Numerical Simulation Of MOCVD Reactor Based On CFD

Metal organic chemical vapor deposition (MOCVD) is the key technology forpreparation of microelectronic and optoelectronic devices, and it has wideapplication prospect and market demand, especially in the preparation of GaN basedLED. The reactor is the core of the whole MOCVD system, which directly affectsthe quality of epitaxial film. Due to the structure of reactor is complex and the flowand temperature fields are unobservable, therefore, it is necessary to master theregularity of flow and heat transfer in MOCVD reactor by using numericalsimulation.Aiming at self-developed61×2″MOCVD, this paper use CFD technology ofFLUENT software to simulate the temperature and flow fields of the chamber, thispaper mainly studies the influence of process parameters (such as inlet flow rate,chamber pressure, growth temperature, wafer carrier rotation rate, distance betweeninlet and susceptor, etc.) on the temperature and flow fields.The study found that increasing inlet flow rate will inhibit the action ofeffective thermal buoyancy. However, increasing the inlet flow rate also generatesvortex. The operation pressure is not sensitive to the chamber temperature and flowfields. Increasing susceptor’s temperature enlarged the temperature gradient betweensusceptor and inlet, high temperature layer to be thinner, with deposition of film, thedeposition rate. The wafer carrier rotation can make flow more closer to substratesurface, so that the reactant distribution within the reactor is more reasonable. WhenIncreased the distance between susceptor and inlet, the velocity gradient decreasedin the vertical direction. Speed value is small above the susceptor, and the ability ofinhibiting thermal buoyancy effect is low. The area of high temperature is thick,which is not conducive to the growth of thin films.Combined with the results of numerical simulation analysis, the study foundthat the reactor corner which is smooth can eliminate vortex, flow field intends to bestable. Increasing axial Reynolds in reactor can effectively inhibit the thermal buoyancy effect, so as to optimize the flow field distribution above the susceptor.The realization of the reactor’s height adjustable can speed up the film depositionrate, improve the film uniformity and increase utilization of MO source.The results of this research has been applied to the design of reactor andepitaxial growth which do help to improve the epitaxial quality.