HOT-CARRIER-INDUCED ELECTRON-MOBILITY AND SERIES RESISTANCE DEGRADATION IN LDD NMOSFETS

The mobility and the series resistant degradation of LDD NMOSFET's were determined independently for the first time. Three device structures with different styles of the drain engineering: 1) the modestly doped LDD; 2) large-angle-tilt implanted drain, and 3) the buried LDD were studied. We observed clearly that the series resistant drift dominates the initial device degradation and the relative importance of the mobility degradation increases as the stress time proceeds. Our work provides a useful guideline for the device reliability optimization and for the development of the device degradation model for the circuits reliability simulation.