Synchrotron radiation induced X-ray standing waves analysis of layered structures

The X-ray standing waves technique is an interesting method to measure distances, concentration distributions and structures on a nanometer scale. In this paper, we will present the method of grazing incidence X-ray standing waves (GI-XSW) that – contrary to other XSW techniques – does not require a periodic crystal structure but only a reflecting surface onto that almost any sample system can be deposited. Characterization of layered structures and element specific measurements are easily possible with GI-XSW. The method is described and the applicability to various kinds of samples is demonstrated and discussed. Germanium layers of various thicknesses ranging from 29 to 309 nm on silicon are characterized, as well as a more complex sample system of an 80 nm polystyrene layer on silicon covered with gold clusters. A detailed description of data evaluation and the corresponding computer simulations of the XSW spectra is given.