OXYGEN-CONTENT OF INDIUM TIN OXIDE-FILMS FABRICATED BY REACTIVE SPUTTERING

Indium tin oxide (ITO) films, which are transparent conductive films, have been widely used in optoelectronic applications. A high quality film with correct stoichiometric composition is essential for its applications, such as a flat panel display. However, it is difficult to estimate the absolute oxygen concentration. There are few studies of oxygen depth profiling for ITO films. We have investigated a relationship between the oxygen content of ITO films and the electrical properties under various deposition conditions. The absolute oxygen concentration has been determined by 160(a, a)160 resonant backscattering of a 3.045 MeV 4He2+ ion beam. It has been found that there is a correlation between the depth profile of oxygen concentration of ITO films and the film properties. In the case of the ITO film fabricated at room temperature, a large deficiency of oxygen can be seen at the surface of the film. When the film was formed at 400 °C, no deficiency of oxygen at the film surface was observed. The observed oxygen concentration will be discussed in terms of the electrical and optical properties of the films. © 1995, American Vacuum Society. All rights reserved.