Abstract: Silicon and silicon-germanium semiconductor-on-insulator structures are formed with strong bonds between the silicon or silicon-germanium layer and the underlying insulating substrate with low defects in the semiconductor and minimal flaws in the bonding between the semiconductor layer and the substrate. An oxide layer is initially formed on the semiconductor wafer, and the wafer may then be annealed, if necessary, to drive off water from the oxide layer so that the oxide layer is well below the water saturation of the oxide. The surfaces of the oxide layer and the substrate are then cleaned and placed into contact at relatively low temperatures to effect a strong bond. The semiconductor layer may then be thinned by mechanical or chemical processes, or both, and the completed structure annealed to perfect the bond between the semiconductor layer and the substrate.