ELASTIC-SCATTERING UNDER SIMULTANEOUS EXCITATION OF X-RAY STANDING WAVES IN MULTILAYERS

We have measured the structure factor of diffuse scattering and amorph ous scattering in a W/Si multilayer under simultaneous excitation of x -ray standing waves. The tuning of the nodes and antinodes to the loca tion of the W and Si sublayers or to the respective interfaces increas es the selective sensitivity to the structure of the respective sublay er or interface. The dynamically broadened first multilayer Bragg peak is modeled by the Darwin theory of dynamic diffraction, which allows for the exact determination of the standing wave phase. The decay of d iffuse intensity, as measured in a grazing incidence geometry at diffe rent standing wave phase shifts, indicates that the height-height self -correlation function is of the same form for both types of interfaces , W/Si and Si/W. The amorphous peaks of the Si sublayer can only be ob served if the angles of incidence and exit are optimized to suppress t he scattering from the otherwise dominating W layers. The peak positio ns are the same as for bulk amorphous silicon. (C) 1998 American Insti tute of Physics.