Self-assembly of Ni nanocrystals on HfO2 and N-assisted Ni confinement for nonvolatile memory application -: art. no. 013107

We demonstrate memory property using Ni nanocrystals with mean diameter of 9 nm embedded in HfO2 high-k dielectric that are formed via a self-assembly process by sputtering and rapid thermal annealing. X-ray photoelectron spectroscopy shows that Ni penetrates into the 5 nm HfO2 after high temperature annealing above 800 degreesC in N-2. However, the diffusion is suppressed by N incorporation into HfO2 by NH3 annealing. Metal-oxide-semiconductor structures were fabricated with Ni nanocrystals embedded in HfO2. An additional counterclockwise hysteresis of 2.1 V due to the charge trapping properties of the Ni nanocrystals was observed from a +/-5 V sweep during capacitance-voltage electrical measurement. (C) 2005 American Institute of Physics.