Abstract: A stationary exit window for an X-ray lithography beamline having a shape and thickness such that the exit window can withstand a pressure differential of 14.7 psi and allows an X-ray beam as passed through the window to have X-rays above and below a desired energy band substantially attenuated. The exit window includes a thin material having a window section disposed within an opening of a frame. The window section has a cylindrical sector shape to capitalize on the pressure load bearing ability of hoop stress to keep the thin material from tearing apart. A method of scanning the X-ray beam through a stationary exit window and onto an exposure field on a wafer is also disclosed.