An analytical approach to the tunnelling current of MOSFETs considering the barrier height reduction caused by the channel electron velocity due to the effective electron mass difference between silicon and oxide

Abstract

AbstractThe 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 × 107 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 × 106 cm/s. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)