Thermal Stability of Fluorinated Amorphous Carbon Thin Films with Low Dielectric Constant

Abstract
Fluorinated amorphous carbon (a-C:F) thin films were deposited by inductively coupled plasma enhanced chemical vapor deposition and annealed with increasing annealing temperature (100, 200, 300, 400°C). The evolution of composition, dielectric constant, and bonding configuration were investigated during the thermal annealing process. As the annealing temperature increased, the dielectric constant varied from 2.4 to 3.6; the atomic ratio of F varied from 25 to 10%, and that of C varied from 75 to 85%; in the C­FxC­Fx bonding configurations, the C-F bondings decrease and the C­F2C­F2 and C­F3C­F3 bondings are almost constant. Thus, the C­F2C­F2 and C­F3C­F3 bonding configurations are thermally more stable than the C-F bonding configuration. The structure of the film changes to a crosslinked structure by an increase in the C-C bonding and a decrease in the C-F bonding. © 2001 The Electrochemical Society. All rights reserved.