Effect of O2 pressure during deposition on properties of rf-sputtered Sn-doped In2O3 films

Abstract

The electrical and optical properties of rf-sputtered Sn-doped In2O3 (ITO) films have been found to depend strongly on the O2 partial pressure during deposition. For the sputtering conditions used, films with both low electrical resistivity (ρ ∼ 3 × 10−4 Ω cm) and high visible transmission (∼ 90%) were obtained only over a narrow range of O2 pressures, from 3 × 10−5 to 4 × 10−5 Torr. Our results appear to explain the difficulties that have previously been encountered in obtaining high-quality ITO films, and indicate that control of the O2 pressure during deposition is essential for reproducible preparation of such films.