Thermoresistive multilayer mirrors antidiffusion barriers for work at the wavelengths 40-50nm

Abstract

To improve the thermal stability of Si/Sc multilayer mirrors, thin layers of W were deposited at interlayer boundaries. Using X-ray scattering and transmission electron microscopy, we studied the interaction of Si and Sc layers at elevated temperatures. It was shown that the W layers of 0.5-0.8 nm thickness form dense WSi2 barriers, which prevent a direct contact between Si and Sc and greatly slow down the formation of scandium silicides. Presented measurements show that Si/W/Sc/W multilayers fabricated by de-magnetron sputtering possess long thermal stability up to 250° C and the normal incidence reflectivity of 24 %.