MULTIPLE FREQUENCY POWER FOR PLASMA CHAMBER ELECTRODE

摘要

First through fifth RF power signals are respectively coupled to first through fifth RF connection points on an electrode of a plasma chamber. The first, second and third RF power signals have distinct first, second and third frequencies, respectively. The second and fourth RF power signals have the same frequency and opposite phase. The third and fifth RF power signals have the same frequency and opposite phase. The second through fifth RF connection points are geometrically arranged as four successive vertices of a quadrilateral convex polygon. The first RF connection point is closer to the center of the electrode. The center strong spatial distribution of the electric field produced by the first RF power signal is offset by the center weak spatial distribution of the electric field produced by the second through fifth RF power signals. An alternative embodiment omits the third and fifth RF power signals and the third and fifth RF connection points.