Mid-chamber gas distribution plate, tuned plasma flow control grid and electrode

摘要

A plasma reactor is provided for processing a workpiece such as a semiconductor wafer or a dielectric mask. The reactor chamber has a ceiling, a side wall and a workpiece support pedestal inside the chamber and facing the ceiling along an axis of symmetry and defining a chamber volume between the pedestal and the ceiling. An RF plasma source power applicator is provided at the ceiling. An in-situ electrode body inside the chamber lies divides the chamber into upper and lower chamber regions. The in-situ electrode comprises plural flow-through passages extending parallel to the axis and having different opening sizes, the passages being radially distributed by opening size in accordance with a desired radial distribution of gas flow resistance through the in-situ electrode body.