Micro-XRF in Scanning Electron Microscopes

Abstract

Abstract Micro-X-ray fluorescence is an established analytical method that is used for approx. 15 years for a sensitive elemental analysis. It could be developed due to the availability of X-ray optics, in particular polycapillary optics which can concentrate divergent tube radiation to spot sizes down to the 10 μm range. After the introduction of separate μ-XRF instruments, this excitation possibility becomes interesting for scanning electron microscopes (SEMs). SEMs typically are equipped with an energy-dispersive detector. Therefore, the X-ray excitation would expand its analytical performance. In particular the sensitivity for trace elements could be increased and the characterization of layer systems will be possible. Additionally, sample preparation would be easier and the sample stress by irradiation with high energetic radiation is reduced. A special benefit is the use of both electron- and X-ray-excited spectra for a combined quantification, and thus, a more complete material characterization is possible. The combination of light element analysis and trace detection improves quantification results.