Morphological instabilities in thin-film growth and etching

Experiments and theory have shown that surface morphology during thin-film growth and etching is often unstable. Pattern formation of the morphology results when a mechanism that destabilizes the morphology on long length scales competes with a mechanism that stabilizes the morphology on short length scales. We review some of the important mechanisms-e.g., asymmetric attachment kinetics at step edges, mechanical stress, curvature dependence of the sputtering yield, capillarity, viscous flow, and the nucleation and growth of new layers-and apply linear stability analysis to determine the length scales and growth rates of the instabilities. (C) 2003 American Vacuum Society.