Substrate Defects Filtration During Epitaxial Lateral Overgrowth of GaAs

Results on the growth of GaAs on (001) GaAs substrates by the epitaxial lateral overgrowth technique are reported. We show that the ratio of normal to lateral growth rates in the epitaxial lateral overgrowth process can be controlled by the crystallographic orientation of the seeds and by Si adding to the melt. Experimental data showing that the dislocations threading from the substrate are efficiently filtered and cannot propagate to the epitaxial lateral overgrowth layers are presented. These findings prove that the epitaxial lateral overgrowth process is the powerful method to grow epilayers with low dislocation density on high dislocation density substrates.