Numerical Simulation of GaN Growth in a MOCVD Process

Abstract

This paper describes a model for the growth of gallium nitride in a vertical impinging metalorganic chemical vapor deposition (MOCVD) reactor. With trimethylgallium (TMGa) and ammonia (NH3) carried by hydrogen (H2) as precursors, the flow, temperature and concentration profiles are predicted by numerical modeling, which is performed using a commercial CFD software package CFD-ACE+. The growth rate is predicted based on detailed reaction mechanisms given in the literature, and related studies are carried out to verify the reliability and adaptability of the chosen chemical kinetics. A detailed mathematical model is developed first, and the complete chemical mechanisms are introduced. Then, the dependence of the growth rate and uniformity of the deposited layers on operating conditions, such as reactor operating pressure, susceptor temperature, inlet velocity and concentration of the precursors, is investigated to gain greater insight into the reactor performance and characteristics. Based on the simulation results, discussion is presented in this paper to offer the possibility of better control of the GaN film growth process, and to ultimately lead to an optimization of the process, with respect to production rate and film quality.