Diamond deposition procedure from microwave plasmas using a mixture of CO2-CH4 as carbon source

Abstract Diamond was deposited on an Mo substrate placed in CO 2 –CH 4 –Ar and CO 2 –CH 4 microwave plasmas. In these plasmas, larger amounts of CO and OH radicals were identified than those of CH and C 2 radicals by OES. Strong peaks due to CO and H 2 were identified by means of QMA. The surface temperature of the substrate was about 1150±20 K. Particles exhibiting cubo-octahedral habit planes were observed in SEM images. The sharp lines due to diamond were identified in X-ray diffraction patterns and Raman spectra. The adsorption of CO on the surface of the deposit from the CO 2 –CH 4 microwave plasma was identified by XPS at the beginning of the deposition. Diamond could be deposited from the CO 2 –CH 4 microwave plasma through the adsorption of CO molecule as precursors.