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.