Bandgap-Engineered Tunneling Layer on Operation Characteristics of Poly-Ge Charge-Trapping Flash Memory Devices

Operation characteristics of polycrystalline germanium (poly-Ge) tri-gate junctionless (JL) charge-trapping (CT) flash memory devices with bandgap-engineered tunneling layers fabricated by a low- temperature process were studied in this work. The poly-Ge tri-gate JL CT flash memory device with GeO
₂
/Al
₂
O
₃
/SiO
₂
(GAS) stacked tunneling layer presents the highest programming speed and superior retention performance, due to the optimal bandgap-engineered in tunneling layer. Based on the simulation results, the GAS device has a higher tunneling current and more electrons can be captured in Si
₃
N
₄
to obtain larger V
_th
shifts. The low-temperature fabrication process for poly-Ge CT flash memory device is promising for embedded memory in monolithic 3D IC.