Impacts of Electrical Field in Tunneling Layer on Operation Characteristics of Poly-Ge Charge-Trapping Flash Memory Device

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 /Al 2 O 3 /SiO 2 tunneling layer are faster than those with GeO x /Al 2 O 3 or GeO x /SiO 2 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 Al 2 O 3 between GeO x and SiO 2 , 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.