Investigating the latent reliability degradation of partially depleted SOI devices induced by high-energy heavy ions irradiation

Abstract

Through electrical stress and annealing experiments performed on irradiated partially depleted SOI MOS devices, high-energy heavy ions induced defects in the gate oxide are shown to affect insulation character and the long time reliability of the devices. A decrease of the time-dependent dielectric breakdown (TDDB) lifetime and an increase of the radiation-induced leakage current (RILC) were observed after irradiation at the nominal operating irradiation bias. But then, the RILC was completely removable using isochronal annealing experiment, while the TDDB lifetime did not increase back to its initial value. We interpreted these results and degeneration mechanisms in terms of the neutral electrons traps and morphological oxide defects induced by high-energy heavy ions, which may be meaningful to evaluate the reliability of the devices used in the radiation environment.