Electron trapping during irradiation in reoxidized nitrided oxide

Abstract

Isochronal detrapping experiments have been performed following irradiation under different gate biases in reoxidized nitrided oxide (RNO) MOS capacitors. These show electron trapping by the nitridation-induced electron traps at low oxide fields during irradiation. A difference in the detrapping behavior of trapped holes and electrons is observed, with trapped holes being detrapped at relatively lower temperatures compared to trapped electrons. Electron trapping shows a strong dependence on the magnitude of the applied gate bias during irradiation but is independent of its polarity. As expected, conventional oxide devices do not show any electron trapping during irradiation by the native electron traps. A comparison of the isochronal detrapping behavior following irradiation and following avalanche injection of electrons has been made to estimate the extent of electron trapping. It is shown that electron trapping by the nitridation-induced electron traps does not play a dominant role in improving the radiation performance of RNO, though its contribution cannot be completely neglected for low oxide field irradiations.