FOCUS RING ASSEMBLY TO SUBSTANTIALLY DELETE FREE PLASMA IN A PLASMA TREATMENT CHAMBER.

摘要

A focus ring assembly configured to substantially surround a workpiece holder of a plasma treatment chamber, which includes: an annular dielectric body; and an electrically conductive shell surrounding said annular dielectric body, said electrically conductive shell being configured to be electrically grounded inside said plasma treatment chamber, including said electrically conductive shell: a tubular part that is located outside said annular dielectric body and surrounding at least a part of said annular dielectric body, characterized by an inwardly oriented collar part that is in electrical contact with said tubular part, said collar part forming a plane that it cuts to said tubular part, said collar part being embedded in said annular dielectric body.