Mechanism of anomalous recovery in advanced SiGe bipolar transistors after low dose rate irradiation for very high total doses

•The physical mechanism of current gain recovery is presented.•Recovery is related to the dependence of maximum saturated damage on dose rate.•Model shows that switching dose rate leads to a lower value of saturation damage.•Qualitative mechanism agrees with experimental data presented in original work.

The possible physical mechanism of the anomalous recovery effect in SiGe bipolar transistors is described. The qualitative analysis of saturated oxide trapped charge and interface trap densities at very high total doses as a function of dose rate affords an explain of decreasing excess base current and increasing current gain during further low dose rate irradiation.