High-quality Al 2 O 3 and Si 3 N 4 dielectrics synthesized in a molecular/atomic deposition system were developed and adopted as blocking oxide and tunnel dielectric, respectively in a SONOS-type NAND flash memory cell. In particular, the use of trap-free Si 3 N 4 as tunnel dielectric enables low-voltage erase operation due to its low barrier height for holes, and the relatively high-k value of Al 2 O 3 enhances the low-voltage and high-speed program/erase (P/E) operations. We fabricated and investigated NAND flash memory cells with metal/Al 2 O 3 /SiN/Si 3 N 4 /Si structure. The fabricated cell shows 3.8-V memory window with P/E conditions of +15 V for 100 µs and −10 V for 10 ms. It also shows good endurance up to 10 000 cycles and more than 1.5-V memory window after ten years.Index Terms-Aluminum oxide, charge trap (CT), flash memory, metal/Al 2 O 3 /SiN/Si 3 N 4 /Si (MANNS), silicon nitride, SONOS, TANOS.

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The authors have measured the electrical properties of metal insulator semiconductor capacitors of GaAs, with ex situ jet-vapor-deposited Si3N4 as a gate dielectric. Unpinning of GaAs surface was demonstrated by ac conductance and capacitance-voltage (C-V) measurement; GaAs surface inversion has been demonstrated by quasistatic C-V and hysteresis C-V measurements. Hydrogen plasma predeposition treatment at 200°C has been shown to reduce interface-state density. The lowest interface-state density that the authors measured was 9×1011∕cm2∕eV at 0.57eV above EV for p-type GaAs, and the smallest hysteresis window was 100mV.

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