PEELS AND EXELFS CHARACTERIZATION OF DIAMOND FILMS GROWN BY THE HF-CVD TECHNIQUE ON NON-SCRATCHED SI SUBSTRATES

We present a detailed energy loss characterization of natural diamond and diamond films grown on non-scratched Si substrates by the hot-fila ment chemical vapor deposition technique (with the help of a SiC buffe r layer). The energy loss experiments were performed in a transmission electron microscope (TEM) with a GATAN-666 parallel electron energy l oss spectrometer (PEELS) attachment Diamond particles are in the 0.5-1 mu m size range as observed by TEM. PEELS spectra show that the plasm on and carbon K-edge main features are very similar (in position and s hapes) in both natural and our diamond film. The radial distribution f unction around the carbon atoms was obtained through the Fourier trans form of the extended fine structure located in a 300 eV range beyond t he carbon K-edge in the energy loss spectra. The values obtained for t he C-C distances are very close (within 0.003 nm) to those of natural cubic diamond structure. These results confirm the good quality of the diamond films produced by our experimental technique. (C) 1997 Elsevi er Science S.A.