Design And Optimization Of The Heating Component For A MOCVD Reactor

MOCVD(Metal organic chemical vapor deposition)is an critical technology in the manufacturing of semiconductor material and optoelectronic device.Heating system is an important part of the MOCVD equipment.Its main function is to heat the substrate rapidly and uniformly so that the semiconductor material can grow in a good thermal environment.Each MOCVD chamber needs a matching heating system.A typical and commercial closed coupled showerhead(CCS)MOCVD chamber is selected to build the 3D simulation model in this article.We focus on the design and optimization of the component in heating system.The resistance-flake heater divided into three zones is investigated first.The research includes the effects of electric current and the thickness and position of the heater on the temperature distribution on the surface of graphite disk,and three kinds of structure include the "S" form,the single ring and the double-deck are applied to the outer heater to compare and analysis.The simulation results are indicated as follow.Changing electric current can only reduce the temperature difference of the graphite disk to some extent.Reducing the heater thickness can give a big increase to the temperature of graphite.But this method is not suitable for the outer heater because the thin flake deforms easily when heating.Increasing the distance between the heater and graphite will decrease the average temperature and worsen the temperature uniformity of graphite disk surface.A "S" form outer heater is not easily deform in high temperature and can give a uniform temperature distribution to the graphite disk surface when applied to the heater system.So it is the best choice for the outer heater.We also optimize the heater port to further improve the temperature uniformity.Then,we investigate the quantity and installation position of the reflector for the purpose of improving the heat efficiency.The results indicate that the average temperature improves but the temperature uniformity get worse when the reflector is added.When the reflector is added to 5,adding more reflector has little influence on heat efficiency improvement.5 installation plans of reflector are also proposed and analyzed.We Apply the optimized heat component to the chamber model according the research results.The simulation result shows that the optimized model has good temperature uniformity performance of graphite surface in difference target temperature 1200 K,1300K and 1400 K.The temperature difference is kept within 10 K.The optimized model can realized the uniform heating in different temperature range.