1. Integrated Systems and Photonics, Department of Electrical and Information Engineering, Kiel University, Kaiserstraße 2, 24143 Kiel, Germany
2. Fraunhofer Institute for Silicon Technology ISIT, 25524 Itzehoe, Germany
3. Kiel Nano, Surface and Interface Science (KiNSIS), Kiel University, Kaiserstraße 2, 24143 Kiel, Germany
4. Microsystem Materials, Department of Materials Science, Kiel University, Kaiserstraße 2, 24143 Kiel, Germany