The effect of film thickness on surface morphology of ITO thin films

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Abstract

AbstractIn this work, we developed the rescaled range method and its formalism to investigate the surface morphology dynamics of indium tin oxide (ITO) thin films. The dynamic scaling behavior of grown ITO thin films, which were prepared by electron beam deposition method on float glass substrates at room temperature, was studied through atomic force microscopy (AFM). AFM data indicated that the average surface roughness values of the films decreased as the film thickness increased from 100 to 250 nm. Based on fractal concept and statistical physics techniques, the irregularities of the ITO films were analyzed. The roughness exponent H and the growth exponent β for ITO films were determined to be 0.71 ± 0.01 and 0.11 ± 0.01, respectively. The fractal analysis reveals that the value of the fractal dimension Df (Df = 3 − H) falls within the range 2.29 to 2.24 depending upon the films thickness. These results show that the growth process of the films can be described by the combination of Edwards-Wilkinson and Mullins diffusion models.

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