Sub-kT/q Switching in Strong Inversion in PbZr0.52Ti0.48O3 Gated Negative Capacitance FETs

Hysteretic switching with a sub-kT/q steep slope (13 mV/decade at room temperature) is experimentally demonstrated in MOSFETs with PbZr0.52 Ti0.48O3 as a ferroelectric (FE) gate insulator, integrated on a silicon channel with a nonperovskite high-k dielectric (HfO2 ) as a buffer interlayer. The steep switching is independent of drain bias. For the first time, sub-kT/q switching due to FE negative capacitance is observed not at low currents, but in strong inversion (Id ∼ 100 μA/μm). Steep switching in strong inversion provides an important point of consistency with the predictions of the Landau–Devonshire theory and the Landau–Khalatnikov equation. INDEX TERMS Ferroelectric (FE) field-effect transistor (FET), lead zirconate titanate, negative capacitance (NC), sub-kT/q switching.