QUANTITATIVE ANALYSIS OF LOW-Z ELEMENTS IN TOTAL REFLECTION X-RAY FLUORESCENCE SPECTROSCOPY

摘要

In trace analysis of low-Z elements by a TXRF system, a correct estimation of the backgrounds is very important. The backgrounds from the tailing of a large Si-Ka peak are undesirable especially for the analysis of Al. Thus, X-ray radiation with excitation energies below the Si K absorption edge should be used to eliminate the Si-Kα peak. The W-Ma line from a W target and a radiation from a SR source are best for this purpose. The radiations with energy below the Si K absorption edge, however, create a background due to inelastic scattering from the existence of resonant X-ray Raman scattering. During an analysis of low-Z elements, the backgrounds caused by Raman scattering must be eliminated. We estimated theoretically the profile of the continuous spectrum of Raman scattering and applied the profile fitting technique to analyze thin films deposited on Si to determine simultaneously the concentrations of low-Z impurities and the Raman backgrounds. We found that the Raman backgrounds are significantly different depending on the X-ray incident angles and the film materials.