Influence of O₂ Flux on Compositions and Properties of ITO Films Deposited at Room Temperature by Direct-Current Pulse Magnetron Sputtering

Indium tin oxide (ITO) films were deposited on glass substrates at room temperature by dc pulse magnetron sputtering. Varying O₂ flux, ITO films with different properties are obtained. Both x−ray diffractometer and x-ray photoelectron spectrometer are used to study the change of crystalline structures and bonding structures of ITO films, respectively. Electrical properties are measured by four-point probe measurements. The results indicate that the chemical structures and compositions of ITO films strongly depend on the O₂ flux. With increasing O₂ flux, ITO films display better crystallization, which could decrease the resistivity of films. On the contrary, ITO films contain less O vacancies with increasing O₂ flux, which could worsen the conductive properties of films. Without any heat treatment onto the samples, the resistivity of the ITO film could reach 6.0×10⁻⁴ Ω⋅cm, with the optimal deposition parameter of 0.2 sccm O₂ flux.