Perspective: Fundamentals of coalescence-related dislocations, applied to selective-area growth and other epitaxial films

Although selective area growth (SAG) and coalesced SAG (cSAG) have been utilized extensively for many years to moderate the material quality of lattice-mismatched films, the geometrical factors controlling dislocations in coalesced films are difficult to visualize, and some confusion regarding the topology of dislocations for cSAG still persists. In this paper, we describe the topology of dislocations during island coalescence for cSAG, framed in terms of fundamental dislocation properties and virtual dislocations, which are used as a helpful visualization tool. We also show how the results and methods are generally applicable to coalescence of any other epitaxial film.Although selective area growth (SAG) and coalesced SAG (cSAG) have been utilized extensively for many years to moderate the material quality of lattice-mismatched films, the geometrical factors controlling dislocations in coalesced films are difficult to visualize, and some confusion regarding the topology of dislocations for cSAG still persists. In this paper, we describe the topology of dislocations during island coalescence for cSAG, framed in terms of fundamental dislocation properties and virtual dislocations, which are used as a helpful visualization tool. We also show how the results and methods are generally applicable to coalescence of any other epitaxial film.