Formation of regular arrays of submicron GaAs dots on silicon

A combination of photolithography written with a near-field scanning optical microscope, gallium electrodeposition, and arsine annealing was used to produce regular arrays of submicron GaAs dots on a silicon substrate. Electrodeposition on a patterned Si surface produced an array of roughly hemispherical Ga dots. Annealing in arsine converted the gallium to GaAs, and caused the dots to develop faceted features. Transmission electron microscope measurements showed that the GaAs dots were polycrystalline, but had only a few grains. The dots did not have a preferred orientation relative to the substrate. Metalorganic chemical vapor deposition growth occurred selectively on these dots, forming regular arrays of GaAs disks up to 20 mum in diameter. The GaAs disks exhibited characteristic GaAs low-temperature photoluminescence. This method has application for precisely positioning semiconductor dots or tailoring the grain size of polycrystalline films. (C) 2004 American Institute of Physics.