ASSESSING POLAR AND AZIMUTHAL CORRELATIONS FOR AN ORIENTED MOSAIC OF (001) DIAMOND CRYSTALLITES ON (001) SILICON

The heteroepitaxial growth of diamond films on (001) silicon by bias-e nhanced, microwave-assisted chemical vapor deposition leads to a mosai c of highly oriented crystallites. The majority of crystallites adopt a ''cube-on-cube'' orientation (diamond{hkl}\\silicon{hkl}), but there are a variety of minor growth textures (including diamond (111)\\sili con(001), diamond(311)\\silicon(001), and diamond(220)\\silicon(001)). Within the diamond(001)\\silicon(001) domain, there is a distribution of crystallite orientations and concurrently heteroepitaxial relation ships. The X-ray precession method has been employed here, together wi th the more widely adopted X-ray rocking curve technique, to assess qu antitatively the nature and breadth of this distribution of orientatio ns and its dependence on film thickness. In brief, the X-ray scatterin g from the mosaic of crystallites can be well approximated by simple g aussian functions, with misorientation angles of a few degrees both pa rallel (azimuthal) and normal (polar) to the surface of the silicon su bstrate. The dependence of these parameters on film thickness is, howe ver, non-monotonic with minima near a diamond him thickness of 20 mu m .