Patterned growth on high-index GaAs 311/A substrates

The selectivity of growth on patterned GaAs 311.A substrates qualitatively differs from that on low-index 100.and 111.substrates. During molecular beam epitaxy MBE.of AlGa.As,w01y1xoriented mesa stripes develop a fast-growing convex sidewall. For shallow mesa height, this new growth mechanism produces quasi-planar quantum wires with excellent optical properties. Nanometer-scale self-faceting in atomic hydrogen-assisted MBE transforms these sidewall quantum wires into a linear array of quantum dots with minimized size fluctuations. Upon rotating the mesa stripe fromw01y1x, a continuous transition occurs from the fast-growing sidewall to the slow-growing sidewall along the perpendicularwy233x direction. This allows their systematic combination at the corner or edge of intersecting mesa stripes appropriately inclined fromw01y1x, thus offering a novel degree of flexibility for the design of lateral functional semiconductor nanostructures. q2000 Elsevier Science B.V. All rights reserved.