On the behaviour of the penetration twin abundance on {100} diamond facets

Abstract

The morphology of isolated diamond crystals and diamond films can be strongly influenced by twin nucleation. For a better understanding of these phenomena, a recently introduced new concept? the twin nucleation surface (a quantity proportional to the probability that a given point is overgrown by a twin) is defined and calculated for penetration twins on {100} facets. The results explain several experimental findings: the dependence of the twin abundance on the relative position on the {100} facet, on the growth parameter alpha = root 3 nu(100)/nu(111) and on the orientation of the twin with respect to the facet boundary. Also, the results offer an explanation for the existence of a narrow window of deposition conditions for which a growing film can rapidly evolve to a high-quality film with a low twin concentration. (C) 1998 Elsevier Science S.A.