We have selectively grown thin epitaxial GaAs films on Ge substrates with the aid of a 200 nm thin SiO2 mask layer. The selectively grown structures have lateral sizes ranging from 1 um width up to large areas of 1 by 1 mm2. The growth is fully selective, thanks to an optimized growth procedure, consisting of a 13 nm thin nucleation layer grown at high pressure, followed by low pressure growth of GaAs. This growth procedure inhibits the nucleation of GaAs on the mask area and is a good compromise between reduction of loading effects and inhibition of anti phase domain growth in the GaAs. Nevertheless, both microscopic and macroscopic loading effects can still be observed on x-section SEM images and profilometer measurements. X-ray diffraction and low temperature photoluminescence measurements demonstrate the good microscopic characteristics of the selectively grown GaAs.
@article{arxiv.cond-mat/0703664,
title = {Selective Epitaxial Growth of GaAs on Ge Substrates with a SiO2 Pattern},
author = {G. Brammertz and M. Caymax and Y. Mols and S. Degroote and M. Leys and J. Van Steenbergen and G. Winderickx and G. Borghs and M. Meuris},
journal= {arXiv preprint arXiv:cond-mat/0703664},
year = {2007}
}