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Title: Wavefront Metrology for EUV Projection Optics by Soft X-ray interferometry in the NewSUBARU

Journal Article · · AIP Conference Proceedings
DOI:https://doi.org/10.1063/1.2436354· OSTI ID:21049311
 [1]; ; ; ; ;  [2]
  1. Laboratory of Advanced Science and Technology for Industry, University of Hyogo, 3-1-2 Kouto, Kamigoori, Ako-gun, Hyogo 678-1205 (Japan)
  2. Extreme Ultraviolet Lithography Association (EUVA), Nishimotokousan Bldg., 3-23 Kanda Nishiki-cho, Chiyoda-ku, Tokyo 101-0054 (Japan)

Precise measurement of the wavefront errors of projection optics with 0.1 nm RMS accuracy is necessary to develop extreme ultraviolet (EUV) lithography. To accomplish this, an experimental EUV interferometer was developed and installed at the NewSUBARU SR facility, with which various types of interferometry experiments can be carried out by replacing optical parts easily. The wavefront error of a Schwarzschild-type test optics was measured by several methods. Finally, reproducibility below 0.045 nm RMS was achieved with the point diffraction interferometer (PDI) method, and the residual systematic error was reduced to 0.066 nm RMS excluding axial symmetric aberration.

OSTI ID:
21049311
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: 10.1063/1.2436354; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
Country of Publication:
United States
Language:
English