Surface Roughness and Fractal Analysis of TiO₂ Thin Films by DC Sputtering

This study investigates the surface roughness and fractal characteristics of TiO₂ thin films deposited via DC reactive magnetron sputtering, using an Ar/O₂ gas mixture and varying sputtering powers. The films' surface morphology was characterized using Scanning Electron Microscopy (SEM) and topographic mapping. Roughness parameters such as Ra (average roughness), Rq (root mean square roughness), Rt (total height of the roughness profile), and Rz (peak-to-valley roughness) were quantified to assess the surface quality. Additionally, fractal analysis was conducted to evaluate the complexity of surface features across multiple length scales, using both "length-scale" and "area-scale" frameworks to explore hierarchical structures.
The key analyses were performed using MountainsMap® software, which enabled 3D surface reconstruction, fractal dimension evaluation, and advanced surface metrology. The TiO₂ thin films were deposited under various O₂ ratios and sputtering powers to explore the influence of these parameters on surface roughness and fractal characteristics.
This investigation combines both roughness and fractal metrics, offering a comprehensive framework for analyzing the interplay between deposition conditions and surface properties. The results provide valuable insights for tailoring TiO₂ thin films for use in applications such as photocatalytic devices, sensors, and other technologies that require precise control of surface topography, enhancing their functionality and performance.