QUANTITATIVE THIN-FILM ANALYSIS WITH AN ENERGY-DISPERSIVE X-RAY-DETECTOR

Recent mathematical approximations of phi(rhoz), the depth distribution of electron-excited x-rays, have opened up the possibility of accurate quantitative analysis of thin-film specimens by electron beam techniques. This method has been used extensively in electron probe microanalysis. This paper demonstrates quantitative analyses of thin films using energy-dispersive x-ray analysis (EDS) coupled with the phi(rhoz) method. Metal and oxide films were analyzed by several techniques, including electron probe microanalysis (EPMA), Rutherford backscattering spectroscopy (RBS), x-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), spectroscopic ellipsometry (SE) and x-ray fluorescence spectroscopy (XRF); the results were compared with those obtained from the EDS thin-film analysis. In the case of Al2O3 films, EDS film thickness results agree to within +/- 4%, +/- 7% and +/- 9% of the TEM, EPMA and SE results, respectively. For metal films, the EDS results agree to within +/- 12% (thicknesses) and +/- 7% (composition) of the RBS, EPMA and XRF results.