Impact of Plasma Etching on Device Hot Carrier and Fowler-Nordheim Reliability

MOSFET can be degraded during plasma processing due to high field induced charging, ion species diffusion and ultraviolet light bombardment. In an ``as processed´´ device, the effect of plasma charging is not seen presumably due to the annealing effects in subsequent processing steps. However, when these devices are subjected to Fowler-Nordheim (F-N) or hot carrier (HC) stress, the effect of damage is revealed. In this paper, we infer that the oxide damage which is due to plasma induced charging leaves the device more susceptible to F-N stress, while the damage due to direct plasma exposure in lightly-doped-drain (LDD) region leaves the MOSFET more susceptible to HC stress.