Methods for manufacturing semiconductor-on-insulator (SOI) integrated circuits are disclosed. An SOI wafer is provided having a first surface and a second surface. The substrate of the SOI wafer forms the second surface. A transistor is formed in the semiconductor layer of the SOI wafer. A handle wafer is bonded to the first surface of the SOI wafer. The substrate layer is then removed to expose a back surface of the buried insulator of the SOI wafer. Conductive material is deposited on the SOI wafer that covers the back surface of the buried insulator. The conductive material is patterned to form a second gate electrode for the transistor on the back surface of the insulator.