Application of X-ray reflection interface microscopy to thin-film materials

New X-ray imaging techniques with excellent spatial resolution are under development for investigating surface and interface structures. X-ray reflection imaging microscopy (XRIM) applies full-field imaging to a specularly reflected X-ray beam from a surface or interface. This technique uses a zone plate objective lens to spatially resolve the reflected X-ray intensity and, by exploiting phase contrast, allows steps or terraces to be directly visualized. Thickness fringes caused by interferences in crystalline thin films grown on single-crystal substrates are observed near Bragg peaks and also carry information related to the termination of the film at either the surface or the film-substrate interface. We have applied the XRIM technique to image X-ray intensity along thickness fringes in complex oxide thin-film systems such as SrRuO(3) on SrTiO(3), EuTiO(3) on DyScO(3), and Bi(2)O(3) on SrTiO(3). Measurements of the contrast variations in the images as a function of momentum transfer. Q allow features to be identified as steps/terraces, or attributed to film inhomogeneities. Using both the Q-resolution and the excellent spatial resolution of the XRIM technique, images of fabricated systems with lateral structures are demonstrated. (C) 2010 Elsevier B.V. All rights reserved.