Morphological instability of growth fronts due to stress-induced mobility variations

We report a comparison between theory and experiment for a general stress-i nduced morphological growth instability that is kinetically rather than ene rgetically driven. Stress variations along a perturbed planar growth front result in variations in interfacial mobility in a manner that is destabiliz ing under one sign of the stress state and stabilizing under the opposite s ign, even for a pure material. Investigation of solid-phase epitaxial growt h at a corrugated Si(001) interface under both compression and tension resu lts in good agreement between experiment and theory with no adjustable para meters, demonstrating that this mobility-based mechanism is dominant in det ermining morphological evolution in this system. (C) 2000 American Institut e of Physics. [S0003-6951(00)01930-6].