VACUUM-ULTRAVIOLET EMISSION FROM RADIO-FREQUENCY PLASMAS OF SF6 AND CF4

The vacuum ultraviolet and ultraviolet emission (115 nm<lambda<300 nm) from radio frequency (rf) discharges through CF4 and SF6 have been in vestigated as a function of source pressure and rf power. Prominent fe atures of the spectra arise from dissociative excitation of the parent species. Other significant emissions are impurity bands from CO (CF4) or SO (SF6) caused largely by oxygen release from the walls of the di scharge tube and subsequent discharge chemistry and excitation. Minor emissions from excited CF4+, CF3, and/or CF2 were obtained from CF4 di scharges. (C) 1996 American Vacuum Society.