2D analytical calculation of the electric field in lightly doped Schottky barrier double-gate MOSFETs and estimation of the tunneling/thermionic current

In this paper we present a new approach to calculate the channel electric field within a Schottky barrier Double-Gate MOSFET (SB-DG-MOSFET) in subthreshold region by solving Poissons equation. The Poisson equation is solved two dimensionally in an analytical closed-form with the conformal mapping technique. A comparison with data simulated by TCAD Sentaurus simulator for channel lengths down to 22 nm was made and shows an accurate agreement. Futhermore, a new way for the estimation of the tunneling current in SB-DG-MOSFET by applying the above 2D solution for the electric field and a 2D solution of the electrostatic potential is presented. Calculating the tunneling current, we use Wentzel–Kramers–Brillouin (WKB) approximation for the estimation of the tunneling probability. For the calculation of the tunneling and thermionic current a comparison with TCAD Sentaurus for channel lengths down to 65 nm was made.

► An analytical approach to calculate the electric field in SB-DG-MOSFETs was presented.
► It is valid for subthreshold region and does not introduce any fitting parameters, all parameters depend on geometry and boundary conditions.
► An approach to calculate the tunneling and thermionic current in SB-DG-MOSFETs was presented.
► The approach shows a good agreement with the simulation results down to 65 nm channel lengths in the subthreshold region.
► The model presented here is able to predict the current well for several barrier heights and geometries.