Conclusions

The development of NAND flash memory started in 1987 in the R&D center of Toshiba Corporation. The target market was the replacement of magnetic memory, such as HDD, and so on. The first NAND flash memory cells of 1-?>m rule was8*F2 cell size by using a wide x-direction pitch of 4 ?>m (4*F) because LOCOS isolation width was 3 ?>m wide due to the limitation of the high-voltage operation. The reasons why the NAND flash memory was accepted to the emerging applications were a low bit cost, high reliability, high performance, and low power consumption. The power consumption of storage memory has been greatly reduced by using NAND flash memory, compared with magnetic memory of HDD. In the data center, SSD based on NAND flash memory can reduce the power consumption of an enterprise server, and replace HDD, because of low power operation in NAND flash memory and low cooling power.