Dynamics of Ferroelectric and Ionic Memories: Physics and Applications

Ferroelectric (FE) and solid polymer electrolytes (SPEs) are being explored for memory and for a variety of purposes in transistors. While considering the dynamics of emerging memories, we note some interesting implications for transistors and transistor memories. In this paper we consider the dynamics of subthreshold swing (SS) in transistors and show that under certain conditions SS can be lowered due to the delay associated with their complex impedance. We show that even a conventional metal oxide semiconductor field-effect transistor (MOSFETs) can exhibit a dynamic SS, lowered by introducing a series resistance in the gate. We show that the when the gate dielectric has a complex response, SS can be decomposed into static and dynamic factors with the static factor given by the usual thermal SS and the dynamic factor related to dynamic gate amplification. In the measurement of SS, slew rate and slew direction can be readily utilized to reveal the SS dependence on dynamics.