Effects of input bias on different commercial technological lines of CMOS inverters with respect to the cumulated dose

The effects of input bias on the sensitivity to cumulative dose effects of 144 commercial CMOS inverters have been studied. The "worst case" irradiation conditions, as well as the most favorable case, have been inferred from these data. A saturation of the switching voltage shift had been measured for a null input bias. This effect appears to be due to the saturation of the NMOS and PMOS transistors threshold voltage shift for a null gate-to-source voltage.