Analysis of In <i>x</i> Ga1− <i>x</i> N growth rate in atmospheric-pressure metal-organic vapor phase epitaxy: Insights into incorporation and desorption processes of GaN and InN for precise growth control

Abstract

We grew GaN/InxGa1−xN superlattices (SLs) on GaN/sapphire substrates by atmospheric-pressure metal-organic vapor phase epitaxy (MOVPE) and determined the InxGa1−xN growth rate using high-resolution x-ray diffraction analysis. The use of SL structures substantially reduced the influence of strain relaxation, phase separation, and mixed 2D/3D growth modes, enabling reliable extraction of the effective GaN and InN growth rates within the alloy. By maintaining identical temperature, pressure, and gas-flow balance, we precisely estimated the individual growth rates and proposed a model that explicitly separates incorporation and desorption processes. For low-In composition (xIn &amp;lt; 0.25), the GaN and InN rates exhibit negligible mutual interaction and depend solely on temperature under constant pressure and flow balance. The model successfully predicts InxGa1−xN growth rates using independent incorporation and desorption terms, and its applicability is confirmed for In vapor-phase ratios &amp;lt;0.7 and sufficiently high V/III ratios, while limitations are identified under excess-In or low-temperature conditions. These results provide practical guidelines for optimizing MOVPE growth, contributing to the efficient design of active and SL layers for high-power light-emitting diodes and green laser diodes.