Measurement of carbon film thickness by inelastic electron scatter

The electron spectra obtained from magnetic media coated with carbon films of varying thickness are presented. Electrons backscattered inelastically dominate the spectra. The intensity of the elastic peak varies in accordance with the Beer/Lambert law and escape depths of 30 and 43 Å for 1 and 2 keV primary beam energies, respectively. The maximum intensity in the inelastic scatter portion of the spectrum decreases in energy and magnitude with increasing film thickness. The spectral differences associated with changes in carbon film thickness are large and provide an alternative to x-ray photoelectron spectrometry for quantitative carbon film thickness measurement.