Integrated circuit interconnect structures with ultra-thin metal chalcogenide barrier materials

Abstract

Integrated circuit interconnect structures including an interconnect metallization feature with a barrier material comprising a metal and a chalcogen. Introduction of the chalcogen may improve diffusion barrier properties at a given barrier material layer thickness with increasing the barrier layer thickness. A barrier material, such as TaN, may be deposited at minimal thickness, and doped with a chalcogen before or after one or more fill materials are deposited over the barrier material. During thermal processing mobile chalcogen impurities may collect within regions within the barrier material to high enough concentrations for at least a portion of the barrier material to be converted into a metal chalcogenide layer. The metal chalcogenide layer may have greater crystallinity than a remainder of the barrier layer.