High-Performance Complementary III-V Tunnel FETs with Strain Engineering

TL;DR

This paper demonstrates that strain engineering significantly enhances the performance of ultra-thin-body III-V TFETs by optimizing band gaps and effective masses, leading to higher ON currents and reduced leakage.

Contribution

It introduces a novel approach of applying strain to UTB III-V TFETs, including local strain in the source and channel regions, to improve device performance.

Findings

Strain reduces band gap and modifies effective masses in InAs UTB TFETs.

Local strain application suppresses OFF state leakage.

Strain-engineered TFETs achieve ON currents comparable to n-type devices.

Abstract

Strain engineering has recently been explored to improve tunnel field-effect transistors (TFETs). Here, we report design and performance of strained ultra-thin-body (UTB) III-V TFETs by quantum transport simulations. It is found that for an InAs UTB confined in [001] orientation, uniaxial compressive strain in [100] or [110] orientation shrinks the band gap meanwhile reduces (increases) transport (transverse) effective masses. Thus it improves the ON state current of both n-type and p-type UTB InAs TFETs without lowering the source density of states. Applying the strain locally in the source region makes further improvements by suppressing the OFF state leakage. For p-type TFETs, the locally strained area can be extended into the channel to form a quantum well, giving rise to even larger ON state current that is comparable to the n-type ones. Therefore strain engineering is a promising option for improving complementary circuits based on UTB III-V TFETs.