ReverseBias Stability and Reliability of Enhancementmode GaNbased MISFET Under reversebias stress with a high drain voltage, larger negative gatebias is found to accelerate positive shift in  V  TH , suggesting a holeinduced gate dielectric degradation mechanism. The holeinduced gate dielectric degradation in the Emode GaN MISFETs could lead to nonrecoverable  V  TH  shifts and devastating timedependent breakdown. Such a degradation can be effectively suppressed by converting the GaN channel into a crystalline GaO x N 1x  channel in the gated region. The valence band offset between GaO x N 1  x  and the surrounding GaN creates a holeblocking ring around the gate dielectric, preventing holes from flowing to the gate dielectric and therefore mitigating the holeinduced degradation.

Comprehensive Understanding of Negative Capacitance FET From the Perspective of Transient Ferroelectric Model Negative capacitance FET (NCFET) is one of the most promising steepsubthreshold slope (SS) transistors. Thanks to the discovery of ferroelectric HfO 2  (FEHfO 2 ), NCFET has been getting more attentions as a highly manufacturable solution. Since the proposal of NCFET and discovery of FEHfO2, there have been many experimental demonstrations of steep SS with NCFET. However, the physical mechanism of steep SS has not been fully understood yet, and confident explanations have not been given to these experimental results. In this paper, we report our recent progress of theoretical and experimental studies toward comprehensive understanding of NCFET regarding steep SS behavior, reverse DIBL and negative differential resistance (NDR). Transient NC theory that we explore is able to consistently explain some class of previously reported experimental results. This paper will help to guide further NCFET research activities.