ANISOTROPY IN MONOCRYSTALLINE CVD DIAMOND GROWTH .3. SURFACE-MORPHOLOGY OF HOT-FILAMENT GROWN FILMS DEPOSITED ON PLANAR SUBSTRATES

The surface morphology of homoepitaxial diamond films grown by hot filament assisted chemical vapour deposition has been studied by phase sensitive optical microscopy. As substrates natural diamond plates, of varying orientations were used. The growth experiments were carried out for several methane-hydrogen gas phase compositions at different temperatures. From surface topography it was deduced that the faces near {111} and {100} grow by a step mechanism. For the {111} faces growth involves lateral interaction between adjacent growth steps over 4 nm; for the {100} faces no evidence for surface diffusion was found. The {110} facets are characterized by a hill and valley pattern. At higher methane fractions amorphous carbon forms on {111} and {110}, while single crystal diamond growth still persists on {100}.