60 MeV proton irradiation effects on NO-annealed and standard-oxide deep submicron MOSFETs

The impact of 60 MeV proton irradiation on the static device parameters of CMOS transistors fabricated in a 0.18 μm technology is reported and studied as a function of the polysilicon gate length L_poly. In addition, the role of the gate dielectric in the radiation response of the threshold voltage, the transconductance, the subthreshold swing, the series resistance and the gate-induced drain leakage (GIDL) current is investigated. For certain parameters, an anomalous length dependence has been observed. Furthermore, a stronger degradation is found for the transistors with an NO-annealed gate dielectric compared with a standard thermal gate oxide. Combining the charge separation technique with the GIDL current, additional insight in the damage mechanisms is gained. It is shown that there is evidence for electron trapping close to the drain in the case of the NO devices.