Study of Warm-Electron Injection in Double-Gate SONOS by Full-Band Monte Carlo Simulation

In this letter, we investigate warm-electron injection in a double-gate SONOS memory by means of 2-D full-band Monte Carlo simulations of the Boltzmann transport equation. Electrons are accelerated in the channel by a drain-to-source voltage $V_{rm DS}$ smaller than 3 V, so that programming occurs via electrons tunneling through a potential barrier whose height has been effectively reduced by the accumulated kinetic energy. Particle energy distribution at the semiconductor/oxide interface is studied for different bias conditions and different positions along the channel. The gate current is calculated with a continuum-based postprocessing method as a function of the particle distribution obtained from Monte Carlo simulation. Simulation results show that the gate current increases by several orders of magnitude with increasing drain bias, and warm-electron injection can be an interesting option for programming when short-channel effects prohibit the application of larger drain bias.