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

• Gd2O3-based flash memories have been fabricated.
• Ti doping and annealing could enhance good memory performance.
• Multiple material analyses confirm that annealing eliminated defects.
• Electrical measurements were used to evaluate memory performance.

In this study, the effects of various annealing temperatures on gadolinium oxide (Gd2O3) fabricated with Al2O3 and Ti-doped gadolinium oxide (GdTixOy) 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 GdTixOy 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 GdTixOy memory device with post-annealing shows promise for future flash memory applications.

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