Lateral patterning of arsenic precipitates in GaAs by a surface stress structure

Lateral patterning of arsenic precipitates in GaAs is reported. The positions of near-surface precipitates in a GaAs layer grown by molecular beam epitaxy at low temperature are controlled by InGaAs stressors 45 nm in width covered by a SiO₂ film. The stressors form a surface grating which governs the precipitate position by modulating the strain in the GaAs near the surface. Electron microscopy clearly reveals the formation of precipitates about 15 nm in diameter aligned with the stressors at a depth of ∼50 nm. It is suggested that this capability to control the position of nanometer-size metallic particles within a semiconductor could open up new possibilities for novel devices.