Highly thermally stable TiN nanocrystals as charge trapping sites for nonvolatile memory device applications

Abstract

TiN nanocrystals formed by a co-sputtering method have been investigated as discrete charge traps for metal–oxide–nitride–oxide–silicon-type nonvolatile memory devices. The formation of isolated TiN nanocrystals embedded in Al2O3 was confirmed by transmission electron microscopy, x-ray photoelectron spectroscopy, and x-ray diffraction analyses. In addition, superior thermal stability of TiN nanocystals embedded in Al2O3 was confirmed. Compared to the control samples without TiN nanocrystals, Al2O3 layers with TiN nanocrystals exhibited wider capacitance–voltage hysteresis and this in turn showed better charge trapping characteristics due to the incorporation of TiN nanocrystals into Al2O3.