Properties of annealed indium tin tantalum oxide films prepared by reactive magnetron sputtering

Indium tin oxide (ITO) and indium tin tantalum oxide (ITTO) films were deposited on glass substrates at room temperature by magnetron sputtering. Properties of the ITO and ITTO films showed a dependence on annealing treatment. ITTO film deposited at room temperature showed the enhancement in (400) orientation and the increasing in grain size. With an increase in annealing temperature, the intensity of XRD peak increased and the grain size showed an evident increasing. The reflection edge in near-IR range and the absorption edge in near-UV range shifted due to the variation in carrier concentration. Ta-doping improved the carrier concentration of the films and widened the corresponding optical band gap. The variations in optical band gap were due to Burstein-Moss effect. The higher value of figure of merit of ITTO films was observed. The tantalum -doped ITO films could find extensive application in some devices.