| 摘要 |
PURPOSE: A method for erasing a flash memory device is provided, which reduces a bit line leakage by preventing an erase cell distribution from being extended due to a slowly erased cell and a fast erased cell. CONSTITUTION: According to the method, a pre program and verification is performed as to a sector divided into a number of blocks, and an erase and a verification is done as to a sector succeeding the result of the pre program and verification. A post program and verification is performed as to the sector succeeding the above erase verification. And an erase verification of each block is performed in sequence as to the sector whose erase verification fails. A post program and verification is performed as to the block whose erase verification result as to each block succeeds(109), and an address of the above block is stored(110). If the erase verification of all blocks succeeds by comparing the address of the block having successful erase verification and the address of the block having failed erase verification with the address of the whole block, the erase operation is ended, and a re-erase is performed only as to the block having a failed erase verification, and then the erase verification and the post program and the verification process per block are performed.
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