Fabrication and characterization of InGaAs-GaAs quantum wire arrays by selective-area metalorganic chemical vapor deposition

Abstract

We discuss the fabrication and optical characterization of strained-layer InGaAs-GaAs nanometer scale wire arrays grown by selective-area MOCVD on silicon dioxide patterned substrates. The wire patterns studied were obtained by high resolution electron beam lithography on PMMA using a silicon dioxide lift-off process. The dependence of the growth structure on the wire orientation is presented. Wire arrays aligned parallel to the [011] crystal direction are found to be the extremely useful for the growth of narrow quantum wire structures. Due to the faceted nature of the growth, a large non-linear enhancement of growth inside the wire region is observed. In addition, the results of gas phase diffusion growth simulations on the expected inhomogeneity of the fabricated quantum wires are presented. The degree of inhomogeneity of fabricated quantum wire arrays was studied by spatially resolved photoluminescence. Our results show that a suitable patterning technique, coupled with proper growth conditions, could allow control of the selective growth profile across the wire array. Finally, the growth of strained wires with a lateral dimension of less than 50 nm is displayed along with optical characterization of the quantum wires by low temperature photoluminescence.