The relaxation of coherency stresses, by the glide of threading dislocations in a layer that was growing coherently on a substrate, was considered. The glide of threading dislocations became energetically favorable when the thickness of the layer exceeded a critical value, hc. The predicted values of hc were often less than those indicated by experimental observations. It was shown that the energy associated with the creation or removal of steps on the surface of a growing layer was important in determining the hc value which was associated with the glide of threading dislocations.

Influence of Surface Steps on Glide of Threading Dislocations during Layer Growth. R.G.Hoagland, J.P.Hirth, A.Misra, D.Mitlin: Applied Physics Letters, 2004, 84[25], 5136-8