Investigation on the abnormal resistive switching induced by ultraviolet light exposure based on HfOx film

Effect of ultraviolet (UV) light exposure on the resistive switching characteristics of a ITO/HfOx/TiN structure were investigated in this study. Samples exposed with and without ITO shield film exhibit distinct switching characteristics, including leakage current, I–V curves, set and reset voltage fluctuation. Based on random circuit network simulation by Liu et al., we suggest the distinction was attributed to the different filament shapes during forming process. Defects preexisted inside the HfOx film can cause large difference on the electrical properties. Therefore, the UV laser exposure is a critical issue on the electrical characteristics of RRAM devices.