EXPERIMENTAL EVALUATION OF THE MINIMUM DETECTABLE OUTDIFFUSION LENGTHFOR ALGAAS GAAS HBTS/

Triple mesa, Be-doped AlGaAs/GaAs HBTs were stressed at low temperatur e by forcing an emitter current density while the devices were biased in the forward active region. The effect on the d.c. characteristics w as investigated and the results demonstrated that a base dopant outdif fusion is the degradation mechanism. By merging the experimental data with numerical simulations we obtained for the first time an experimen tal evaluation of the minimum detectable outdiffusion length. The meas ured value is in fair agreement with the theoretical value reported in the literature. (C) 1998 Published by Elsevier Science Ltd.