A Quantum Chemical Study of the Gas-Phase Reaction Pathways in Metal–Organic Chemical Vapor Deposition Growth of InAlN

Based on quantum chemical theory, the gas-phase chemical cross-reaction pathways in metal–organic chemical vapor deposition of InAlN films have been investigated. First, calculations of the oligomerization reactions of Al and In amides were performed to investigate the relative difficulty of generating several dimers and trimers within this system. The elimination reaction pathways were then investigated. The final stable products of the polymers were analyzed from both thermodynamic and kinetic perspectives, and the propensities of the reaction pathways were assessed from the viewpoint of the reaction rates. The results indicated that in the gas-phase reaction pathways of InAlN grown by metal–organic chemical vapor deposition, the equilibrium temperature for the dimerization reactions lies between 960 and 1061 K, and above this temperature range, dimers cannot form. Trimer formation is unlikely during the InAlN growth process. At higher reaction temperatures, the oligomers tend to first undergo intramolecular elimination, losing two CH4 molecules to form intermediate products, which then react with NH3 via intermolecular elimination to yield stable products. At lower reaction temperatures, the tendency is for continuous intermolecular elimination with NH4 to generate stable, methyl-free products.