Analysis of InAs-Si heterojunction nanowire tunnel FETs: Extreme confinement vs. bulk

Abstract

Extremely narrow and bulk-like p-type InAs-Si nanowire TFETs are studied using a full-band and atomistic quantum transport simulator based on the sp3d5s* tight-binding model and a drift-diffusion TCAD tool. As third option, the WKB approximation has been adapted to work in heterostructures through a careful choice of the imaginary dispersion. It is found that for ultra-scaled InAs-Si nanowire TFETs, the WKB approximation and the quantum transport results agree very well, suggesting that the former could be applied to larger hetero-TFET structures and considerably reduce the simulation time while keeping a high accuracy.