Direct observation of mobile protons in SiO(sub 2) thin films: Potential application in a novel memory device

摘要

In this work we show that annealing of silicon/silicon-dioxide/silicon structures in forming gas (N(sub 2):H(sub 2); 95:5) above 500(degrees)C leads to spontaneous incorporation of mobile H(sup +) ions in the buried SiO(sub 2) layer. We demonstrate that, unlike the alkali ions feared as killer contaminants in the early days, the space charge distribution of these mobile protons within the buried oxide layer can be very well controlled and easily rearranged with relatively high speed at room temperature. The hysteresis in the flat band voltage shift provides a unique vehicle to study proton kinetics in silicon dioxide thin films. It is further shown how this effect can be used as the basis for a reliable nonvolatile FET memory device that has potential to be competitive with state-of-the-art Si-based memory technologies. The power of this novel device is its simplicity; it requires few processing steps, all of which are standard in Si integrated-circuit fabrication.