Numerical Analysis of Multi-Material and Segmented Focus Rings for Electromagnetic Field Analysis in CCP Using FDTD

Recent advances in semiconductor manufacturing have led to increasing research on segmented and multi-material focus rings for controlling electromagnetic environments in capacitively coupled plasma (CCP) reactors [1-2]. In this study, we utilized the finite-difference time-domain (FDTD) method in cylindrical coordinates to directly analyze the electromagnetic field (EM) distributions in CCP systems. FDTD simulations coupled with an external circuit model [3] were performed to investigate how various focus ring dielectric properties, as well as structural parameters such as the gap between the electrode and the focus ring, affect the electromagnetic field distribution in a CCP reactor. The simulation results were systematically compared with those obtained from a fluid model based on COMSOL Multiphysics. By varying the dielectric constant, segmentation, and geometric configuration of the focus ring, we analyzed the resulting changes in electric and magnetic field profiles. These comparative results are expected to be useful for quantitatively evaluating the influence of different focus ring design parameters on the electromagnetic characteristics of CCP reactors.