Trapping and de-trapping characteristics in PBTI and dynamic PBTI between HfO2 and HfSiON gate dielectrics
PBTI degradation for HfO2 and HfSiON NMOSFETs has been demonstrated. The generated oxide trap dominated the PBTI characteristics for Hf-based gate dielectrics. In addition, the reduction of DeltaVTH and oxide trap generation under PBTI indicates that the HfSiON is better than HfO2. On the other hand, the electron trapping/de-trapping effect has been investigated. As compared to HfO2 dielectrics, the HfSiON has shallower charge trapping level due to elimination of deep dielectric vacancies, and the temperature effects are quite different between the HfSiON and HfO2 gate dielectrics.