Detailed Characterisations of GaAs Films on Si Obtained by Conformal Growth.

Abstract

ABSTRACTConformal growth is a confined epitaxial lateral overgrowth technique capable of yielding low dislocation density GaAs films on Si. This technique makes extensive use of selective epitaxy and crystal growth is confined by a dielectric cap as well as by the self-passivated Si surface itself.In this paper, we have performed a detailed characterisation of the state of stress of the GaAs films in various configurations (after conformal growth and removal of the seed regions, and after the regrowth of an MBE layer) by photoluminescence measurements at 5K and X-ray diffraction experiments. Although the as-grown conformal films are found in the same state of stress than reference MOCVD GaAs epilayers on Si, we report a significant decrease of this stress after MBE regrowth on conformal films.