Influences of gallium and nitrogen partial pressure on step-bunching and step-meandering morphology of InGaN quantum barrier layer

Abstract As the templates for the growth of the quantum well layer, the morphology of the quantum barrier layer is crucial. Through a cross-comparison among samples grown under different conditions, the effect of TMGa flux, NH3 flux, indium content, and temperature on morphology of InGaN quantum barrier grown by Metal-Organic Chemical Vapor Deposition (MOCVD) is studied. It is found that TMGa and NH3 flux increments are counterbalancing each other in terms of adatom diffusion. Without balanced V/III fluxes, the surface roughens either by spiral hillocks or by strong step meandering. The morphology can be quite different even under a similar V/III ratio. LED samples using the V/III unbalanced quantum barriers, compared to the V-III balanced ones, present inferior optical properties.