ON THE DEVELOPMENT OF CVD DIAMOND FILM MORPHOLOGY DUE TO THE TWINNINGON (111)-SURFACES

CVD diamond films were grown under various conditions corresponding to various values of the growth parameter alpha=root 3v(100)/v(111). It was observed that the boundaries of the growing crystals nearly remain ed free of twins. Further, the experiments suggest that the overall tw in abundance on a parent facet depends on alpha. A theoretical explana tion for these facts is given using a new concept: the nucleation surf ace. This surface is proportional to the twin coverage probability at a given point on the parent crystal face, and it can be calculated in detail for every position on the parent facet and for every type of tw in. The concept of the nucleation surface can be used to explain and p redict film morphologies in cases where twinning is important during d eposition. (C) 1997 Elsevier Science S.A.