1. RWTH Aachen University, Faculty of Electrical Engineering and Information Technology, Chair of Electronic Devices, Otto-Blumenthal-Strasse 2, 52074 Aachen, Germany
2. AMO GmbH, Advanced Microelectronic Center Aachen, Otto-Blumenthal-Strasse 25, 52074 Aachen, Germany
3. University of Siegen, Department of Chemistry and Biology, Adolf-Reichwein Strasse 2, 57076 Siegen, Germany
4. RWTH Aachen University, Central Facility for Electron Microscopy, Ahornstrasse 55, 52074 Aachen, Germany
5. Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Research Centre Jülich, 52425 Jülich, Germany