Post-annealing effects on the surface roughness of undoped and Al-doped ZnO thin films deposited by atomic layer deposition

The post-annealing effects on the surface morphological changes of undoped and Al-doped ZnO (ZnO:Al) thin films deposited by atomic layer deposition (ALD) were investigated. The as-grown films were deposited by ALD at growth temperature of 200°C and also, post-annealing of the samples was accomplished at 300°C for 1 h under nitrogen atmosphere. The X-ray diffraction of the films was monitored to study the crystallinity of the films according to post-anneal. The field emission-scanning electron microscopy and atomic force microscopy were conducted to observe the surface morphological changes and measure the root-mean-square roughness of the films in order to analysis the post-annealing effects on the surface roughness of the films.