Improvement of depth resolution in XPS analysis of fluorinated layer using C60 ion sputtering

Depth profile of C60 ion-used X-ray photoelectron spectroscopy (XPS) was studied on fluorinated organic layers with different thicknesses. We found that the depth resolution decreased, the sputtering rate went down and the surface turned rough as the layer thickness increased. This is because carbon-rich layer was formed on the surface by cross-linking reaction of the polymer and/or accumulation of degraded C60 through continuous sputtering. Surprisingly, the high sputtering rate drastically improved the resolution of the analysis. The rate over 48.7 nm/min did not show any deterioration on the depth resolution, the sputtering rate and surface smoothness.