DEPOSITION OF DIAMOND FROM PLASMA JETS WITH CHLOROBENZENES AS CARBON SOURCE

The diamond deposition on a molybdenum substrate was examined in an Ar -H-2 DC plasma jet adding C6H5Cl, C6H4Cl2 and C6H3Cl3 as the carbon so urces, compared with adding C6H6 to examine the effect of chlorine spe cies on diamond deposition. Well-faceted high-quality diamond was form ed from the Ar-C6H4Cl2-H-2 plasma jet. A small amount of graphite and/ or amorphous carbon were identified on the surface of the deposits fro m other plasma jets. Hydrogen abstraction of surface-adsorbed chlorine , chlorine abstraction of surface-adsorbed hydrogen and/or dehydrochlo rination play a dominant role in providing higher diamond deposition r ates and the removal of graphite and/or amorphous carbon. Excess amoun ts of chlorine, however, seem to foster the deposition of non-diamond carbon phase. (C) 1997 Elsevier Science S.A.