Development and study of the reactor design for metal-organic gas-phase epitaxy of group III nitrides

Abstract

This article presents the design, numerical simulation, and experimental validation of a III-N metalorganic vapor-phase epitaxy reactor, alongside the experimental growth of AlN films. A key feature of this reactor is its coaxial precursor delivery system combined with active water cooling of the intermediate zone, which effectively suppresses parasitic gas-phase reactions and buoyancy-driven convection. Computational fluid dynamics simulations demonstrate that this design maintains gas temperatures below 450 °C prior to the mixing point, thereby preventing the premature decomposition of metalorganic precursors. Additionally, the growth parameters for AlN films on Si(100) substrates were experimentally optimized. The results indicate that a maximum thickness of 800 nm for the dense, coalesced layer is achieved at a substrate temperature of 700 °C and a TMA/NH3 flow ratio of 0.53, corresponding to a transition to a diffusion-controlled growth regime. Finally, the potential of utilizing high-frequency plasma activation for the synthesis of metastable AlGaInN solid solutions is discussed.