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 reac tor employing laser heating. A mixture of CH4 (1-3 vol%) and H-2 was p assed over a tantalum filament having a temperature of approximately 2 200 degrees 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, isolat ed islands of polycrystalline diamond or graphite could be deposited o n the silicon substrate. The deposited diamond and graphite spots mere characterized by micro-Raman spectroscopy, scanning electron microsco py and scanning force microscopy.