Effect of strain and diameter on electronic and charge transport properties of indium arsenide nanowires

TL;DR

This study investigates how strain and diameter influence the electronic and charge transport properties of indium arsenide nanowires, revealing that crystallographic orientation and quantum effects dominate, but strain is crucial for accurate transistor performance predictions.

Contribution

It provides a comprehensive analysis combining first principles calculations and transport modeling to understand strain and size effects on InAs nanowire transistors.

Findings

Strain significantly affects band structure and device performance.

Quantum confinement and orientation dominate nanoscale behavior.

Strain must be considered for accurate transistor modeling.

Abstract

The impact of uni-axial compressive and tensile strain and diameter on the electronic band structure of indium arsenide (InAs) nanowires (NWs) is investigated using first principles calculations. Effective masses and band gaps are extracted from the electronic structure for relaxed and strained nanowires. Material properties are extracted and applied to determine charge transport through the NWs described within the effective mass approximation and by applying the non-equilibrium Green's function method. The transport calculations self-consistently solve the Schrodinger equation with open boundary conditions and Poisson's equation for the electrostatics. The device structure corresponds to a metal oxide semiconductor field effect transistor (MOSFET) with an InAs NW channel in a gate-all-around geometry. The channel cross sections are for highly scaled devices within a range of 3x3 nm2 to 1x1 nm2. Strain effects on the band structures and electrical performance are evaluated for different NW orientations and diameters by quantifying subthreshold swing and ON/OFF current ratio. Our results reveal for InAs NW transistors with critical dimensions of a few nanometer, the crystallographic orientation and quantum confinement effects dominate device behavior, nonetheless strain effects must be included to provide accurate predictions of transistor performance.