Nondestructive Evaluation of Surface Roughness of Thin Films through Fractal Analysis

摘要

Fractal geometry developed by Mandelbrot has emerged as a potential tool for analyzing complex systems in the diversified fields of science, social science, and technology. Self-similar objects having the same details in different scales are referred to as fractals and are analyzed using the mathematics of non-Euclidean geometry. In the present work Fractal analysis has been carried out on the Atomic Force Microscopic (AFM) images of zinc sulphide (ZnS) film, with different concentration of copper incorporation, prepared by Radio Frequency (RF) sputtering technique. It is found that the fractal dimension decreases with copper (Cu) incorporation. The fractal dimension is also found to have strong correlation with surface roughness of the film. The analysis shows that greater the fractal dimension lesser is the surface roughness.