Dislocation reduction in gaas grown on Si by MOMBE using multiple indium atomic plane structures

Abstract

This paper investigates the effectiveness of multiple indium atomic planes in reducing the dislocation density in GaAs epitaxial layers grown by metalorganic molecular beam epitaxy on GaAs-coated Si substrates prepared by metalorganic chemical vapor deposition.In situ reflection high-energy electron diffraction patterns show that, during the growth of multiple indium atomic-plane structures, two-dimensional growth takes place. Cross-sectional transmission electron microscope observation shows that InAs sublayers are commensurate; hence the critical thickness of the InAs layer in this structure is more than one-monolayer. Cathodoluminescence examination indicates that the defect density decreases as the number (<60) of indium atomic planes increases. This new structure is more effective in dislocation reduction than conventional In0.1Ga0.9As/GaAs strained-layer superlattices.