Simulation of ion energy and angular distribution functions using Monte Carlo method coupled with multidimensional radio frequency sheath model developed utilizing COMSOL Multiphysics

We have developed a numerical tool to precisely predict the ion energy and angular distribution functions (IEDF and IADF) for an if sheath formed around an arbitrary surface geometry in a single- or dual-frequency capacitively coupled plasma (CCP). A Monte Carlo method is utilized to simulate ion trajectories and collisions with neutrals in an oscillating sheath calculated with our multidimensional if sheath model based on a finite element method. The IEDF calculated for a one-dimensional sheath in a dual-frequency CCP agreed very well with the measured data. The comparison proved the validity of the present model. We also present the IEDF and IADF obtained for a two-dimensional sheath around a wafer edge and an adjacent focus ring in another dual-frequency CCP to demonstrate a multidimensional capability of the present model. (C) 2014 The Japan Society of Applied Physics