Degradation of DC characteristics of InGaAs/InP single heterojunction bipolar transistors under electron irradiation

The effects of high-energy (similar to 1 MeV) electron irradiation on the d e characteristics of InGaAs/InP single heterojunction bipolar transistors ( SHBT's) are investigated. The device characteristics do not show any signif icant change for electron doses <10(15/)cm(2). For higher doses, devices sh ow a decrease in collector current, a degradation of common-emitter current gain, an increase in collector saturation voltage and an increase in the c ollector output conductance, A simple SPICE-like device model is developed to describe the de characteristics of SHBT's. The model parameters extracte d from the measured de characteristics of the devices before and after irra diation are used to get an insight into the physical mechanisms responsible for the degradation of the devices.