Study of intermixing in InGaAs/(Al)GaAs quantum well and quantum dot structures for optoelectronic/photonic integration

Two of the most important intermixing techniques, ion implantation and impurity free vacancy disordering, are investigated and compared in InGaAs/(Al)GaAs quantum well (QW) and quantum dot (QD) structures. For ion implantation induced intermixing, arsenic implantation was performed and the amount of interdiffusion created was found to vary as a function of implantation dose and temperature. Impurity free vacancy disordering was also enhanced by deposition of SiO₂ in both QW and QD structures and annealing at different temperatures. In order to obtain large differential energy shifts for device integration using both methods, the essential issue of suppression of thermal interdiffusion using a TiO₂ capping layer was also addressed.