Heat stability of Mo/Si multilayers inserted with compound layers

Mo/Si multilayers inserted with silicon oxide (SiO2) layers have been deposited on Si substrates by means of the ion beam sputtering method to improve the heat stability of the Mo/Si multilayer. Fabricated samples were annealed at temperatures up to 600 °C in a vacuum furnace. The Mo/Si/SiO2 multilayer after annealing at 400 °C retains almost the same soft X-ray reflectivity as the as-deposited sample at a wavelength of approximately 13 nm, with little change in the peak wavelength. This temperature is 100 °C higher than that for conventional Mo/Si multilayers. The Mo/SiO2/Si/SiO2 multilayer has the most thermally stable structure up to 600 °C.