Control of the growth morphologies of GaAs stripes grown on patterned substrates by HVPE

Selective growth experiments of GaAs were carried out by HVPE on (0 0 1) GaAs substrates. [l 1 0] and [1 -1 0] oriented stripes exhibited various morphological profiles bounded by (0 0 i), (1 1 0) or (1 1 1) faces, depending on the III/V ratio, the supersaturation parameter and the temperature. Criteria for the appearance of the faces were determined and summarised through straightforward mathematical relations. The growth morphology depends on the growth anisotropy, precisely on the hierarchies of the growth rates of the low index faces. Kinetic Wulff constructions were built by referring to the growth rates that were experimentally assessed on (1 1 0) and (1 1 1) substrates. The good adequacy between the constructions and the morphology of the selective stripes demonstrates again that HVPE growth is mainly governed by surface kinetics. (C) 2001 Elsevier Science B.V. All rights reserved.