Plasma processing including asymmetrically grounding a susceptor

摘要

An asymmetrically grounded susceptor used in a plasma processing chamber for chemical vapor deposition onto large rectangular panels supported on and grounded by the susceptor. A plurality of grounding straps are connected between the periphery of the susceptor to the grounded vacuum chamber to shorten the grounding paths for RF electrons. Flexible straps allow the susceptor to vertically move. The straps provide a conductance to ground which is asymmetric around the periphery. The straps may be evenly spaced but have different thicknesses or different shapes or be removed from available grounding point and hence provide different RF conductances. The asymmetry is selected to improve the deposition uniformity and other qualities of the PECVD deposited film.