| 摘要 |
PURPOSE: A method for erasing a flash memory device with a charge trap element as a unit cell is provided to suppress a reverse tunneling about all unit cells regardless of an erase speed. CONSTITUTION: Unit cells are classified into the unit cell with a fast erase speed and the unit cell with a slow erase speed. The unit cell with the fast erase speed is erased with a first initial bias(208). The unit cell with the slow erase speed is erased with a second initial bias higher than the first initial bias(210). The erase operation and the check operation are repeated using the increment bias adding the step bias to the first initial bias and the second initial bias. The unit cell with a fail is erased using the increment bias prior to the bias inducing the fail. |
