SEQUENTIAL DEPOSITION OF DIAMOND FROM SPUTTERED CARBON AND ATOMIC-HYDROGEN

The growth of diamond thin films on a scratched silicon crystal surfac e by a chemical-vapor deposition technique is reported. The substrate was bombarded by sputtered carbon from a graphite target in a helium d c glow discharge, and subsequently exposed to atomic hydrogen generate d by a hot tungsten filament. The resulting diamond films were charact erized by Raman spectroscopy and scanning electron microscopy. Deposit ed film quality and growth rate were studied as functions of carbon an d atomic hydrogen exposure. An increase in growth rate of diamond was observed with atomic hydrogen exposure. We also observe that only the first monolayer of carbon deposited with each exposure appears to be u tilized. These observations suggest that the diamond growth is a surfa ce reaction. Further, calculations based upon the carbon utilization i n traditional hot filament reactors indicate that a gas-phase reaction process can account for neither the growth rate nor the saturation be havior observed. Based on this work it is proposed that the growth of diamond films is govemed by surface reactions, and that the necessity of gas-phase precursors can be precluded.