Channel Hot-Carrier degradation under static stress in short channel transistors with high-k/metal gate stacks

Channel hot-carrier (CHC) degradation in short channel transistors with a high-k gate stack processed in CMOS technology has been analysed. For short channel transistors (L < 0.15mum), the most damaging stress condition has been found to be VG = VD instead of the "classical" V_G = V_D/2 for long channel transistors. In this work, we have demonstrated that this shift is not caused by the presence of the high-k layer but due to short channel effects. Furthermore, the CHC degradation lifetime has been evaluated, revealing larger operating voltages for high-k than for SiO₂ transistors.