H-ACTINOMETRY WITH CF4 ADDITION IN MICROWAVE PLASMA-ASSISTED CHEMICAL-VAPOR-DEPOSITION OF DIAMOND

Optical emission spectroscopy (OES) and exhaust gas mass spectrometry were used io study the gas phase during diamond growth in microwave pl asma-assisted chemical vapor deposition (MPACVD). Mixtures with CF4, a ddition in H-2/Ar and H-2/Ar/CH4, have been studied. The relative emis sion intensity of atomic hydrogen line H, has been measured by actinom etry. This work presents a systematic study that has been performed wi th regard to the dependence of the relative intensity of the H, line ( 656.3 nm) with CF, addition. CF, concentrations in the range of 0-5% h ave been studied. We also investigated the influence or oxygen additio n on the relative intensity of the H-alpha line for fixed mixtures wit h H-2/Ar/CH4 and H-2/AR/CF4. Our results have shown that CF4 and O-2, addition increases considerably the atomic hydrogen concentration. The se results suggest that the CF4 and O-2 addition can promote diamond g rowth using systems with lower activation power. (C) 1997 Elsevier Sci ence S.A.