System Performance Analysis of Bit-Alterable 3D NAND Flash Devices for High-Performance Solid-State Drive (SSD) Applications

NAND Flash is not bit-alterable in the erase operation, and the erase is often carried out in a very large block size. This deteriorates the overall system performances. In this work, we propose a novel bit-alterable 3D NAND Flash that can overcome the drawback of large block size for erase. Such bit-alterable 3D NAND device is possible by adopting novel dual-channel floating-body 3D NAND devices, where both +FN programming and -FN erasing are selectable with suitable inhibit methods. Because erase can be carried out in a much smaller page unit rather than a large block, our evaluation indicates significant improvements in garbage collection (GC) and effective programming time. Moreover, the write amplification effect is reduced so that the data life time is expanded.