Metal-Induced Oxygen Vacancy Control in InGaZnO/Hf_0.5Zr_0.5O₂ Ferroelectric Field-Effect Transistor Arrays for...

Zirconium-doped HfO₂ (HZO)-based ferroelectric field-effect transistors (FeFETs) with indium gallium zinc oxide (IGZO) channels are considered one of the key technologies for future nonvolatile memories. However, realization of the technology through a simple, industry-oriented process from single devices to array levels remains challenging. While prior studies have primarily focused on the stable ferroelectric switching of HZO, optimization of the IGZO channel is also essential to facilitate polarization switching through bound charge compensation without degrading its semiconducting properties. Herein, a co-optimization process using a W/IGZO multilayer as a capping layer for HZO is presented to modulate the oxygen vacancy distribution in IGZO/HZO. A thermodynamically driven oxygen vacancy gradient across the IGZO/HZO stack simultaneously facilitates the ferroelectric switching operation in HZO and stable semiconducting behavior in IGZO. By simply using W and IGZO as source/drain electrodes and channels, respectively, the resulting FeFET exhibits excellent performance, including a memory window of 4.13 V, a minimum subthreshold swing of 70 mV·dec^-1, robust endurance up to 10⁷ cycles, and a projected retention time of 10 years. To validate array-level feasibility, a 16 × 16 FeFET array is successfully implemented based on optimized conditions, demonstrating strong potential for scalable and industry-compatible integration of oxide-semiconductor-based FeFETs into next-generation nonvolatile memory technologies.