A METHODOLOGY OF MEASURING NITROGEN-CONTENT IN THIN NITROGENATED CARBON OVERCOATS ON MAGNETIC THIN-FILM MEDIA

Thin nitrogenated carbon overcoats were deposited on magnetic rigid di sks by unbalanced DC-magnetron sputtering using a mixture of argon and nitrogen gases. Nitrogen content of nitrogenated carbon is important in determining its tribological performance. Two techniques, including Raman spectroscopy and reflectometry, were evaluated to measure nitro gen content. It will be shown that conventional deconvolution of Raman spectra into D- and G-band cannot be correlated to nitrogen content i n thin nitrogenated carbon unambiguously. On the other hand, a trend i n the optical constants of nitrogenated carbon will be described that allows rapid quantitative determination of nitrogen content calibrated against ESCA. Measurements of nitrogen content ranging from 0 to 25 a t.% will be presented.