Influence of multilayer films condenser on imaging uniformity of Schwarzschild microscope

The method for improving the uniformity of the image using multilayer films condenser is proposed. The optical structure of the condenser is designed, which concentrates 80% energy radiated by plasma to about 0.8 mm diameter range. Based on the system’s wavelength and incidence angle of light, the Mo/Si multilayer films with period of 9.64 nm and layers of 30 is designed and the coatings are deposited with magnetron sputtering. The reflectivity of optical elements at 18.2 nm is 51.7%. The grid backlit by EUV rays focused using condenser is imaging via Schwarzschild microscope on CCD. The results show that spatial resolution of 2.5 μm can be achieved in the 1.2 mm field, and the non-uniformity of image caused by the obscuration of objective is eliminated absolutely.