MEDSI2016 - List of Authors (Sunayama, R.)

Paper	Title	Page
TUPE22	Low-Order Aberrations Correction of Extreme Ultraviolet Imaging Objective with Deformable Multilayer Mirrors	213
	M. Toyoda, R. Sunayama, M. Yanagihara Tohoku University, Institute of Multidisciplinary Research for Advanced Materials, Sendai, Japan
	For at-wavelength observation of a lithography mask, recently, we proposed an EUV microscope consisting of multilayer-mirror objective (operating wavelength: 13.5 nm, numerical aperture: 0.25). To provide diffraction-limited spatial resolution below 30 nm, reduction of wave aberrations of low order, i.e., spherical aberration, coma, and astigmatism, should be key technical challenge for the microscope. In this paper, firstly, we describe detail of optical design and instrumentation of the point diffraction interferometer (PDI), so as to provide high enough sensing accuracy of 100 pm, which would be required for an optical axis adjustment of the EUV objective. Next, experimental results of wave front correction on the EUV objective are reported. We corrected spherical aberration and coma by precisely aligning an optical axis of the mirrors, while effects of astigmatism were also minimized with a figure-deformable mirror which can control radius of curvature in two mutually orthogonal directions. We confirmed that these low order terms should be less than 0.3 nm RMS.
	Poster TUPE22 [3.217 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-MEDSI2016-TUPE22
About •	paper received ※ 06 September 2016 paper accepted ※ 22 September 2016 issue date ※ 22 June 2017
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Low-Order Aberrations Correction of Extreme Ultraviolet Imaging Objective with Deformable Multilayer Mirrors

213

M. Toyoda, R. Sunayama, M. Yanagihara
Tohoku University, Institute of Multidisciplinary Research for Advanced Materials, Sendai, Japan

For at-wavelength observation of a lithography mask, recently, we proposed an EUV microscope consisting of multilayer-mirror objective (operating wavelength: 13.5 nm, numerical aperture: 0.25). To provide diffraction-limited spatial resolution below 30 nm, reduction of wave aberrations of low order, i.e., spherical aberration, coma, and astigmatism, should be key technical challenge for the microscope. In this paper, firstly, we describe detail of optical design and instrumentation of the point diffraction interferometer (PDI), so as to provide high enough sensing accuracy of 100 pm, which would be required for an optical axis adjustment of the EUV objective. Next, experimental results of wave front correction on the EUV objective are reported. We corrected spherical aberration and coma by precisely aligning an optical axis of the mirrors, while effects of astigmatism were also minimized with a figure-deformable mirror which can control radius of curvature in two mutually orthogonal directions. We confirmed that these low order terms should be less than 0.3 nm RMS.

Poster TUPE22 [3.217 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-MEDSI2016-TUPE22

About •

paper received ※ 06 September 2016 paper accepted ※ 22 September 2016 issue date ※ 22 June 2017

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)