Detailed investigation of the transient local tunneling in gate oxides

A detailed investigation of the local transient tunneling currents due to substrate- and gate-near traps generated by Fowler-Nordheim stress in nitrided oxide MOS structures has been performed. We demonstrate that for the correct interpretation of these transient SILC currents it is essential to include the effects of the substrate and poly-Si capacitances. This leads to gate voltage dependent weighting factors, which relate the measured current transients to the local trap tunnel currents near the substrate and the gate. By a combination of these measurements with transient capacitance measurements it is possible to separately determine the local tunnel currents and thus densities of traps generated close to the substrate and to the gate.