Life testing of GaAs/AlGaAs heterojunction bipolar transistors

GaAs/AlGaAs heterojunction bipolar transistors (HBTs) are life tested under accelerated DC and high temperature storage conditions. The experimental procedures, measurement results, and statistical evaluation of the data are discussed. The results obtained so far indicate that the main failure mechanisms are activated almost entirely by high current densities. The high temperature storage tests without bias indicate diffusion at interfaces is a secondary, but important, failure mechanism. Studies have shown that longer lifetimes are obtained with material that exhibits low 1/f noise. These and other results related to the reliability of the devices are presented