Extra-Side-Facet Control in Selective Molecular Beam Epitaxial Growth of InGaAs Ridge Quantum Wires for Improvement of Wire Uniformity

Abstract

For InP-based InGaAs ridge quantum wires fabricated by selective molecular beam epitaxy (MBE) on <110>-oriented InP mesa-stripes, the origin of wire inhomogeneity and the possible methods to improve the wire uniformity were investigated in detail. The appearance of extra-side-facets on (111)A sidewalls was found to be the major reason for ridge waving, leading to wire inhomogeneity. Use of mis-oriented mesa-stripes and high-temperature growth of InGaAs buffer layer were found to be significantly effective for reducing the width of the extra-facets, resulting in the suppression of ridge waving and a marked improvement of wire uniformity. The narrow photoluminescence (PL) peak of the InGaAs ridge quantum wire formed with the present extra-side-facet control indicated the realization of a wire having the best uniformity of all the InP-based InGaAs quantum wires reported so far and comparable or better uniformity than most of the GaAs-based quantum wires reported so far.