Arsenic precipitation in GaAs for single-electron tunneling applications

Compositional control of precipitate position by preferential precipitation in a GaAs well sandwiched between low-temperature grown AlGaAs arsenic supply layers is examined for single-electron tunneling applications, where closely spaced particles a few nanometers in diameter are required. Control of small particles formed at low annealing temperatures where positional control is expected to be more difficult is examined. The use of a superlattice supply layer to intentionally increase the arsenic diffusion from the AlGaAs into the GaAs well is also examined. The results suggest useful directions for realizing controlled precipitation at scales of interest for single-electron tunneling applications.