ATOMIC-FORCE MICROSCOPY STUDY OF SELF-ORGANIZED ZNCDSE NANOSTRUCTURESFABRICATED ON THE CLEAVAGE-INDUCED GAAS (110)SURFACE

The self-organized nanostructures of Zn1-xCdxSe were fabricated on the (110)-oriented GaAs whose surface was obtained by cleaving under ultr a high vacuum (UHV) in the chamber of molecular beam epitaxy (MBE). Th e surface steps produced by cleaving process and the ridges transforme d from the wetting layers are preferred nucleation sites for adatoms r esulting in linearly arranged islands. Such ridges or step edges act a s the sink of adatoms, inhibiting island nucleation to produce the dep letion regions at both its sides. The orientation-dependent sticking c oefficient of adatoms and dangling bonds at the step edges, and the pe riodic strain distributions on the ridges are suggested to account for the preferred nucleation of the islands. (C) 1998 Elsevier Science B. V. All rights reserved.