The present disclosure provides a semiconductor device. The semiconductor device includes a substrate, a conductive feature, a redistribution layer, at least one through silicon via and at least one bump. The conductive feature is disposed over a front surface of the substrate, and the redistribution layer is disposed over a back surface opposite to the front surface. The through silicon via penetrates through the substrate and contacts the conductive feature embedded in an insulative layer. The bump contacts the redistribution layer and the through silicon via and serves as an electrical connection therebetween.