Simulation of flow and thermal field in a PECVD reaction chamber

The distribution of gas flow and temperature is one of the most important reasons that account for the film uniformity and deposition rate of Plasma enhanced chemical vapor deposition (PECVD). This paper analyzed the gas flow and temperature distribution of the PECVD chamber based on the continuous fluid and heat transfer model, and discussed the gas flow velocity pressure and temperature distribution near the wafer based on four kinds of flow stabilized chamber at the condition of 400°C heat-platform, 5000 sccm gas flowing into and 133 Pa pressure on the exhaust port. Then we compared the results, and discussed the flow filed at different mass flow (20-5000 sccm) inlet condition on the one model. The result shows that the bias of thermal and flow field inside the chamber are insignificant, though the exhaust port is biased, which indicates that the biased exhaust port has little influence on process uniformity. The thermal filed is uniform and stable, near the heater, and has a little fluctuation with the mass flow of inlet, which shows good stability; the pressure distribution has the parabolic character which the pressure is higher at the center and lower at the edge and the flow velocity distribution has the linear character which the velocity is slower at the center and faster at the edge; the gas flow pressure and velocity near the wafer and showerhead inlet increase with the rise of the inlet mass flow. The result has important significance on design of chamber structure and control of process.