The characteristics of multi-layered InAs/GaAs self assembled quantum dots (SAQDs) annealed after the growth were here studied using a combination of capacitance-voltage (C-V) measurements,Raman scattering and photoluminescence (PL) spectroscopy. The combination of the results obtained with the three techniques, gave evidences that the annealing at 500º C causes the sharpness of the SAQDs interfaces, while the annealing at 600º C eliminated the SAQDs. However, the comparison with the case of single layered SAQDs, revealed a thermal stability of the last system even at an annealing temperature of 700º C, thus confirming the role of the interlayer strain in the low temperature diffusion process.
