Two-dimensional simulation of ion energy and angular distributions at the wafer in low-pressure RF discharges

Summary form only given. We have developed a two-dimensional, electromagnetic, PIC-MCC code to study the ion energy and angular distributions in the RF biased sheaths. At the bulk-sheath boundary, the ion flux distribution into the sheath region can be specified, say, from our simple two-dimensional fluid simulation slightly different from Paranjpe's (1994) in that we use global model to determine the electron temperature. The electron flux into the sheath region is adjusted to satisfy the quasi-neutrality condition at every fixed time interval during the simulation. We will present simulation results of ion energy and angular distributions, ion flux incident on the wafer, and self-bias at the wafer as a function of the applied RF frequency, the amplitude of the RF bias, ion mass, and the blocking capacitance. The results from particle simulations will also be compared with analytic calculations. We found if the incoming ion flux is uniform, then the ion flux striking the wafer remains nearly uniform across the wafer. The spread of ion angular distribution was found to be larger near the wafer's edge than the center of the wafer.