Radiation induced kink effects on SOI PMOS transistors

The authors discuss the influence of back oxide trapped charges on the degradation of the output characteristics of irradiated SOI PMOS transistors. It is found that a positive back gate bias during gamma irradiation promotes an accumulation of trapped holes at the Si-SiO₂ interface in the buried oxide. The induced parasitic kink effect, which is usually present in SOI NMOS, has been observed and characterized in a PMOS transistor. These results, explained by the increased electric field near the drain, are confirmed by a 2-D analysis. This phenomenon, related to P-channels, should be taken into account for analogical device and circuit optimization