Initial results from an extreme ultraviolet interferometer operating with a compact laser plasma source
- Advanced Electronic Manufacturing Dept., Sandia National Laboratories, Livermore, California 94550-0969 (United States)
- Department of Electrical Engineering and Computer Science, University of California-Berkeley, California 94720 (United States)
- Optics and Exploratory Technologies Department, Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States)
- Lucent Technologies, Bell Laboratories, 510E Brookhaven Lab, Upton, New York 11973 (United States)
When characterizing an extreme ultraviolet (EUV) lithographic optical system, visible light interferometry is limited to measuring wave front aberration caused by surface figure error while failing to measure wave front errors induced by the multilayer coatings. This necessitates the development of interferometric techniques at an EUV camera{close_quote}s operational wavelength (at-wavelength testing), which is typically around 13 nm. While a laser plasma source (LPS) is being developed as a lithography production source, it has generally been considered that only an undulator located at a synchrotron facility can provide the necessary laserlike point source brightness for EUV interferometry. Although an undulator-based approach has been successfully demonstrated, it would be advantageous to test a camera in its operational configuration with an LPS. We are developing the latter approach by utilizing extended source size schemes to provide usable flux throughput. A slit mounted at the source plane can provide the necessary spatial coherence for lateral shearing interferometry. Initial results from an EUV lateral shear interferometer based on the Ronchi test are presented. {copyright} {ital 1996 American Vacuum Society}
- OSTI ID:
- 399796
- Report Number(s):
- CONF-960582--
- Journal Information:
- Journal of Vacuum Science and Technology. B, Microelectronics Processing and Phenomena, Journal Name: Journal of Vacuum Science and Technology. B, Microelectronics Processing and Phenomena Journal Issue: 6 Vol. 14; ISSN JVTBD9; ISSN 0734-211X
- Country of Publication:
- United States
- Language:
- English
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