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.