A Computational Study on the Three-Dimensional Reacting Flow to Simulate GaN Deposition in a Shallow Closed-Coupled Showerhead MOCVD System

Abstract

A numerical study is conducted on the reacting flow for an epitaxial growth of a GaN film in a closed-coupled showerhead metal-organic chemical vapor deposition reactor. A model based on the ANSYS Fluent is employed to simulate the three-dimensional flow and associated transport phenomena of reacting gases, namely trimethylgallium and ammonia, that are injected from a number of nozzles, with hydrogen used as a carrier gas. The results show that considering some simplistic chemical reactions enables a resonable prediction of the GaN deposition rate that is closely related to concentration distribution of key species. In addition, the three-dimensional flow characteristics derived from inertia effects of injected gases lead to a local nonuniform growth of GaN. Several numerical experiments were conducted with varying flow rate, pressure and rotation rate. The results of this study can be used as a guideline for an optimal operation.