Fractal processing of AFM images of rough ZnO films

Fractal image processing has been applied to characterize the surface roughness of ZnO films as measured by atomic force microscopy. The simple fractal analysis suggests that the fractal dimension D can be used to describe the change of the whole grain morphology along the growth direction. Multifractal analysis shows that the scaling range is close to three orders of magnitude, which is larger than that of a simple fractal and most empirical fractals. The width of the multifractal spectrum can be used to characterize the roughness of the film surface quantitatively and the shape of multifractal spectrum can describe the ratio between the number of the lowest valleys and the highest peaks statistically.