A design study for synchrotron-based high-numerical-aperture scanning illuminators

✍ Scribed by Patrick P Naulleau; Paul E Denham; Brian Hoef; Senajith Rekawa

• Publisher: Elsevier Science
• Year: 2004
• Tongue: English
• Weight: 311 KB
• Volume: 234
• Category: Article
• ISSN: 0030-4018
• DOI: 10.1016/j.optcom.2004.02.021

✦ Synopsis

Scanning illumination systems provide for a powerful and flexible means of controlling illumination coherence properties. In these systems, the desired illumination divergence is synthesized through a scanning process. This method has recently been used at extreme ultraviolet (EUV) wavelengths to implement a programmable pupil fill microfield exposure system employed to lithographically characterize a 0.1-numerical aperture (NA) a-class EUV stepper optic. The specifics of the implementation used in that case, however, make it difficult to directly extend the implementation to higher NA optics. Here we present scanning illuminator configurations suitable for implementing high-NA lithography capabilities at a synchrotron beamline. In particular we consider the application to a 0.3-NA EUV optic with a design field of view of 1 Â 3 mm at the object plane.