摘要
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 GeOx/Al2O3/SiO2 tunneling layer are faster than those with GeOx/Al2O3 or GeOx/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 GeOx 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.