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Murano T, Koshiya S, Koike M, Hatano T, Pirozhkov AS, Kakio T, Hayashi N, Oue Y, Konishi K, Nagano T, Kondo K, Terauchi M. Laminar-type gratings overcoated with carbon-based materials to enhance analytical sensitivity of flat-field emission spectrograph in the VUV region. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2023; 94:125113. [PMID: 38156956 DOI: 10.1063/5.0176783] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2023] [Accepted: 12/04/2023] [Indexed: 01/03/2024]
Abstract
Laminar-type spherical diffraction gratings overcoated with carbon-based materials were designed, fabricated, and evaluated for the purpose of enhancing the analytical sensitivity of the flat-field spectrograph in a vacuum ultraviolet region of 35-110 eV. As the design benchmark for numerical calculations, diffraction efficiency (DE) and spectral flux, which are defined by the product of the DE and numerical aperture and correlate with the analytical sensitivity of the spectrograph, were used. To simplify the feasibility study on the overcoating effects, we assumed a laminar-type grating having a grating constant of 1/1000 mm and coated with a Au layer of 30.0 nm thickness and an incidence angle of 84.0°. The optimized groove depth and duty ratio were 30.0 nm and 0.3, respectively. In addition, the optimum thicknesses of the overcoating layer were 44, 46, 24, and 30 nm for B4C, C, diamond-like-carbon, and SiC, respectively. Based on these results, we have fabricated a varied-line-spacing holographic grating overcoated with B4C with a thickness of 47 nm. For the experimental evaluation, we used the light source of Mg-L and Al-L emissions excited by the electron beam generated from an electron microscope, an objective flat-field spectrograph, and a CCD imaging detector. The experimental results showed that the spectrograph employing a new grating overcoated with the B4C layer indicated almost the same spectral resolution and 2.9-4.2 times higher analytical sensitivity compared with those obtained with a previously designed Au-coated grating having a grating constant of 1/1200 mm and used at an incidence of 86.0°.
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Affiliation(s)
- T Murano
- SA Business Unit, JEOL Ltd., Akishima, Tokyo 196-8558, Japan
| | - S Koshiya
- SA Business Unit, JEOL Ltd., Akishima, Tokyo 196-8558, Japan
| | - M Koike
- Kansai Institute for Photon Science, Foundational Quantum Technology Research Directorate, National Institutes for Quantum Science and Technology, Kyoto 619-0215, Japan
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai, Miyagi 980-8577, Japan
- Department of Chemical Biology, Graduate School of Engineering, Osaka Metropolitan University, Sumiyoshi-ku, Osaka 558-8585, Japan
| | - T Hatano
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai, Miyagi 980-8577, Japan
| | - A S Pirozhkov
- Kansai Institute for Photon Science, Foundational Quantum Technology Research Directorate, National Institutes for Quantum Science and Technology, Kyoto 619-0215, Japan
| | - T Kakio
- Device Department, Shimadzu Corp., Nakagyo-ku, Kyoto 604-8511, Japan
| | - N Hayashi
- Device Department, Shimadzu Corp., Nakagyo-ku, Kyoto 604-8511, Japan
| | - Y Oue
- Device Department, Shimadzu Corp., Nakagyo-ku, Kyoto 604-8511, Japan
| | - K Konishi
- Device Department, Shimadzu Corp., Nakagyo-ku, Kyoto 604-8511, Japan
| | - T Nagano
- Device Department, Shimadzu Corp., Nakagyo-ku, Kyoto 604-8511, Japan
| | - K Kondo
- Kansai Institute for Photon Science, Foundational Quantum Technology Research Directorate, National Institutes for Quantum Science and Technology, Kyoto 619-0215, Japan
| | - M Terauchi
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai, Miyagi 980-8577, Japan
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Garoli D, Frassetto F, Monaco G, Nicolosi P, Pelizzo MG, Rigato F, Rigato V, Giglia A, Nannarone S. Reflectance measurements and optical constants in the extreme ultraviolet-vacuum ultraviolet regions for SiC with a different C/Si ratio. APPLIED OPTICS 2006; 45:5642-50. [PMID: 16855662 DOI: 10.1364/ao.45.005642] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Reflectance versus incidence angle measurements have been performed from 5 to 152 nm on samples of SiC with a different C/Si ratio deposited with rf magnetron sputtering. The optical constants of the material at different wavelengths have been determined by using a curve-fitting technique of reflectance values versus incidence angle. Complementary measurements of the incident beam polarization, film thickness, surface roughness, and stoichiometry were performed to complete the analysis of the samples.
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Affiliation(s)
- Denis Garoli
- Department of Information Engineering, University of Padua, Via Gradenigo 6/b, 35131 Padua, Italy.
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