Abstract
This paper reports structural characterization on semipolar GaN films grown on r-plane sapphire substrates by metalorganic vapor-phase epitaxy. The polar orientation of semipolar GaN is assigned that the N-polar plane faces the surface side. The epitaxial relationship of the semipolar GaN/r-plane sapphire is determined as [000 (1) over bar](GaN)parallel to[1 (2) over bar 13](sapphire) and [1 (1) over bar 00](GaN)parallel to[1 (1) over bar0 (1) over bar](sapphire). An anomalous phase orthogonal-twisted around the c-axis is revealed by transmission electron microscope, which is almost localized at the surface.