An efficient method which integrates a 2-D energy transport model, impact ionization model, gate current model, a discretized gate-capacitor EPROM model, and a post-processing quasi-transient programming/erase method, was developed for deep-submicron EPROM/Flash device simulation. The predicted results showed on the average better than 90% accuracy, and it took only few minutes CPU time on a SUN/SPARC2 to generate EPROM/Flash Vt shift curves.

The velocity overshoot and hot carrier effects in thin-film SOI-nMOSFETs have been studied using a two-dimensional device simulator based on the energy transport model. It has been found that the velocity overshoot effect in a nearly-intrinsic device becomes pronounced in the short channel region because of their high carrier mobility. The distribution of the electron velocity in a 0.2 µm channel length SOI device shows that the velocity overshoot takes place over the whole channel region, which enhances the drive capability significantly. The behaviors of hot carriers injected into the gate oxide and the back oxide have been simulated for the first time by using the energy distribution functions of electrons and holes at the SOI-SiO2 interface and solving the current continuity equation in the oxide layer. It has been found that hot carriers are injected not only into the gate oxide but also into the back oxide, which can degrade hot-carrier reliability in small-featured thin-film SOI-MOSFETs.