Structural studies on Si‐N gradient thin layers by grazing incidence X‐ray diffraction

Abstract

In this paper, the application of combined method – the powerful tool for structure analysis – used for the structure determination of non‐ordered gradient Si‐N thin films is presented. The method is based on the combination of well‐known methods, like radial distribution function (RDF), pair distribution function (PDF) analyses and the Rietveld refinement. The values of radii and number of coordination spheres, obtained from RDF and PDF analyses, were compared to the theoretical values calculated for typical crystalline structures. Then, the most probable model of the hypothetical ‘unit cell’ of the analysed material might be chosen for the Rietveld refinement. In case of the gradient materials and thin films, the structure analysis is more complicated because the experiment has to be prepared in grazing incident X‐ray diffraction geometry. The X‐ray diffraction patterns collected for different angles of the incident beam show different shape, what indicate different kind of order in layers. Finally, it was stated that the Si‐N layers are nonhomogenous, and their structure depends on the penetration depth. Moreover, there was a possibility to create the complete structure model of whole gradient Si‐N thin film. Copyright © 2014 John Wiley & Sons, Ltd.