CO2 LASER-INDUCED PLASMA CVD SYNTHESIS OF DIAMOND

A novel technique for CVD synthesis of materials that does not demand a vacuum chamber and provides high deposition rates has been developed . It is based on CO2 laser maintenance of a stationary optical dischar ge in a gas stream, exhausting over a substrate into the air (laser pl asmatron). Nano- and polycrystalline-diamond films were deposited on t ungsten substrates from atmospheric-pressure Xe(Ar):H-2:CH4 gas mixtur es at flow rates of 2 l/min. A 2.5-kW CO2 laser focused beam produced plasma. The deposition area was about 1 cm(2) and growth rates were up to 30-50 mu m/h. Peculiarities and advantages of laser plasmatrons ar e discussed.