1. Fraunhofer Institute of Integrated Systems and Device Technology (IISB), Schottkystrasse 10, 91058 Erlangen, Germany, phone: +49 9131 / 761 341, fax: +49 9131 / 761 360, email: berberich@iisb.fraunhofer.de
2. Fraunhofer Inst. of Integrated Syst. & Device Technol., Erlangen