Analysis of Critical Schottky Distance Effect and Distributed Set Voltage in HfO2-based 1T-1R Device

High resistance state (HRS) resistance on the set voltage in hafnium oxide-based resistance random access memory (RRAM) is investigated. Set voltage has a positive correlation to HRS in statistics. For analyzing the switching characteristics at different HRS resistance level, filament properties in the switching layer are analyzed by current-fitting technique. The fitting results show that Schottky distance becomes saturated at high resistance HRS. Finally, a physical model is proposed to explain our observation.