Development of an EUV and OoB Reflectometer at NewSUBARU synchrotron light facility

摘要

We develop the monochromator and reflectometer to evaluate optical properties of an EUV optics and EUV resist at the BL3 beamline in NewSUBARU synchrotron light facility. This system supports from the EUV to out-of-band (OoB) energy region which corresponds at the wavelength region from 10 to 300 nm. This monochromator design is collimatedplane- grating monochromator with the constant-line-spaced grating of 1,000 lines/mm. The deviation angles are 150° for EUV region and 120° for the OoB region. The absorption edges of Si, Al and Mg filters are clearly observed using this system. The beam size on a sample position is 0.6(H) × 0.3(V) mm~2. We measured the EUV and OoB reflectance of a Mo/Si multilayer, an absorber TaN on the multilayer, and glass substrate which is used as a substrate of the black border on an EUV mask. The OoB reflectance of glass substrate was over 20%, which would affect to the EUV imaging performance in an EUV exposure tool. In addition, the OoB reflectance of the Mo/Si multilayer was quite different from that in calculation. Thus, it is important for evaluate the actual OoB reflectance of an EUV optics.