New Framework for the random charging/discharging of oxide traps in HfO2 gate dielectric: ab-initio simulation and experimental evidence

A new framework for first-principle simulation on random charging/discharging of individual oxide traps is established and adopted for detailed studies on HfO2 high-k gate dielectrics for the first time. The proposed framework provides an effective solution to the challenges in conventional multi-phonon simulation methodology, and successfully explains various experimental results in HfO2 devices. 1-DOV defect, instead of traditionally assumed SOV, is found to be the crime oxide trap in HfO2. And the anomalous RTN observations strongly support the high-order four-state model, which can be well explained by the two metastable states found in the 2-DOV defect. The framework is helpful for the fundamental understanding of RTN and NBTI reliability.