A methodology of measuring nitrogen content in thin nitrogenated carbon overcoats on magnetic thin film media

Abstract

Thin nitrogenated carbon overcoats were deposited on magnetic rigid disks 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 nitrogen content. It will be shown that conventional deconvolution of Raman spectra into D‐ and G‐band cannot be correlated to nitrogen content in thin nitrogenated carbon unambiguously. On the other hand, a trend in 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 at.% will be presented.