Study on Magnetron Sputtered Nb-Doped ZnO Thin Films switching properties for RRAM Applications

Resistive switching characteristics of ZnO-based nanomaterials make them useful candidates for applications in resistive random access memory (RRAM). In the present work, Nb-doped ZnO thin films prepared using RF sputtering with varying doping concentrations were studied using XRD, UV-Vis spectroscopy, Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive X-ray Spectroscopy (EDS), I-V, XPS and AFM measurements to investigate the structural, optical, electrical properties and roughness of the films. The XRD analysis revealed a shift in the (002) peak corresponding to hexagonal wurtzite structure, towards lower angles with increasing doping concentration, indicating a doping-induced modification of crystal structure. The UV-Vis spectroscopy showed an increase in the band gap energy with increasing doping concentration. The electrical conductivity of the films was found to increase with doping concentration, as determined by I-V measurements. The XPS analysis confirmed the presence of Nb in the doped films and provided information on the chemical states of the elements. Overall, the results suggest that Nb doping can significantly modify the structural properties of ZnO thin films which alters the electrical properties to match the requirements for potential applications in memory devices. The research addresses the fabrication of Nb doped ZnO for resistive memory applications via RF magnetron sputtering. The discussion of the structure of film is based on XRD and XPS. UV spectroscopy is used to determine the band gap of a film. By using FESEM, Selected area FESEM, and AFM, one may compare the surface shape, thickness, and roughness.image