3-dimensional analysis on the cell string current of NAND flash memory

The cell string current of NAND flash memory is very small due to large resistance from the cells connected in series. In this paper, scaling effects on the cell current are analyzed for 70/60/50 nm NAND flash technologies using 3-dimensional TCAD simulation. The geometrical and process parameters are varied and their effects are quantified. It is identified that the coupling ratio has the most significant impact on the cell current and the LDD engineering is more relevant for higher cell current.