Nature of Interface Defect Buildup in Gated Bipolar Devices Under Low Dose Rate Irradiation

The buildup of radiation-induced switching states in ELDRS-sensitive bipolar base oxides is measured with dc current-voltage and charge pumping techniques. These states include both faster interface traps (P_b) centers) and slower border traps. After irradiation, border traps and interface traps mostly decrease with annealing time and temperature in devices irradiated at 0 V. However, for devices irradiated at -50 V, there is a decrease in border trap density but an increase in interface trap density. These differences in interface-trap buildup and annealing are attributed to the dependence of defect passivation and depassivation on the concentrations of hydrogen and dangling Si bond defects near the Si/SiO₂ interface