STUDY OF AN AR-CH4-H2 MICROWAVE POSTDISCHARGE UNDER DIAMOND DEPOSITION CONDITIONS - CORRELATIONS BETWEEN ANALYSIS PERFORMED IN THE GAS-PHASE AND IN CARBON THIN-FILMS

Active species are produced in various Ar-CH4-H-2, microwave plasma mi xtures. The purpose of this work is to establish correlations between results of diagnostics performed in the gas phase and the characterist ics of diamond layers deposited onto silicon wafers. The results revea l the important effect of CH(x) (x < 3) radicals on the growth and cha racteristics of carbon layers. X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) were performed and the results are d iscussed. XPS analysis of carbon films shows that the percentage of sp 3 C-C bonds is improved when the density of simple CH(x) (x < 3) speci es close to the surface of the substrate increases. AFM analysis shows that nucleation at the surface of the silicon wafer is improved by io nic bombardment.