U. Zeimer^a, U. Pietsch^b, J. Grenzer^b, J. Fricke^a, A. Knauer^a and M. Weyers^a

Published in:

J. Alloys Compd., vol. 401, no. 1-2, pp. 226-230 (2005).

Abstract:

Recently it has been shown that lateral carrier confinement in an InGaAs quantum well (QW) embedded in GaAs can be achieved by using a laterally patterned InGaP stressor layer on top of the heterostructure. To exploit this effect in a device the structure has to be planarized by a second epitaxial step. It has been shown that the lateral strain modulation almost vanishes after overgrowth with GaAs, whereas overgrowth with a single ternary layer of opposite strain compared to the stressor layer suffers from strain induced decomposition. Here we show that the lateral carrier confinement of the initially free standing nanostructure can almost be maintained using a two step process for overgrowth, where a strained thin ternary layer is grown first followed by GaAs up to complete planarization of the patterned structure. Thickness and composition of the ternary layer are adjusted on the basis of finite element calculations of the strain distribution (FEM). The strain field achieved after overgrowth is probed by X-ray grazing-incidence diffraction (GID).

Keywords:

Nanostructures; Strain engineering; Finite-element method; X-ray grazing-incidence diffraction

© 1999-2005, Elsevier Science B.V. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the Elsevier Science B.V.

Full version in pdf-format.