Xenon Plasma Focused Ion Beam Milling for Obtaining Soft X-ray Transparent Samples

• Published in: Crystals (Basel) Vol. 11; no. 5; p. 546
• Main Authors: Mayr, Sina, Finizio, Simone, Reuteler, Joakim, Stutz, Stefan, Dubs, Carsten, Weigand, Markus, Hrabec, Aleš, Raabe, Jörg, Wintz, Sebastian
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.05.2021
• Subjects: Ion beams; Microscopy; Soft x rays; soft X-ray transparency; Substrates; Thin films; transmission X-ray microscopy; X ray imagery; X ray microscopy; X-rays; Xe plasma focused ion beam; Xenon
• ISSN: 2073-4352; 2073-4352
• DOI: 10.3390/cryst11050546

We employ xenon (Xe) plasma focused ion beam (PFIB) milling to obtain soft X-ray transparent windows out of bulk samples. The use of a Xe PFIB allows for the milling of thin windows (several 100 nm thick) with areas of the order of 100 µm × 100 µm into bulk substrates. In addition, we present an approach to empirically determine the transmission level of such windows during fabrication by correlating their electron and soft X-ray transparencies. We perform scanning transmission X-ray microscopy (STXM) imaging on a sample obtained by Xe PFIB milling to demonstrate the conceptual feasibility of the technique. Our thinning approach provides a fast and simplified method for facilitating soft X-ray transmission measurements of epitaxial samples and it can be applied to a variety of different sample systems and substrates that are otherwise not accessible.