In recent years technological developments in the area of extreme ultraviolet lithography (EUVL) have
experienced great improvements. So far, there are already intense light sources based on discharge or laser
plasmas, light guiding and imaging optics, and detection equipment. Currently, the application of EUV
radiation apart from microlithography, such as metrology, high-resolution microscopy, or surface analysis
comes more and more into focus. One objective is to make use of the strong interaction between soft x-ray
radiation and matter for surface-near probing, modification or structuring techniques.
In this contribution, along with first applications, we present a setup capable of generating and focusing
EUV radiation, utilizing a table-top laser-induced plasma source. In order to obtain a focal spot of high
EUV fluence, a modified Schwarzschild objective consisting of two spherical mirrors with Mo/Si
multilayer coatings is adapted to this source. By demagnified (10x) imaging of the source an EUV spot of
30 μm diameter with an energy density of ~100 mJ/cm2 is generated.
We present first applications of this integrated source and optics system, demonstrating its potential for
high-resolution modification and structuring of solid state surfaces. As an example, direct photo-etching of
PMMA with resolution up to 130 nm will be displayed. In this context, the influence of so called "out-ofband
radiation" to the etching depth of PMMA was determined by an EUV diffraction experiment.
Moreover, the fragmentation of PMMA under influence of low-energy EUV radiation was investigated. For
this reason the reflectivity of EUV irradiated PMMA was measured around the carbon K-edge using a
table-top XUV reflectometer. This modified NEXAFS (near-edge x-ray absorption fine structure) setup in
combination with FTIR (fourier transformation infrared) spectroscopy was used to identify changes in the
chemical structure of the irradiated PMMA.