Resistive switching mechanism of Cu doped ZrO2-based RRAM

ZrO₂-based resistive random access memory devices composed of a thin Cu doped ZrO₂ film sandwiched between an oxidizable top electrode and an inert bottom electrode are fabricated by e-beam evaporation at room temperature. The devices show reproducible nonpolar resistive switching. The formation and annihilation of localized conductive filaments is suggested to be responsible for the resistive switching characteristics according to a series of convincing evidences. Temperature-dependent resistive switching behaviors show that a metallic conductive channel is responsible for the low resistance state. Further analysis reveals that the physical origin of this metallic channel is the nanoscale Cu conductive filament. The metal filaments are observed by TEM and the component is also confirmed. We propose that the set and reset process stem from the thermal effect assisted electrochemical reactions.