The spatial distribution of arsenic precipitates formed in a nonstoichiometric AlGaAs/GaAs quantum well is examined for different annealing temperatures and times. Preferential precipitation in the GaAs layer of samples annealed at 600°C is found to be much weaker than in samples annealed at 850°C because of the reduced diffusion of arsenic at lower temperatures. Nevertheless, it is demonstrated that strong preferential precipitation is possible at low annealing temperatures, provided that the annealing time is sufficiently long. Limitations to the preferential precipitation process imposed by interface mixing and the decrease in gallium vacancy concentration during annealing are also examined.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)