In this paper, we demonstrate low-thermal-budget ferroelectric field-effect
transistors (FeFETs) based on two-dimensional ferroelectric CuInP2S6 (CIPS) and
oxide semiconductor InZnO (IZO). The CIPS/IZO FeFETs exhibit non-volatile
memory windows of ~1 V, low off-state drain currents, and high carrier
mobilities. The ferroelectric CIPS layer serves a dual purpose by providing
electrostatic doping in IZO and acting as a passivation layer for the IZO
channel. We also investigate the CIPS/IZO FeFETs as artificial synaptic devices
for neural networks. The CIPS/IZO synapse demonstrates a sizeable dynamic ratio
(125) and maintains stable multi-level states. Neural networks based on
CIPS/IZO FeFETs achieve an accuracy rate of over 80% in recognizing MNIST
handwritten digits. These ferroelectric transistors can be vertically stacked
on silicon CMOS with a low thermal budget, offering broad applications in
CMOS+X technologies and energy-efficient 3D neural networks