Effects of Electrodes on the Filament Formation in HfO2- Based Resistive Random Access Memory

The resistance switching characteristics of HfO2-based resistive random access memory (RRAM) with Cu/HfO2/ITO and TiN/HfO2/ITO structures were investigated. Results show that both devices exhibit a stable and reproducible bipolar switching behavior during successive cycles. The formation of Cu conducting filaments is believed to be the reason for the resistive switching of Cu/HfO2/ITO device. For TiN top electrode, the interfacial layer between TiN and HfO2 film is formed and acts as an oxygen reservoir therefore, oxygen vacancy filaments are responsible for the resistive switching of TiN/HfO2/ITO device.