PILLAR CELL FLASH MEMORY TECHNOLOGY

摘要

An array of a pillar-type nonvolatile memory cells ( 803 ) has each memory cell isolated from adjacent memory cells by a trench ( 810 ). Each memory cell is formed by a stacking process layers on a substrate: tunnel oxide layer ( 815 ), polysilicon floating gate layer ( 819 ), ONO or oxide layer ( 822 ), polysilicon control gate layer ( 825 ). Many aspects of the process are self-aligned. An array of these memory cells will require less segmentation. Furthermore, the memory cell has enhanced programming characteristics because electrons are directed at a normal or nearly normal angle ( 843 ) to the floating gate ( 819 ).