(In,Ga)As islands formed on shallow patterned GaAs (1 0 0) substrates by molecular beam epitaxy

We investigate the growth on GaAs (100) substrates patterned with shallow mesa gratings along [011], [010], and View the MathML source, respectively. Nonplanar surfaces consisting of steps and (100) terraces are formed during GaAs overgrowth. The pattern direction determines the type of steps distributed on the surface, which drastically affects the evolution of the surface morphology. Ordering of (In,Ga)As islands is found on the sample with mesas along View the MathML source after growth of In0.34Ga0.66As on the nonplanar GaAs surface. Type and density of the pattern-induced steps play an important role for formation and alignment of islands along View the MathML source.