A new observation of enhanced bias temperature instability in thin gate oxide p-MOSFETs

Bias temperature instability (BTI) and its underlying physical mechanism are studied for thin gate oxide MOSFETs. For p-MOSFETs stressed in inversion for a long-time, BTI increase is observed at high stress temperature. This is shown to be due to higher interface trap generation because of faster hydrogen diffusion in the gate poly. Enhanced BTI affects device lifetime and is strongly influenced by gate oxide scaling, as discussed.