Interdiffusion in InGaAs/GaAs: The effect of growth conditions

The effect of growth temperature and group-V to group-III flux ratio on the intermixing process in molecular beam epitaxial grown InxGa1−xAs/GaAs multiquantum wells were studied by means of photoluminescence coupled with repetitive thermal anneal experiments. We have shown that, for a wide range of growth conditions (growth temperatures from 565 to 636 °C and flux ratios from 5:1 to 25:1) the interdiffusion is controlled solely by a constant background concentration of vacancies which are probably introduced into the substrate during its manufacture. We have shown that, only growth at very low temperatures (470 °C) will result in appreciable excess vacancies.