A theoretical analysis of quantum-wire fabrication by vacancy-enhanced interdiffusion of quantum wells

The fabrication of quantum-wire structures using vacancy enhanced interdiffusion of quantum wells is analyzed theoretically. A phenomenological equation is used to describe the effects of strain on vacancy diffusion. The quantum-wire confinement potentials are studied as a function of the trench opening widths and the separation distances from the SiO ₂-AlGaAs interface. The lateral confinement energy is not a monotonic function of the trench opening width. It first increases and then decreases when the trench opening width is decreased. When the separation distance of the quantum wire from the interface is reduced, the confinement potential is changed from a nonsquare profile to a square-well profile.