Diagnostics of etching plasmas

Radio-frequency excited, low-pressure plasmas in halogen-containing gases are widely used to etch submicronic features in a range of materials during integrated circuit manufacture. Costly process-drift problems are often caused by the ubiquitous deposition of polymer layers on the reactor walls. Simple and robust sensors of the reactor performance are needed to monitor and manage these effects. This paper presents results obtained in industrial plasma-etching machines using a deposition-tolerant ion flux probe and broadband UV-vis absorption spetroscopy.