Impact of Channel Material, Interface Quality, and Polarization on Memory Window of Interfacial Layer-Free FeFET With Oxide Semiconductor

This study systematically investigates the modulation of the memory window (MW) in interfacial layer (IL)-free and Hfx $Zr_{{1}-{x}}$ O2 (HZO)-based ferroelectric field-effect transistors (FeFETs) with oxide channel by engineering oxide semiconductor materials, annealing processes, and polarization in HZO. Our findings reveal that the MW in such an FeFET is predominantly governed by the positive charge supply capability of the semiconductor layer and the interface properties between the ferroelectric (FE) layer and the semiconductor. Specifically, higher doping concentrations in the channel material and less interface trapping are shown to enhance the MW. In contrast, polarization shows limited effect. These results provide critical insights into the underlying mechanisms of MW optimization in FeFETs with oxide semiconductor channels.