Modeling of MOS Radiation and Post Irradiation Effects

The radiation response and long term recovery effects in a n-channel MOSFET due to a pulse of ionizing radiation were modeled assuming that electron tunneling from the semiconductor into the oxide and the buildup of interface states were the postirradiation recovery mechanisms. The modeling used convolution theory and took into account the effects of bias changes during the recovery period and charge yield effects. Changing the bias condition during the post-irradiation recovery period changed the recovery rate. The charge yield effects changed the density of trapped positive charge in the oxide but did not change the recovery characteristics for a given oxide thickness. The modeling results were compared to previous experimental results.