Growth and characterization of GaN epilayers grown at various flow rates of trimetylgallium during growth of nucleation layers

GaN epilayers have been grown on GaN nucleation layers as a function of the flow rate of TMG (trimetylgallium) decreases by deposition (MOCVD). The size of crystalline and amorphous GaN droplets became smaller as the flow rate of TMG (10.0, 8.0, 6.0, 4.0 SCCM, respectively) decreases during the growth of nucleation layers having the same thickness. The surface morphology and crystallinity of the epilayers characterized by DCXRD (double crystal X-ray diffractometer) depend on the TMG flow rate during growth of the GaN nucleation layers. The GaN epilayers grown on a nucleation layer at a rate of 8.0 SCCM exhibits the best crystallinity.