A semiconductor device includes a first substrate including a surface, and a pad array on the surface of the substrate, wherein the pad array comprises a first type pad and a second type pad located on a same level. The semiconductor device further includes a conductive bump connecting either the first type pad or the second type pad to a second substrate and a via connected a conductive feature at a different level to the first type pad and the via located within a projection area of the first type pad and directly contacting the first type pad. The semiconductor device also has a dielectric in the substrate and directly contacting the second type pad, wherein the second type pad is floated on the dielectric.