Contribution of Latent Defects Induced by High-Energy Heavy Ion Irradiation on the Gate Oxide Breakdown

From annealing and electrical stress experiments performed on irradiated MOS devices, swift energetic ions-induced morphological oxide defects are shown to act as a contributing part of the oxide breakdown occurring during post gate stress, without being possibly electrically detected before the onset of breakdown itself. A reduction of the charge to breakdown and an increase of the radiation-induced leakage current were first observed after irradiation. Then, leakage current has been shown to be fully removable using isochronal annealing while charge to breakdown was not increased back to its initial value.