A 2D analytical model for SCEs in MOSFETs with high-k gate dielectric

In this paper, a two-dimensional (2D) analytical potential model for MOSFETs with high-k gate dielectric is derived based on solving a boundary value problem with 2D Poisson's equation. A novel approach to estimate short-channel threshold voltage (VT) roll-off analytically is also presented and an explicit expression for the short-channel VT roll-off is obtained. Results show that the minimum surface potential along the channel, the inverse slope of subthreshold current, short-channel VT roll-off and drain-induced barrier lowering (DIBL) predicted by the analytical model are in close agreement with 2D numerical simulation (TCAD Sentaurus) without any fitting parameters even down to a sub-20 nm channel length. This model offers a physical insight into short-channel effects and how each of the parameters of a MOSFET quantitatively impacts on ΔVT and other key features of the device. It also serves for compact modeling of high-k gate dielectric MOSFETs.