Synchrotron radiation X‐ray topography and X‐ray diffraction of homoepitaxial GaN grown on ammonothermal GaN

In this study, homoepitaxial GaN grown on ammonothermal GaN substrates is non-destructively investigated by synchrotron radiation X-ray topography (SR-XRT) and X-ray diffraction (XRD). The homoepitaxial GaN layer was found to be of excellent crystal quality with individual dislocations clearly visible in the SR-XRT images. SR-XRT images and XRD rocking curves suggest the dislocations are mainly of mixed type. To the best of our knowledge the measured dislocation density is the lowest reported in a homoepitaxial GaN film (© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)