Improved GaN Homo-Junction, Ultraviolet, Light-Emitting Diodes Grown on Step-Free 4H-SiC Mesas

We report improvements in ultraviolet (380 nm) electroluminescence (EL) output of GaN pn homojunctions grown on 4H-SiC mesas with step-free surfaces of 49% on average in comparison to their stepped counterparts. The GaN on step-free 4H-SiC growth process has been previously reported to lead to 100-fold reductions in threading dislocation densities in III-N heterofilms. Despite the intense EL from the GaN on step-free SiC devices, significant current leakage was observed through the periphery of the device, possibly due to the lack of GaN junction isolation processing.