Multi-electrode source assembly for plasma processing

Abstract

Apparatus and methods for controlling the uniformity of a plasma formed using a radio frequency (RF) source power assembly that includes one or more resonant tuning circuits coupled to two or more electrodes disposed within a multi-electrode source assembly. Improved plasma uniformity control and reduced system cost are achieved by eliminating multiple RF generators and matches that power the multiple electrodes separately. Multiple frequencies may also be provided to multiple electrodes at the same time, which can include another cost savings when using a multi-frequency RF source assembly. Local plasma density and sheath voltage over a surface of a substrate are controlled with segmented electrodes disposed within the processing region of a plasma processing chamber. The ion flux and direction, as well as energetic electron flux towards the substrate, are controlled to address the plasma non-uniformity and global tilt during processing of a semiconductor substrate.