A microelectronic assembly having a through hole extending through a first wafer (or chip) and a second wafer (or chip) are provided. The first and second wafers (or chips) have confronting faces and metallic features at the faces which are joined together to assemble the first and second wafers (or chips) leaving a gap between the confronting faces. A hole is etched in the first wafer (or chip), then material is sputtered to form a wall of material in the gap between wafers (or chips). Etching continues to extend the hole into or through the second wafer (or chip). The hole is filled to form a substantially vertical through silicon conductive via.