Surface topographic study of chalcogenide thin films of GexSb(As)40-xS50Te10 glasses.

The surface topography and fractal properties of GexSb(As)40-xS50Te10 (x=10, 20, 27 at.%) films, evaporated onto glass substrates, have been studied by atomic force microscopic imaging at different scales. The surface of the chalcogenide films is smooth (<5 nm roughness), isotropic and having some particular differences in texture. All films are self-similar with Mean Fractal Dimension in the range of 2.25-2.63. The films with GexSb40-xS50Te10 composition are more uniform in terms of surface morphology (grains structure) than those with GexAs40-xS50Te10 composition for which the film surface exhibits a superimposed structure of large particles at x=10 and 20 at.%.