Proposal of a Hysteresis-Free Zero Subthreshold Swing Field-Effect Transistor

An ideal switch with hysteresis-free S_ideal = 0 mV/decade switching is desired to keep Moore´s law alive, but has never been achieved. Classical field-effect transistors (FETs) have supported Moore´s law for 50 years, albeit with a thermodynamically limited value of subthreshold swing S ≥ 60 mV/decade. Alternatives, such as, tunnel FETs, impact ionization FETs, and negative capacitance FETs promise S <; 60 mV/decade, but ideal switching is not expected, even in theory. In this paper, we propose a zero subthreshold swing FET (ZSubFET), which is similar to a classical FET with a suspended-gate and a ferroelectric gate insulator. ZSubFET exhibits ideal switching through integration of two negative capacitors (namely, a ferroelectric and an air-gap) in the gate-stack, in series with the channel capacitance. We believe that the proposed device concept should not only lower the power dissipation in an IC, but also open up new research directions for the alternative of classical-FET.