Multi-level reading method by using PCI(Paired Cell Interference) in vertical NAND flash memory

摘要

The 3-dimensional folded NAND array having vertical channels has a large integration density and reliable memory characteristics without short channel effect. But, this kind of 3-D memory with vertical channels experiences inevitable interference between cells on both sides of a single silicon pillar, which is called PCI(Paired Cell Interference). As the thickness of silicon fin is scaled down, this phenomenon becomes severer. Consequently, the PCI is a crucial scaling restriction factor of vertical type flash memory. In this paper, we propose a multi-level reading method which utilizes PCI.