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We have produced diffraction gratings for obtaining high resolution X-ray phase imaging, such as X-ray Talbot interferometer. These diffraction gratings were required to have a fine, high accuracy, high aspect ratio structure. Therefore, we decided to use the X-rays lithography technique that used synchrotron radiation of the directivity for a manufacture process. The accuracy of the completed structure depends largely on the accuracy of the X-ray mask. In our group, a resin material is conventionally used for the membrane of large X-ray masks. However, X-ray masks comprising a resin membrane have the disadvantage that, after several cycles of X-ray exposure, they crease and sag due to X-ray-derived heat. As a substitute for the conventional resin membrane, we experimentally fabricated a new X-ray mask using a carbon wafer membrane. The newly fabricated X-ray mask was subjected to X-ray exposure experiment. We succeeded in making the structure body which was almost shape. And the experimental results verified that the new mask did not deteriorate even when used repeatedly, demonstrating that it was highly durable.

X-ray radiographic imaging techniques have been applied in many fields. Previously we proposed a method for X-ray phase imaging using X-ray Talbot interferometry which requires the use of X-ray gratings. In this work, we fabricated the X-ray gratings needed for X-ray Talbot interferometry using an X-ray lithography technique. For X-ray lithography the accuracy of the fabricated structure depends largely on the accuracy of the X-ray mask. Conventionally a resin material is used for the support membrane for large area X-ray masks. However, resin membranes have the disadvantage that they can sag after several cycles of X-ray exposure due to the heat generated by the X-rays. For our new proposal we used thin carbon wafers for the membrane material because carbon has an extremely small thermal expansion coefficient. This new type of X-ray mask is very easy to process, and it is expected that it will lead to more precise X-ray masks. We fabricated carbon membrane X-ray masks on 6 inch wafers with a 1:1 line-to-space ratio and a pitch of 5.3 μm, covering a large effective area of 100 × 100 mm2.

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