The role of diluent in NF/sub 3/ RF plasmas

Summary form only given. Optical emission spectroscopy (OES) and a Langmuir probe were used to study the chemical and physical state of NF/sub 3/ RF plasma discharges with respect to diluent. The diluents examined include Ar, He, N/sub 2/, O/sub 2/, an N/sub 2/O. OES was used to determine the amount of fluorine and other atomic and ionic species present in the NF/sub 3/ plasma. The Langmuir probe was used to determine plasma potentials, electron density, ion density, and electron temperature. Diluent was found to have a dramatic effect on the state of the plasma and etch rates measured. As expected for an electronegative gas, the ratios of electron density to ion density in the NF/sub 3/ mixes were much lower than those found in the plasmas of the pure diluents. Etch rates for SiO/sub 2/ and Si/sub 3/N/sub 4/ were found to have the slowest etch rates. Nitrogen was found to produce the highest etch rate for SiO/sub 2/. Argon diluted NF/sub 3/ was found to have the highest etch rate for Si/sub 3/N/sub 4/, followed closely by the nitrogen mix.