Interaction of reactively sputtered TaOx thin films with In-Sn-O thin films and properties of TaOx thin films

Abstract

The interaction of reactively sputtered TaOx films with In-Sn-O (ITO) films was investigated. Phenomena observed in the TaOx/ITO layer structure after a postannealing were studied. These phenomena were: a rise in electrical resistance of the ITO films and a change in color of the layer from transparent to yellowish. Monitoring the gases evolved from the TaOx films during the heating under vacuum showed that incorporation of water into the TaOx films takes place. Evolution of this water from the TaOx films started at around 350 °C, peaked at around 500 °C, and was largely complete at around 650 °C. It was found that the occurrence of the phenomena described above appeared at precisely the temperature at which water was evolved from the TaOx films. It was concluded that the water component incorporated into the TaOx films was the origin of both phenomena. Water present in the conditions under which discharge deposition takes place would be the cause of that incorporation.