Strain state in single quantum well GaAs/1ML-InAs/GaAs(100) analysed by high-resolution X-ray diffraction

¹ Laboratoire de Minéralogie-Cristallographie, Universités Paris VI et Paris VII, CNRS URA009, 4 place Jussieu, 75252 Paris Cedex 05, France
² Istituto di Elettronica dello Stato Solido, Consiglio Nazionale delle Ricerche, via Cineto Romano 42, I-00156 Roma, Italy

Corresponding author: zheng@lmcp.jussieu.fr

Received: 13 October 1997
Accepted: 27 January 1998

Abstract

The epitaxy-induced tetragonal strain in one monolayer of InAs buried in a GaAs(100) crystal is determined by measuring weak oscillations in X-ray reflectivity profiles. It is shown that the reflectivity of such heterostructure consists of a sinusoidal modulation of the usual rocking curve of a thick crystal. The oscillation period provides the distance of the buried layer from the crystal surface and the maximum positions in oscillations give the displacement induced by the buried layer. The vertical spacing between the In and As atom planes is found to be 1.64 ± 0.02 Å, which is consistent with an elastic behaviour.