Impact of Fowler-Nordheim and channel hot carrier stresses on MOSFETs with 2.2nm gate oxide

We studied the degradation of NMOSFETs with 2.2mn gate oxide subjected to Fowler-Nordheim and channel hot carrier stresses. We highlighted the differences between the two types of stresses, in particular concerning the behavior of the gate current. Before hard breakdown, Fowler-Nordheim stressed devices showed pre-breakdown and/or soft-breakdown, while progressive breakdown was much more common with channel hot carrier stresses, especially at V-gs = V-ds/2. The impact of the stresses on the transfer and output characteristics of the devices was then considered. Finally, the effect of the degradation on adjacent, nominally identical MOSFETs was studied, showing potential issues for circuits that rely on matching.