IN-SITU RAMAN INVESTIGATION OF DIAMOND FILMS DURING GROWTH AND ETCHING PROCESSES

Diamond films were prepared in a microwave plasma-assisted chemical va pour deposition (CVD) reactor. The deposition parameters were delibera tely optimized to obtain mixtures of diamond and different carbonaceou s compounds. We present the results of an in-situ Raman study of the g rowth of such films and of their etching under different atmospheres. At least six Raman bands in the range 1100-1600 cm-1 were observed; th eir relative intensity variation with the elaboration parameters, with the excitation wavelength and with the etching conditions led to the conclusion that at least three different carbonaceous forms are presen t in CVD diamond films. During the growth process, one first obtains t he diamond phase along with a diamond-like compound; the disordered gr aphitic form appears only in a second stage.