NonpolarGaN and semipolarGaN have been studied for minimization of quantum confined Stark effect in c-plane GaN. A(1122) semipolarGaN layer was grown on m-plane sapphire substrates via epitaxial lateral overgrowth (ELOG) by metalorganic chemical vapor deposition. Cross section filed emission scanning electron microscopy revealed a semipolarGaN layerwith a smooth surface and an inverted trapezoid growth shape. For the layers not fully merged laterally, the structuralanisotropic characteristics were reduced slightly. After merging laterally, the structural anisotropy was reduced significantly. In the [1100] directions of the X-ray beams, the full width at half maximum (FWHM)of the x-ray rocking curve of the (1122)plane was 1195 arcsec for semipolarGaN on unpatterned template and the FWHM decreased to 468 arcsec for mergedsemipolarGaN by ELOG.In addition, the optical properties of (1122) semipolarGaN using ELOG were improved significantly.
Keywords: Epitaxial lateral overgrowth, MOCVD, SemipolarGaN, Refractive Index