Measurement of Wear Cross Section with Energy Dispersive X-ray Spectrometer (EDS)

The durability of carbon protective layers of thin film magnetic disks was examined with pin-on-disk tests, and the wear crosssection was estimated as the quantity of material worn away. However, measurement of the precise wear crosssection is difficult because the wear quantity in such tests is very small. Therefore, EPMA (electron probe microanalysis) with an EDS (energy-dispersive X-ray spectrometer) was used in attempts to measure the wear quantity. If the thickness of the film is small, the characteristic X-ray intensity is proportional to the film thickness of the irradiated region. However, it is well known that hydrocarbon contamination induced by electron beam irradiation occurs. The influence of the contamination was suppressed by wide electron beam scanning; in addition, the acceleration voltage was optimized to maximize the peak-to-background ratio and sensitivity. The high accuracy of this method is demonstrated in this paper.