A model of dislocation blocking and its application to the development of misfit dislocation arrays

During the relaxation of strained semiconductor layers, gliding threading dislocations can be blocked by pre-existing misfit dislocations lying perpendicular to the glide direction. It has been suggested that this process is less significant when the layer is grown on an off-cut (i.e. vicinal plane) substrate. We present a statistical analysis of the simpler cases and a computer simulation of the more complex cases which shows that there should be no difference between the blocking behaviour on exact or off-cut substrates.