Single Crystalline CuO Nanowire for Resistive Random Access Memory Application

For the development of high density memory arrays of resistive random access memory (RRAM), nanowires provide the potential to reduce the device size to overcome the limitation of conventional lithography. In this work, copper oxide nanowires were synthesized and served as the building block for 1-D RRAM nanodevice. The phase of Copper oxide was identified to be CuO by selected area electron diffraction (SAED) patterns and energy dispersive spectrometer (EDS). We fabricated the Au/CuO-nanowire/Au RRAM nanodevice by electron-beam lithography techniques. From I-V measurement, the forming voltage and RESET voltage were 0.64 V and 5.2 V, respectively. This low forming voltage and ultra-high reset voltage may result from stacking fault in the core of CuO nanowires. From scanning electron microscope (SEM) image ,the as-formed protrusion near the anode and reduction near the cathode after several electrical measurements indicated that  the diffusion of oxygen vacancies generating the conducting filament from cathode, result in the change of nanowire morphology. The result will be beneficial to understand the switching properties of nonvolatile memory device at nanoscale.