Electrical characterization of metal-ferroelectric (Mn-substituted BiFeO3)-insulator (HfO2)-semiconductor capacitors for nonvolatile memory applications

Metal-ferroelectric (Mn-substituted BiFeO3)-insulator (HfO2)-semiconductor has been fabricated by co-sputtering technique. X-ray diffraction (XRD) patterns have proven the existence of a substitution phase. The shift in binding energy of Fe ions and the change in atom ratio of Mn to Fe were analyzed by X-ray photoelectron spectra (XPS). The memory windows as functions of insulator film thickness and annealing temperature were compared. The maximum memory window is 3 V at the sweep voltage of 8 V with thicker (60 nm) HfO2. The leakage current and the charge injection effect can be reduced with increasing the amount of substituting Mn for Fe-site.