RESISTIVE SWITCHING IN NANOSTRUCTURED THIN FILMS

Abstract

The present study explores the resistive switching behaviour of Zinc Oxide thin films. Pulsed Laser Deposition has been used to synthesize thin films of zinc oxide. Structural characterization has been done by X-ray Diffraction, FE-Scanning Electron Microscopy and Atomic Force Microscopy to find out crystal specifications and grain size for our films. For the purpose of resistive switching four TE/Insulator/BE structures were fabricated. N-silicon, copper, titanium and chromium were used as bottom electrodes (BE). Copper top electrode (TE) was used in all the four samples. Keithley 4200 semiconductor parameter analyzer was used for IN characterization of the samples. Bipolar Resistive Switching (BRS) was observed in Cu/ZnO/n-Si and Cu/ZnO/Cu for voltages -3 to +3 volts. Of all the four samples the best resistive switching behaviour was observed for Cu/ZnO/Cu structure which reported the resistance rario of - iø. For Cu/ZnO/Ti and Cu/ZnO/CR structures tJnipo!ar Resistive Switching (URS) was observed at SET and RESET voltages below I V and 0.5 V respectively. The conduction mechanism behind the switching behaviour has been investigated and is explained with energy band diagrams. The results suggest that the switching phenomenon in insulating thin film is electrode dependent.