11 research outputs found
Trenches around and between self-assembled silicon/germanium islands grown on silicon substrates investigated by atomic force microscopy
Self assembled silicon/germanium islands grown on silicon at
high growth temperatures are investigated. The islands are
studied with transmission electron microscopy (TEM) and trench
formation around the islands is clearly identified. Selective
wet chemical etching is used to remove the islands and
facilitate atomic force microscopy (AFM) studies of the trench
shape, Trenches are round to be anisotropic and the 4-fold
symmetry of the trenches is related to the cubic symmetry of
the elastic properties of the Si crystal. A simulation of the
strain energy distribution under a SiGe island is presented and
found to be in good qualitative agreement with the observed
trench shape. It is verified by comparison of islands before
and after etching that the etching process does not introduce
artifacts. (C) 2002 Elsevier Science B.V. All rights reserved