Channel length dependence of the formation of quantum dots in GaN/AlGaN FETs

TL;DR

This study explores how the length of the channel in GaN/AlGaN FETs influences the formation of quantum dots, revealing fewer dots form as the channel shortens and how thermal and light treatments alter the disordered potential.

Contribution

It provides new insights into the channel length dependence of quantum dot formation and the effects of thermal and optical stimuli on disordered potential in GaN/AlGaN FETs.

Findings

Quantum dots decrease with shorter channel length.

Few quantum dots form at 0.05 μm gate length.

Thermal cycling and illumination modify the disordered potential.

Abstract

Quantum dots can be formed in simple GaN/AlGaN field-effect-transistors (FETs) by disordered potential induced by impurities and defects. Here, we investigate the channel length dependence of the formation of quantum dots. We observe decrease of the number of formed quantum dots with decrease of the FET channel length. A few quantum dots are formed in the case with the gate length of 0.05~$\mu $m and we evaluate the dot parameters and the disordered potential. We also investigate the effects of a thermal cycle and illumination of light, and reveal the change of the disordered potential.