Surface Roughness and Fractal Study of CaF_2 Thin Films

摘要

Calcium fluoride (CaF_2) thin films of thicknesses 20, 50 and 100 nm were deposited by electron beam evaporation technique at room temperature. The structural properties of the films were studied using glancing angle X-ray diffraction (GAXRD) and atomic force microscopy (AFM). It is found that grain size, average surface roughness and interface width increased with film thicknesses. A scaling law analysis is performed on AFM images for fractal measure, which showed decrease in the fractal dimension with increase in film thickness. On the other hand, increase in the Hurst exponent was observed with film thickness.