An electrode structure with an alloy interface is provided. In one aspect, a method of forming a contact structure includes: patterning a via in a first dielectric layer; depositing a barrier layer onto the first dielectric layer, lining the via; depositing and polishing a first metal layer (Element A) into the via to form a contact in the via; depositing a second metal layer (Element B) onto the contact in the via; annealing the first and second metal layers under conditions sufficient to form an alloy AB; depositing a third metal layer onto the second metal layer; patterning the second and third metal layers into a pedestal stack over the contact to form an electrode over the contact, wherein the alloy AB is present at an interface of the electrode and the contact; and depositing a second dielectric that surrounds the pedestal stack. A contact structure is also provided.