Development of a synchrotron-based EUV microscope for actinic mask inspection

We have been developing an EUV microscope for actinic mask inspection based on a bending magnet beamline in Shanghai Synchrotron Radiation Facility (SSRF), China. The new microscope has a Fourier synthesis illuminator via scanning a Fresnel Zone Plate (FZP), and an off-axis FZP for imaging, which provides a theoretical spatial resolution of 33nm. In this work, we will present the optical and mechanical design of the microscope. We have validated the design and performance of the microscope by using a visible laser. We expect to have the microscope installed in SSRF and obtain preliminary results using 13.5nm EUV by the end of this year.