Nonvolatile operation of vertical ferroelectric gate-all-around nanowire transistors

Abstract

Ferroelectric gate-all-around (GAA) transistors with a nanowire (NW) channel standing vertically on the substrate would be a potential breakthrough to overcome limitations in the high-integration of ferroelectric memories. In the present study, we fabricated vertical ferroelectric GAA NW transistors (VFGAANWTs) with ZnO NWs (average diameters: 53-193 nm) as the channel, (Hf,Zr)O2 film (average thicknesses: 9.3-58 nm) as the gate ferroelectric, and Ti as the gate electrode. The channel length was 100-300 nm. The VFGAANWTs showed n-channel operation with on/off ratios of ∼10, and their on/off states were retained for at least 2 min by the ferroelectric polarization of (Hf,Zr)O2 after the gate bias was removed, demonstrating the nonvolatile electric field effect in the VFGAANWTs. The results confirm the strong potential of the VFGAANWTs in high-density ferroelectric memory applications.