An analytical physical model for short-channel MOSFETs

Abstract

In the light of a modified two-dimensional Poisson equation, an analytical model for the threshold voltage Vth of deep-submicrometre MOSFETs is developed, which can show Vth's nonlinear dependence on drain voltage Vds. Meanwhile, by introducing a normalized effective gate voltage Vgtx to obtain continuous channel charge characteristics from the subthreshold to the strong inversion region and properly including major small-geometry and high-field effects such as carrier velocity saturation, DIBL, field dependent mobility, inversion layer capacitance and channel-length modulation etc, an accurate, continuous and scaled-down drain current physical model Ids is obtained. The model's output for channel length L = 0.26-0.8 µm fits both the experimental data and MINIMOS simulation well in all operation regions, and is available for VLSI simulation and reliability applications.