[1] Univ Stuttgart, Inst Robust Power Semicond Syst, Stuttgart, Germany
[2] Radiometer Phys GmbH, Meckenheim, Germany
[3] Fraunhofer Inst Appl Solid State Phys, Freiburg, Germany
[4] Univ Stuttgart, Inst Modelling Hydraul & Environm Syst, Stuttgart, Germany
[5] Max Planck Inst Solid State Res, Stuttgart, Germany