Area selective laser chemical vapor deposition of diamond and graphite

High quality diamond and graphite has been deposited area selectively on silicon substrates in a hot filament chemical vapor deposition reactor employing laser heating. A mixture of CH4 (1–3 vol%) and H2 was passed over a tantalum filament having a temperature of approximately 2200°C. A laser beam was used to raise the temperature locally on the substrate surface. By a proper choice of filament temperature, substrate background temperature and laser induced temperature, isolated islands of polycrystalline diamond or graphite could be deposited on the silicon substrate. The deposited diamond and graphite spots were characterized by micro-Raman spectroscopy, scanning electron microscopy and scanning force microscopy.