THERMAL EVOLUTION OF W/SI AND W/C MULTILAYERS UNDER PULSED LASER-HEATING AND CLASSICAL ANNEALING

The thermal behaviour of nanometer-thick W/Si and W/C multilayers was studied because they can be used as X-ray optics under intense synchrotron X-ray beams. Two types of annealing were performed: pulsed laser annealing and classical thermal annealing in a furnace. Depending on the composition and the structure of the layered materials, thermal stability or diffusion mechanisms were observed and analysed by X-ray scattering, transmission electron microscopy and Auger electron spectroscopy. Simulations of the small angle X-ray scattering curves take well account of the thermal evolution under homogenous furnace annealings and allowed us to compare the resulting evolution under short laser irradiation. Under both treatments, the final state was the crystallization in the tetragonal WSi2 phase for samples containing silicon, and the partial graphitization of the carbon and the W2C compound formation for samples containing carbon. © 1990.