Share Email Print
cover

Proceedings Paper

Comparison of EUV interferometry methods in EUVA project
Format Member Price Non-Member Price
PDF $14.40 $18.00
cover GOOD NEWS! Your organization subscribes to the SPIE Digital Library. You may be able to download this paper for free. Check Access

Paper Abstract

We are developing an at-wavelength interferometer for EUV lithography systems. The goal is the measurement of the wavefront aberration for a six-aspherical mirror projection optic. Among the six methods that EEI can measure, we selected CGLSI and PDI for comparison. PDI is a method well-known for its high accuracy, while CGLSI is a simple measurement method. Our comparison of PDI and CGLSI methods, verified the precision of the CGLSI method. The results show a difference between the methods of 0.33nm RMS for terms Z5-36. CGLSI measurement wavefronts agree well with PDI for terms Z5-36, and it is thought of as a promising method. Using FFT analysis, we estimated and then removed the impact of flare on the wavefront. As a result of having removed the influence of flare, the difference between CGLSI and PDI improved to only 0.26nm RMS in Zernike 5-36 terms. We executed PDI wavefront retrieval with FFT, which has not been used till now. By confirming that the difference between methods using FFT and Phase shift is 0.035nm RMS for terms Z5-36, we have proven that PDI wavefront analysis with FFT is possible.

Paper Details

Date Published: 6 May 2005
PDF: 8 pages
Proc. SPIE 5751, Emerging Lithographic Technologies IX, (6 May 2005); doi: 10.1117/12.600468
Show Author Affiliations
Seima Kato, Canon/Extreme Ultraviolet Lithography System Development Association (Japan)
Chidane Ouchi, Canon/Extreme Ultraviolet Lithography System Development Association (Japan)
Masanobu Hasegawa, Canon/Extreme Ultraviolet Lithography System Development Association (Japan)
Akiyoshi Suzuki, Canon/Extreme Ultraviolet Lithography System Development Association (Japan)
Takayuki Hasegawa, Canon/Extreme Ultraviolet Lithography System Development Association (Japan)
Katsumi Sugisaki, Nikon/Extreme Ultraviolet Lithography System Development Association (Japan)
Masashi Okada, Nikon/Extreme Ultraviolet Lithography System Development Association (Japan)
Yucong Zhu, Nikon/Extreme Ultraviolet Lithography System Development Association (Japan)
Katsuhiko Murakami, Nikon/Extreme Ultraviolet Lithography System Development Association (Japan)
Jun Saito, Nikon/Extreme Ultraviolet Lithography System Development Association (Japan)
Masahito Niibe, Univ. of Hyogo (Japan)
Mitsuo Takeda, Univ. of Electro-Communications (Japan)


Published in SPIE Proceedings Vol. 5751:
Emerging Lithographic Technologies IX
R. Scott Mackay, Editor(s)

© SPIE. Terms of Use
Back to Top