New Understanding of Negative Capacitance Devices for Low-Power Logic Applications

This paper presents the new physical understanding of negative capacitance (NC) and hysteresis behaviors in ferroelectric-based NC-FETs for low-power logic applications. Instead of traditional stabilized switching theory, we demonstrate that the dynamic polarization switching of ferroelectric is the physical origin of the NC phenomenon which can be only obtained under relatively low frequency. Moreover, it is found that there is an intrinsic optimization conflict between the subthreshold slope and hysteresis under low frequency applications, considering both the sweeping voltage and ferroelectric parameters. The direct experimental observation of NC phenomenon in a standalone ferroelectric capacitor and the transient measurement results of fabricated NC devices further confirm the theoretical results.