Proposal of a physics-based compact model for nanoscale MOSFETs including the transition from drift-diffusion to ballistic transport

We present an analytical model for nanoscale MOSFETs capable to describe the transition from drift-diffusion to ballistic transport. We start from a closed-form model of ballistic Fully Depleted SOI (FDSOI) and Double Gate (DG) MOSFETs with non degenerate statistics, and, on the basis of the Büttiker interpretation of dissipative transport in terms of virtual voltage probes, we show that a long channel MOSFET described in terms of drift-diffusion equations can be rigorously represented by a finite chain of ballistic MOSFETs. Such results allow us to recover velocity saturation as a consequence of the ballistic limit, and to propose a novel mobility model.