Lateral Confinement of Electrons in Vicinal N-polar AlGaN/GaN Heterostructure

TL;DR

This study investigates how orientation affects electron transport in vicinal N-polar AlGaN/GaN heterostructures, revealing anisotropic charge behavior and proposing polarization-induced lateral confinement as a novel mechanism.

Contribution

It introduces a polarization-engineered electrostatic confinement model explaining charge anisotropy in vicinal N-polar AlGaN/GaN heterostructures.

Findings

Significant anisotropy in charge transport observed.

Electrostatic confinement can be achieved via polarization charges.

Model supports potential for low-dimensional device applications.

Abstract

We studied orientation dependent transport in vicinal N-polar AlGaN/GaN heterostructures. We observed significant anisotropy in the current carrying charge parallel and perpendicular to the miscut direction. A quantitative estimate of the charge anisotropy was made based on gated TLM and Hall measurements. The formation of electro-statically confined one-dimensional channels is hypothesized to explain charge anisotropy. A mathematical model was used to verify that polarization charges distributed on miscut structure can create lateral one-dimensional confinement in vicinal substrates. This polarization-engineered electrostatic confinement observed is promising for new research on low-dimensional physics and devices besides providing a template for manufacturable one-dimensional devices.