The relaxation of compressive intrinsic stress in a film/substrate system was modelled using discrete dislocation dynamics. The compressive stress arose due to the diffusion of extra material into the grain boundaries during deposition. Dislocation nucleation and motion relaxed the stress in the thin film. The effect of the microstructure upon the process was found to be two-fold. As the grains became finer, the initial compressive stress became higher and more homogeneous, while impenetrable grain boundaries also caused greater hardening. The two effects seemed to be balanced when there were few sources available for dislocation nucleation. When the density of sources was high, the relaxation behaviour seemed to be less affected by the microstructure since both effects became weaker when the limit of continuum behaviour was approached.

Dislocation Dynamics Simulations of the Relaxation of Intrinsic Stress in Thin Films. C.Ayas, E.Van der Giessen: Philosophical Magazine, 2008, 88[30-32], 3461-77