A method for fabricating a pad redistribution layer. First, at least one bonding pad exposed by a first passivation layer is provided. A diffusion barrier layer and a seed layer are then formed over the first passivation layer and the bonding pad. A patterned mask layer is then formed over the seed layer to expose a portion thereof over the bonding pad, and a metal layer is then formed thereon. A sacrificial layer is then formed over the substrate and the sacrificial layer over the patterned mask layer is removed. The conductive film exposed by the metal layer and the remaining sacrificial layer is then removed, leaving a pad redistribution layer for the bonding pad.