SPONTANEOUSLY ORDERED INAS SELF-ASSEMBLED QUANTUM DOTS GROWN ON GAAS INP SUBSTRATE/

In this paper, we present a method to control the nucleation sites of InAs self-assembled quantum dots (QDs). Tensile strained material, suc h as GaAs used here was grown on InP substrate before InAs deposition. This thin GaAs layer can provide a surface with gridded trenches whic h have the same function as atomic steps and are promising for the for mation of QDs with nucleation sites controlled. Atomic-force microscop y measurement was performed and the AFM images indicate that the InAs islands grown with our technique is grid aligned and have good homogen eity and low-size fluctuation. In addition, another kind of three-dime nsional structure with larger size would co-exist with normal QDs if 3 0 nm thick GaAs layer were deposited. (C) 1998 Published by Elsevier S cience B.V. All rights reserved.