Charge-Trapping-Type Flash Memory Device With Stacked High- $k$ Charge-Trapping Layer

Operating properties of charge-trapping-type Flash memory devices with single or stacked structures on trapping layer are investigated in this letter. Improved operation and reliability characteristics can be achieved by adapting the stacked high-k films as charge-trapping layer due to the modification in the trap density and the energy level of traps, the mechanism of electron/hole transmission, and the suitable band offset. Moreover, with a small bandgap of second film in the stacked trapping layer, operating characteristics of devices are further enhanced.