Layer interdiffusion in Se-doped AlxGa1−xAs-GaAs superlattices

Transmission electron microscopy and carrier concentration measurements are used to characterize the layer interdiffusion (Al-Ga interdiffusion) mechanism of a Se-doped AlxGa1−xAs-GaAs superlattice (SL) under high-temperature annealing. By varying the annealing environment and comparing the results with similarly annealed undoped SL’s and Mg-doped SL’s, we find that the layer interdiffusion occurs through interaction of the Se impurity with native defects associated with As-rich conditions, the most likely of which is the column III vacancy.