Direct tunneling stress-induced leakage current in nMOS devices with ultrathin gate oxides

Stress mode (constant current and voltage) dependence of the gate leakage current has been systematically investigated using the tantalum nitride (TaN) gated metal-oxide-silicon (MOS) capacitors at negative bias in the direct tunneling (DT) regime. It is shown that constant voltage stress-induced leakage current (SILC) is higher than the constant current SILC at an equal stress time. Based on the electron energy in DT regime, our experimental results also give a better physical insight of the conduction mechanism of SILC in ultrathin silicon dioxide (SiO/sub 2/) films.