GROWTH AND STRUCTURE OF WC/Si MULTILAYER X-RAY MIRROR

WC/Si multilayer X-ray mirrors (MXMs) with nominal layers thicknesses of 0.2 ... 30.3 nm (periods: 0.7 ... 38.9 nm) were deposited by direct current magnetron sputtering and studied by X-ray diffraction and cross-sectional transmission electron microscopy (TEM). Carbide and silicon layers are amorphous throughout the studied thickness range. The WC layers interact with Si layers with formation of tungsten silicides (WSi2, W5Si3) and silicon carbide in as-deposited state. The bottom interlayer (WC-on-Si) consists of two subzones of approximately equal thickness. An estimation of the thickness, density, and composition of all layers is made. Based on the experimental data, a five-layer model of the WC/Si MXM structure is suggested.