Interdiffusion in Semiconductor Quantum Dot Structures

Abstract

ABSTRACTThe potential profile of InGaAs quantum dots (QDs) was shown to be easily modified with annealing. We also demonstrate the use of spin-on-glass to create interdiffusion in QDs but the degree of interdiffusion was strongly dependent on the properties of the oxide. By using TiO2 significant suppression of thermal diffusion of the quantum dots could be achieved. On the other hand, very large additional blue shifts (in excess of 120 meV) could be obtained with both H and As implantation. The different nature of defects created by both ions and how they affect the interdiffusion of quantum dots were illustrated. In the dose and annealing temperature range studied, the degree of interdiffusion ultimately depends on the availability of free point defects or point defects liberated from clusters/extended defects to diffuse across the quantum dots.