TDDB(Time-Dependent Dielectric Breakdown)
Time-Dependent Dielectric Breakdown is a phenomenon where the oxide underneath the gate degrades. A complementary combination of field-induced polar-bond stretching and current-induced bond-catalysis seems to be required, at the molecular level, to explain the generally accepted TDDB observations.
The Effect of TDDB(Time-Dependent Dielectric Breakdown)
The effect is a short from the gate to the source or drains completely destroying transistor functionality and potentially, destroying the functionality of the larger circuit in which it resides. This also adds to the leakage current which will consume more power, raise
the temperature, and ultimately shorten the mean time to failure.
Another from TDDB is the breakdown is caused by the formation of a conducting path through the gate oxide to the substrate due to electron tunneling current when MOSFETs. TDDB is also called an aging effect in VLSI design.