70nm NAND flash technology with 0.025 μm2 cell size for 4Gb flash memory

摘要

A 4 Gb NAND flash memory with a 70 nm design rule is developed for mass storage applications. The cell size is 0.025 μm2, which is the smallest value ever reported. For the integration, an ArF lithography process along with resolution enhancing techniques was utilized, and poly-Si/W gate technology with an optimized re-oxidation process was implemented.