Roughness of amorphous, polycrystalline and hemispherical-grained silicon films

We have performed atomic-force-microscopy studies of the roughness and spatial and correlation properties of the surface for three typical LPCVD films of silicon: amorphous and polycrystalline films with a relatively smooth surface, as well as polycrystalline films with hemispherical grains (HSG-Si) having considerable surface roughness. As follows from analysis of the correlation function and power spectral density function, the model of a self-affine surface is suitable for describing morphology of amorphous and polycrystalline silicon films, while the model of a mounded surface is preferable for HSG-Si films.