Arrangement and method for improved downward scaling of higher conductivity metal-based interconnects

Abstract

For downwardly-scaled semiconductor processing, high-conductivity metal diffusion is blocked using extremely thin barrier films/layers. Diffusion of a highly-conductive metal is minimized using a dielectric barrier layer positioned a distance under the high-conductivity metal and a distance above the active regions of a semiconductor device. According to one embodiment, a semiconductor device also includes a highly-conductive metal interconnect patterned over a conductive partial diffusion barrier and adhesion promoting film. An underlying dielectric barrier layer against diffusion of the metal interconnect is formed above the active area but not in direct contact with the metal interconnect and is used to block diffusion that is not blocked by the partial diffusion barrier and adhesion promoting film. In a more specific embodiment, the metal interconnect is coated on the upper surface and edges with a thin electrolessly deposited partial barrier film, such as nickel or cobalt.