End-point detection in plasma etching by monitoring radio frequency matching network

摘要

The present invention relates to a system and method for detecting the end-point of a layer being removed from a semiconductor wafer by a plasma etching system. The invention determines end-point by referencing first and second positions of matching components of a matching network between a radio frequency source and the plasma etching system chamber. Comparison of a first position representative of chamber load impedance before end-point, and a second position representative of a change in chamber load impedance is utilized to determine end point.