Impact of 7.5-MeV proton irradiation on front-back gate coupling effect in ultra thin gate oxide FD-SOI n-MOSFETs

The degradation of deep submicron (0.1 mum) fully depleted (FD)-silicon-on-insulator (SOI) n-channel metal oxide semiconductor field effect transistors (MOSFETs) subjected to 7.5-MeV proton irradiation is reported. The radiation-induced damage is investigated by studying the static characteristics of devices with different geometries and bias conditions. Special attention is paid to the analysis of the front-back gate coupling effect by changing the back-gate bias V-BG. The change of the front and back channel parameters, the impact of the gate coupling effect and the gate-induced floating body effect are clarified. A correction procedure is proposed for the extraction of the front- and back-interface and oxide trap charge contribution to the threshold voltage shift by accounting for the front-back gate coupling.