Total dose dependence of off currents in the irradiated PD-SOI devices

Total dose dependence of off currents in the partially depleted SOI devices with standard and enclosed gate structures was presented. The experimental results show that increases in the radiation induced off current are result from the effect of trench sidewall leakage, the conduction of back gate parasitic transistor and the coupling effect of band-to-band tunneling and back gate leakage currents. In the standard structures, trench sidewall leakages are increased by the positive charge trapping in the field oxide, thus the off currents in the front and back gate is increased significantly. In the enclosed gate structures, increases in the off current are more caused by the conduction of back gate parasitic transistors and the drain current dependence on total dose at negative gate-source voltage are caused by the coupling effects of band-to-band tunneling and back gate leakage currents. These results can be used for hardness assurance by improving of device layout structures.