Ferroelectric (FE) field-effect transistors (FETs) are attractive for their non-destructive readout and energy efficiency but are challenging to integrate on silicon platforms. This research demonstrates FE ZrxAl₁₋ₓOY (ZAO) by utilizing compressive strain in contact with ZnO. The metal-ferroelectric-semiconductor-metal (MFSM) capacitor shows a remnant polarization of 15.2 µC cm², and a bowknot-like anti-clockwise hysteresis in capacitance curves. The FE-ZAO gated ZnO thin-film transistor (TFT) exhibits a large memory window (3.84 V), low subthreshold swing (55 mV dec⁻¹), high Ion/IOFF ratio (≈10⁷), and low off-state current (1 pA). GI-XRD and HAADF-STEM analyses reveal the ferroelectric rhombohedral phase (space group R3m) in nanocrystalline ZAO. Multi-level memory and synaptic weight performance are demonstrated, achieving a high learning accuracy of 91.82% in neuromorphic computing applications.

Md Mobaidul Islam, Arqum Ali, Chanju Park, Taebin Lim, Dong Yeon Woo, Joon Young Kwak, Jin Jang