Development of Al-based multilayer optics for EUV
Abstract
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.
- Publication:
-
Applied Physics A: Materials Science & Processing
- Pub Date:
- January 2010
- DOI:
- 10.1007/s00339-009-5445-2
- Bibcode:
- 2010ApPhA..98..111M
- Keywords:
-
- 42.70.-a;
- 61.05.Cm;
- 68.35.Ct;
- 78.67.Pt;
- 81.07.-b;
- Optical materials;
- Interface structure and roughness;
- Multilayers;
- superlattices;
- Nanoscale materials and structures: fabrication and characterization