Non-Parabolicity and Non-Maxwellian Effects on Gate Oxide Tunneling

Simulation of gate oxide tunneling currents in subquartermicron devices requires correct modeling of the electron energy distribution function in the channel region. However, the common assumption of a heated Maxwellian distribution function leads to a dramatic overestimation of the high-energy tail of the distribution function near the drain region which leads to spurious gate currents for short-channel devices. Our approach is based on a recently presented transport model which accounts for six moments of the Boltzmann transport equation. Using this model, the shape of the distribution function can be reproduced more accurately and the gate current behavior of short-channel devices shows a more reasonable behavior.