Fabrication of High?Aspect Ratio Nanogratings for Phase?Based X?Ray Imaging

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 structures with high aspect ratios at the nanoscale creates opportunities to further advance applications, especially terms relaxing source coherence requirements. This is because typical grating-based phase techniques (e.g., Talbot self-imaging) require length least one grating period ideally longer. In this paper, fabrication challenges achieving high-aspect ratio nanogratings filled gold addressed by combination laser interference nanoimprint lithography, physical vapor deposition, metal assisted chemical etching (MACE), electroplating. relatively simple cost-efficient approach unlocked an innovative post-MACE drying step hexamethyldisilazane, which effectively minimizes stiction nanostructures. The theoretical limits discussed and, experimentally, >40 demonstrated. Finally, their excellent diffractive abilities shown when exposed hard (12.2 keV) monochromatic beam synchrotron facility, thus potential applicability phase-based imaging.