The dissociative recombination of fluorocarbon ions III: CF⁺₂and CF⁺₃

Abstract

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Cross sections for vibrational excitation and dissociative recombination of the CF3+ ion in collisions with low-energy electrons

“…The value was used in several studies [4,17] until 2004, when the value of 2.8 ± 0.8 × 10 −7 cm 3 s −1 at 300 K, about a factor of three smaller than the above one, was measured using a flowing afterglow Langmuir probe-mass spectrometer apparatus [18]. A similar value of 2.6 × 10 −7 cm 3 s −1 at 300 K was obtained from the DR cross section measured in the ASTRID storage ring experiment two years later [11]. A further measurement of the rate coefficient was performed by another FALP experiment in 2013 [19], which produced the value of 3.1 ± 0.9 × 10 −7 cm 3 s −1 .…”

“…The branching ratio for the two channels was determined in the ASTRID storage ring experiment to be 80 ± 10% and 20 ± 10%, respectively [11]. CF and CF 2 radicals in the plasma contribute to the polymerization of fluorocarbon on the substrate surface, which impacts significantly the etching rate and selectivity [12].…”

CF3+and CF2H+: new reagents for n-alkane determination in chemical ionisation reaction mass spectrometry

“…At pressures of 10 -6 Torr, Eyler et al 28 observed that CF2 + ions were only present in small traces that reacted swiftly with the CF4 neutral species to form CF3 + ions and so they were essentially absent from the ICR-MS work within 5 ms. At pressures of 0.1 Torr and higher Ehlerding et al 29 produced CF2 + ions in substantial quantities at 1 Torr in quantities sufficient to provide feed stock for CF2H + generation. At 50 Td the CF2 + ions can react with H2O by proton extraction to form CF2H + .…”

“…29 produced CF 2 + ions in substantial quantities and at 1 Torr in quantities sufficient to provide feed stock for CF 2 H + generation. At 50 Td the CF 2 + ions can react with H 2 O…”

A global model study of low pressure high density CF4 discharge

“…Cross sections and branching ratios for electron-impact dissociative recombination by + CF 3 and + CF 2 were measured by Ehlerding et al [134] through ASTRID and CRYRING storage rings. Flowing Afterglow-Langmuir Probe (FALP) measurements carried out by Fournier et al [135] agreed with the previous results for dissociative recombination of + CF 3 [134,136]. Electron-impact dissociative recombination by CF + was studied by Novotny et al [137][138][139].…”