An Impact Ionization Model Including Non-Maxwellian and Non-Parabolicity Effects

Accurate modeling of impact-ionization is a critical issue for submicron devices. It is well known that models based on the electric field or on the average carrier energy give a rather poor description of the problem. We show that by accounting for the average square energy an accurate analytical description of the distribution function can be given which can then be used to evaluate microscopic models in a macroscopic device simulator. The new model is accurate for both bulk and submicron devices and involves only local quantities.