Structural and chemical surface analysis with EUV/XUV radiation using a broadband laser plasma source and optics system

This paper presents the development of a laser-driven plasma source for soft X-ray production in the 2-20 nm spectral range. In the experiment, a Nd:YAG laser (1064 nm, 800 mJ, 6 ns) is focused into a gas-target, that leads to the formation of a plasma, which in turn emits characteristic soft X-ray radiation. A flexible Kirkpatrick-Baez optics is developed for focusing, which provides broadband light steering due to grazing incidence reflection. The carbon-coated mirrors of this device are formed by bent silicon wafer slices, that allow continuous tuning to the desired curvatures. Structural and chemical surface analysis are shown by utilizing the described system. Results on near-edge X-ray absorption fine structure spectroscopy (NEXAFS) at the carbon K-edge are also presented. Hence, NEXAFS spectroscopy using a table-top XUV source can be considered as a highly surface sensitive fingerprint method for chemical analysis.