5.7 Relationship between Gate Leakage Current and Interface States

5.7 Relationship between Gate Leakage Current and Interface States

Gate leakage current had not been a major concern in the past as the amount is small and

insignificant. However, it increases in integration density of the Integrated Circuits and reduction of size of the MOSFETs makes leakage current associated to the interface states to be significant [21].

Reduction in transistor size entails very important electric field in the transistor channel. This caused injection of hot carriers in the gate oxide and creates defects in the SiSiO2 interface (interface states). The defects I the SiSiO2 interface in turn cause leakage current in the gate [19, 21].

This gate current is responsible for the degradation in device operating characteristics with time. This “reliability” issue is of considerably importance as the lifetime of electronic parts has to be guaranteed [19, 21].