Amorphous SixC1-x(a-SixC1-x) films with x ranging from 0 to 0.4 have been produced using a high energy ion beam deposition method. The resulting films have been characterized by Raman annihilation spectroscopy and positron annihilation spectroscopy (PAS). Hardness and wear resistance have also been measured. It has been shown that the open volume defects and their distribution through the films have an important role in determining the mechanical behavior of the as-deposited and thermal treated films.