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 PbZr
_0.52
Ti
_0.48
O
₃
as a ferroelectric (FE) gate insulator, integrated on a silicon channel with a nonperovskite high-
k
dielectric (HfO
₂
) 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 (
${I}_{d}\sim $
100
$\mu \text{A}/\mu \text{m}$
). Steep switching in strong inversion provides an important point of consistency with the predictions of the Landau–Devonshire theory and the Landau–Khalatnikov equation.