Comparison of electrical and physical characteristics between Gd₂O₃ and Ti-doped GdTi_xO_y trapping layers

In this study, the effects of various annealing temperatures on gadolinium oxide (Gd₂O₃) fabricated with Al₂O₃ and Ti-doped gadolinium oxide (GdTi_xO_y) fabricated with SiO₂ blocking were examined for use in metal/oxide/high-k material/oxide/silicon (MOHOS) memory devices. To investigate the effects of annealing, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) were used to characterize the trapping layers. Capacitance voltage curves (CV), and P/E (program/erase) cycle experimental details were also applied to analyze the electrical properties of the experimental samples. Study results show that a GdTi_xO_y charge trapping layer annealed at 900 °C had a higher window in a current-voltage (CV) hysteresis loop and a higher charge retention capability than under any of the other fabrication conditions. These results were attributed to higher probability of deep-level charge trapping and lower leakage current. A GdTi_xO_y memory device with post-annealing shows promise for future flash memory applications.