Ordered InAs nanodots formed on the patterned GaAs substrate by molecular beam epitaxy

Ordered indium arsenide (InAs) nanodots are formed by molecular beam epitaxy (MBE) on patterned gallium arsenide (GaAs) substrates, which are prepared by implanting manganese (Mn) ions through anodic aluminum oxide (AAO) membranes into the GaAs wafers. Morphology and structure of the patterned GaAs substrate is determined both by the oxygen desorption and the Mn ion diffusion. Suitable patterned GaAs substrates with the same dosage of Mn ions for the following epitaxy can be obtained by controlling the deoxidization As4 pressures during the oxygen desorption. Images of samples with different Mn ion implantation dosages and different molecular beam epitaxial conditions for the following deposition of InAs nanodots on the patterned GaAs substrates are characterized by atomic force microscopy (AFM). The order of the InAs nanodots is determined both by the AAO membrane and dosage of Mn ions. The density of InAs nanodots has great relation to the pore density of the AAO.