1. Centre de Nanosciences et de Nanotechnologies (CNRS—Université Paris-Sud), Avenue de la Vauve, 91120 Palaiseau, France
2. Raith GmbH, Konrad-Adenauer-Allee 8, 44263 Dortmund, Germany
3. Helmholtz-Zentrum Dresden-Rossendorf, Institute of Ion Beam Physics and Materials Research, Bautzner Landstrasse 400, 01328 Dresden, Germany