Effect of edge roughness in graphene nanoribbon transistors

TL;DR

This paper investigates how edge irregularities in graphene nanoribbon transistors affect their electrical performance, revealing increased leakage, reduced on-current, and significant device variability due to edge roughness.

Contribution

It provides a detailed atomistic simulation analysis of edge roughness effects on graphene nanoribbon transistors, highlighting the impact on leakage, on-current, and device variability.

Findings

Leakage current increases with edge irregularity

On-current decreases due to reduced quantum transmission

Device variability is significant, especially for short channels

Abstract

The effects of edge irregularity and mixed edge shapes on the characteristics of graphene nanoribbon transistors are examined by self-consistent atomistic simulations based on the non-equilibrium Green's function formalism. The minimal leakage current increases due to the localized states induced in the band gap, and the on-current decreases due to smaller quantum transmission and the self-consistent electrostatic effect in general. Although the ratio between the on-current and minimal leakage current decreases, the transistor still switches even in the presence of edge roughness. The variation between devices, however, can be large, especially for a short channel length.