On the short and long term degradation of GaInP/GaAs heterojunction bipolar transistors

This work deals with the short and long term effects of a current stress performed at room temperature on Carbon doped GaInP/GaAs heterojunction bipolar transistors, The investigation has been carried out by means of DC characterizations and low frequency noise (LFN) measurements in the 250 Hz-100 kHz frequency range. During the stress the devices were biased in the forward active region, a collector-emitter voltage of 7.7 V and a collector current density of 2.2 x 10(4) A/cm(2) were imposed. The effect of the stress on the DC and LFN characteristics were compared and discussed in terms of two recombination mechanisms, The discussion points out that both extrinsic and intrinsic recombination processes have to be taken into account in order to justify the short and long term effects of the electrical stress. (C) 1999 Elsevier Science Ltd. All rights reserved.