Nucleation of semicircular misfit dislocation loops from the epitaxial surface of strained-layer heterostructures

The nucleation of semicircular misfit dislocations from the epitaxial surface in strained-layer heterostructures is considered. It is shown that the model of J. W. Matthews, A. E. Blakeslee, and S. Mader [Thin Solid Films 33, 253 (1976)], which considered a semicircular dislocation loop expanding in a semi-infinite layer, needs modification when an epilayer/substrate interface is involved.