Smoothening of thin film surfaces

Surface morphologies of thin dielectric films are studied with atomic force microscopy. It is shown that the deposition temperature greatly affects the structure and the surface roughness of the films. Films deposited at room temperature are found to be amorphous and smooth. Films grown at 200/spl deg/C are amorphous, but also contain single inclusions of crystallites. Finally, fine grain films with quasiperiodic wave-like surface topography are grown at 300-500/spl deg/C. The introduction of S and Se atoms is observed to suppress 3D island growth and to decrease the surface roughness of the films. Both root-mean-square roughness and fractal dimension are proposed to characterize film surfaces.