ENHANCED DIAMOND NUCLEATION DENSITY UTILIZING SEEDING

This paper reports on a new technique for surface pre-treatment of sil icon and other substrate materials to enhance diamond nucleation befor e diamond deposition. Polycrystalline diamond particles (ballas or cau liflower diamond particles) are grown in a CVD environment under hydro carbon concentrations of 8-15%. After 15 min of growth, the substrate is removed from the process equipment and mechanically treated so that the ballas diamonds are disintegrated into their constituent nanomete r-sized diamond crystals and are evenly spread over the surface of the substrate. The small diamond crystals then act as nuclei for the form ation of a diamond film in the subsequent diamond growth process. Nucl eation densities on virgin silicon wafers of 5 x 10(10) cm(-2) have be en achieved with this method, and it is believed that even higher nucl eation densities can be achieved by further optimisation of the proces s. (C) 1998 Elsevier Science S.A.