Abstract: A method for forming a pad in a wafer with a three-dimensional stacking structure includes: (a) a first process of bonding a device wafer and a handling wafer; (b) a second process of thinning a back side of an Si substrate which is formed on the device wafer, after the first process; (c) a third process of forming an anti-reflective layer and a PMD (preferential metal deposition) dielectric layer, after the second process; (d) a fourth process of forming vias on back sides of super contacts which are formed on the Si substrate, after the third process; and (e) a fifth process of forming a pad, after the fourth process.