Comparison of quantitative X-Ray Fluorescence Spectrometry under normal and grazing incidence condition by means of buried nanolayers

Non-destructive thickness determination of nanolayer and thin films becomes more and more important. The quantitative X-Ray Fluorescence Spectrometry (XRF) with synchrotron radiation is a well-established method for thickness determination of thin layers. Under grazing incidence condition (GIXRF), due to total reflection of the incidence beam the X-ray standing wave (XSW) field occurs. That enables near surface quantification of lowest depositions and the possibility of buried nanolayer quantification. In this work quantitative XRF and GIXRF are compared and the advantages and limits of both methods are demonstrated. Within a project of the German Science Foundation (DFG), a special sample system was investigated. It consists of buried borcarbide nanolayers varying in thickness deposited on 10 nm titanium and covered with 2.5 nm silicon dioxide. All layered structures are deposited on silicon-wafers. The measurements were carried out in the PTB laboratory at BESSY II. The result of the buried nanolayer thicknesses matches in both methods.