Michalska, Martyna;
Rossi, Alessandro;
Kokot, Gašper;
Macdonald, Callum M;
Cipiccia, Silvia;
Munro, Peter RT;
Olivo, Alessandro;
(2023)
Fabrication of High‐Aspect Ratio Nanogratings for Phase‐Based X‐Ray Imaging.
Advanced Functional Materials
, Article 2212660. 10.1002/adfm.202212660.
(In press).
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Abstract
Diffractive optical elements such as periodic gratings are fundamental devices in X-ray imaging – a technique that medical, material science, and security scans rely upon. Fabrication of such structures with high aspect ratios at the nanoscale creates opportunities to further advance such applications, especially in terms of relaxing X-ray source coherence requirements. This is because typical grating-based X-ray phase imaging techniques (e.g., Talbot self-imaging) require a coherence length of at least one grating period and ideally longer. In this paper, the fabrication challenges in achieving high-aspect ratio nanogratings filled with gold are addressed by a combination of laser interference and nanoimprint lithography, physical vapor deposition, metal assisted chemical etching (MACE), and electroplating. This relatively simple and cost-efficient approach is unlocked by an innovative post-MACE drying step with hexamethyldisilazane, which effectively minimizes the stiction of the nanostructures. The theoretical limits of the approach are discussed and, experimentally, X-ray nanogratings with aspect ratios >40 are demonstrated. Finally, their excellent diffractive abilities are shown when exposed to a hard (12.2 keV) monochromatic X-ray beam at a synchrotron facility, and thus potential applicability in phase-based X-ray imaging.
| Type: | Article |
|---|---|
| Title: | Fabrication of High‐Aspect Ratio Nanogratings for Phase‐Based X‐Ray Imaging |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1002/adfm.202212660 |
| Publisher version: | https://doi.org/10.1002/adfm.202212660 |
| Language: | English |
| Additional information: | © 2023 The Authors. Advanced Functional Materials published by Wiley-VCH GmbH This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. |
| Keywords: | collapse behaviors, electrodepositions, metal assisted chemical etching, nanoimprint lithography, phase-based X-ray imaging, X-ray nanogratings |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science > Dept of Electronic and Electrical Eng UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science > Dept of Mechanical Engineering UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science > Dept of Med Phys and Biomedical Eng |
| URI: | https://discovery-pp.ucl.ac.uk/id/eprint/10164219 |
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