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 fil ament assisted chemical vapour deposition has been studied by phase se nsitive optical microscopy. As substrates natural diamond plates, of v arying orientations were used. The growth experiments were carried out for several methane-hydrogen gas phase compositions at different temp eratures. From surface topography it was deduced that the faces near { 111} and {100} grow by a step mechanism. For the {111} faces growth in volves lateral interaction between adjacent growth steps over 4 nm; fo r the {100} faces no evidence for surface diffusion was found. The {11 0} facets are characterized by a hill and valley pattern. At higher me thane fractions amorphous carbon forms on {111} and {110}, while singl e crystal diamond growth still persists on {100}.