Prediction of NBTI degradation for circuit under AC operation

A model predicting the negative bias temperature instability (NBTI) reliability of high performance nitrided oxides is developed from discrete p-type metal-oxide-semiconductor field effect transistor (PMOSFET) data and verified with ring oscillator degradation in various frequencies for up to 1GHz. Based on the experimental data and the simulation results, hole traps generation is considered to be major factor for AC NBTI degradation. An AC/DC NBTI improvement factor of around 10 has been observed at low frequency of 0.01Hz while it is significantly larger (∼10000) at 1GHz frequency range. It is established that the measurement techniques are very crucial for accurate NBTI reliability estimation.