A method for forming electrical interconnects having different diameters and filler materials through a semiconductor wafer comprises forming first and second openings through a semiconductor, wherein the first opening has a narrower width (smaller diameter) than the second opening. A first conductive material is formed over the semiconductor wafer to completely fill the narrower opening and only partially fill the wider opening. The first conductive material is optionally removed from the wider opening using an isotropic etch. A second conductive material is subsequently formed over the semiconductor to completely fill the wider opening.