Charge transport and trapping model for scaled nitride-oxide stacked films

Experimental measurements, including capacitance-voltage and temperature-dependent current-voltage measurements of two nitride/oxide dual-layer films, have been used to characterize the charge transport and trapping mechanisms for scaled nitride-oxide stacked films. For charge transport from the cathode electrode to the adjacent oxide or nitride, electron Fowler-Nordheim tunneling is the dominant mechanism and the tunneling barriers are 3.2 eV for oxide and 2 eV for nitride, respectively. For charge transport from the nitride to the oxide, electron tunneling with limited electron supply from the nitride/oxide injecting interfaces was observed. A new charge transport and trapping model for scaled nitride-oxide stacked films is evolved from the experimental observations. According to the model, nitride-oxide stacked films can be thought of as an oxide film with electron trapping at the nitride/oxide interface. The electron trapping reduces the leakage current and lowers the incidence of early failures for nitride-oxide stacked films.