摘要

The effects of the barrier height reduction caused by the channel electron velocity due to the effective electron mass difference between silicon and oxide on the gate leakage current in a MOSFET are discussed The calculations show such a barrier height reduction will have a large effect on the direct tunnelling current and the Fowler-Nordheim tunnelling current when the channel electron velocity is higher than 2 x 10(7) cm/s. The relative increase in the tunnelling current caused by such a barrier height reduction increases with increasing oxide electric field in the regime of the direct tunnelling, but decreases with increasing oxide electric field in the regime of the Fowler-Nordheim tunnelling. The A-factor in the Fowler-Nordheim expression increases but the B-factor decreases with channel electron velocity, and they remain constant when the channel electron velocity is less than 3 x 10(6) cm/s.