A method of making a semiconductor device includes providing a substrate, and forming a first conductive layer over the substrate. A patterned layer is formed over the first conductive layer. A second conductive layer is formed in the patterned layer. A height of the second conductive layer is greater than a height of the first conductive layer. The patterned layer is removed. A first bump and a second bump are formed over the first and second conductive layers, respectively, wherein the second bump overlaps the first bump, and wherein an uppermost surface of the second bump is vertically offset from an uppermost surface of the first bump. Bond wires are formed on the first and second bumps. The bond wires are arranged in a straight configuration. Lowermost surfaces of the first conductive layer and second conductive layer are substantially coplanar.