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 DeltaV_TH 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.