Enhancement of optical properties of InGaAs/GaAs self-assembled quanum dots by thermal annealing with a SiNx/SiO2 capping layer

초록

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℃ by varying annealing time under the N2-gas ambient. It waas confirmed from the PL measurement after the thermal annealing that, the emmision energy of SAQDs was blue-shifted by 190 meV, the FWHM(full width at half maximum) was narrowed from 76 meV to 47 meV and the PL intensity was increased. SiNx-SiO2 double capping layer have been found to induce larger PL intensity and better carrier confinement after the thermal annealing of SAQDs conpared to SiO2 single capping layer.