Synchrotron x-ray topography analysis of GaAs layers grown on GaAs substrates by liquid phase epitaxial lateral overgrowth

Synchrotron x-ray topography techniques in section and back-reflection geom etries have been applied to silicon and tin doped GaAs layers grown by the liquid phase epitaxial lateral overgrowth (ELO) technique on (100) GaAs sub strates. Back-reflection topographs show that the laterally grown parts of the ELO layers are nearly dislocation free in spite of a large density of d efects in the substrate. Section topographs reveal novel and unique feature s which are attributed to the bending of the ELO layers induced by their in teraction with the SiO2 mask.