Atomic force microscopy and multifractal analysis in diamond-like carbon films

To date, the multifractal approach has been extensively employed to characterize the structure and processes in the experimental systems. Herein, we examine surface morphological variations of DLC thin films deposited by pulsed laser deposition (PLD) at two different target–substrate distances (d = 45 and 65 mm). First, the surface morphology of the produced samples is measured by the atomic force microscopy (AFM) technique. Further, we developed the multifractal approach to depict the morphological characteristics of the constructed samples from their AFM micrographs. An apparent correlation between target-to-substrate distance, multifractal spectra width, and the quality of surface morphology was found. Furthermore, AFM revealed that DLC films are deposited denser and smoother with smaller surface roughness for shorter d (45 mm). In addition, the height probability of lower uniformity and broader spectral singularity was observed for d = 65 mm. Finally, results revealed that multifractality is more significant in the sample deposited at a larger target–substrate distance (S65 sample).