Fabrication of Diffraction Grating with High Aspect Ratio Using X-ray Lithography Technique for X-ray Phase Imaging

Abstract

The use of conventional X-ray radiography is limited due to weak absorption. This problem is resolved by using phase-sensitive imaging methods to improve the contrast, such as X-ray Talbot interferometry. With a spatially coherent light source and two diffraction gratings for Talbot interferometry, we measured the phase change differential. Using this technique, diffraction gratings were designed to have a fine high-accuracy high-aspect-ratio structure. Then, we fabricated a high-aspect-ratio diffraction grating using a deep X-ray lithography technique. A diffraction grating with a period of 8 µm and a height of about 30 µm was fabricated. This diffraction grating can be used for X-ray phase imaging for X-ray Talbot interferometry.