Interaction of dislocations on crossed glide planes in a strained epitaxial layer

The full three-dimensional Peach-Koehler formalism is implemented numerically and used to investigate encounters between threading and misfit dislocations in a strained epitaxial layer. The possible outcomes of such interactions are found to include blocking, binding, repulsive passage, and attractive instabilities. We show that blocking is a weak effect, and that the peculiar substrate pileup structures previously attributed to a ''modified Frank-Read mechanism'' are actually a natural consequence of having sources operating on intersecting glide planes.