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Applied Optics

Applied Optics


  • Vol. 43, Iss. 32 — Nov. 10, 2004
  • pp: 5955–5962

Structural characterization and lifetime stability of Mo/Y extreme-ultraviolet multilayer mirrors

Benjawan Kjornrattanawanich and Saša Bajt  »View Author Affiliations

Applied Optics, Vol. 43, Issue 32, pp. 5955-5962 (2004)

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We have observed a dramatic dependence of the extreme ultraviolet (EUV) reflectivity of Mo/Y multilayers on the oxygen content of yttrium. This is explained as being due to a change in the microstructure and an increase in roughness of the yttrium layers and not just to an increase in absorption owing to the amount of oxygen within the yttrium layers. We found that the best reflectivity of 38.4% was achieved with an oxygen content of 25%, which was reduced to 32.6% and 29.6% for multilayers manufactured from oxygen-free yttrium and 39%-oxygen yttrium, respectively. These results highlight the importance of including experimentally determined optical constants as well as interface roughness in multilayer calculations. In addition, the lifetime stability of Mo/Y multilayers with different capping layers was monitored for 1 year. The molybdenum- and palladium-capped samples exhibited low surface roughness and ∼4% relative reflectivity loss in 1 year. The relative reflectivity loss of the yttrium-capped sample (yttrium with 39% oxygen) was ∼8%. However, the reflectivity loss in all three capping layers occurred within the first 100 days after the deposition, and the reflectivity remained stable afterward.

© 2004 Optical Society of America

OCIS Codes
(230.0230) Optical devices : Optical devices
(230.4170) Optical devices : Multilayers
(310.0310) Thin films : Thin films
(310.6860) Thin films : Thin films, optical properties

Original Manuscript: May 20, 2004
Revised Manuscript: August 23, 2004
Published: November 10, 2004

Benjawan Kjornrattanawanich and Saša Bajt, "Structural characterization and lifetime stability of Mo/Y extreme-ultraviolet multilayer mirrors," Appl. Opt. 43, 5955-5962 (2004)

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  1. See http://sdo.gsfc.nasa.gov/ for more details about the Solar Dynamics Observatory mission.
  2. C. Montcalm, P. A. Kearney, J. M. Slaughter, B. T. Sullivan, M. Chaker, H. Pépin, C. M. Falco, “Survey of Ti-, B-, and Y-based soft x-ray extreme ultraviolet multilayer mirrors for the 2- to 12-nm wavelength region,” Appl. Opt. 35, 5134–5147 (1996). [CrossRef] [PubMed]
  3. B. Sae-Lao, S. Bajt, C. Montcalm, J. F. Seely, “Performance of normal-incidence molybdenum-yttrium multilayer-coated diffraction grating at a wavelength of 9 nm,” Appl. Opt. 41, 2394–2400 (2002). [CrossRef] [PubMed]
  4. R. Soufli, E. M. Gullikson, “Absolute photoabsorption measurements of molybdenum in the range 60–930 eV for optical constant determination,” Appl. Opt. 37, 1713–1719 (1998). [CrossRef]
  5. B. Sae-Lao, R. Soufli, “Measurements of the refractive index of yttrium in the 50–1300-eV energy region,” Appl. Opt. 41, 7309–7316 (2002). [CrossRef] [PubMed]
  6. R. C. Weast, M. J. Astle, eds., CRC Handbook of Chemistry and Physics, 63rd ed. (CRC Press, Boca Raton, Fla., 1982); see also http://www.webelements.com .
  7. B. L. Henke, J. Y. Uejid, H. T. Yamada, R. T. Tackaberry, “Characterization of multilayer x-ray analysers: model and measurements,” Opt. Eng. 25, 937–947 (1986). [CrossRef]
  8. E. M. Gullikson, S. Mrowka, B. B. Kaufmann, “Recent developments in the EUV reflectometry at the Advanced Light Source,” in Emerging Lithographic Technologies V, E. A. Dobisz, eds., Proc. SPIE4343, 363–373 (2001). [CrossRef]
  9. D. L. Windt, “IMD: software for modeling the optical properties of multilayer films,” Comput. Phys.12, 360–370 (1998). The software can be downloaded at http://cletus.phys.columbia.edu/∼windt/imd/ .
  10. F. R. de Boer, R. Boom, W. C. M. Mattens, A. R. Miedema, A. K. Niessen, Cohesion in Metals: Transition Metal Alloys, Vol. 1 of the Cohesion and Structure Series (North-Holland, Amsterdam, 1988).

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