Two-dimensional bias dependent model for the screening length in double-gate Tunnel-FETs

In this paper we present an analytical model for the band-to-band tunneling current and 2D screening length calculation in double-gate Tunnel-FETs through a physical-based analysis. The model was derived from two-dimensional solutions for potential distribution and band-to-band tunneling probabilities through Wentzel-Kramers-Brillouin approximation (WKB). The model captures the influence of the band structure and device geometry on the channel electrostatics, and hence the device current. Those results lead to a 2D analytical calculation of the electrostatic screening length at the source tunneling junction which is valid in the saturation region.