Apparatus and method for metal plasma vapor deposition and re-sputter with source and bias power frequencies applied through the workpiece

摘要

Physical vapor deposition and re-sputtering of a barrier layer in an integrated circuit is performed by providing a metal target near a ceiling of the chamber and a wafer support pedestal facing the target near a floor of the chamber. A process gas is introduced into said vacuum chamber. A target-sputtering plasma is maintained at the target to produce a stream of principally neutral atoms flowing from the target toward the wafer for vapor deposition. A wafer-sputtering plasma is maintained near the wafer support pedestal to produce a stream of sputtering ions toward the wafer support pedestal for re-sputtering. The sputtering ions are accelerated across a plasma sheath at the wafer in a direction normal to a surface of the wafer to render the sputter etching highly selective for horizontal surfaces.