In situ x-ray mask distortion measurement by a shear interferometer

Abstract

We describe the in situ x-ray mask distortion measurement by a shear interferometer. The principle and a detailed layout of the shear interferometer are presented and the relationship between mask distortion and interference patterns is also explored. The in-plane and out-of-plane distortion of an x-ray mask during a synchrotron radiation x-ray exposure are observed on the shear interferometer. We believe this is the first reported experiment on the observation of the in situ x-ray mask distortions during synchrotron radiation exposure. We also have recorded the interferogram and measured the amount of distortions from interference fringes. The measurement of the in situ mask distortion helps us to understand the physical causes of the mask distortion.