Study of wake-up and fatigue properties in doped and undoped ferroelectric HfO2 in conjunction with piezo-response force microscopy analysis

This paper reports wake-up and fatigue effects in ferroelectric HfO2 with and without Y-doping by comparing macroscopic capacitor characteristics with nano-level piezo-response force microscopy (PFM) analysis. Even though initial characteristics are almost the same between with and without Y-doping, endurance characteristics are really different macroscopically, and PFM study microscopically supports the endurance characteristics as well. This fact suggests that the robustness of HfO2 ferroelectricity should be sensitive to the doping.