The present disclosure provides a method of making an integrated circuit (IC). The method includes forming an electric device on a front side of a substrate; forming a top metal pad on the front side of the substrate, the top metal pad being coupled to the electric device; forming a passivation layer on the front side of the substrate, the top metal pad being embedded in the passivation layer; forming an opening in the passivation layer, exposing the top metal pad; forming a deep trench in the substrate; filling a conductive material in the deep trench and the opening, resulting in a though-wafer via (TWV) feature in the deep trench and a pad-TWV feature in the opening, where the top metal pad being connected to the TWV feature through the pad-TWV feature; and applying a polishing process to remove excessive conductive material, forming a substantially planar surface.