Evaluation of program, erase and retention times of flash memories with very thin gate dielectric

We have developed a code for the simulation of the complete program and erase process of a flash EEPROM via direct Fowler-Nordheim tunneling from the channel. The code is based on the solution of the Poisson-Schrodinger equation in one dimension, and on the computation of the tunneling current from the detailed solution of the barrier transmission problem. We are able to compute the program, erase and retention time of a flash memory structure with a given gate stack, and therefore to design an optimized layer structure with respect to the trade-off between program and retention times.