Optical emission spectroscopy (OES) and exhaust gas mass spectrometry (MS) were used in a microwave plasma assisted chemical vapour deposition (MWPACVD) reactor. The dissociation mechanism of CCl4 associated with O2 addition in the gas phase for diamond growth have been analysed. OES was used to observe the Ha line intensity as a function of CCl4 anel O2 concentration in the feed gas. The results have shown an increase of atomic hydrogen concentration over 200% for addition of 3% CCl4. It was also observed an additional increase in the H generation when O2 is added in the H2/CCl2 mixtures. The films grown in different concentrations of CCl4 and O2 were analysed by scanning electron microscopy anel Raman spectroscopy.
