Structural, electrical, and optical properties of reactively sputtered SnO₂ thin films

SnO₂ thin films prepared by reactive rf magnetron sputtering have been investigated to examine the effect of deposition parameters on its crystallinity and electrical and optical properties. Of particular interest was whether the nonequilibrium nature of sputtering could create large departures from the bulk defect properties, especially in amorphous films. Two deposition parameters were examined: substrate temperature (Tsub) and oxygen content. The films were characterized by X-ray diffraction (XRD), optical transmission, four point probe electrical conductivity, and Hall effect measurements. The crystallinity was found to be enhanced by the incease in each of the three processing variables. Below a substrate temperature of 300 °C a large processing window for depositing amorphous SnO₂ was found.