It occurs due to defects created in the gate oxide during electrical stressing.
Increased leakage is a common failure mode of electronic devices.
The most well-studied defects assisting in the leakage current are those produced by charge trapping in the oxide.
This model provides a point of attack and has stimulated researchers to develop methods to decrease the rate of charge trapping by mechanisms such as nitrous oxide (N2O) nitridation of the oxide.
The SILC may be measured to determine the neutral trap density in that oxide.