Temperature dependence of the negative bias temperature instability in the framework of dispersive transport

Negative bias temperature instability (NBTI) is studied in multiple-gate field-effect transistors with an ultrathin gate oxide. It is observed that the threshold voltage shift in these devices follows a power-law function of time, with the exponent depending linearly on temperature. An analytic model is proposed that explains this temperature dependence by dispersive diffusion of hydrogen in the bulk of the gate oxide. Based on both the experimental data and the model, it is concluded that NBTI is an inherently non-Arrhenius process. (C) 2005 American Institute of Physics.