Cobalt nanodots formed by annealing the CoSiO layer for the application of the nonvolatile memory

Co nanodot memory devices formed by oxidation processes were studied. Transmission electron microscopy and x-ray photoelectron spectroscopy analyses showed that overoxidation of the cobalt and silicon degraded the charge-storage ability seriously. However, a precapped oxide can mildly oxidize the CoSi(2) film to protect the overoxidation to occur. In addition, an oxygen-incorporated CoSi(2) film is proposed to improve the oxidation process further. Through incorporating the limited oxygen during sputtering process, the Co nanodot memory device obtains a larger memory window. Also, the reliability characteristic of the Co nanodot memory device formed by annealing the oxygen-incorporated CoSi(2) film has been demonstrated.