Impact of Body Thickness and Scattering on III-V Triple Heterojunction TFET Modeled with Atomistic Mode-Space Approximation

Abstract

The triple heterojunction tunnel field-effect transistor (TFET) has been originally proposed to resolve the TFET's low ON-current challenge. The carrier transport in such devices is complicated due to the presence of quantum wells and strong scattering. Hence, the full-band atomistic nonequilibrium Green's function (NEGF) approach, including scattering, is required to model the carrier transport accurately. However, such simulations for devices with realistic dimensions are computationally unfeasible. To mitigate this issue, we have employed the empirical tight-binding mode-space approximation to simulate the triple heterojunction TFETs with the body thickness up to 12 nm. The triple heterojunction TFET design is optimized using the model to achieve a sub-60-mV/decade transfer characteristic under realistic scattering conditions.