Gate-induced drain leakage current degradation and its time dependence during channel hot-electron stress in n-MOSFETs

The effects of channel hot-electron stress on the gate-induced drain leakage current (GIDL) in n-MOSFETs with thin gate oxides have been studied. It is found that under worst case stress, i.e. a high density of generated interface states Delta D_it, the enhanced GIDL exhibits a significant drain voltage dependence. Whereas Delta D_it increases significantly the leakage current at low V_d, it has minor effects at high V_d. On the other hand, the electron trapping was found to increase the leakage current rather uniformly over both low and high V_d regions. In addition, GIDL degradation can be expressed as a power law time dependence (i.e. Delta I_leak=A.tⁿ), and the time dependence value n varies according to the dominant damage mechanism (i.e. electron trapping against Delta D_it), similar to that reported for on-state device degradation.