INVESTIGATION OF VOIDS DISTRIBUTION IN AMORPHOUS HYDROGENATED CARBON NITRIDE FILMS BY POSITRON-ANNIHILATION AND THERMAL GAS EVOLUTION EXPERIMENTS

An investigation of the voids distribution in hard amorphous carbon ni tride films (a-CNx:H) and carbon (a-C:H) films deposited by self-bias glow-discharge was carried out by means of thermal gas evolution analy sis and positron annihilation spectroscopy. Internal stress measuremen ts were also performed. Our results for the carbon nitride films indic ate a clear correlation between the noticeable reduction of the intern al stress of the films and the increase of the voids concentration. Th e concentration of voids increases with the amount of incorporated nit rogen.