Abstract: Integrated circuitry interconnect structures comprising a first metal and a graphene cap over a top surface of the first metal. Within the interconnect structure an amount of a second metal, nitrogen, or silicon is greater proximal to an interface of the graphene cap. The presence of the second metal, nitrogen, or silicon may improve adhesion of the graphene to the first metal and/or otherwise improve electromigration resistance of a graphene capped interconnect structure. The second metal, nitrogen, or silicon may be introduced into the first metal during deposition of the first metal, or during a post-deposition treatment of the first metal. The second metal, nitrogen, or silicon may be introduced prior to, or after, capping the first metal with graphene.