Characterization and electrical response of reactively sputtered thin film deposited at oxygen and nitrous oxide environment

Abstract

Niobium oxynitride (NbON) thin films were deposited on silicon substrate using DC reactive magnetron sputtering technique of niobium metal targets at different nitrous oxide (N2O) and oxygen flow in the plasma during deposition. To get NbON thin films, the deposition parameters were also optimized. X-ray reflectivity (XRR) technique was used to estimate the film thickness of the as deposited films. The films' surface morphology and chemical compositions were investigated by field-emission scanning electron microscopy (FE-SEM) and x-ray photoelectron spectroscopy (XPS) techniques. SEM images indicate the smooth surface morphology of the deposited films. XPS study exposes the noticeable presence of N2 in the niobium oxynitride films deposited with only 20 sccm nitrous oxide flows in the plasma. The leakage current-voltage (I-V) measurement reveals the reduction in leakage current with higher N2O and lowers oxygen flow rates. The resistivity of the thin films was measured. The thin films deposited with higher N2O flow give high resistivity because of lesser availability of defect states. It may be stated that nitrous oxide content reduces the leakage current thus, improves the film and interface properties.