Electron attachment to C2 fluorocarbon radicals at high temperature.

Area of Science:

• Plasma chemistry
• Chemical kinetics

Background:

• Understanding electron attachment to fluorinated radicals is crucial for plasma processes.
• Previous kinetic modeling predicted high-temperature behavior.

Purpose of the Study:

• Investigate thermal electron attachment to C2F3 and C2F5 radicals.
• Validate existing kinetic models at elevated temperatures.

Main Methods:

• Variable Electron and Neutral Density Attachment Mass Spectrometry (VENtreeMS).
• Studied temperature range: 300–890 K.
• Measured attachment to C2F3Br and C2F5Br precursors.

Main Results:

• Both C2F3 and C2F5 radicals exclusively form F(-) via dissociative attachment.
• C2F5 attachment rate constant remained stable (~4 × 10⁻⁹ cm³/s).
• C2F3 attachment rate constant increased significantly with temperature (3 × 10⁻¹¹ to 1 × 10⁻⁹ cm³/s).

Conclusions:

• Experimental data align with predictions from a simplified kinetic modeling approach.
• The kinetic modeling approach is validated for high-temperature electron attachment studies.
• Provides essential data for plasma process modeling involving fluorinated compounds.