SYNTHESIS OF NANOCRYSTALLINE DIAMOND THIN-FILMS FROM AN AR-CH4 MICROWAVE PLASMA

Nanocrystalline diamond thin films have been synthesized in an Ar-CH4 microwave discharge, without the addition of molecular hydrogen. X-ray diffraction, transmission electron microscopy, and electron energy lo ss spectroscopy characterizations show that the films consist of a pur e crystalline diamond phase with very small grain sizes ranging from 3 to 20 nm. Atomic force microscopy analysis demonstrates that the surf aces of the nanocrystalline diamond films remain smooth independent of the film thicknesses. Furthermore, the reactant gas pressure, which s trongly affects the concentration of C-2 dimer in the Ar-CH4 plasma as well as the growth rate of the films, has been found to be a key para meter for the nanocrystalline diamond thin film depositions. (C) 1998 American Institute of Physics.