Abstract
Dielectric breakdown in nanosize gate stack of state-of-the-art Si nanoelectronic devices has been one of the key reliability concerns. We present the recent development in using physical analysis techniques to decode the nature of the breakdown path or more commonly called as percolation path in ultrathin SiON and HfO2-based gate materials. The influence and extent of the dielectric breakdown to the surrounding material and structural modification are reviewed. Our results suggest that if the material and microstructural changes can be controlled upon breakdown, the conductance in the breakdown path in the broken dielectrics can still be maintained in a very low leakage mode, resulting in prolonged and good charge coupling from the gate to the channel for reducing transistor degradation.