Monte Carlo study of quantitative analysis method of trace elements in thin aluminum films

We have suggested a quantitative analysis method for the determination of trace elements (100–1200 mass ppm) in thin Al films. One of the features of this method is to use calibration curves (K-ratio vs mass ppm in bulk targets) obtained using a Monte Carlo (MC) simulation of electron scattering. First, we verified the calibration curves using bulk standard Al-Cu alloys. As a result, good agreement was obtained with chemical analysis results. Consequently, we confirmed that the MC simulation correctly expressed the electron trajectories in the targets. Here the X-ray generation ratio was defined as the ratio between the X-ray production from an element in a film and the X-ray production by the same element in the same bulk sample. After that, using this MC simulation, we investigated the relation among the X-ray generation ratio, the trace element concentration and the Al film thickness. As a result, we found that the X-ray generation ratio is in relation to the film thickness, however it is not in relation to the concentration of trace element. Namely, if the thickness of unknown samples is known, using the X-ray generation ratio we can transfer from relative X-ray intensity of the film into the relative X-ray intensity of the bulk sample. Also, from the relation that the K-ratio is corresponding to the relative X-ray intensity, using the calibration curves (K-ratio vs mass ratio in bulk targets), we can obtain the concentration (mass ppm) in thin films. Further, in this study, we provided the X-ray generation ratios and the calibration curves of trace elements such as Mg, Si, Ti, Cr, Mn, Fe, Ni, Cu, Zn in the bulk Al matrix. C 2005 Springer Science + Business Media, Inc.