Atomic layer deposition of zinc oxide films on lateral high-aspect-ratio test structures using diethylzinc and water as precursors

Zinc oxide is a wide bandgap semiconductor with a variety of applications as a thin film material. In this work, a set of zinc oxide thin films were grown on lateral high-aspect-ratio test structures using atomic layer deposition. Diethylzinc and water were used as precursors, and several processing conditions were examined. The grown films were characterized for conformality using energy-dispersive electron probe x-ray microanalysis supported by x-ray reflectometry studies of additional reference samples. To analyze growth kinetics and film thickness profiles, diffusion-reaction simulations were made. Most importantly, it was found that at the 200 °C growth temperature, the film thickness profile followed nearly perfectly the ideal saturation profile expected for self-terminating reactions. The obtained result, thus, establishes an excellent reference case for process optimization.