Modeling of tunneling P/E for nanocrystal memories

This paper presents a detailed study of the program/ erase (P/E) dynamics under uniform tunneling for nanocrystal (NC) memories. Calculating the potential profile and the tunneling currents across the dielectric barriers, we evaluate NC charging and discharging transients during P/E operations. The calculated P/E windows and times compare well with experimental data for memory cells with different oxide thicknesses. The model accounts for the typical features of threshold voltage (Vt) shift as a function of applied gate voltage, and can be used as a valuable tool for optimizing the cell geometry and parameters for maximum performance.