Design and Fabrication of High Reflection Multilayer for the Wavelength Range 50~110 nm
50~110 nm波段高反射率多层膜的设计与制备

A design method of sub-quarter-wave multilayers with enhanced normal reflectance in the strong absorbing range 50~110 nm has been presented.The multilayers consisted in the superposition of a few layers of strong absorbing materials.The optical thickness of each layer in the multilayers is less than quarter-wave thickness.Compared to the standard multilayers,this multilayer structure more suits to enhance reflectance of strong absorbing wavelength range.High reflectance multilayers Si/W/Co was designed at wavelength of 50 nm by using this method,and then optimized based on this initial condition by using Levenberg-Marquart algorithm in a wide wavelength range 50~110 nm.The calculated results suggest that the reflectance of the multilayer is as high as 45%.The sample was fabricated by using a high vacuum direct current magnetron sputtering.Then,the multilayer was characterized by a low angle X-ray diffraction.The results suggest that the fabricated multilayer structure meets the design requirement.