High-k Nd[sub2]O[sub3) and NdTiO[sub3] Charge Trapping Layers for Nonvolatile Memory Metal-SiO[sub2]-High-k-SiO[sub2]-Silicon Devices.

In this article, we proposed high-k Nd[sub2]O[sub3] and NdTiO[sub3] films as the charge trapping layer in metal-oxide-high-k-oxide-silicon (MOHOS)-type nonvolatile memory devices. X-ray diffraction, X-ray photoelectron spectroscopy, and atomic force microscopy were used to study the structural, compositional, and morphological features of these films after annealing at different temperatures. Compared to the Nd[sub2]O[sub3] film, a MOHOS-type memory device prepared under the NdTiO[sub3] film exhibited superior memory characteristics, such as a higher window of 9 V in the capacitance-voltage hysteresis loop, a larger fiatband voltage shift of 4 V, and a lower charge loss rate of 3% at room temperature. The improvement can be explained by the Ti content in the Nd[sub2]O[sub3] film, which helps to enhance the grain growth and suppress the formation of interfacial SiO[sub2] and silicate layer at the NdTiO[sub3]/oxide interface, and produce a deeper trap energy level in the NdTiO[sub3]. [ABSTRACT FROM AUTHOR]