Patterned self-assembly of one-dimensional arsenic particle arrays in GaAs by controlled precipitation

A process for the patterned self-assembly of nanometer-scale particles within a solid is described. The process uses crystal strain and composition to guide the formation of arsenic precipitates in GaAs-based epitaxial layers grown at low temperature by molecular beam epitaxy. The lateral particle position is controlled by the strain produced by a surface stress structure while the vertical position is controlled by the epitaxial layer composition. Arsenic particles ∼16-nm in diameter are fabricated in one-dimensional arrays with a 23-nm edge-to-edge particle spacing at a depth of 45 nm below stressors 200 nm in width, thereby demonstrating this technique.