NBT-induced hot carrier (HC) effect: positive feedback mechanism in p-MOSFET's degradation

We demonstrate a new mode of Hot-Carrier (HC) degradation of p-MOSFETs. A positive feedback HC degradation caused by positive fixed oxide charge increasing the electric field at the drain edge is observed. When TTL AC stress (HC and NBT stress one after another) is applied, this degradation is enhanced. It is assumed that NBT stress produces positive fixed oxide charges easily (NBT-induced HC degradation). It is also shown that this new degradation can be suppressed by halo design.