Hafnium-Based Ferroelectric Field-Effect Transistors With Oxide Semiconductors: Ferroelectric Materials...

The emergence of ferroelectricity in hafnium oxide (HfO₂)-based materials marks a transformative advancement for next-generation nonvolatile memory and neuromorphic computing. Unlike conventional perovskite ferroelectrics, HfO₂-based materials offer robust ferroelectricity at nanoscale thicknesses, large coercive fields (E_c), and innate compatibility with mainstream CMOS technology, thus overcoming long-standing integration challenges. This review comprehensively examines the development of HfO₂-based ferroelectric field-effect transistors (HfO₂-FeFETs) employing oxide semiconductor (OS) channels such as indium oxide (In₂O₃) and indium gallium zinc oxide (IGZO). We first discuss material-level optimizations via atomic layer deposition (ALD) processes, interfacial engineering, and capping layers to enhance ferroelectric performance and endurance. At the device level, we analyze the operational principles, unique challenges, including the weak erase effect due to the absence of hole carriers, and emerging solutions such as defect-assisted switching and novel gate-stack designs. We also highlight recent demonstrations of high-density 3D FeFET arrays and energy-efficient in-memory computing applications like ternary content-addressable memory (TCAM). Finally, we outline remaining challenges in scalability, variability, and switching linearity, pointing toward future research directions aimed at harnessing the full potential of OS-FeFETs for beyond-von Neumann computing architectures.