A packaged semiconductor device includes a semiconductor substrate, a metal pad, a metal base, a polymer insulating layer, a copper-containing structure and a conductive bump. The metal pad and the metal base are disposed on the semiconductor substrate. The polymer insulating layer overlies the metal base and the semiconductor substrate. The copper-containing structure is disposed over the polymer insulating layer, and includes a support structure and a post-passivation interconnect (PPI) line. The support structure is aligned with the metal base. The PPI line is located partially within the support structure, and extends out through an opening of the support structure, in which a top of the support structure is elevated higher than a top of the PPI line. The conductive bump is held by the support structure.