A recently observed mechanism of elastic stress relaxation in mismatched layers was considered. Relaxation was achieved by the inclination of pure edge threading dislocation lines with respect to the layer-surface normal. The relaxation was not assisted by dislocation glide, but was rather caused by the effective climb of edge dislocations. The effective dislocation climb could result from film growth and was not necessarily related to bulk diffusion. The contribution of dislocation inclination to strain relaxation was formulated, and the energy release due to dislocation inclination in mismatched stressed layers was determined. This mechanism explained the observed relaxation of compressive stresses in the (00▪1) growth of AlGaN layers.

Stress Relaxation in Mismatched Layers due to Threading Dislocation Inclination. A.E.Romanov, J.S.Speck: Applied Physics Letters, 2003, 83[13], 2569-71