Graphene sacrificial deposition layer on beol copper liner-seed for mitigating queue-time issues between liner and plating step

Abstract

After forming a copper seed layer on a diffusion barrier layer present on sidewalls and a bottom surface of at least one opening, a graphene sacrificial layer is deposited over the copper seed layer before the copper seed layer is exposed to an environment that oxidizes the copper seed layer, thus providing process flexibility for longer queue times (Q-times) between copper seed layer deposition and copper plating. Next, the graphene sacrificial layer is subjected to a plasma treatment to introduce disorders and defects into the graphene sacrificial layer for removal just before the copper plating. The entire structure is then immersed in a copper plating solution. The copper plating solution dissolves the plasma treated graphene sacrificial layer and forms a copper-containing layer on the re-exposed copper seed layer.