Hydride vapor phase epitaxy of high quality {101̄3̄} semipolar GaN on m-plane sapphire coated with self-assembled SiO2 nanospheres

• A method to grow high quality semipolar {101̄3̄} GaN on self-assembled SiO2 nanospheres sapphire (SSNS) is present.
• The density of the defects reduced in the SSNS semi-GaN due to nanoepitaxial lateral overgrowth.
• The stress is partially relaxed in the SSNS semi-GaN.

Semipolar {101̄3̄} GaN layers were grown on self-assembled SiO2 nanospheres sapphire (SSNS) by hydride vapor phase epitaxy. The RMS roughness was 1.1 nm for the scan of 20×20 µm2 and the striated surface morphology almost disappeared. The full widths at half maximum of on-axis X-ray rocking curves were 324 arcsec rocking toward the [303̄2̄] direction and 413 arcsec rocking toward the [12̄10] direction, respectively. Compared to the GaN layer grown on the planar sapphire, the reduction of the defect density of semi-GaN grown on SSNS, such as basal stacking faults, partial dislocations and perfect dislocations, was demonstrated by both X-ray rocking curves and low-temperature photoluminescence. In addition, the Raman analyses also showed the partial relaxation of the stress using SSNS.