Voltage stress exposing degradation rate of 28nm HK/MG nMOSFETs under different nitridation annealing temperatures

Exposing the feasible annealing temperature to the high-k dielectric after deposition as gate oxide is very important to increase the capability of dielectric against the leakage and the increase of high-k value. The study does not only focus on the quality of high-k dielectric, but the reliability concern. Using the voltage stress, the recovery of gate dielectric with tested samples under different annealing temperatures shows the various consequences. The tested device with higher annealing temperature device has the better performance rather than the lower one in recovery and drive current, but the worse in reliability stress.