Reflection Passband Broadening by Aperiodic Designs of EUV/Soft X-ray Multilayers
- Research Center for Soft X-ray Microscopy, IMRAM, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577 (Japan)
By using three conventional optimization algorithms, we have developed computer programs of layer thickness designing for reflection passband broadening of EUV/soft X-ray multilayers. Three programs with optimization by Simplex, quasi-Newton and Gradient methods were found to be effective to search for aperiodic Mo/Si multilayers of a leveled reflectance of 35% within a wavelength region between 13 nm and 15 nm, though the thickness structures were considerably different. For much shorter wavelengths in the water window, solutions of Cr/Sc multilayers were also found for a leveled 30% reflectance between 3.14 nm and 3.16 nm, and also for a 15% reflectance between 3.13 nm and 3.17 nm. The bandwidth {lambda}/{delta}{lambda} of these designs were improved from 286 of periodic multilayer to 137 and 66, respectively. Two practical design solutions were used to fabricate aperiodic Mo/Si multilayer mirrors by our ion beam sputtering system. The samples show EUV reflectance of more than 15% between 13 nm and 15 nm.
- OSTI ID:
- 21049312
- Journal Information:
- AIP Conference Proceedings, Vol. 879, Issue 1; Conference: 9. international conference on synchrotron radiation instrumentation, Daegu (Korea, Republic of), 28 May - 2 Jun 2006; Other Information: DOI: 10.1063/1.2436355; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
- Country of Publication:
- United States
- Language:
- English
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