1 October 2009 Development progress of optics for extreme ultraviolet lithography at Nikon
Author Affiliations +
J. of Micro/Nanolithography, MEMS, and MOEMS, 8(4), 041507 (2009). doi:10.1117/1.3238522
The full-field extreme ultraviolet (EUV) exposure tool named EUV1 is integrated and exposure experiments are started with a numerical aperture of the projection optics of 0.25, and conventional partial coherent illumination with a coherence factor of 0.8. 32-nm elbow patterns are resolved in a full arc field in static exposure. In a central area, 25-nm line-and-space patterns are resolved. In scanning exposure, 32-nm line-and-space patterns are successfully exposed on a full wafer. Wavefront error of the projection optics is improved to 0.4-nm rms. Flare impact on imaging is clarified, dependent on flare evaluation using the Kirk test. Resolution enhancement technology (RET) fly-eye mirrors and reflection-type spectral purity filters (SPFs) are investigated to increase throughput. High-NA projection optics design is also reviewed.
Katsuhiko Murakami, Tetsuya Oshino, Hiroyuki Kondo, Masayuki Shiraishi, Hiroshi Chiba, Hideki Komatsuda, Kazushi Nomura, Jin Nishikawa, "Development progress of optics for extreme ultraviolet lithography at Nikon," Journal of Micro/Nanolithography, MEMS, and MOEMS 8(4), 041507 (1 October 2009). https://doi.org/10.1117/1.3238522


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