Flash program modeling using nonquasi-static and tunneling techniques

We present a detailed and accurate physics based transient simulation for modeling flash memory programming characteristics using nonquasi-static and tunneling equations versus the typical Lucky-Electron Model. The result is a set of simple expressions that were originally developed for a MOSFET and adapted for use in floating gate memory. Of greater importance is the extensive use of physical parameters as opposed to the scale factors and probabilities used in other models. This technique allows floating gate memory designers to determine the nominal programming characteristics of single-level and multi-level memory cells prior to the fabrication process. This technique also allows designers to determine the effects of fabrication tolerances on the performance of the memory cell. The accuracy of this model was validated through comparison with experimental data and simulation results presented in several publications.

Nonquasi-static and charge coupling techniques can be used to accurately determine the programming characteristics of flash memory if the entire channel region is included in the calculations.Figure optionsDownload as PowerPoint slideHighlights
► We developed a model to predict the programming characteristics of flash.
► Model was developed using a nonquasi-static MOSFET model as a foundation.
► All physics based equations, derivations and simulation steps are presented.
► Model has demonstrated accurate results when channel lengths were reduced.