Resistivity and oxygen content of indium tin oxide films deposited at room temperature by pulsed-laser ablation

Abstract

Transparent, conductive indium tin oxide (ITO) films were fabricated by pulsed-laser deposition on substrates held at room temperature. We investigated the relationship between electrical/optical properties of the films and the material stoichiometry, measured by Rutherford backscattering. The lowest resistivity films (∼4×10−4 Ω cm) have excessive oxygen compared with the stoichiometric composition ITO. After annealing in argon at 400 °C for 1.5 h, the oxygen-to-(indium+tin) ratio approaches the stoichiometric composition of 1.5 and resistivities of annealed samples are ∼2.5×10−4 Ω cm. The room-temperature ITO resistivity dependence on chamber gas pressure is explained in terms of a gas-dynamic model and oxygen content of the film.