Self-ordered nanostructures grown by organometallic chemical vapor deposition on V-grooved substrates: experiments and Monte-Carlo simulations

The growth the GaAs/GaAlAs quantum wires by organometallic chemical vapor deposition on V-grooved substrates relies on the formation of a self-limiting AlGaAs surface profile and the thickness modulation in the form of a crescent of the GaAs layer. In order to gain understanding on the growth process at the atomic level, we developed a two-dimensional Monte-Carlo simulation based on the solid-on-solid model. In good agreement with experimental results, our kinetic model shows that the self-limited profile results from the competition between the growth rate anisotropy on the different facets of the groove and the surface diffusion of adatoms. The predictions of the growth modeling are experimentally employed to control at the nanometer scale the shape of quantum wins using successive changes in the growth conditions. This understanding of the growth mechanisms opens the way to an accurate control of the quantum confinement in quantum wires. (C) 1999 Elsevier Science Ltd. All rights reserved.