A device includes a substrate having a first surface, and a second surface opposite the first surface. A through-substrate via (TSV) extends from the first surface to the second surface of the substrate. A dielectric layer is disposed over the substrate. A metal pad is disposed in the dielectric layer and physically contacting the TSV, wherein the metal pad and the TSV are formed of a same material, and wherein no layer formed of a material different from the same material is between and spacing the TSV and the metal pad apart from each other.