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.