NOISE-INDUCED ROUGHENING EVOLUTION OF AMORPHOUS SI FILMS GROWN BY THERMAL EVAPORATION

We report a growth front morphology study of thermally evaporated amor phous Si films using atomic force microscopy. Since there are no well- defined atomic steps on an amorphous film surface, there is no Schwoeb el barrier effect which would give rise to a moundlike morphology. The dynamic scaling characteristics observed during growth are unambiguou sly explained by a noise-induced growth mechanism. The roughness and g rowth exponents measured are consistent with the Mullins diffusion mod el with noise.