New methodologies for measuring film thickness, coverage, and topography

We describe how the techniques of X-ray reflectivity (XRR), electron spectroscopy for chemical analysis (ESCA), and atomic force microscopy (AFM) can be used to obtain the structural parameters-thickness, coverage, and topography-of thin films used on magnetic recording disks. We focus on ultra-thin amorphous nitrogenated carbon (CNx) overcoats on disks. Each technique has its own strengths: XRR measures film thickness absolutely, ESCA determines the chemical composition of the films, and AFM maps topography accurately. For the CNx overcoats investigated, we find incomplete coverage for thicknesses less than 20 Å, and we find a small surface roughness with rms roughness ≤11 Å.