Deposition of highly crosslinked fluorinated amorphous carbon film and structural evolution during thermal annealing

Highly crosslinked fluorinated amorphous carbon films are obtained by increasing deposition temperature, enhancing ion bombardment, and fine tuning the fluorine-to-carbon ratio. The as-deposited films undergo significant mechanical, chemical, and electrical changes after thermal annealing. Most importantly, these changes occur only at the initial stage of annealing. After the thermal treatment, the films tend to be thermally stable and retain reasonably good electrical properties for use as a low-k dielectric.