Neutron irradiation induced degradation of the collector–emitter offset voltage in InP/InGaAs single heterojunction bipolar transistors

In this article, we report the results of our investigation of neutron irradiation effects on the collector–emitter offset voltage of InP/InGaAs single heterojunction bipolar transistors. We find that the offset voltage of these devices increases by more than 0.1 V for neutron doses $∼6×1014$ $cm−2.$ We present an analysis of the forward and inverse Gummel plots that clearly shows that the increase in offset voltage is caused by the degradation of the base–collector junction due to the neutron-induced displacement damage in the collector.