Accelerated life test results of InGaAs/InP heterojunction bipolar transistors

In this paper, we report the accelerated life test results of Vitesse InGaAs/InP heterojunction bipolar junction transistors (HBT). This HBT process is designed for Ft and Fmax over 150 GHz and has produced InP integrated circuits with 5000 transistors at 40 GHz clock rate. The tests were carried out at junction temperatures of 165/spl deg/C, 185/spl deg/C, and 205/spl deg/C for up to 6500 hours. The devices were biased into two separate regions of high current and high voltage operations. Critical device parameters, including turn-on voltage, common-emitter current gain, and leakage currents, were measured during the life test. These parameters showed no significant degradations throughout the test. To our knowledge, the reliability of the turn-on voltage and current gain is among the best reported for InP HBTs.