Properties of indium oxide films prepared by the reactive evaporation of indium

Abstract

Indium oxide films with an electrical resistivity of about 4 × 10 −4 Ω cm and good optical quality were prepared by the reactive evaporation of pure indium in the presence of 10 −4 Torr of oxygen. The Auger electron spectrum of these films shows a deficiency of oxygen and corresponds to a composition which can be represented as In 2O 2.85. In the absence of foreign doping agents, the conduction electrons are provided by indium atoms which are adjacent to oxygen vacancies and act as a donor level. The electrical conductivity of the films is shown to be modulated by variations in the partial pressure of oxygen over the film which change the extent of the non-stoichiometry of the oxide by incorporation of oxygen into or extraction of oxygen from the film.