Sub-diffraction-limited multilayer coatings for the 0.3 numerical aperture micro-exposure tool for extreme ultraviolet lithography
Multilayer coating results are discussed for the primary and secondarymirrors of the micro-exposure tool (MET): a 0.30 NA lithographici maging system with a 200 {mu}m x 600 {mu}m field of view at the wafer plane, operating in the extreme ultraviolet (EUV) region at an illumination wavelength around 13.4 nm. Mo/Simultilayers were deposited by DC-magnetron sputtering on large-area, curved METcamera substrates. A velocity modulation technique was implemented to consistentlyachieve multilayer thickness profiles with added figure errors below0.1 nm rmsdemonstrating sub-diffraction-limited performance, as defined by the classical diffraction limit of Rayleigh (0.25 waves peak to valley) or Marechal (0.07 waves rms). This work is an experimental demonstration of sub-diffraction-limited multilayer coatings for high-NA EUV imaging systems, which resulted in the highest resolution microfield EUV images to date.
- OSTI ID:
- 20929751
- Journal Information:
- Applied Optics, Journal Name: Applied Optics Journal Issue: 18 Vol. 46; ISSN 0003-6935; ISSN APOPAI
- Country of Publication:
- United States
- Language:
- English
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