Analysis of factors affecting temperature uniformity of high-temperature electrostatic chucks in CVD equipment

The electrostatic chuck is a semiconductor process equipment that uses electrostatic adsorption force to attach a wafer to a surface and controls the surface temperature of the wafer through thermal conduction as the main temperature control method. It plays a key role in current integrated circuit equipment. The uniformity of temperature (temperature difference) directly affects the quality of wafer film formation and is one of the crucial indicators. This study focuses on the factors affecting heat transfer in electrostatic chucks under high-temperature CVD process environment. Firstly, a thermal conduction model between CVD chamber environment and electrostatic chuck is established using ANSYS Workbench; Then, the influence of different electrostatic chuck structures and engineering errors on the surface temperature uniformity of electrostatic chucks under CVD process environment is analyzed; Finally, experiments also verified the simulation results of one type of electrostatic chuck through CVD chamber. Based on the above analysis, the results indicate that for this type of electrostatic chuck, the contact structure between the disc body and the shaft, as well as the distribution of heating wires, have a significant impact on the temperature field distribution. The inclination of the heating wire has almost no effect on the temperature field distribution, The thermal conductivity of the shaft, the thickness of the shaft wall, and the size of the electrostatic chuck have an impact on the local temperature field distribution. The research content of this article has important guiding significance for the improvement of heat transfer theory of electrostatic chucks and the subsequent design optimization of electrostatic chucks.