The surface diffusion of Ga on an AlGaN/GaN facet structure in the MOVPE growth

The growth of a trapezoidal AlGaN/GaN heterostructure was attempted on a (111) Si substrate by selective area metal organic vapour phase epitaxy. On the trapezoidal sample we found that the manner of ridge growth is different in GaN growth from that in AlGaN growth. Analysing the thickness and composition with scanning electron microscopy (SEM), reflection electron microscopy (REM) and cathode luminescence (CL) spectroscopy, the diffusion length of Ga chemical species on the (0001) AlGaN surface was determined.