Transient program operation model considering distribution of electrons in 3D NAND flash memories

Abstract

We developed a new compact model for the program operation of 3D NAND Flash memories. A modified 1-D Poisson equation was proposed that shows better accuracy than the existing model by reflecting the spatial distribution of electrons trapped by the program operation. Under various conditions of program voltage (V_PGM) and program time (t_PGM), the threshold voltage shift (ΔV_t) was extracted by TCAD (Technology Computer-Aided Design) simulation, and we used this data to validate our new model. It also provides validity of the model for program operation in 3D NAND flash memory along with various TCAD analysis data.