Ferroelectric negative capacitance MOSFET: Capacitance tuning & antiferroelectric operation

A design methodology of ferroelectric (FE) negative capacitance FETs (NCFETs) based on the concept of capacitance matching is presented. A new mode of NCFET operation, called the “antiferroelectric mode” is proposed, which, besides achieving sub-60mV/dec subthreshold swing, can significantly boost the on-current in exchange for a nominal hysteresis. Design considerations for different device parameters (FE thickness, EOT, source/drain overlap & gate length) are explored. It is suggested that relative improvement in device performance due to FE negative capacitance becomes more significant in very short channel length devices because of the increased drain-to-channel coupling.