Development of Al-based multilayer optics for EUV

作者：Meltchakov E^*; Hecquet C; Roulliay M; De Rossi S; Menesguen Y; Jerome A; Bridou F; Varniere F; Ravet Krill M F; Delmotte F

来源：Applied Physics A-Materials Science & Processing, 2010, 98(1): 111-117.

DOI：10.1007/s00339-009-5445-2

We report on the development of multilayer optics for the extreme ultra-violet (EUV) range. The optical performance of Al-based multilayer mirrors is discussed with regard to promising reflectivity and selectivity characteristics and the problems of the interfacial roughness for this type of multilayers. We demonstrate a possibility to reduce the average roughness by introducing additional metal layer (W or Mo) rather than depositing a buffer layer at each interface. We have prepared and tested Al/SiC, Al/W/SiC and Al/Mo/SiC multilayers of various periods for the spectral range from 15 to 40 nm, which is the range of increasing interest for high-order harmonic generation, synchrotron radiation and astrophysics. The structure of the three-component systems has been optimized in order to obtain the best reflectivity for each wavelength within the spectral range. We have shown that introduction of refractory metal in Al-based periodic stack can improve the optical performance of multilayer reflecting coatings designed for the EUV applications.

• 出版日期2010-1