A review was presented of the topological theory of defects and interfaces in crystalline materials, with particular regard to cases relevant to nitride films and interfaces. Crystallographic calculations of hexagonal and trigonal crystals, using the Frank system,

were described. The principal methods of a priori and a posteriori defect characterization were also treated in a unified manner and their equivalence, circumstances under which each was applicable and practical aspects of their deployment, were summarized. A number of experimental observations were analyzed, and useful conclusions were drawn concerning, for example, admissible defects, structure-mechanism relationships and the effect of defects upon properties. These included threading, stacking-fault and interfacial dislocations in GaN epilayers, the influence of the epitaxial interface upon the appearance of inversion and stacking disorder, the structural transformations of inversion domain boundaries due to their intersections with stacking faults and double-positioning twinning in TiN contact layers deposited on GaN.

Topological Analysis of Defects in Epitaxial Nitride Films and Interfaces. G.P.Dimitrakopulos, P.Komninou, R.C.Pond: Physica Status Solidi B, 2001, 227[1], 45-92