HETEROEPITAXY OF DIAMOND ON C-BN - GROWTH MECHANISMS AND DEFECT CHARACTERIZATION

Diamond films grown on {100}, {111} boron-terminated, and nitrogen-ter minated facets of cubic boron nitride (c-BN) single crystals were char acterized by Raman spectroscopy, scanning electron microscopy (SEM), a nd transmission electron microscopy (TEM). The evolution of morphology and microstructure of the diamond films at different stages during th e growth process were followed by SEM investigation. The results indic ate that diamond growth proceeds by nucleation of oriented three-dimen sional islands followed by their coalescence. Cross-sectional TEM spec imens were prepared from thick (over 10 mum) continuous diamond films grown on {111} boron-terminated surfaces. Selected-area diffraction an d high resolution TEM images show that the diamond film has a parallel orientation relationship with respect to the substrate. Characteristi c defects, common to diamond films obtained by chemical vapor depositi on on other substrates, are also discussed.