Investigation of Ti-doped Gd2O3 charge trapping layer with HfO2 blocking oxide for memory application

In this study, Ti-doped gadolinium oxide (Gd2TiO5) is investigated by X-ray diffraction, atomic force microscopy, and capacitance voltage curves (C–V) as the charge trapping layer in metal-oxide-high-k material-oxide-silicon structure memories. It was found that the Gd2TiO5 charge-trapping layer with an HfO2 blocking layer annealed at 900 °C had a larger window of 4.8 V in the C–V hysteresis loop, a faster program/erase speed and good retention without significant drift up to 104 cycles. This excellent performance was attributed to the well-crystallized Gd2TiO5 structure and the higher probability of charges being trapped in the deep trap energy level of the Gd2TiO5. This Gd2TiO5 memory device with post-annealing shows considerable promise for use in future flash memory applications.