Optimization of Digital Growth of Thick N-Polar InGaN by MOCVD

Smooth 200 nm thick N-polar InGaN films were grown by metal-organic chemical vapor deposition (MOCVD) on sapphire using a digital approach consisting of a constant In, Ga, and N precursor flow with pulsed injection of H-2 into the N-2 carrier gas. Using this growth scheme, the H-2 injection time was altered and the effect on the morphology and indium incorporation in the films observed. The effect of periodic insertion of additional GaN inter-layers on the surface morphology of the InGaN layers was also studied.