Investigation of defect formation in InGaAs on GaP/Si (100) substrates

Abstract

Monolithically integration of III-V compounds on Si (100) substrates has gained extensive interest due to its great potential in silicon photonics. However, it is greatly challenging to grow InGaAs on Si (100) because of massive defects arise in result of large lattice mismatch. In this paper, In0.53GaAs on GaP/Si (100) substrates by applying InxGa1-xAs/InP superlattices (SLs) dislocation filter layers were grown by solid-state molecular beam epitaxy (SSMBE). High-resolution X-ray diffraction (HRXRD), atomic force microscopy (AFM), cross-sectional transmission electron microscopy (TEM), and energy dispersive spectrometer (EDS) mapping were used to investigate the defect formation and evolution in epitaxial layers. Three different types of defects were found on the surface. Defect formation was directly linked to different growth stages, in which oval defect was attributed to over desorption during the initial substrate treatment, and irregular defect was originated from the region between GaP islands in GaP buffer layer, while “pair” defect was constructed by stacking faults generated in the dislocation filter layers.