Design of large horizontal gallium nitride hydride vapor-phase epitaxy equipment and optimization of process parameters

Gallium nitride (GaN) has been extensively investigated in the last two decades owing to its excellent characteristics and massive commercialization potential. GaN substrates have been increasingly investigated to enhance the quality and efficiency of GaN-based optoelectronic devices. Hydride vapor-phase epitaxy (HVPE) method is generally employed for preparing GaN substrates. Herein, a six-inch horizontal HVPE equipment was designed using computational fluid dynamics (CFD) for depositing GaN epitaxial thin films. First, the original model was structurally designed, and baffles and other structures were set to achieve uniform outlet velocity. Second, single-factor variable method was used to analyze the influence of process parameters (flow rate, chamber pressure, and rotating speed) on deposition rate. An orthogonal design was used to optimize the main process parameters for uniform film deposition on six-inch substrates. Numerical simulation results provide a theoretical basis for optimizing a large-size HVPE reaction cavity and process conditions, paving the way for high-quality large-size GaN epitaxial thin films.