InAs/InP Quantum Dots, Dashes, and Ordered Arrays

Abstract

This paper reviews the growth and characterization of epitaxial self-assembled InAs/InP(100) quantum dots (QDs), quantum dashes (QDashes), and ordered QD arrays fabricated by the chemical-beam epitaxy (CBE). The buffer layer surface morphology of lattice-matched InGaAsP on InP(100) substrates is identified as the key parameter to determine either InAs QD or QDash formation. Growth conditions leading to the formation of QDashes are always accompanied by a rough buffer layer surface morphology, while well-shaped and symmetric QDs are reproducibly observed on smooth buffer layers. On such buffer layers the creation of laterally ordered linear InAs QD arrays based on self-organized anisotropic strain engineering of InAs/InGaAsP superlattice (SL) templates is achieved. InAs QD ordering is governed by local recognition of the lateral strain field modulation on the SL template which produces wirelike InAs structures along [001] due to anisotropic adatom surface migration and lateral/vertical strain correlation. Stacking in multilayers of linear InAs QD arrays with identical emission wavelength in the 1.55-µm region is realized upon insertion of ultrathin GaAs interlayers beneath the QDs with increasing thickness in successive layers, demonstrating a three-dimensionally self-ordered QD crystal with fully controlled structural and optical properties.