Inert gas diffusion in DLC-Si films

Abstract Inert-gas diffusion in DLC–Si films was studied by thermal effusion experiments. It is shown that the motion of inert gases in the films is controlled by diffusion, greatly depending on the size of the diffusing species. The results provide qualitative information on the microstructure size in agreement with the doorway diffusion model, in which the mechanical stiffness of the material and the doorway radius are the important parameters that govern the diffusion process. Maximum effusion temperature is found to increase as the silicon content of the samples is increased, indicating smaller openings and/or increasing rigidity of the network. Analysis of inert-gas diffusion in annealed films suggests that the diffusion process cannot be directly related to carbon bonding and hydrogen content in the films. Network reconstruction effects are found to play an important role in the case of DLC–Si films.