Planar laser-induced fluorescence of CF2 in O-2/CF4 and O-2/C2F6 chamber-cleaning plasmas: Spatial uniformity and comparison to electrical measurements

Planar laser-induced fluorescence (PLIF) measurements were made to determin e two-dimensional spatial maps of CF2 density as an indicator of chemical u niformity in 92% CF4/O-2 and 50% C2F6/O-2 chamber-cleaning plasmas at press ures between 13.3 Pa (100 mTorr) and 133.3 Pa (1000 mTorr). Measurements we re also made of broadband optical emission and of discharge current, voltag e and power. All measurements were made in a Gaseous Electronics Conference Reference Cell, a capacitively coupled, parallel-plate platform designed t o facilitate comparison of results among laboratories. The CF2 PLIF and emi ssion results were found to correlate with discharge current and voltage me asurements. Together, these optical and electrical measurements provide ins ight into the optimization of chamber-cleaning processes and reactors, sugg est new methods of monitoring plasma uniformity, and identify important spa tial effects which should be included in computer simulations. [S0734-2101( 99)02602-0].