Defect reduction of GaAs epitaxy on Si (001) using selective aspect ratio trapping

Abstract

Metal-organic chemical vapor deposition growth of GaAs on Si was studied using the selective aspect ratio trapping method. Vertical propagation of threading dislocations generated at the GaAs∕Si interface was suppressed within an initial thin GaAs layer inside SiO2 trenches with aspect ratio >1, leading to defect-free GaAs regions up to 300nm in width. Cross-sectional and plan-view transmission electron microscopies were used to characterize the defect reduction. Material quality was confirmed by room temperature photoluminescence measurements. This approach shows great promise for the fabrication of optoelectronic integrated circuits on Si substrates.