Fabrication of multilayer Laue lenses by a combination of mechanical polishing and focused ion beam milling (Conference Presentation)

摘要: X-ray nanoprobes with 10 nm or sub-10 spatial resolution are highly desirable for the next-generation synchrotron beamlines due to nanoscale imaging capability high sensitivity elemental, chemical and structural variations they provide. Multilayer Laue lens (MLL), a type of volume diffractive optics, was shown in theory be able focus X-rays well below 1 [1]. In addition this very resolution, it can also achieve much higher efficiency than conventional Fresnel zone plate An MLL is fabricated by sectioning thousands planar depth-graded layers nanometer thickness cross-sectionally into several tens micron thick slivers. The section critical optimum at desired energy. requirement high-aspect-ratio structure an presents enormous challenges post-growth processing, especially as aperture size (deposition thickness) keeps increasing therefore residual stress increases well. Sectioning without damaging multilayers becomes more difficult. At National Synchrotron Light Source II (NSLS-II), we have demonstrated that quality MLLs successfully combining mechanical polishing focused ion beam (FIB) milling. former removes most unwanted material latter used fine final process [2]. 53 microns made method demonstrate around focusing [3], suggesting no additional aberration introduced processing. Wedged best option focusing, because produce compared flat same [4]. However, wedged stringent (in terms both efficiency) only achieved specific one optimized presentation, I will introduce process, advantages, technical difficulties using combined FIB make MLLs. strategies tackle problems site-specific presented. [1] J. Maser, G.B. Stephenson, S. Vogt, W. Yun, A. T. Macrander, H. C. Kang, Liu, R. Conley, “Multilayer lenses high-resolution x-ray optics”, Design Microfabrication Novel X-Ray Optics II, edited Snigirev, D. Mancini, Proc. SPIE 5539, 185-194, SPIE, Bellingham, WA, (2004) [2] Yan, N. Bouet, Y. Chu, “Hard nanofocusing multilayer lenses”, Journal Physics D: Applied 47, 263001 (2014) [3] Zhou, X. Huang, E. Nazaretski, Xu, P. Cocco, K. Chiu, Brinkman “Multimodal hard approaching 10nm studies science”, Nano Futures, 2, 011001 (2018) [4] Q. Shen, G. “Takagi-Taupin description dynamical diffraction from optics large numerical aperture”, Phys. Rev. B, 76, 115438 (2007).