Heteroepitaxy of dissimilar materials: effect of interface structure on strain and defect formation

Differences in crystal symmetry, bonding, and lattice parameter play important roles in the epitaxy of dissimilar materials. We emphasize on how these differences influence the interface structure and the resulting epitaxial growth. Case studies are presented including the hexagonal MnAs–cubic GaAs and hexagonal GaN–tetragonal LiAlO2 systems. The interfaces are structurally analyzed and reveal low-energy configurations promoting the epitaxial alignment. The results are explained with an extended coincidence model considering strain and defect formation.