Simulation of Low-Pressure Capacitively Coupled Plasmas Combining a Parallelized Particle-in-Cell Simulation and Direct Simulation of Monte Carlo

A parallelized particle-in-cell (PIC) simulation and direct simulation of Monte Carlo (DSMC) are combined to simulate low-pressure discharges. A two-dimensional (2-D) PIC simulation parallelized with graphics processing units is used to examine the discharge characteristics of a capacitively coupled plasma device at pressures <; 10 mTorr, whereas a DSMC method is used to calculate the neutral distribution instead of a fluid model. The neutral distribution profile is transferred to the PIC simulation as the initial condition. At low gas pressures, the neutral density profile shows nonuniform properties, which also changes the simulation results of plasma uniformity. Overall, the inclusion of an accurate neutral density profile is essential for obtaining exact simulation results that are comparable with the experimental results.