DIFFUSION IN SEVERAL MATERIALS RELEVANT TO CU INTERCONNECTION TECHNOLOGY

Knowledge or copper diffusion in conducting, dielectric and diffusion barrier thin films relevant to the upcoming Cu interconnection technology is important in order to understand electromigration and prevent degradation of the active devices in Si. Copper diffusion in several thin films considered essential for substitution of Al with Cu interconnects to reduce RC delays is discussed, and the available data are compiled. Fast diffusion of Cu has been observed through inorganic and organic dielectric films, so that the conducting Cu films will require encapsulation. Diffusion of Cu through CVD-W, TiAl3-0.5%Cu, TiCu and beta-Ta diffusion barriers has also been studied in a comparative manner.