8 November 2000 Present status of the ASET at-wavelength phase-shifting point diffraction interferometer
Author Affiliations +
The precise alignment of Extreme Ultra-Violet Lithography (EUVL) imaging system is necessary in order to achieve diffraction-limited performance. Interferometric testing at the exposure wavelength is needed to ensure proper alignment and to achieve an acceptable final wavefront. We have built a prototype at-wavelength interferometer at the NewSUBARU facility. This interferometer is a phase-shifting point diffraction interferometer (PS/PDI) testing specially constructed Schwarzschild optics. Preliminary experiments using visible light were performed in order to learn this PS/PDI. The Schwarzschild optics were aligned using visible wavefront measurements with the interferometer. The precision of the visible measurements was evaluated. Experiments using EUV radiation have been started.
© (2000) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Katsumi Sugisaki, Yucong Zhu, Yoshio Gomei, Masahito Niibe, Takeo Watanabe, Hiroo Kinoshita, "Present status of the ASET at-wavelength phase-shifting point diffraction interferometer", Proc. SPIE 4146, Soft X-Ray and EUV Imaging Systems, (8 November 2000); doi: 10.1117/12.406675; https://doi.org/10.1117/12.406675

Back to Top