The intermixing of InGaAs/GaAs quantum dot using isoelectric ion implantation followed by rapid thermal annealing is presented. The implantation was carried out at 200 degrees C with arsenic (As+) and phosphorus (P+) ions, at various doses, where the ions were accelerated at 360keV with the ion angle tilted by 7 degrees. Compared with impurity-free induced intermixing, the intermixing degree is significantly enhanced by temperature-assisted implantation followed by a rapid thermal annealing below 750 degrees C. The diffusion transient was observed at a longer annealing duration suggesting the complete intermixing of the implantation-induced damage. A blue shift as large as 126meV has been observed from the P+-implanted sample, whilst only similar to 14meV has been measured from the SixNy-capped sample after annealing at 750 degrees C. The result indicates that a highly selective and low-temperature spatial intermixing, which has a strong potential for photonic integration, could be developed. (c) 2005 Elsevier B.V. All rights reserved.