Design, fabrication, and characterization of high-efficiency extreme-ultraviolet diffusers

As the development of extreme-ultraviolet (EUV) lithography progresses, interest grows in the extension of traditional optical components to the EUV regime. Because of the strong absorption of EUV by most materials and because of its extremely short wavelength, however, it is difficult to implement many components that are commonplace in the longer-wavelength regimes. One such example is the diffuser that is often implemented with ordinary ground glass in the visible light regime. Here we demonstrate the fabrication of reflective EUV diffusers with high efficiency within a controllable bandwidth. Using these techniques, we have fabricated diffusers with efficiencies exceeding 10% within a moderate angular single-sided bandwidth of approximately 0.06 rad.