed in this paper