Physical Insights into the Impact of Internal Metal Gate on the Subthreshold Behavior of NCFET Based on Domain Switching Dynamics

In this work, the influences of the internal metal of gate stack in Negative Capacitance FET (NCFET) are clarified based on domain switching dynamics physically. By analyzing the equivalent ferroelectric (FE)/dielectric (DE) series capacitor, a new method is proposed to study the domain switching process for metal-ferroelectric-insulator-metal (MFIM) structure. Our results illustrate that NC effect of FE/DE series capacitor is closely related to the switching capabilities of FE layer, embodied by the distribution of switching activation field Ea of domains, which also provide the design direction of FE layer for the subthreshold swing optimization of NCFET.