Numerical simulation of flow field and thermal field with variable struction in reactive ion etching cavity

In order to improve the uniformity of etching, continuous fluid model and heat transfer model of gas flow were established for 400mm reactive ion etching(RIE) chamber. Pressure, velocity and temperature distribution in the reaction chamber were studied. When cooling plate was kept at 285K, the distributions of velocity, pressure and temperature near the wafer in the cavity were analyzed by changing the inlet flow rate and outlet pressure in turn. Then the distance between the plates (30mm~60mm), the diameter of the intake port (300mm~620mm) and the diameter of the exhaust port (50mm~250mm) were changed in turn. Air flow and temperature distribution in the reaction chamber were analyzed. The results show that, the distribution of air pressure is characterized by low edge and high center. The flow velocity is characterized by high edge and low center. The uniformity of air pressure is better at low flow rate. The uniformity of pressure distribution increases with the increase of the distance between the chamber plates. It also increases with the decrease of the outlet area and the increase of the inlet area of the chamber gas. The temperature field near the top of the wafer is uniform and stable. It is almost unaffected by the fluctuation of inlet flow. Thermal stability is good. The research results are of great significance to the structural design improvement of large-aperture RIE chamber and the control of large-aperture reactive ion etching process.