A Bottom-gate Depletion-mode Nanowire Field Effect Transistor (NWFET) Model Including a Schottky Diode Model

Abstract

We present a compact model for a bottom-gate depletion-mode nanowire field-effect transistor (NWFET) including a Schottky diode model for efficient circuit simulation. The NWFET model is based on an equivalent circuit corresponding to two back-to-back Schottky diodes for the metal-semiconductor (MS) contacts separated by a depletion-mode NWFET for the intrinsic NWFET. The previously developed depletion-mode NWFET model is used for the intrinsic part of the NWFET. The Schottky diode model for the M-S contacts includes the thermionic field emission (TFE) and the thermionic emission (TE) mechanisms for reverse bias and forward bias, respectively. Our newly developed model is integrated into Advanced Design System (ADS), in which the extrinsic part (Schottky diode model) and the intrinsic part of the NWFET are developed by utilizing the symbolically defined device (SDD) for an equation-based nonlinear model. The results simulated from the newly developed NWFET model reproduce the experimental results within 10% errors. The mobilities extracted from the newly developed NWFET model are compared with those extracted from the previously reported NWFET model which replaced the Schottky diodes with series resistances.