[1] EME/CEMIC, Dept. of Electronics Assoc. Univ. to CNM-CSIC, Microlectron. Eng. Ctr., C/Marti i Franques 1, 08028 Barcelona, Spain
[2] Laboratoire Physique de la Matière, Institut National des Sciencies Appliquées, Bâtiment 502, 20 Avenue Albert Einstein, 69621 Villeurbanne Cedex, France
[3] Mechanical Reliability and Micro Materials Department, Fraunhofer Institut Zuverlässigkeit und Mikrointegration, Gustav-Meyer Allée 25, D-13355 Berlin, Germany
[4] Tel.: +34-9-3402-1140, Spain