Microfocus EUV tube for at-wavelength reflectometry

Reliable and compact extreme ultraviolet (EUV) laboratory sources are strongly required for in-house characterization of optical components and for the precise calibration of EUV diagnostic instruments. The EUV tube, based on the transfer of advanced microfocus x-ray tube technology into the EUV spectral range around 13.5 nm, is an important tool for these applications. Great benefits of this source are a compact and flexible design, debris-free operation, and high temporal and spatial long-term stability. Detailed characteristics of the source performance are reported and different examples for at-wavelength metrology are presented.