Effect of elevated substrate temperature on growth, properties, and structure of indium tin oxide films prepared by reactive magnetron sputtering

The paper correlates the growth and structure formation with the properties of indium-tin-oxide (ITO) films fabricated by pulsed reactive magnetron deposition onto amorphous substrates held at elevated temperatures ranging from room temperature to 510 °C. The evolution of the microstructure is consistent with the well-known structure zone model. The temperature dependence of the film texture is described with consideration of the interplay between the shadowing and surface-diffusion processes. It is shown that deposition at elevated temperatures lowers the crystallization threshold and is more effective in reducing resistivity than the postdeposition vacuum annealing at comparable temperatures. The films grown at a substrate temperature of 400 and 510 °C have the lowest resistivity of 1.2 × 10−4 Ω cm, the highest free electron density of 1.2 to 1.0 × 1021 cm−3, and mobility of 35–42 cm2 V−1 s−1 and exhibit the strongest (222) texture with the largest grain size.