An integrated circuit structure with a back side through silicon via (B/S TSV) therein and a method of forming the same is disclosed. The method includes the steps of: receiving a wafer comprising a substrate having a front side that has a conductor thereon and a back side; forming a back side through silicon via (B/S TSV) from the back side of the substrate to penetrate the substrate; and filling the back side through silicon via (B/S TSV) with a conductive material to form an electrical connection with the conductor. Thus a back side through silicon via penetrates the back side of the substrate and electrically connects to the conductor on the front side of the substrate is formed.