2-D imaging of temperature in CF4 plasmas

Two-dimensional maps of rotational temperature were determined in CF₄ plasmas using planar laser-induced fluorescence of CF. Experiments were performed in a capacitively-coupled, parallel plate plasma reactor at pressures from 26.7 Pa (200 mtorr) to 107 Pa (800 mtorr) and powers of 10-30 W. Temperatures, which ranged from 273 ± 15 K to 480 ± 15 K, increased with pressure and power and were fairly axially symmetric with radial gradients. Temperature gradients, such as those observed here, can have a strong impact on density measurements that probe a single rotational level, as well as on reaction rate constants and interpretation of density gradients.