Annealing of plasma charging damage and residual degradation in MOS transistors

This paper presents data on an important mode of plasma-induced damage, namely residual charging damage in MOS devices. The antenna dependence of residual degradation is observed in the device threshold voltage, transconductance, and sub-threshold behaviour. The residual damage is observed due to incomplete annealing of oxide charge and interface states, and its level depends on the intensity of plasma charging stress and on the gate oxide thickness. Auxiliary experiments with electrical stressing of NMOS devices and their subsequent anneal confirm the dependence of residual damage on the degree and polarity of previous degradation and indicate the importance of the annealing conditions