Plasma Characteristics Analysis and Coil Optimization in Inductively Coupled Chambers

With the increasing demand for semiconductor coating uniformity and etching accuracy, advanced requirements are put forward for the coating and etching process. However, the coating characteristics of the existing PECVD equipment always have shortcomings, such as thick middle and thin edge, and the coating uniformity needs to be improved. In this study, the COMSOL simulation software is used to simulate the factors affecting the inductive coupling to generate plasma in the process of developing PECVD equipment. The results show that the electron density increases with the increase of the polar distance, and simultaneously the chamber pressure, electron density, gradient value, coil power, and electron density are likely to change. The plasma, AC/DC, and optimization modules of the simulation software are used to optimize the placement of the coil. The gradient value on the user-defined radial electron density detection line is used as the objective function, and the coil is moved radially through the constraint function to obtain the plasma. Under optimal conditions, the coil distribution map with uniform volume distribution improves the electron density uniformity by 34.7%. The created approaches of this paper are successfully applied to the self-developed PECVD equipment and manifest their consequential potential tool, which meets the requirements of users.