Radiation-induced base current broadening mechanisms in gated bipolar devices

Ionizing radiation experiments on gated lateral bipolar junction transistors (BJTs) show a broadening in the peak base current profile after irradiation. The primary mechanism for this effect is identified as the change in the charge state of interface traps in the oxide over the base. Simulations and theoretical analysis not only describe the mechanism in detail, but also suggest possible solutions for extracting information from the shape of the profile. The effects of the interface-trap energy distribution are investigated, showing that traps between flatband and threshold contribute to the width of the base-current peak.