Changhwan Shin

In this work, the effect of interlayer on the ferroelectric properties of Hf 0.5 Zr 0.5 O 2 (HZO)‐based metal–ferroelectric–metal (MFM) capacitor is investigated. In detail, a 1 nm thick interlayer of amorphous Al 2 O 3 and fluorite‐structured ZrO 2 is inserted in the HZO ferroelectric film. Grazing incidence X‐ray diffraction (GIXRD) analysis reveals that the amorphous structure of Al 2 O 3 (vs. the fluorite‐structured ZrO 2 ) effectively blocks the grain boundary growth of HZO layer. In contrast, X‐ray photoelectron spectroscopy (XPS) analysis demonstrates that ZrO 2 with a fluorite structure like HZO induces fewer oxygen vacancies at the ferroelectric–insulator interface, and thereby, it provides fewer defects in the HZO layer, achieving fatigue‐free endurance characteristics and a higher remanent polarization (2 P r ) of 4.6 μC cm −2 .