Predicting switched-bias response from steady-state irradiations MOS transistors

A novel semiempirical model of radiation-induced charge neutralization is presented. This model is combined with 12 heuristic guidelines derived from studies of oxide- and interface-trap charge ( Delta V/sub ot/ and Delta V/sub it/) buildup and annealing to develop a method to predict MOS switched-bias response from steady-state irradiations, with no free parameters. For n-channel MOS devices, predictions of Delta V/sub ot/, Delta V/sub it/, and mobility degradation differ from experimental values through irradiation by less than 30% in all cases considered. This is demonstrated for gate oxides with widely varying Delta V/sub ot/ and Delta V/sub it/ and for parasitic field oxides. Preliminary results suggest that n-channel MOS Delta V/sub ot/ annealing and Delta V/sub it/ buildup following switched-bias irradiation and through switched-bias annealing also may be predicted with less than 30% error. The p-channel MOS response at high frequencies (>1 kHz) is more difficult to predict.>