Stacked HZO/α-In2Se3 Ferroelectric Dielectric/Semiconductor FET With Ultrahigh Speed and Large Memory Window

In this work, by integrating the ferroelectric Hf0.5Zr0.5O2 (HZO) gate insulator and 2-D ferroelectric semiconductor
$\alpha $
-In2Se3 channel, ferroelectric field effect transistors (FeFETs) featured with both enhanced large memory windows (MWs) and ultrahigh-speed are demonstrated. Contributing to HZO/
${\alpha }$
-In2Se3 stacked ferroelectrics and the adoption of HZO gate dielectric with the high coercive electric field (
${E}_{c}{}$
), large MWs (4.2 V at
${V}_{\text {GS}}$
sweep range (SR) of ±4 V) are obtained. Besides, owing to the enhanced cross-electric field and the fast polarization switching speed of the HZO layer, the FeFETs show an ultrahigh writing speed of 10 ns. Furthermore, the FeFETs exhibit excellent performances with a high drain current ON/ OFF ratio (
$10^{{7}}$
), high endurance cycles (
$10^{{4}}$
cycles), and long retention time (
$10^{{4}}$
s). These results demonstrate that the FeFETs have considerable potential in ultra-fast nonvolatile memory (NVM) applications.