ORIENTED DIAMOND ON GRAPHITE FLAKES

Diamond was deposited by the microwave plasma chemical vapor deposition method on a Si(100) substrate on which graphite flakes had been spread with their basal planes parallel to the substrate before deposition. Before diamond deposition, the substrate was preheated at 1200-degrees-C under hydrogen at 60 Torr to clean the surface of graphite flakes. Scanning electron micrographs showed that most of diamond particles were cubo-octahedral in morphology. The {111} planes of some diamond particles, which were judged by their triangular shape, were often parallel to the (0001) plane of graphite. Furthermore, some [111]-oriented diamond particles were clearly nucleated at the edge of graphite. The possibility of heteroepitaxy of diamond on graphite was discussed based on crystallographic considerations.