Method and apparatus for treating wafer edge region with toroidal plasma

摘要

Method and apparatus for treating an edge region of a wafer. A toroidal shaped plasma cavity has an inner diameter which is slightly less than the diameter of the wafer being treated so that only the edge region of the wafer extends into the toroidal plasma cavity. An inert gas is flowed across a front and back side of the wafer into the plasma cavity. A reactive gas is flowed directly into the plasma cavity. The gases exit the plasma cavity without flowing over the surface of the wafer.