Abstract:
Using detailed experimental data, we demonstrate that for the correct interpretation of negative bias temperature instability (NBTI) degradation behavior with stress time, it is essential to include the effect of trapping of hydrogen species in the oxide. A new oxide trap-assisted NBTI degradation model is proposed and shown to fit the experimental data very well. Our proposed model can also be used to explain the recently observed phenomenon of higher NBTI degradation for increasing nitrogen concentration in the oxide. We show from numerical calculations that, for higher nitrogen concentration at the interface, one would expect higher NBTI degradation, as also reported recently.