Silicon-induced faceting of vicinal GaAs(001)

This article presents in situ x-ray diffraction studies of the evolution of the morphology of 0.5 degrees-miscut vicinal GaAs(001) surfaces during and following undoped and silicon-doped growth using organometallic vapor-phas e epitaxy. Undoped growth leads to ordered monolayer steps. However, growth in the presence of silicon destabilizes this surface morphology and trigge rs faceting. Coarsening of the facet size proceeds even after the growth ha s stopped and results in large singular regions of GaAs(001) surface separa ted by step bunches. Dosing the surface with silicon without growing materi al does not trigger faceting. Growth of undoped GaAs on faceted surfaces re covers the initial state of ordered monolayer steps. (C) 2000 American Inst itute of Physics. [S0021-8979(00)06419-7].