Effect of FN stress and gate-oxide breakdown on high-frequency noise characteristics in deep-submicrometer nMOSFETs

The impact of Fowler-Nordheim (FN) stress and oxide breakdown on high-frequency noise characteristics in 0.18 μm nMOSFET has studied. Noise characteristics of the devices at different leakage levels and breakdown hardness are compared. The results have shown a strong dependence of degradation of noise parameter on the gate leakage. The degradation mechanisms are analyzed by extraction of the channel and gate noise using a noise equivalent circuit model. It has been found that gate shot noise, which is commonly ignored in the as-processed nMOSFET, plays a dominant role in determining the high frequency noise in the post-oxide breakdown nMOSFET. The effect of FN stress and oxide breakdown is negligible.