A study of effects of plasma-induced charging damage on hot-carrier lifetime using pre-stressed data

The hot-carrier response of a device is an accurate measure of the gate oxide integrity. Differences in hot-carrier lifetimes for plasma etched devices depend on the tunneling current (and the resultant changes in charge trap density) in the oxide during etch. The pre-stress device parameters are a strong function of the active charge traps in the oxide. Thus, pre-stress device parameters can be used to estimate the post-hot-carrier-stress response of plasma-etched devices. Our study, using LDD MOSFETs, shows a linear relationship between pre-stress and post-stress device characteristics. Thus, post-stress behavior of plasma-etched devices can be predicted from pre-stress data, simplifying wafer-level reliability and device characterization.