文摘
In the synthesis of epitaxial heterostructures with appreciable lattice misfit, dislocations represent a crucial linear defect. Since device quality is typically deteriorated by their presence, minimizing the dislocation density by optimized growth strategies is a key challenge for R&D. This especially holds also for the system diamond-on-iridium with its difference in lattice constants of more than 7%. As a consequence of this misfit, the initial dislocation density is very high. In this review we discuss different aspects of dislocations in heteroepitaxial diamond growth. They vary from mutual interaction mechanisms for an efficient reduction in density, over interaction with surface structures, their crucial role in the formation of intrinsic stress, their presumable role in formation of highly anisotropic stress and also their role as sink for the segregation of boron dopants. Finally, it is pointed out that the dislocation mediated stress formation may be used intentionally to strengthen devices by formation of compressively stressed surface layers. The present article is focused on recent studies from the authors’ research group.
