Disordering of Si-implanted GaAs-AlGaAs superlattices by rapid thermal annealing

Abstract

We have studied the disordering phenomenon in GaAs-AlGaAs superlattices induced by Si implantation followed by rapid thermal annealing. Disordering has been detected in superlattices implanted with 220 keV Si+ at doses ≥1×1015 cm−2 and annealed at 1050 °C for 10 s. The amount of disordering saturates with time after 10 s annealing, whence the lattice damage caused by the implantation is predominantly annealed out and little Si diffusion detected. The transient disordering is attributed to defect-induced layer intermixing occurring during the annealing of the implantation damage. The defect-induced disordering has been simulated by solving two coupled diffusion equations for aluminum and vacancies, and good qualitative agreement with experimental results has been obtained.