In-situ optical reflectance and synchrotron X-ray topography study of defects in epitaxial dilute GaAsN on GaAs

In order to investigate the possibilities of in-situ monitoring of GaAsN bulk layer growth and the crystal quality concerning the formation of misfit dislocations, GaAsN bulk samples with different layer thicknesses were grown using a metal-organic vapor phase epitaxy system equipped with a normal incidence optical reflectance setup. High-resolution X-ray diffractometry and synchrotron radiation X-ray topography were used to characterize the samples after growth. Combining the results from topography images and in-situ reflectance data, the formation of the misfit dislocations can be roughly identified from the reflectance curves and thus observed during growth.