Temperature and field dependence of the generation of interface states in the Si-SiO₂ system after high-field stress

We have studied the time dependence of the generation of interface states in the Si-SiO₂ system after metal-oxide-semiconductor capacitors were stressed by a 7.4-MV/cm gate positive electric field for 8 h at 90 K. The interface state density increased logarithmically with time for temperatures between 180 and 300 K with fields between +2 and -2 MV/cm. An analysis based upon a distribution of formation energies is proposed to explain the logarithmic time dependence. We find that there are two peaks in this distribution. One peak at 0.7 eV is field independent while the other at 0.9 eV disappears when a zero or negative bias is applied.