Methods and apparatus for forming through-vias are presented, for example, a method for forming a via in a portion of a semiconductor wafer comprising a substrate. The method comprises forming a trench surrounding a first part of the substrate such that the first part is separated from a second part of the substrate, forming a hole through the substrate within the first part, and forming a first metal within the hole. The trench extends through the substrate. The first metal extends from a front surface of the substrate to a back surface of the substrate. The via comprises the hole and the first metal.