Interconnect structures with nitrogen-rich dielectric material interfaces for low resistance vias in integrated circuits

Abstract

Integrated circuit structures including an interconnect feature without a higher-resistance liner material. In absence of a liner, metal of low resistance directly contacts an adjacent dielectric material, enabling lower resistance interconnect. Even for low-k dielectric compositions, adhesion of the metal to the dielectric material is improved through the incorporation of nitrogen proximal to the interface. Prior to deposition of the metal upon a surface of the dielectric, the surface is exposed to nitrogen species to form a nitrogen-rich compound at the surface. The metal deposited upon the surface may then be nitrogen-lean, for example a substantially pure elemental metal or metal alloy.