An embodiment integrated circuit structure includes a substrate, a metal pad over the substrate, a post-passivation interconnect (PPI) structure over the substrate and electronically connected to the metal pad, a first polymer layer over the PPI structure, an under bump metallurgy (UBM) extending into an opening in the first polymer layer and electronically connected to the PPI structure, and a barrier layer on a top surface of the first polymer layer adjacent to the UBM.