Unified compact theory of tunneling gate current in metal-oxide-semiconductor structures: Quantum and image force barrier lowering

摘要

A compact model of gate current due to Fowler-Nordheim tunneling is presented, which agrees closely with the self-consistent numerical analyses of the surface inversion region of metal-oxide-semiconductor field-effect transistors (MOSFETs). The model can quantify the measured data with the accuracy practically identical to the time consuming numerical simulation. It is also shown conclusively that image force lowering of the oxide barrier height is negligible for the oxide as thin as 1 nm. The quantum barrier lowering resulting from subband splitting is rigorously incorporated, including the effect of two-dimensional electrons inverted at the higher lying subbands. Finally, it is pointed out that the compact model can be readily generalized to include the direct tunneling in deep submicron MOSFETs.