Crystallization behavior during transparent In₂O₃-ZnO film growth

Structural evolution of transparent conductive In₂O₃-ZnO (IZO) films with increasing substrate temperature during sputtering was studied using transmission electron microscopy (TEM) and spectroscopic ellipsometry. Increasing the substrate temperature can induce film crystallization in the initial growth stage, and enhance the crystallization of IZO films. Extensive simulations using ellipsometry data demonstrated a decrease in the crystallization rate for IZO films deposited between 200 and 300 °C, which is attributed to the influence of the interference between nearby growing grains. TEM observations also reveal that the growth competition between different crystallites leads to an increase in the lateral grain size with increasing substrate temperature.