ESD induced damage on ultra-thin gate oxide mosfets and its impact on device reliability

We investigated the effects of destructive and non-destructive Electrostatic Discharge (ESD) events applied either to the gate or drain terminal of MOSFETs with ultra-thin gate oxide, emulating the occurrence of an ESD event at the input or output IC pins, respectively. We studied how ESD may affect MOSFET reliability in terms of Time-To-Breakdown (TTBD) of the gate oxide and degradation of the transistor electrical characteristics under subsequent electrical stresses. The main results of this study are that ESD stresses may modify the MOSFET current driving capability immediately after stress and during subsequent accelerated stresses, but do not affect the TTBD distributions. The damage introduced by ESD in MOSFETs increases when the gate oxide thickness is reduced.