Thermal treatment of InGaAs/GaAs self-assembled quantum dots with SiNx and SiO2 capping layers

Abstract

Intermixing effects of MOCVD (metal organic chemical vapor deposition) grown InGaAs SAQDs (self-assembled quantum dots) covered With SiO2 and SiNx -SiO2 dielectric capping layers were investigated. The intermixing of SAQDs was isothermally performed at 700 degreesC by varying annealing time tinder the N-2-gas ambient. It was confirmed from the PL measurement after the thermal annealing that, the emission energy of SAQDs was blue-shifted by 190 meV, the FWHM (full width at half maximum) was narrowed from 76 meV to 47 meV an the PL intensity was increased. SiNx-SiO2 double capping layer have been found to induce larger PL intensity after the thermal annealing of SAQDs compared to SiO2 single capping layer.