Neutron irradiation effects on AlGaAs/GaAs heterojunction bipolar transistors

AlGaAs/GaAs heterojunction bipolar transistors irradiated with 10/sup 15/ neutrons/cm/sup 2/ demonstrated superior performance to silicon bipolar transistors. The postneutron current gain was dominated by recombination in the emitter-base depletion region. The base current exhibited an ideality factor n>2 after irradiation, which was attributed to two possible recombination mechanisms associated with neutron-induced traps: tunneling-assisted trapping and recombination arising from a nonuniform distribution of Shockley-Read-Hall centers within the depletion region. The emitter-base heterojunction was degraded more than the collector-base homojunction after irradiation. >