LOW-TEMPERATURE (APPROXIMATELY-400-DEGREES-C) GROWTH OF POLYCRYSTALLINE DIAMOND FILMS IN THE MICROWAVE PLASMA OF CO/H-2 AND CO/H-2/AR SYSTEMS

In order to elucidate the growth conditions for pure diamond of good crystallinity, the correlation of the properties of deposited films and gas phase species in microwave plasma of CO/H-2 and CO/H-2/Ar systems was investigated through film characterization and optical emission spectroscopic measurements. It was found that the increase of gas phase atomic hydrogen and the suppression of gas phase acetylene were effective for the growth of pure diamond of good crystallinity. Low temperature growth was proposed to realize these growth conditions. It was confirmed that diamond films with good crystallinity and optical transparency could be synthesized at 410-degrees-C (diamond film growth was possible even at 365-degrees-C). The growth rate was accelerated in a CO/H-2/Ar system (0.33-mu-m/h at 410-degrees-C), which was several times faster than that obtained in a CO/H-2 system (0.14-mu-m/h at 450-degrees-C).