A first metal-containing material (22) is formed over a semiconductor device substrate (10). A second metal-containing material (32) is formed over the first metal containing material (22). The combination of the second metal-containing material (32) formed over the first metal-containing material (22) forms a metal stack (34). The metal stack (34) is annealed and a post-anneal stress of the metal stack (34) is less than an individual post-anneal stress of either one of the first conductive film (22) or the second conductive film (32).