At-wavelength interferometry for extreme ultraviolet lithography
| Autor: | Hector Medecki, Jeffrey Bokor, Alastair A. MacDowell, David Attwood, Phillip J. Batson, Sang Hun Lee, Kenneth A. Goldberg, Edita Tejnil, Paul Denham |
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| Rok vydání: | 1997 |
| Předmět: |
Physics
business.industry Extreme ultraviolet lithography Astrophysics::Instrumentation and Methods for Astrophysics General Engineering Physics::Optics Numerical aperture law.invention Point diffraction interferometer Root mean square Interferometry Wavelength Optics law Extreme ultraviolet Optoelectronics Photolithography business |
| Zdroj: | Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures. 15:2455 |
| ISSN: | 0734-211X |
| Popis: | A phase-shifting point diffraction interferometer is being developed for at-wavelength testing of extreme ultraviolet lithographic optical systems. The interferometer was implemented to characterize the aberrations of a 10× Schwarzschild multilayer-coated reflective optical system at the operational wavelength of 13.4 nm. Chromatic vignetting effects are observed and they demonstrate the influence of multilayer coatings on the wave front. A subaperture of the optic with a numerical aperture of 0.07 was measured as having a wave front error of 0.090 wave (1.21 nm) root mean square (rms) at a 13.4 nm wavelength. The wave front measurements indicate measurement repeatability of ±0.008 wave (±0.11 nm) rms. Image calculations that include the effects of the measured aberrations are consistent with imaging performed with the 10× Schwarzschild optic on an extreme ultraviolet exposure tool. |
| Databáze: | OpenAIRE |
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