Fabrication of High Aspect Ratio X-ray Grating Using X-ray Lithography

Abstract

X-ray radiographic imaging technique has found applications in various fields. However, it is not enough to get clear X-ray images of samples with low absorbance, such as biological soft tissues. To resolve this problem, we proposed a method using an X-ray Talbot interferometer of X-ray phase imaging. In this X-ray Talbot interferometer, X-ray gratings were required to have a fine, high accuracy, high aspect ratio structure. Then, we have developed and succeeded high aspect ratio X-ray gratings with a pitch of 5.3 μm and a height of 30 μm using X-ray lithography technique. We discuss that the X-ray gratings having a large effective area in order to obtain imaging size of practical use in medical application. In currently study, we have fabricated the X-ray gratings with a large effective area of 60 mm×60 mm. And, we conducted X-ray phase tomography of mouse at the chest and abdominal using X-ray Talbot interferometer. As a result, we successfully observed soft tissues and high density tissues. With the aim of broadening a field of view, we try to fabricate X-ray gratings that have a pitch of below 5.3 μm and larger area of 100 mm square. This result suggests that X-ray Talbot interferometer is a novel and simple method for phase sensitive X-ray radiography.