Characterisation of engineered defects in extreme ultraviolet mirror substrates using lab-scale extreme ultraviolet reflection ptychography.

Autor: Lu H; Zepler Institute(1), University of Southampton, Southampton SO17 1BJ, UK; Experimental Physics of EUV, JARA-FIT, RWTH Aachen University, 52074 Aachen, Germany., Odstrčil M; Zepler Institute(1), University of Southampton, Southampton SO17 1BJ, UK; Experimental Physics of EUV, JARA-FIT, RWTH Aachen University, 52074 Aachen, Germany., Pooley C; Zepler Institute(1), University of Southampton, Southampton SO17 1BJ, UK., Biller J; Experimental Physics of EUV, JARA-FIT, RWTH Aachen University, 52074 Aachen, Germany; Peter Grünberg Institut (PGI-9), JARA-FIT, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany., Mebonia M; Experimental Physics of EUV, JARA-FIT, RWTH Aachen University, 52074 Aachen, Germany; Peter Grünberg Institut (PGI-9), JARA-FIT, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany., He G; Department of Engineering Science, University of Oxford, Oxford OX1 3PJ, UK., Praeger M; Zepler Institute(1), University of Southampton, Southampton SO17 1BJ, UK., Juschkin L; Experimental Physics of EUV, JARA-FIT, RWTH Aachen University, 52074 Aachen, Germany; Peter Grünberg Institut (PGI-9), JARA-FIT, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany., Frey J; Department of Chemistry, University of Southampton, Southampton SO17 1BJ, UK., Brocklesby W; Zepler Institute(1), University of Southampton, Southampton SO17 1BJ, UK. Electronic address: wsb@orc.soton.ac.uk.
Jazyk: angličtina
Zdroj: Ultramicroscopy [Ultramicroscopy] 2023 Jul; Vol. 249, pp. 113720. Date of Electronic Publication: 2023 Mar 21.
DOI: 10.1016/j.ultramic.2023.113720
Abstrakt: Ptychography is a lensless imaging technique that is aberration-free and capable of imaging both the amplitude and the phase of radiation reflected or transmitted from an object using iterative algorithms. Working with extreme ultraviolet (EUV) light, ptychography can provide better resolution than conventional optical microscopy and deeper penetration than scanning electron microscope. As a compact lab-scale EUV light sources, high harmonic generation meets the high coherence requirement of ptychography and gives more flexibilities in both budget and experimental time compared to synchrotrons. The ability to measure phase makes reflection-mode ptychography a good choice for characterising both the surface topography and the internal structural changes in EUV multilayer mirrors. This paper describes the use of reflection-mode ptychography with a lab-scale high harmonic generation based EUV light source to perform quantitative measurement of the amplitude and phase reflection from EUV multilayer mirrors with engineered substrate defects. Using EUV light at 29.6nm from a tabletop high harmonic generation light source, a lateral resolution down to ∼88nm and a phase resolution of 0.08rad (equivalent to topographic height variation of 0.27nm) are achieved. The effect of surface distortion and roughness on EUV reflectivity is compared to topographic properties of the mirror defects measured using both atomic force microscopy and scanning transmission electron microscopy. Modelling of reflection properties from multilayer mirrors is used to predict the potential of a combination of on-resonance, actinic ptychographic imaging at 13.5nm and atomic force microscopy for characterising the changes in multilayered structures.
Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2023. Published by Elsevier B.V.)
Databáze: MEDLINE
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