Methods for forming interconnects in microelectronic workpieces and microelectronic workpieces formed using such methods are disclosed herein. One embodiment, for example, is directed to a method of processing a microelectronic workpiece including a semiconductor substrate having a plurality of microelectronic dies. The individual dies include integrated circuitry and a terminal electrically coupled to the integrated circuitry. The method can include forming a first opening in the substrate from a back side of the substrate toward a front side and in alignment with the terminal. The first opening has a generally annular cross-sectional profile and separates an island of substrate material from the substrate. The method can also include depositing an insulating material into at least a portion of the first opening, and then removing the island of substrate material to form a second opening aligned with at least a portion of the terminal. In several embodiments, the method may include constructing an electrically conductive interconnect in at least a portion of the second opening and in electrical contact with the terminal.