Bipolar resistive switching properties of Cu-CuO-InGaZnO-AZO multilayer structure thin film

A multilayer structure (Cu/CuO/InGaZO/AZO) resistive switching based on multi-component metal oxide is proposed and demonstrated. Al doped ZnO (AZO) thin film prepared on quartz substrate was chosen to be a bottom electrode owing to its high transparency and conductivity, then an InGaZnO (IGZO) thin film with high electronic mobility and ductility was grown on the substrate acting as a dielectric layer. We designed a CuO layer to be an electronic buffer layer between IGZO and top Cu electrode, which can play a critical role in increasing the On/Off current ratio. All of these four layers were prepared by RF magnetron sputtering at a low temperature of 200°C. Test results indicate that Cu/CuO/IGZO/AZO switching devices have about 102 on/off current ratio, (3.8∼4 V)/(−4∼−3.6 V) set/reset threshold voltage, and over 103 cycles anti-fatigue properties.