Fabrication on nanostructures using MBE and MOVPE

Two different fabrication techniques to obtain nanometer scale structures without the use of lithography are demonstrated. Quantum dots are made on GaAs by growing strained InP islands by metal-organic vapour phase epitaxy. Quantum confinement of carriers is achieved by the growth of quantum wells on the InP islands. Molecular beam epitaxy is used for the fabrication of a gold island mask on GaAs. Reactive ion etching through the gold mask produces a high density of GaAs columns with diameters down to 20 nm