The metalorganic chemical vapor deposition growth of GaAs on patterned Si (001) substrates, which utilized the aspect ratio trapping method, was reported. It was found that, when growing GaAs above a SiO2 trenched region, coalescence-induced threading dislocations and stacking faults originated on top of the GaAs/SiO2 interfaces. These defects were found to be indirectly related to the initial defect-trapping process during trenched GaAs growth. The causes of coalescence defect formation and its reduction were experimentally investigated by employing a two-step growth optimization scheme. An improvement in material quality was characterized by using cross-sectional and plan-view transmission electron microscopy and X-ray diffraction.

Defect Reduction of GaAs/Si Epitaxy by Aspect Ratio Trapping. J.Z.Li, J.Bai, C.Major, M.Carroll, A.Lochtefeld, Z.Shellenbarger: Journal of Applied Physics, 2008, 103[10], 106102