Adaptive erase methods for non-volatile memory

摘要

A method includes an erase of a plurality of blocks of memory cells in which the memory cells within a block are simultaneously erased. The erase of each block of the plurality of blocks is performed using an erase pulse applied multiple times. The erase pulse is applied to the plurality of blocks in parallel. An erase verify is performed after each application of the erase pulse. After a number applications of the erase pulse, it is determined if a condition comprising one of a group consisting of any memory cell has been more erased than a first predetermined amount and any memory cell has been erased less than a second predetermined amount has been met. If the condition has been met, erasing is continued by applying the erase pulse to the block having the memory cell with the condition independently of the other blocks of the plurality of blocks.

主权项

1. A method of performing an erase of a plurality of blocks of memory cells, wherein the memory cells within a block are simultaneously erased and an erase of each block of the plurality of blocks is performed using an erase pulse applied multiple times, the method comprising:
applying the erase pulse to the plurality of blocks in parallel and performing an erase verify after each application of the erase pulse; after a predetermined number applications of the erase pulse, determining if a condition comprising any memory cell has been more erased than a first predetermined amount; and if the determining finds the condition has been met, continue erasing by applying the erase pulse to the block having the memory cell with the condition independently of other blocks of the plurality of blocks.