Copper oxide phase content and its effect on the electric pulse induced resistive switching characteristics of CuxO resistive random access memory

• Bipolar resistance switching behavior in copper oxide films is identified
• Copper oxide phase composition characterized for different growth parameters
• Resistance switching linked to copper oxide phase composition in thin films
• Good bipolar switching characteristics obtained for low temperature growth
• Cu4O3 composition shows best bipolar switching characteristics

The electric pulse induced resistance (EPIR) switching phenomenon in CuxO thin films has been related to the oxidation states of copper in the films. A quantitative measurement of the copper oxide phase content in the grown CuxO films shows a composition change from a Cu rich CuxO (Cu4O3) phase to a CuO phase on increasing the growth temperature under RF sputtering from 200 °C to 500 °C. This composition change decreases the film resistance, and affects the forming process required for resistive switching and the EPIR switching phenomenon in the film. Stable EPIR switching has been seen only for films with Cu4O3 as the major phase and such films also exhibit two bipolar resistance switching modes.