Interaction of EUV radiation with surfaces


The activities are focused on the following main topics:

  1. Analysis of surfaces and thin film systems by multi-angle spectroscopic EUV-Reflectometry (Contact person Lukas Bahrenberg)
  2. High-Intensity EUV irradiation of surfaces and membranes (Contact person Serhiy Danylyuk)

Analysis of surfaces and thin film systems by multi-angle spectroscopic EUV-reflectometry

Spectroscopic EUV reflectometer Copyright: Fraunhofer ILT Spectroscopic EUV reflectometer (left) Inside of the EUV reflectometer (right).

The research concentrates on the development of table-top EUV reflectometry and of the corresponding modelling software. Using measured multi-angle spectroscopic reflectivity data, one can not only obtain information about thicknesses of unknown layer systems, but also other material parameters, such as roughness and density. The presence of absorption edges in this wavelength region (for example Si L‑edge at 12.4 nanometer) further enhances the chemical sensitivity due to near edge absorption fine structures (NEXAFS). Together with high possible throughput, this makes this non-destructive metrology technique attractive for quality-control applications in semiconductor industry and research. Achieving a maximum precision and unambiguity of the results is the main research task in this topic.


High-Intensity EUV irradiation of surfaces and membranes

Grazing incidence EUV collector Copyright: Fraunhofer ILT Grazing incidence EUV collector used for the focusing .

Life-time investigations for EUV optical components are becoming increasingly important, as the output power of industrial EUV sources continues to grow. Within this topic, modifications of material properties by high-intensity EUV irradiation are studied. Using highly focused EUV radiation with 13.5 nanometer wavelength a radiation-induced degradation of scintillators, thin films, EUV filters and pellicle materials can be investigated.


Selected Publications

L. Bahrenberg, S. Danylyuk, S. Brose, I. Pollentier, M. Timmermans, E. Gallagher, J. Stollenwerk, P. Loosen, "Characterization of pellicle membranes by lab-based spectroscopic reflectance and transmittance measurements in the extreme ultraviolet," Proc. SPIE 10450, International Conference on Extreme Ultraviolet Lithography 2017, 104501L (2017).

S. Danylyuk, S. Herbert, P. Loosen, R. Lebert, A. Schäfer, J. Schubert, M. Tryus, L. Juschkin, “Multi-angle spectroscopic extreme ultraviolet reflectometry for analysis of thin films and interfaces," Phys. Status Solidi C 12(3), pp.318-322 (2015).

M. Banyay, L. Juschkin, E. Bersch, D. Franca, M. Liehr, A. Diebold, “Cross characterization of ultrathin interlayers in HfO2 high-k stacks by angle resolved x-ray photoelectron spectroscopy, medium energy ion scattering, and grazing incidence extreme ultraviolet reflectometry," J. Vac. Sci. Tech. A 30(4), 041506 (2012).

M. Banyay, L. Juschkin, “Spectral sharpening algorithm for a polychromatic reflectometer in the extreme ultraviolet," Appl. Spectroscopy. 64(4), pp. 401-408 (2010).

M. Banyay, L. Juschkin, “Table-top reflectometer in the extreme ultraviolet for surface sensitive analysis," Appl. Phys. Lett. 94(6), 063507 (2009).

M. Banyay, L. Juschkin, T. Bücker, P. Loosen, A. Bayer, F. Barkusky, S. Döring, C. Peth, K. Mann, H. Blaschke, I. Balasa, D. Ristau, “XUV metrology: Surface analysis with extreme ultraviolet radiation," Proc. SPIE 7361, 736113 (2009).