X-Ray Analysis of Twist and Tilt of GaN Prepared by Facet-Controlled Epitaxial Lateral Overgrowth (FACELO)

The tilt and twist of GaN prepared by facet-controlled epitaxial lateral overgrowth (FACELO) were evaluated by the X-ray rocking curve measurement of symmetric and asymmetric reflections. Compared to the underlying GaN, the tilt and twist values became substantially smaller at 130 and 250 arcsec, respectively, which are consistent with published results of transmission electron microscopy and cathode luminescence analyses. Moreover, FACELO-GaN is almost free of small angle tilt boundaries in contrast to GaN prepared by simple epitaxial lateral overgrowth.