Data writing method to improve reliability of 3D NAND flash memory

摘要

The data writing method for improving the reliability of the 3D NAND flash memory is based on the 3D structure of the NAND flash memory, and after writing a set of special data into the dictionary data storage area before erasing the data, erase and rewrite the data. The special data is divided into two types, one is completely identical to the data to be stored, and the other is data that allows the storage unit to have the same state. Different storage areas are divided to perform different operations based on different data retention characteristics requirements. As a result of the experiment, if the same data is written twice in succession, the error rate effect of the 3D NAND flash memory is the best, and the retention characteristics are also relatively good. The present invention is applied not only to an unused storage area, but also to an area in which an erase or write operation is performed several times, and in this way, error data of about 30% or more can be reduced. After performing the maintenance operation on the data, the obtained error rate is also greatly reduced compared to the conventional method, thereby improving reliability.