LAUSR

Operation characteristics of polycrystalline germanium (poly-Ge) tri-gate junctionless (JL) charge-trapping (CT) flash memory devices with stacked tunneling layer were studied in this work. The programming speeds of poly-Ge tri-gate JL flash device with GeO_x/Al₂O₃/SiO₂ tunneling layer are faster than those with GeO_x/Al₂O₃ or GeO_x/SiO₂ ones, thanks to the modified electric field in the tunneling layer. Better retention characteristics are also achieved due to a larger barrier height and physical thickness, because Ge diffusion is effectively suppressed by adding an Al₂O₃ between GeO_x and SiO₂, which can improve the quality of tunneling layer. A poly-Ge CT flash device fabricated with low-temperature process is promising for embedded memory in Ge CMOS or 3D IC.