A new erase method for scaled NAND flash memory device

A suitable bird-beak thickness is crucial to the cell reliability. However, the process control for bird-beak thickness in the edge region is very difficult. A new erase method is proposed in this work to modulate the electron tunneling region of 40 nm floating gate NAND flash memory device. The erasing electron can move to gate center from gate edge under back bias at 0.3 V/− 0.8 V. The Fowler-Nordheim (FN) current of erase operation distributes on the whole channel region, not located at the gate edge region. Results show that the proposed method can improve cell reliability about 33%. TCAD analysis is employed to explain and prove the mechanism. This new erase method is promising for scaled NAND flash memory.