Thickness Engineered Tunnel Field-Effect Transistors based on Phosphorene

TL;DR

This paper proposes a thickness-engineered phosphorene TFET that leverages layer-dependent bandgap properties to achieve high performance, scalability, and reduced interface issues, outperforming traditional TFETs in key metrics.

Contribution

It introduces a novel TE-TFET design using spatially varying layer thickness in 2D materials, demonstrating improved performance and scalability over existing TFETs.

Findings

Achieves ON-current of 1280 μA/μm at 15nm channel length

Scalable down to 9nm channel length with constant field scaling

Outperforms homojunction phosphorene and TMD TFETs in energy-delay product

Abstract

Thickness engineered tunneling field-effect transistors (TE-TFET) as a high performance ultra-scaled steep transistor is proposed. This device exploits a specific property of 2D materials: layer thickness dependent energy bandgap (Eg). Unlike the conventional hetero-junction TFETs, TE-TFET uses spatially varying layer thickness to form a hetero-junction. This offers advantages by avoiding the interface states and lattice mismatch problems. Furthermore, it boosts the ON-current to 1280$\mu A/\mu m$ for 15nm channel length. TE-TFET shows a channel length scalability down to 9nm with constant field scaling $E = V_{DD}/L_{ch}= 30V/nm$. Providing a higher ON current, phosphorene TE-TFET outperforms the homojunction phosphorene TFET and the TMD TFET in terms of extrinsic energy-delay product. In this work, the operation principles of TE-TFET and its performance sensitivity to the design parameters are investigated by the means of full-band atomistic quantum transport simulation.