GaAs/AlGaAs quantum-well intermixing using shallow ion implantation and rapid thermal annealing

Abstract

Low-energy As+-ion implantation followed by rapid thermal annealing (RTA) was utilized to modify exciton transition energies of GaAs/AlGaAs quantum wells (QW). A variety of structures were irradiated at an energy low enough that the disordered region was spatially separated from the QWs. After RTA, exciton energies showed large increases which were dependent on QW widths and the implantation fluence with no significant increases in peak linewidths. The observed energy shifts were interpreted as resulting from the modification of the shapes of the as-grown QWs due to enhanced Ga and Al interdiffusion at heterointerfaces in irradiated areas. These results are consistent with the model of enhanced intermixing of Al and Ga atoms in depth of the material due to diffusion of vacancies generated near the surface.