A processing chamber includes a ground shield and a cover ring. The ground shield includes an annular body, and at least one guide pin extending from the annular body. The cover ring is positioned on the ground shield, and includes an annular body including at least one recess. At least a part of the at least one guide pin is receivable in the at least one recess, an inner cylindrical ring extends from the annular body, and an outer cylindrical ring extends from the annular body and is radially separated from the inner cylindrical ring by a horizontally extending portion of the annular body.