This study investigated the material and electrical characteristics of hydrogen, nitrogen plasma-treated fluorinated amorphous carbon (a-C:F) films in relation to their thermal stability. Experimental results indicate that the nitridation passivation layer and hydrogen passivated chemical bonds on the film surface effectively suppress thermal decomposition during high temperature annealing. Accordingly, a multiple plasma treatment on a-C: F films was proposed. In this treatment, nitrogen plasma nitridation was performed not only to passivate the a-C: F films against copper diffusion, but also to prevent the fluorine contents from penetrating into copper intermetals. Hydrogen plasma treatment then recovered unstable bonds formed during the nitridation process, thus yielding stable chemical structures and inducing hydrophobic characteristics of the film surface. The multiple plasma-treated a-C: F films demonstrated the desired performance as interlayer dielectrics.