THE STRUCTURAL CHARACTERIZATION OF AMORPHOUS THIN-FILMS AND COATINGS IN THEIR AS-DEPOSITED STATE USING X-RAYS AT SHALLOW ANGLES OF INCIDENCE

We demonstrate the method of x-ray diffraction at shallow angles of in cidence, using the intrinsically highly collimated x-ray beam generate d by a synchrotron source, to study the atomic-scale structure of amor phous thin films and coatings in their as-deposited (i.e., on-substrat e) state. As the incident angle is decreased, scattering from the film /coating can be isolated as contributions from the substrate are reduc ed. Systems studied include chemical vapor deposition (CVD) diamond fi lms deposited onto both silicon and steel substrates, where evidence o f an interfacial region between the film and silicon wafer has been ob served, but we focus on a range of amorphous films/coatings (mixed TiO 2:SiO2 sol-gel spun films, hydrogenated carbon films and ''glassy'' ca rbon coatings, silicon: germanium semiconducting films and alumina coa tings). The data are used both to comment upon the systems studied and to elucidate the potential, and the limitations, of the experimental method.