Abstract

Diffraction-limited optical imaging systems for extreme ultraviolet (EUV) lithography require wave front aberrations to be limited to a fraction of the EUV wavelength. Surface figure metrology and wave front measurement at this level of accuracy represent key challenges in the development of EUV lithography. We have constructed and operated a wave front measuring interferometer at 12–13 nm wavelength. This interferometer is being used to measure the aberrations in 0.1 numerical aperture Fresnel zone plate lenses. Factors limiting the resolution and accuracy of the interferometer were studied. Substantial progress toward λ/20 wave front measurement accuracy has been made.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.