Micromorphology analysis of TiO₂ thin films by atomic force microscopy images: The influence of postannealing

This work describes an analysis of titanium dioxide (TiO₂ ) thin films prepared on silicon substrates by direct current (DC) planar magnetron sputtering system in O₂ /Ar atmosphere in correlation with three-dimensional (3D) surface characterization using atomic force microscopy (AFM). The samples were grown at temperatures 200, 300, and 400°C on silicon substrate using the same deposition time (30 min) and were distributed into four groups: Group I (as-deposited samples), Group II (samples annealed at 200°C), Group III (samples annealed at 300°C), and Group IV (samples annealed at 400°C). AFM images with a size of 0.95 μm × 0.95 μm were recorded with a scanning resolution of 256 × 256 pixels. Stereometric analysis was carried out on the basis of AFM data, and the surface topography was described according to ISO 25178-2:2012 and American Society of Mechanical Engineers (ASME) B46.1-2009 standards. The maximum and minimum root mean square roughnesses were observed in surfaces of Group II (Sq = 7.96 ± 0.1 nm) and Group IV (Sq = 3.87 ± 0.1 nm), respectively.