Modeling of $V_{\rm th}$ Shift in nand Flash-Memory Cell Device Considering Crosstalk and Short-Channel Effects

Abstract

A threshold-voltage (Vth) shift of sub-100-nm NAND flash-memory cell transistors was modeled systematically, and the modeling was verified by comparing with the data from measurement and 3-D device simulation. The Vth shift of the NAND flash-memory cell was investigated by changing parameters such as gate length, width, drain voltage, dielectric material between cells, space between cells, lightly doped-drain depth, and adjacent-cell bias. The proposed model covers two dominant device physics: capacitance coupling effect between adjacent cells and short-channel effect. Our model showed an accurate prediction of the Vth shift of NAND flash-memory array and a good agreement with the data from simulation and measurement.