Structural Properties of Post Annealed ITO Thin Films at Different Temperatures

Indium tin oxide (ITO) thin films were deposited on glass substrates by RF sputtering using an ITO ceramic target (In2O3-SnO2, 90-10 wt. %). After deposition, samples were annealed at different temperatures in vacuum furnace. The post vacuum annealing effects on the structural, optical and electrical properties of ITO films were investigated. Polycrystalline ITO films have been analyzed in wide optical spectrum, X-ray diffraction and four point probe methods. The results show that increasing the annealing temperature improves the crystallinity of the films. The resistivity of the deposited films is about 19×10-4 Ωcm and falls down to 7.3×10-5 Ωcm as the annealing temperature is increased to 500 °C in vacuum.