Temperature dependence of resistance of conductive nanofilament formed in Ni/NiOx/Pt resistive switching random access memory

We investigated the resistive switching characteristics and temperature dependence of resistance of a Ni/NiOx/Pt resistive switching memory. The device was operated in a unipolar operation mode. From the temperature dependence of resistance, it is suggested that the conduction mechanism of the low-resistance state is metallic. Moreover, a deformed site that may correspond to the conductive filament appeared after the forming process. Cross-sectional transmission electron microscopy with energy dispersive X-ray analysis showed that the Ni atomic content at the NiOx of the deformed area was larger than those of other areas. It is strongly suggested that the conductive filament formed in the NiOx layer is composed of Ni atoms.