Some implementations provide a semiconductor device (e.g., die) that includes a substrate, several metal layers and dielectric layers coupled to the substrate, a pad coupled to one of the plurality of metal layers, a first metal redistribution layer coupled to the pad, and a second metal redistribution layer coupled to the first metal redistribution layer. The second metal redistribution layer includes a cobalt tungsten phosphorous material. In some implementations, the first metal redistribution layer is a copper layer. In some implementations, the semiconductor device further includes a first underbump metallization (UBM) layer and a second underbump metallization (UBM) layer.