Figure 5

XPS spectra of O 1s peak evolution with etching time of (a) 24, (b) 30, (c) 48, and (d) 60 s from the top surface in bilayer HfO2/HfO2−x structure (inset table: percentage of area under each peak of two binding energies).

XPS spectra of O 1s peak evolution with etching time of (a) 24, (b) 30, (c) 48, and (d) 60 s from the top surface in bilayer HfO2/HfO2−x structure (inset table: percentage of area under each peak of two binding energies).