A SPICE Compact Model for Ambipolar 2-D-Material FETs Aiming at Circuit Design

We report a charge-based analytic and explicit compact model for field effect transistors (FETs) based on two-dimensional materials (2DMs), for the simulation of 2DM- based analog and digital circuits. The device electrostatics is handled by invoking 2D density of states and Fermi-Dirac statistics, that are later combined with Lambert-W function and Halley’s correction, so to eventually obtain explicit expressions for the electron and hole charges, which are exploited in the calculation of drift-diffusion currents for both carriers. Further, the charge model is extended to obtain characteristics of 2DM- based negative capacitance FETs. The model is benchmarked against experimental MoS2 FET measurements, and experi- mental ambipolar characteristics of narrow band-gap materials such as black phophorous. Its soundness for SPICE circuit-level simulations is also demonstrated.