[1] Aix Marseille Univ, F-13384 Marseille 13, France
[2] CNRS, UMR CNRS 6242, Inst Mat Microelect & Nanosci Provence IM2NP, F-13384 Marseille 13, France
[3] JINR, Dzhelepov Lab Nucl Problems, Dubna 141980, Moscow Region, Russia
[4] STMicroelectronics, F-38926 Crolles, France