Ion energy and angular distributions at the anode of RF etch reactors

Abstract

The authors present calculations of ion energy and angular distributions (IEDs and IADs) for ions striking the grounded electrode (anode) of RIE reactors. These distributions were calculated using a Monte Carlo simulation program incorporating a model for ion trajectories in the oscillating sheath region. They compare these IEDs and IADs to previously calculated distributions for the driven electrode (cathode). The effect upon the IEDs of varying the ratio of the area of the cathode:anode from 0.01 to 1.0 has been investigated. They also examine the effect upon IEDs of decreasing the frequency from 13.56 MHz to 100 kHz. IEDs for CF3+, CF2+ and CF+ ions have been simulated and compared with experimentally observed distributions. The calculated distributions closely resemble experimental IEDs, confirming that the simulations model anode processes as accurately as they model cathode processes.