Morphological evolution of surfaces irradiated by gas cluster ion beams during thin film deposition

摘要

Ta2O5 films were deposited with O-2 cluster ion beam assisted deposition at various incidence angles theta, between 0 degrees and 80 degrees from surface normal. The surface morphology and cross-sectional images were studied. The film structure was significantly affected by incidence angle. When theta was between 0 degrees and 30 degrees, dense and flat Ta2O5 films were formed. However, in the case of theta between 30 degrees and 60 degrees, ripples were formed on the surface whose wave vector was in the incidence direction and the film surface was rough. On the other hand, when theta was above 70 degrees, the wave vector of the ripple was rotated to perpendicular and surface roughness decreased to the same value at normal incidence. Ripples formed during thin film assisted deposition were similar to surface morphological evolution during the sputtering process. (c) 2005 Published by Elsevier B.V.