Growth of GaAs nanostructures by area selective epitaxy by migration-enhanced epitaxy

Abstract We have carried out area selective epitaxial growth of GaAs nanostructures using solid source molecular-beam epitaxy (MBE) which makes it possible to achieve ‘damage-free’ structures. However, area selective epitaxy by MBE is very difficult unless the substrate temperature is very high. This problem has been solved by using migration-enhanced epitaxy (MEE) deposition sequence. To achieve well-defined nanostructures, lateral growth beyond the SiO 2 mask boundaries has to be strictly prohibited. By MEE method, uniform two-dimensional lattice structures with vertical sidewalls can be fabricated without shrinking holes, even though the mask diameter is as small as 30 nm with a dot density as high as 5.0×10 9 cm −2 . Also uniform one-dimensional channel structures have been successfully grown.