Characterization of a-plane InGaN light-emitting diodes with a SiNx interlayer grown on a patterned sapphire substrate by metal-organic chemical vapor deposition

Nonpolar, a-plane InGaN light-emitting diodes (LEDs) were grown on a hemispherical r-plane patterned sapphire substrate (HPSS) by the in situ deposition of SiNx masks and on a planar sapphire substrate by metalorganic chemical deposition (MOCVD). The use of the SiNx interlayer together with HPSS resulted in a reduced density of defects, such as basal plane stacking faults (BSFs) and partial dislocations (PDs) in the GaN epilayers, as compared with the use of GaN on a conventional planar substrate. The optical power of the InGaN LEDs with the SiNx layer and HPSS was approximately 2.5- and 10-fold higher than those of LEDs on SiNx and on a planar substrate at a current of 100 mA, respectively.