Stacked gate mid-channel injection flash EEPROM cell-Part II: analysis of gate current and modeling of programming characteristics

The programming characteristics of the stacked gate mid-channel injection (SMCI) flash memory cell is quantitatively analyzed vis a vis the stacked gate device. In the present model, the hot electrons in the high field channel region are described by the elevated temperature model. The programming speed and efficiency depend, among other factors, on the carrier lifetime, which is limited by both the recombination process and the carrier dwell time in the channel. The gate currents from the reference devices are quantitatively analyzed and specified empirically via the applied voltages and the device parameters. These results are applied to modeling the shift in time of the threshold voltage and the simulated values are shown to fit the data with a fair degree of accuracy.